THE NEXT 100 MW POWER PLANT FOR OAHU

University of Hawaii at Manoa Graduate Division

Civil & Environmental Engineering

CEE 699 – Directed Research Report

Prepared by Gabriel A. El-Swaify

In partial fulfillment of MSCE requirements

Submitted to Professor Panos Prevedouros

May 6, 2013

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ABSTRACT

The objective of this study is to address Hawaii’s energy dependence on fossil fuels by investigating the

cost effectiveness of options for the next 100MW alternative energy power plant for Oahu. Nine

different energy sources (coal, oil, natural gas, geothermal, hydroelectric, photovoltaic solar, on-shore

wind, waste-to-energy (WtE), and nuclear) were compared and analyzed.

Most individual power plant specifications (capacity factor, construction cost, needed acreage, etc.)

were retrieved from online corporate power plant profiles and from online periodicals and government

energy-related sources. Plant construction costs were equalized 2012 dollars using historical

Construction Cost Indices (CCI) provided by Engineering News Record (ENR). The U.S. Energy Information

Administration (EIA) provided data for national electricity generation pie charts; national historical

power plant development charts; and the values necessary to conduct the 30 year power plant

comparison analysis (i.e. capacity factors, costs of fuel, MWh generated per unit of fuel used, etc.). The

Hawaii Department of Business, Economic Development and Tourism (DBEDT) provided data for local

electricity generation pie charts, and for Hawaii energy trends. The EIA, the United States Department of

Energy, and the National Renewable Energy Laboratory (NREL) provided information for energy source

profiles and national energy trends.

The results of this study indicate that WtE is superior (in terms of cost) to any other technology in the

long term. Because fuel for WtE is municipal solid waste, it is the only option that profits from the

source of energy while providing electricity. Ranking 2nd and 3rd are geothermal and hydro technologies,

but these resources do not exist on the island of Oahu. Ranking 4th is natural gas, and although is not a

renewable energy source, it is a more affordable and cleaner fossil fuel option than oil. Ranking 5th is

coal, but coal use is counter-intuitive to the Hawaii Clean Energy Initiative (HCEI) goals of reducing fossil

fuel dependence because coal produces the most pollution of all fossil fuels. Ranking 6th is nuclear, but

nuclear plants do not come with nameplate capacities of less than 500 MW and the average capacity of

nuclear power plants in this study was 2,000 MW. Additionally, approval for nuclear power generation in

Hawaii is a long and intensive process that will likely take years to approve if ever pursued. Ranking 7th

and 8th is wind and solar, respectively. High costs for construction and standby energy are associated

with their low capacity factors. Ranking 9th is petroleum, which is unfortunate because oil-fired power

plants currently generate the supermajority of Oahu’s electricity.

Given these results and the fact that Oahu already has a 3-boiler installation of WtE that take advantage

of the solid waste production on the island, the next best choice for the next 100MW power plant is LNG.

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TABLE OF CONTENTS

ABSTRACT ...................................................................................................................................................... i

LIST OF FIGURES .......................................................................................................................................... iii

LIST OF GRAPHS ........................................................................................................................................... iv

INTRODUCTION ............................................................................................................................................ 1

POWER GENERATION BY ENERGY SOURCE ................................................................................................. 4

CHARACTERISTICS OF POWER GENERATION TECHNOLOGY ..................................................................... 11

COST ESTIMATES FOR ALTERNATIVE 100 MW POWER PLANTS ............................................................... 23

CONCLUSIONS & FUTURE WORK ............................................................................................................... 26

REFERENCES ................................................................................................................................................ 28

APPENDIX A – ADDITIONAL TABLES .......................................................................................................... 30

APPENDIX B – PRELIMINARY ROOFTOP PV ESTIMATES ............................................................................ 31

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LIST OF FIGURES

Figure 1. Pie Chart of Hawaii’s Petroleum Use, By Sector (DBEDT, 2013) 1

Figure 2. Electricity Production in Hawaii and the U.S. (Hawaii DBET, 2013) 2

Figure 3. Nuclear Fission. 6

Figure 4. Combined cycle power generation (Gushwehnta Developmnets, 2007) 9

Figure 5. US Total Energy Development, 1900 – 2011. 11

Figure 6. US Renewable Energy Development, 1900 – 2011. 12

Figure 7. Coal Total Capacity and Generator Units in the U.S. 12

Figure 8. Petroleum Total Capacity and Generator Units in the U.S. 13

Figure 9. Natural Gas Total Capacity and Generator Units in the U.S. 14

Figure 10. Nuclear Total Capacity and Generator Units in the U.S. 15

Figure 11. 2011 Electricity Generation by Renewables in the U.S. 16

Figure 12. 2011 Electricity Generation by Renewables in Hawaii 16

Figure 13. Solar PV & Thermal Total Capacity and Generator Units in the U.S. 17

Figure 14. Solar Energy as a % of Total Renewable Generation in Hawaii. 17

Figure 15. Wind Total Capacity and Generator Units in the U.S. 18

Figure 16. Biomass Total Capacity and Generator Units in the U.S. 19

Figure 17. Geothermal Total Capacity and Generator Units in the U.S. 20

Figure 18. Conventional Hydroelectric Total Capacity and Generator Units in the U.S. 21

Figure 19. Pumped Hydroelectric Total Capacity and Generator Units in the U.S. 21

Figure 20. Levelized Cost for Power Production: This study vs EIA averages 27

Figure B.1. Usable roof space in downtown Honolulu area. 31

Figure B.2. Iwilei Costco utilizing roof space for solar PV. 31

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LIST OF TABLES

Table 1. Fossil Fuel Emission Levels 5

Table 2. Power Generation Plant Data to Produce 876,000 Mwh per Year 24

Table 3. Power Plant Costs with Standby Power to Provide 90% Capacity 24

Table A.1. Constants used to Calculate Values for Table 2 and Table 3. 30

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INTRODUCTION

The state of Hawaii is a unique and beautiful land, rich in history, culture, and natural resources.

Literally the most isolated population center on the planet (over 2,000 miles from the nearest land

mass), there truly is no other place on Earth like Hawaii. Before Captain James Cook made contact with

Hawaii in 1778, the islands had a self-sustained population of an estimated 1 million people (La Croix,

2001). Today, however, the economy of Hawaii is almost entirely dependent on outside trade and

commerce. Although Hawai’i has plentiful agricultural land and year-round growing conditions, the

state still imports more than 85% of its food and supermarkets have less than a 7-day supply of food in

stores at any given time (Agroforestry Net, Inc.). On the island of Oahu, many of the prime agricultural

lands which are currently used to grow crops such as pineapple, watermelon, and seed corn (8), are

being re-zoned for the construction of the Honolulu Rail Transit and for the Ho’opili housing

development projects (Choon, 2012).

Even more alarming than Hawaii’s food security issue is Hawaii’s energy dependence on imported oil.

Deriving 90% of its primary energy resources from oil (Arent et al, 2009), Hawaii is the most heavily

dependent state in the nation on petroleum for its needs such as electricity generation, ground

transportation, and commercial aviation as seen below in Fig. 1. All of this oil is imported from the

mainland or from other foreign countries, which adds to the rising costs of oil, priced at $96 per barrel in

April 2013 (EIA1, 2012). At a total statewide petroleum use of 43 million barrels per year (DBEDT, 2013),

that equates to 4.13 billion USD per year leaving Hawaii’s economy to supply its energy needs.

Figure 1. Pie Chart of Hawaii’s Petroleum Use, By Sector (DBEDT, 2013)

As seen in Fig. 1, 75% of Hawaii’s electricity production is based on fuel oil. The average residential

electricity price in Hawaii in the first quarter of 2013 was nearly $0.35/kWh; over 300% higher than the

national average (DBEDT, 2013). Even though Hawaii has the 4th lowest average residential monthly

electricity consumption in the nation (585 kilowatt-hours), it still has the highest residential monthly

electricity bill in the nation ($202.72), nearly two times that of the national average (EIA2, 2012). U.S.

electricity production is primarily supplied by coal (45%) and natural gas (24%), which have fuel costs of

$24 and $28 per megawatt-hour (MWh) respectively, as compared to oil, which has a much higher fuel

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cost of $177 per MWh (EIA3, 2012). This explains why Hawaii has the highest electricity cost in the

nation.

Figure 2. Electricity Production in Hawaii and the U.S. (Hawaii DBET, 2013)

With growth in population, tourism, and the economy, there has been a significant and growing demand

for energy in the commercial, industrial, transportation, and residential sectors. Additionally, with

lifestyle improvements and a high standard of living, a growing market for electric vehicles (EVs) and

plug in hybrid vehicles (PIHV), and the retirement of old oil burning units (some of which date back to

1923) (EIA4, 2012), there is a growing demand for energy that needs to be met by alternative energy

sources.

A number of renewable energy sources are available in Hawaii: it has two active volcanoes, and is only

one of eight states in the U.S. with installed geothermal power generation; has great solar resources

(e.g., Hawaii ranks first in the nation for solar water heaters installed per capita); has one of the most

robust and consistent wind regimens in the world; has an excess of municipal solid waste that can be

used as fuel for Waste-to-Energy (WtE) plants; and is surrounded by the Pacific Ocean, making it rich in

hydrokinetic and thermal resources. One would think that with all these resources, renewable energy in

Hawaii would contribute more than the current 11%.

There have been several actions taken to increase the contribution of renewable energy to Hawaii’s

electrical grid. The state launched the Hawaii Clean Energy Initiative (HCEI) which mandates 70% clean

energy by 2030, with 30% from efficiency measures, and 40% coming from locally generated renewable

sources. By law, the Hawaiian Electric Company (HECO) on Oahu, and its sisters1 on the neighbor islands

Maui Electric Company (MECO) on Maui, Molokai, and Lanai, and Hawaii Electric Light Company (HELCO)

on the Big Island, are required to establish a renewable portfolio standard of 10% of its net electricity

sales by December 31, 2010; 15% by December 31, 2015; 25% by December 31, 2020, and 40% of its net

electricity sales by December 31, 2030 (HCEI, 2010).

1 Hawaii, as an island state, has a unique power generation and distribution system where its island has an isolate system and all but Kauai are owned by HEI, Hawaii Electric Industries, a publically held corporation that consists of HECO, MECO, HELCO and American Savings Bank.

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With oil generating 75% of electricity, coal 14%, and renewables 11%, the first goal has been met, and

Hawai’i is on its way to meet the additional 4% of renewable electricity production by December 2015

(Fig. 2). Currently, the primary renewable energy sources include H-Power on Oahu, which burns

municipal waste to produce electricity, the Puna Geothermal Plant on the Big Island, which uses heat

from volcanic sources to produce electricity, and wind turbines on Big Island, Maui and Oahu2 to

produce electricity. Currently, there are more than 1,000 megawatts (MW) of renewable projects in

service (about 43% of the state’s total electricity generation capacity) under construction, awaiting

approval, or being negotiated. (HECO, 2013)

The HCEI seeks to address the following core challenges facing our state (HCEI, 2010):

1. To be more independent and less reliant on other economies.

2. To achieve greater security.

3. To be more economically stable by keeping an estimated $6 billion in state that would otherwise

go toward foreign oil investments.

4. Establish a new, green economies sector that will counter-balance a reliance on tourism and the

military.

5. To position Hawai’i as a worldwide leader in the clean energy category and that will attract

more business and expertise to the region.

In the long run, fabricating a society and economy that is less dependent on imported energy will

benefit future generations. In the short run, it will provide greater security in the case of a natural

disaster or war-time complications that could easily discontinue our imported supply of petroleum.

Either way, this issue is of critical importance and must be addressed in a timely fashion.

The objective of this study is to address Hawaii’s energy dependence on fossil fuels by finding the next

100MW alternative energy power plant for Oahu. In order to simplify matters, the focus is on providing

the next 100 megawatt (MW) power plant. Granted, 100 MW is only around 6% of Oahu’s total

electrical generation capacity (1,817 MW) (HECO2, 2013), but this capacity size of 100 MW is easily

scalable and can act as a pilot for larger renewable energy projects in the future. By focusing on Oahu

there is no need to consider the prospect of an undersea inter-island transmission cable to transport

electricity from island to island. This study will also only consider technologies that are currently in

operation; it will not consider those technologies that are still in the research and development stages.

Nine different energy sources (coal, oil, natural gas, geothermal, hydroelectric, photovoltaic solar, on-

shore wind, WtE, and nuclear) were compared and analyzed to determine the best option for the next

100 MW power plant on Oahu.

2 The only wind farm on Oahu in Kahuku is inoperable since an August 1, 2012 fire at its battery storage assembly.

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POWER GENERATION BY ENERGY SOURCE

Energy vs. Power

Energy is a measure of how much fuel is contained within something, or used by something over a

specific period of time. The watt-hour (Wh) is a unit of energy, but in this large scales, the kilowatt-hour

(kWh = 103 Wh) and megawatt-hour (MWh = 106 Wh) will be used. Power is the rate at which energy is

generated or used. The watt (W) is a unit of power, but in large scales, kilowatts (kW = 103 W) and

megawatts (MW = 106 W) are used (Energy Lens, 2013). Generally speaking, the Earth has a lot of energy

but the humans on it have a limited ability to generate power from it. Power, not energy, enables the

maintenance and improvement of people’s standard of living. Thus the focus of this research is on

power generation from various energy sources.

The power rating of a generating plant is referred to as capacity. Renewable Energy Magazine explains

with the helpful analogy: “Capacity for a power plant (kW or MW) is probably best explained with a

highway analogy. A 10-lane highway is able to allow more cars to get from one point to another in a

given time period when compared to a three-lane highway. Likewise, a 1,000 MW power plant has the

ability to put more energy, or MWh, to the grid in a given time period than a 500 MW power plant. The

size of the highway is analogous to the capacity, or MW rating, of the power plant. The number of cars

that pass from one point to another on the highway during a given time period is analogous to the

energy, or MWh, that the power plant delivers during the same time period. So, the more lanes on the

highway, the more cars that can pass from one point to another in one hour. Therefore, the larger the

power plant’s capacity, the more energy the plant can deliver to the grid in one hour.” (Hynes, 2009)

For the analysis, this study considered the costs of operating a 100 MW power plant at theoretical

capacity of 100%, which means it produces electricity 24 hours a day for 365 days a year. That translates

to annual energy generation of 876,000 MWh. There is no generating plant that has 100% capacity;

nuclear and geothermal have the highest capacity factor at 90% and wind and solar are the lowest with

capacity factors ranging between 20 and 35%. Scaling all generating plants to a 876,000 MWh energy

output is one way to levelize costs.

Energy Sources

Energy sources are classified in Non-Renewable and Renewable sources. Non-renewable sources are

primarily fossil fuels such coal, petroleum, and natural gas. Millions of years ago, the remains of plants

and animals (diatoms) decayed and built up in thick layers. This decayed matter from plants and

animals is called organic material — it was once alive. Over time, the sand and silt changed to rock,

covered the organic material, and trapped it beneath the rock. Pressure and heat changed some of this

organic material into coal, some into oil (petroleum), and some into natural gas — tiny bubbles of

odorless gas. Fossil fuels are considered non-renewable resources because they cannot be replenished

on a human timeframe. Power plants burn these fossil fuels to make steam, and the steam turns

turbines that generate electricity.

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Extraction of fossil fuels from the Earth often requires deep drilling, which is an energy intensive

process3 that often produces runoff and spills. Refineries produce wastewater which can contain

pollutants and can have high temperatures. Releasing this contaminated and higher temperature water

into aquatic ecosystems, whether intentionally or unintentionally, can have drastic environmental

consequences. Combustion of all fossil fuels releases pollution into the air, with coal emitting the most

pollutants, then oil, and then natural gas. Table 1 gives some average values of emission levels for the

three fossil fuels:

Table 1. Fossil Fuel Emission Levels

Fossil-fueled power plants use large quantities of water for steam production and cooling. When power

plants remove water from an aquatic ecosystem, plant, animal, and human life can be interrupted and

compromised (EPA, 2011).

The advantage to fossils fuels are their high fuel heat contents; their capacity to generate vast amounts

of electricity in a single location; their cost-effectiveness (for gas and coal); their transportation through

oil and gas pipelines; their consistency in continuous electricity production (base-load); their chemical

stability; their existing infrastructure for harvesting, refining, and power generation.

Strictly speaking nuclear energy is produced by a non-renewable source of energy because uranium ore

is a finite source. However, the amount of ore needed for power generation versus the known deposits

or uranium on Earth makes it incomparably more abundant than any of the aforementioned fossil fuels.

In addition, nuclear power production is considered “clean energy” thus in some classifications nuclear

energy is included together with clean, renewable energy sources. Nuclear energy is the energy in the

nucleus of an atom. By breaking the bonds that hold the nucleus together, an enormous amount of

energy is released. Nuclear power generation plants utilize nuclear fission to break these bonds to

3 The difficulty and cost of extraction has generated pass hyperbolas such as “Peak Oil.” Obviously a number of fossil fuel sources are not possible to extract and take to market when oil is priced at $30 per barrel. This limitation evaporates quickly if the price of oil doubles or triples. Thus “peak oil” is a moving target. Furthermore, very high oil prices for oil, e.g., $150 per barrel, dramatically reduce consumption and therefore push “peak oil” much further to the future. A 2010 analysis of Oil Reserves by The Economist indicates decades and centuries of reserves for the various oil producing countries. (The Economist, 2011)

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produce electricity (Fig 3). During nuclear fission, a neutron hits the atom and splits it, releasing a large

amount of energy as heat and radiation. In the process, more neutrons are released, bombarding other

atoms, and the process repeats itself over and over again creating a chain reaction. (EIA5, 2012)

Figure 3. Nuclear Fission.

Unlike fossil fuel-fired power plants, nuclear reactors do not produce air pollution when generating

electricity. The mining process of uranium and the construction materials of nuclear power plants,

however, do require large amounts of energy. This energy is usually supplied by fossil fuels which

release pollutants into the air. However, the primary environmental concern of nuclear power is

radioactive wastes such as uranium mill tailings and spent reactor fuel. Although most of the waste

related to the nuclear power industry has a relatively low-level of radioactivity, they can remain a

human health hazard for thousands of years. There is currently no permanent disposal facility in the U.S

for higher levels of nuclear waste, so the storage of spent reactor fuel and the decommissioning of

nuclear power plants pose an environmental concern. (EIA5, 2012)

Renewable sources include …

Solar: The potential for harnessing the sun as an energy source is enormous - more energy falls on the

Earth in one hour than is used by everyone in the world in one year (NREL, 2012). This energy can be

used directly for heating and lighting homes and buildings, for hot water heating and for generating

electricity. Some of the technologies that convert sunlight to usable energy include solar photovoltaic

(PV) and concentrated solar power (CSP).

Literally translated as light-electricity, solar PV cells convert sunlight directly into electricity. Solar panels

are typically made from solar cells combined into modules. These panels are combined together to

create a single system called a solar array. For large electric utility or industrial applications, hundreds of

solar arrays are interconnected to form a large utility-scale PV system. Traditional solar cells are made

from silicon, are usually flat-plate, and generally are the most efficient. (NREL, 2012)

CSP systems collect the sun's energy using long rectangular, curved (U-shaped) mirrors. The mirrors are

tilted toward the sun, focusing sunlight on tubes (or receivers) that run the length of the mirrors. The

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reflected sunlight heats a fluid flowing through the tubes. The hot fluid then is used to boil water in a

conventional steam-turbine generator to produce electricity. There are two major types of linear

concentrator systems: parabolic trough systems, where receiver tubes are positioned along the focal

line of each parabolic mirror; and linear Fresnel reflector systems, where one receiver tube is positioned

above several mirrors to allow the mirrors greater mobility in tracking the sun. (NREL, 2012)

The main benefit of solar energy is that it does not produce air pollutants or carbon-dioxide, and when

located on building roofs, they have minimal impact on the environment. Its main disadvantage is that

the amount of sunlight that arrives at the Earth’s surface is not constant, which means intermittent

electricity production. Sunlight constancy varies by location, time of day, time of year, and the weather.

Additionally, in order to harness a useful amount of energy, a large surface area is required to collect the

sun’s rays. (EIA6, 2012)

Wind: Historically, wind energy has been harnessed through windmills to pump water or to grind grain.

Today the wind turbine, the windmill’s modern equivalent, uses the wind’s energy to generate

electricity. Wind turbines use blades to collect the wind’s kinetic energy. The wind flows over the blades

creating lift, like the effect on airplane wings, which causes them to turn. The blades are connected to a

drive shaft that turns an electric generator to produce electricity (EIA6, 2012). Wind turbines can be used

as stand-alone applications, or they can be connected to a utility power grid or even combined with a

photovoltaic (solar cell) system. For utility-scale (MW-sized) sources of wind energy, a large number of

wind turbines can be built close together to form a wind farm. (NREL, 2012)

The main benefit of wind energy is that it is a clean, free and renewable source of energy. Wind turbines

do not release emissions and do not require water for cooling. Additionally, a wind turbine has a small

physical footprint relative to the amount of electricity it can produce. Its main disadvantage is that wind

does not blow constantly, and is therefore an intermittent power source, unable to produce electricity

consistently. At those times, other types of power plants must be used to generate electricity. A few

other disadvantages include wind turbines’ visual and sound impacts, their need for service roads which

require energy for construction, their relatively short life of 10-12 years (The Courier, 2012), and the

impacts they have on some species of birds and bats (EIA6, 2012).

Biomass energy has been used since people began burning wood to cook food and to keep warm. This

“bioenergy” is harnessed from plants and plant-derived materials such as wood, food crops, grassy and

woody plants, residues from agriculture or forestry, oil-rich algae, and the organic component of

municipal and industrial wastes. Even the fume from landfills (mostly methane, the main component of

natural gas) can be used as a biomass energy source. (NREL, 2012)

Biomass energy supports U.S. agricultural industries, forest-product industries, and cities. The main

biomass feedstocks for power are paper mill residue, lumber mill scrap, and municipal waste. Instead of

being landfilled, this ‘waste’, through incineration, can be converted into electricity by creating steam

that powers turbines. This process has a double benefit of saving space and producing energy. Waste-to-

energy (WtE) plants, however, do produce air pollution and can release harmful chemicals and

substances found in the waste if not properly controlled. An additional challenge is the disposal of ash

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created by the combustion process of WtE plants. Ash can contain high concentrations of various metals

that were present in the original waste. Not all ash is useless, however, as one-third of it is used in

landfills as a daily or final cover layer, to build roads, to make cement blocks and artificial reefs for

marine animals (EIA6, 2012).

Landfill gas, or biogas is composed mainly of methane and carbon dioxide that forms as a result of

biological processes in sewage treatment plants, waste landfills, and livestock manure management

systems. Many of these facilities capture and burn the gas for heat or electricity production. Burning

methane (CH4) is actually beneficial because CH4 is a more potent greenhouse gas than CO2. (EIA6, 2012)

Liquid biofuels, ethanol and biodiesel, were the fuels used in the first automobile and diesel engines, but

lower cost gasoline and diesel fuel made from crude oil became the dominant engine fuels. The federal

government has promoted ethanol use in vehicles to help reduce oil imports since the mid-1970s.

Although biofuels are considered carbon-neutral because the plants that are used to make biofuels

absorb CO2 as they grow, growing plants for biofuels is controversial as the land, fertilizers, and energy

used to grow biofuel crops could be used to grow food crops instead. Ethanol and ethanol gasoline

mixtures burn cleaner and have higher octane than pure gasoline, but have higher “evaporative

emissions” from fuel tanks and dispensing equipment, contributing to the formation of harmful, ground

level ozone and smog (EIA6, 2012).

Geothermal: technologies harness heat resources from within the Earth including heat retained in

shallow ground, hot water and rock found a few miles beneath the Earth’s surface accessed by drilling,

and extremely high-temperature molten rock (magma) located deep in the Earth accessed by

geothermal reservoirs (volcanoes). Most geothermal activity is located in the western U.S., Alaska, and

Hawaii.

Geothermal resources can be used on large and small scales for producing heat directly from hot water

within the Earth (direct use), for generating electricity (power plants), and for heating and cooling using

the Earth’s shallow ground temperature (heat pumps) (NREL, 2012).

Geothermal direct use has been used since people began using hot springs for bathing and cooking food.

In modern systems, a well is drilled into a geothermal reservoir to provide a steady stream of hot water

called brine. The brine is brought up through the well, and a mechanical system—piping, a heat

exchanger, and controls—delivers the heat directly for its intended use. A disposal system re-circulates

most of the cooled brine to minimize demand for water resources. (NREL, 2012)

Geothermal power plants use steam produced from reservoirs of hot water (300°F to 700°F) found a few

miles or more below the Earth's surface to produce electricity. These resources are accessed by drilling

wells (1-2 miles deep) into the Earth and piping the steam or hot water to the surface. There are three

basic types of geothermal power plants: dry steam, flash steam, and binary cycle power plants. (EIA6,

2012)

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Geothermal heat pumps take advantage of the nearly constant temperature of the Earth to heat and

cool buildings. The shallow ground, or the upper 10 feet of the Earth, maintains a temperature between

50° and 60°F (10°–16°C). This temperature is warmer than the air above it in the winter and cooler in the

summer. (NREL, 2012)

Geothermal power is a baseload power source, so plants produce electricity consistently and

continuously regardless of weather. Generally, plants are compact, using less land per MWh than coal,

wind or solar. (NREL, 2011) Geothermal power plants do not burn fuel to produce electricity, so their

emission levels are very low. Scrubber systems are utilized to clean the air of hydrogen sulfide that is

found naturally in the steam and hot water. Once the steam and water from a geothermal reservoir has

been used, they are injected back into the Earth. Geothermal power plants release less than 1% of the

CO2 emissions and less than 3% of the acid rain-causing sulfur compounds emitted by fossil fuel plants.

(EIA6, 2012)

Of all renewable power plants geothermal plants and some CSP plants use

the combined cycle (CC) power production methods used by fossil-fueled

plants. CC is a series of heat engines that work in tandem using the same

source of heat. Typically residual hot steam or other heat source that

was used in the primary turbine for power generation is reused as

shown in the numbered parts of Fig. 4: 1) Electric generators, 2) Steam

turbine, 3) Condenser, 4) Pump, 5) Boiler/heat exchanger, 6) Gas turbine.

Figure 4. Combined cycle power generation (Gushwehnta Developments, 2007)

Hydropower technologies harness power from flowing water by directing it through a pipe, or penstock,

so that it pushes against and turns blades in a turbine to spin a generator to produce electricity.

Conventional hydro consists of run-of-the-river systems, where the force of the current applies the

needed pressure, and storage systems, where water is accumulated in reservoirs created by dams, then

released as needed to generate electricity. Pumped hydro facilities pump water from a lower reservoir

to an upper reservoir when demand for electricity is low. When demand is high, the water is released

back to the lower reservoir to generate electricity. (EIA6, 2012)

Hydropower is a clean renewable energy source fueled by water, that doesn’t release emissions of air

pollutants. Since water is flowing consistently, hydropower is considered a baseload power source and

can produce electricity on demand. In some cases the combination of drought, evaporations and

seepage may cause insufficient storage of water and result in reduced or curtailed power production.

Although hydropower generators do no directly produce emissions, hydropower dams, reservoirs and

the operation of generators can negatively impact native plants and animals by obstructing fish

migration and altering the natural water temperatures, chemistry, flow characteristics, and silts loads.

Reservoirs may cover important natural areas and agricultural lands, causing the relocation of entire

communities. The construction of new hydropower dams require the manufacturing of steel and

concrete which requires energy. This energy is usually supplied by fossil fuels which release pollutants

into the air (EIA6, 2012).

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Ocean: The ocean has vast amounts of energy potential, from tidal, to wave, to ocean thermal

conversion, but most technologies are still in the research and development stage and currently do not

produce any significant amounts of electricity. There have been two successful applications of tidal

energy harnessing: the 240 MW Rance Tidal Power Station in France which opened in 1966 (Wyre Tidal

Energy, 2013), and the 245 MW Sihwa Lake Tidal Power Station in South Korea which opened in 2011

(Renewable Energy World, 2005).

Tidal energy: Tides are caused by the gravitation pull of the moon and sun, and the Earth’s rotation.

Near shore, tides can cause water levels to rise and recede up to 40 feet. Tidal barrages, tidal fences and

tidal turbines are three technologies that capture tidal energy. Tidal barrages have sluice gates (gates

commonly used to control water levels and flow rates) to allow the tidal basin to fill on the incoming

high tides and to empty through the turbine system on the outgoing tide, also known as the ebb tide.

There are two-way systems that generate electricity on both the incoming and outgoing tides. A tidal

fence has vertical axis turbines mounted in a fence. All the water that passes is forced through the

turbines. Tidal fences can be used in areas such as channels between two landmasses. Tidal turbines are

basically wind turbines in the water that can be located anywhere there is strong tidal flow. (EIA6, 2012)

Wave Power: Waves are caused by currents in the ocean and winds blowing over the ocean. Ocean

waves produce tremendous amounts of energy; an estimated total potential off the coasts of the US is

252 billion kWhs a year, which is about 6% of the US’ electricity generation in 2011. One way to harness

this energy is to focus the waves into a narrow channel, increasing their power and size. The waves can

then be channeled into a catch basin or used directly to spin turbines. Ocean Power Technologies has

been testing a single 40 kW buoy in 90 ft. depth water in Kaneohe Marine Corps Base Hawai‘i (HNMREC,

2013).

Ocean Thermal Energy Conversion (OTEC): Solar energy heats the surface water of the ocean, making it

much warmer than the deep water. OTEC systems harness the temperature difference, which must be

greater than 77F, to produce electricity. Hawaii has worked with OTEC since the 1970s, but there are

many challenges with this technology including energy efficiency and water pumping. A 2006

announcement to build an OTEC plant on the Big Island mentioned on a HEI website (HECO3, 2013) did

not occur.

11

CHARACTERISTICS OF POWER GENERATION TECHNOLOGY

This part of the study provides a general overview of the past and current energy outlook for the U.S.

and Hawaii. A data set was collected from EIA to compile a list of every power plant on record, dating as

far back to the late 1800s and spanning the years until 2011. The total wattage and the total number of

generating units were plotted over time for each type of power plant. These plots act as a visual

representation of the development of different energy in the U.S. In order to look at the current energy

situation in the U.S. and Hawaii, 2011 data was collected for total electricity generation by energy

source. The data were extracted from EIA and DBEDT sources.

Fig. 5 reveals that coal, natural gas, and nuclear are the top three sources for total installed capacity.

Conventional hydro has the longest history and the highest installed capacity of all renewable sources.

Wind and pumped hydro are second and third in installed capacity, but have only taken off within the

past 30 years. The trends of each major energy source on a national level and in Hawaii are compared

and discussed below.

Figure 5. US Total Energy Development, 1900 – 2011.

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Nuclear

ConventionalHydro

Wind

SolarThermal & PV

Wood

Geothermal

Otherbiomass

PumpedStorage

12

Figure 6. US Renewable Energy Development, 1900 – 2011.

Around 87% of total electricity generation in the US is provided by non-renewable sources (Fig 2). In

Hawaii, 89% of total electricity generation is provided by non-renewable sources.

Figure 7. Coal Total Capacity and Generator Units in the U.S.

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In 1961, coal became the major fuel used by electric utilities to generate electricity. In 1973-74, the oil

embargo by the Organization of Petroleum Exporting Companies (OPEC) focused attention on the

energy crisis, resulting in an increase of demand for U.S. coal. With the popularity of natural gas

skyrocketing in the mid 1980s, the construction of new coal power plants declined. Through the Energy

Policy Act of 2005, clean coal technologies are promoted (American Coal Foundation, 2005). Today coal

accounts for 43% of the nation’s total electricity generation (Fig. 7).

Coal in Hawaii accounts for 14% of the state’s total electricity production (Fig. 2). This electricity is

provided by one 203 MW coal plant (AES Hawaii) that was built in 1992. There are currently no

proposals, either active or cancelled, to build coal-fired plants in Hawaii. (Sourcewatch, 2011)

Figure 8. Petroleum Total Capacity and Generator Units in the U.S.

Petroleum in the US only accounts for 1% of the nation’s total electricity production. It is mostly used for

transportation or home heating purposes.

Petroleum in Hawaii accounts for 75% of the state’s total electricity production (Fig. 2). With the

Hawaiian Clean Energy Initiative mandate of 15% renewable by 2015, HECO and its sisters on Maui and

the Big Island are incorporating more renewable energy sources into the fuel mix. The Hawaii Public

Utilities Commission has developed programs such as net energy metering and feed-in tariffs to

encourage individuals, small, businesses, or government entities to sell renewable energy to their utility.

(HECO1, 2013)

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Figure 9. Natural Gas Total Capacity and Generator Units in the U.S.

In the 1950s and 1960s, thousands of miles of pipeline were constructed throughout the U.S., which led

to rapid growth of natural gas markets. It was during this time that the first gas-fired electrical plants

came on-line. Technological advancements over the years such as hydraulic fracturing or “fracking” have

increased gas well productivity, while new drilling techniques have allowed extraction of gas from shale,

and have made offshore sites more valuable. The record-setting hurricane season of 2005 caused

massive damage to the U.S. natural gas and petroleum infrastructure, curbing development. However,

the popularity of natural gas worldwide is on the rise because of its low CO2 emissions (for a fossil fuel)

and the discovery of new reserves in Texas, Louisiana, and Wyoming as well as in Poland, Russia, China

and elsewhere (EIA5, 2012). Currently natural gas accounts for 24% of the total electricity generation in

the US (Fig. 2).

Currently natural gas is not used for electricity generation in Hawaii. However, according to Hawaii Gas

Company’s proposed 3-step liquefied natural gas (LNG) plan, electrical generation is a goal for the near

future (Levine, 2012).

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Figure 10. Nuclear Total Capacity and Generator Units in the U.S.

The first large-scale US commercial nuclear power plant was commissioned in Shippingport, PA in 1957.

Since then, the use of nuclear-generated electricity has grown, increasing quickly from 5% in 1973 to 9%

in 1975 and then to the current level of 20% by 1988. The last nuclear plant to begin commercial

operation was the Tennessee Watts Bar plant in 1996. Since then, the capacity of existing plants has

been expanded through “uprating”. Four new nuclear reactors, Vogtle Units 3 and 4 and Summer Units

2 and 3, are expected to come on-line between 2016 and 2017 (EIA5, 2012). Currently, nuclear power

accounts for 19% of the nation’s total energy production (Fig. 2).

Currently nuclear power is not used for electricity generation in Hawaii, and there are no proposals for

implementing nuclear power for that purpose. Although at any time there are at least a handful of large

nuclear powered vessels in Pearl Harbor (less than 10 mile distance from Honolulu), an article of

Hawaii’s Constitution (Article XI, Section 8 ) prohibits the installation of nuclear power plants anywhere

in the state. A two thirds majority of the State Senate is required to modify this constitutional

prohibition. (HECO4, 2013)

Solar (PV and CSP), wind, biomass, geothermal and hydro power are the main renewable energy sources

that have been harnessed to generate electricity in Hawaii and the U.S. In the U.S. around 13% of total

electricity generation is provided by renewable sources. In Hawaii, 11% of total electricity generation is

provided by renewable sources. Although the totals are very similar, the mix is vastly different with US

mainland renewable power production clearly dominated by hydro (Fig. 11), whereas Hawaii has a more

diversified portfolio with WtE claiming about one third of the pie (Fig. 12).

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Figure 11. 2011 Electricity Generation by Renewables in the U.S.

Figure 12. 2011 Electricity Generation by Renewables in Hawaii

Hydro62%

Wind24%

Solar0%

Biomass11%

Geothermal3%

2011 Electricity Generation by Renewables in US

(Approx 13% of

total generation)

Source: 2013 EIA Electric Power Monthly

Biomass13%

H-Power31%

Hydro11%

Geothermal16%

Wind25%

PV 4%2011 Electricity Generation by

Renewables in HI(Approx 11% of total

generation )

Source: 2011 State of Hawaii Data Book

17

Figure 13. Solar PV & Thermal Total Capacity and Generator Units in the U.S.

Solar accounts for 0.4% of the nation’s total renewable energy production, making it the smallest

contributor (Fig. 11). There has been a sharp rise in total solar developments since 2006. This is primarily

due to government subsidies that encourage solar PV and CSP projects, and the declining production

cost of these technologies.

Solar energy in Hawaii accounts for 4% of the state’s total renewable energy production, making it the

smallest contributor (Fig. 12). However, due to Hawaii’s high energy prices, great solar resource

potential, and progressive energy policies, the state has experienced rapid growth in solar generation

(Fig. 14). Solar PV capacity increased 150% in Hawaii in 2011, making it the 11th biggest state for PV

capacity (EIA7, 2012). Two important energy policies include Net Energy Metering (NEM), which allows

residential customers to receive full retail value for excess solar energy occasionally fed to the grid, and

Feed in Tariffs (FIT), which allow the owners of small renewable energy projects to receive fixed rates of

renewable electricity provided to the grid (DBEDT, 2013). Because of the intermittent nature of solar as

well as Hawaii’s small, individual, non-interconnected island grids, the integration of large amounts of

solar generation can be challenging. Therefore, solar power is generated mostly through distributed

panels on residences and businesses. Commercial solar farms contribute minimally to power generation.

Figure 14. Solar Energy as a % of Total Renewable Generation in Hawaii.

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Figure 15. Wind Total Capacity and Generator Units in the U.S.

In the wake of the oil shortages of the 1970, an interest was created in alternative energy sources,

providing an opportunity for the re-entry of the windmill to generate electricity. With the growing

concern for the emissions of fossil fuel generation and the rising costs of these fuels, state policies

(production tax credit and state renewable electricity portfolio standards) have continued the push for

wind energy development, which has skyrocketed in the last dozen years. (EIA6, 2012). Currently wind

accounts for 24% of the nation’s total renewable energy generation (Fig. 11).

Wind energy is Hawaii’s second most utilized renewable resource, accounting for 25% of the state’s

total renewable energy generation (Fig. 12). Existing projects are located on the islands of Oahu, Maui,

and Hawaii. Hawaii has one of the most robust and consistent wind regimes in the nation that could

potentially provide over 1000 MW of wind energy, which would constitute 94% of the State’s HCEI goals.

Unfortunately, since over 70% of Hawaii’s energy load is on Oahu, but over 90% of the existing wind

potential is on the outer islands, reaching that level of production would require interconnection of the

electricity grids of the islands (DBEDT, 2013). There has been talk about an Inter-Island Transmission

Cable, but there is no action toward its construction.

In August of 2012, a major fire destroyed the battery storage facility of the 30 MW Kahuku Wind Farm.

The wind farm also experienced two previous fires that destroyed inverters after coming online in 2011.

Repairs to the farm are not expected to be completed until the third quarter of 2013. Unfortunately,

besides the Kawailoa wind project this is only the only other wind farm installed on Oahu, and does not

help promote wind power in Hawaii. (Cocke, 2012)

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Figure 16. Biomass Total Capacity and Generator Units in the U.S.

Combustion of wood and wood derived fuels at a large scale has been around since the 1940s. Capacity

and generator units have steadily increased over the years, with a jump between 1980 and the late

1990s that was most likely caused by a rise in construction of WtE plants. Currently biomass accounts for

11% of the nation’s total renewable energy generation (Fig. 11).

Biomass energy is Hawaii’s most utilized renewable resource, accounting for 44% of the state’s total

renewable energy generation (Fig. 12). By-products from food, feed, or fiber production account for 13%

of the total. Hawaiian Commercial and Sugar (HC&S) generates energy from the fiber by-product of

sugar production (DBEDT, 2013). Burning of waste materials such as used cooking oil and municipal

solid waste accounts for 31% of the total. H-Power recently installed a third boiler and now has a total

operating capacity of 90 MW, incinerating up to 1,100,000 tons of waste annually and reducing the need

to landfill Oahu’s municipal waste (Covanta Energy, 2013).

Hawaii has the world's largest commercial electricity generator fueled exclusively with biofuels. The

State’s energy plan aims for an agricultural biofuels industry that, by 2025, can provide 350 million

gallons of biofuels (EIA7, 2012). Currently, however, there is no local production of biodiesel fuel, and

imported biodiesel fuel costs are significantly higher (by nearly 200%) than the fossil-based fuels used

for electricity generation in Hawaii (DBEDT, 2013).

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Figure 17. Geothermal Total Capacity and Generator Units in the U.S.

In 1960, the country’s first large-scale geothermal electricity-generating plant began operation at The

Geysers, CA. Several legislative actions were taken between 1970 and 1980 to encourage the

development of geothermal resources for power generation and direct-heat uses. In the early 1980s two

developments, binary technology and crystallizer-clarifyer technology, allowed feasibility of larger-scale

commercial power plants, causing a steep increase in total capacity and generator units until the mid

1990s. Currently, geothermal accounts for 3% of the nation’s total renewable energy generation (Fig.

11). Recently, geothermal development is slowly on the rise. (DOE, 2011)

Geothermal energy is Hawaii’s third most utilized renewable resource, accounting for 16% of the state’s

total renewable energy generation (Fig. 12. This energy is produced exclusively by the 40 MW Puna

Geothermal Venture (PGV) on the Big Island. Draft requests for proposals have been issued by HELCO on

the Big Island for a 50 MW addition to PGV, and by MECO on Maui for 30 MW of renewable firm

dispatchable capacity resource, which could include geothermal. (DBEDT, 2013)

Continued geothermal exploration is taking place on Maui, focusing on the southwest rift zone of

Haleakala, with partial funding from the U.S. Department of Energy. Although geothermal resources are

difficult to characterize without exploration and drilling, estimates from exploration efforts in the 1970s

and 1980s have shown that there may be possible geothermal reserves of over 1,000 MW, sufficient to

provide 200% of the State’s HCEI goals. Reaching that level of production, however, would require

interconnection of the islands’ electricity grids.

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Figure 18. Conventional Hydroelectric Total Capacity and Generator Units in the U.S.

Figure 19. Pumped Hydroelectric Total Capacity and Generator Units in the U.S.

Hydropower is one of the oldest sources of energy, first used thousands of years ago to turn a paddle

wheel for such purposes as grinding grain. Hydropower was first used to produce electricity in 1880

when Michigan’s Grand Rapids Electric Light and Power Company used a dynamo belted water turbine

to light up 16 brush-arc lamps. Since then, conventional hydroelectric generation has steadily grown,

with the efficiency of generators increasing especially from 1900 to 1970. Construction of new

conventional hydro power plants leveled off in the 1990s. Pumped hydro took off in 1960, with

construction leveling off in the early 2000s. Today, there is about 80,000 MW of conventional capacity

and 18,000 MW of pumped capacity (DOE, 2011), accounting for about 62% of the nation’s total

renewable energy generation (Fig. 11).

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Hydroelectric power accounts for 11% of the state’s total renewable energy generation (Fig. 12). While

Oahu has no streams suitable to harness hydroelectric power, small-scale, “run-of-the-river” plants

provide hydroelectricity on Maui and the Big Island when rainfall provides sufficient flowing water.

These small scale plants range in capacity from 0.5 MW to 4.5 MW. Generally for the state of Hawaii,

there are no rivers that could drive large hydroelectric plants. (HECO5, 2012)

COST ESTIMATES FOR ALTERNATIVE 100 MW POWER PLANTS

This part of the study estimates the cost for nine different 100 MW rated power plants. These power

plants were ranked on three levels: 1) cost to install, 2) cost to install and run for 30 years, and 3) cost to

install and run for 30 years plus the cost of standby power to cover intermittency and capacity

limitations.

A literature and internet review was conducted to compile a database of over 75 power generation

plants for the following energy sources:

Coal

Petroleum

Natural gas

Nuclear

Solar

Wind

WtE (biomass)

Geothermal

Hydro

Plant capacity (MW), construction costs (2012 $), and footprint (acre) were recorded. This information

was used to calculate plant construction cost per MW (M$US/MW) and land productivity (acre/MW).

Using the cost of farmland on Oahu (M$US/acre), the plant Installation Cost was calculated for each

energy source. This is the first level for ranking the power generation alternatives, as shown in top half

of Table 2.

The capacity factor, cost of fuel, MWh generated per unit of fuel, and maintenance costs were obtained

from the EIA online database (See Appendix A for references). Using this information, the annual

Operational Cost was determined for each technology. By adding the Installation Cost and the annual

Operational Cost, and multiplying it over a period of 30 years, the total 30 year cost was determined for

each technology. This is the second level for ranking the power generation alternatives, as shown in

bottom half of Table 2.

For those technologies with a capacity factor less than 0.9, natural gas was assumed as standby power

so that the technology could produce electricity 100% of the time. The total 30 year cost plus the cost of

23

natural gas as standby power is the third level for ranking the power generation alternatives, as shown

in Table 3.

Table 2. Power Generation Plant Data to Produce 876,000 MWh per Year

Table 3. Power Plant Costs with Standby Power to Provide 90% Capacity

At the first level of ranking, natural gas comes in first as the most affordable at 95 M$US, and oil is

second at 110 M$US. In last place is solar, wind, and then WtE at 2.3 B$US, 1.7 B$US, and 1.0 B$US,

respectively. When considering only installation cost, fossil-fueled power plants are most affordable,

while renewable energy fueled power plants are least affordable.

However, when considering the installed cost plus the annual operational cost over 30 years, WtE comes

in first as the most affordable at -1.3 B$US (1.3 B$US profit), and hydro and geothermal in second and

third at 356 M$US and 573.9 M$US. In last place is oil at 4.8 B$US, solar at 2.6 B$US, and wind at 2.0

B$US. The biggest difference between renewable and non-renewable energies over the 30 year cost is

the cost of fuel. WtE pays, renewable energy is free, and fossil fuel costs.

At a tipping fee of $81 per ton of municipal solid waste, WtE technology generates electricity and

profits! Although wind and solar energy are free, PVs and turbines have low capacity factors and require

more solar panels and wind turbines to produce the same amount of electricity. This significantly

increases construction costs. Additionally, the life expectancy of a wind turbine is between 10 to 12

years, which means it must be replaced 2 to3 times over a span of 30 years, more than doubling the

original construction cost. Oil-fueled plants do not make sense in light of high oil prices ($180/MWh).

Natural gas fueled plants, however, do make sense because of the relative affordability of natural gas

($28/MWh) (EIA3, 2012).

To Produce 876000 Mwh (100Mw*24hr*365day) Coal Oili Natural Gas Nuclear Solar Windii WTE - trash Geothermal Hydro

Equivalent Capacity (MW) 118 115 115 111 400 294 120 109 192

Construction cost for Equivalent Capacity (M$US) $290.62 $110.48 $94.56 $672.53 $2,287.42 $1,644.69 $1,029.88 $247.36 $225.02

Req'd acreage for Equivalent Capacity (acres) 46 30 9 97 1744 315 75 116 824

Cost of land for Equivalent Capacity (M$US) $1.14 $0.75 $0.22 $2.43 $43.61 $7.87 $1.87 $2.90 $20.60

Install Cost: Cost of LAND + cost of CONSTRN (M$US) $291.76 $111.24 $94.78 $674.96 $2,331.03 $1,652.56 $1,031.76 $250.26 $245.62

1st level ranking 5 2 1 6 9 8 7 4 3

Annual energy produced (Mwh) 876,000 876,000 876,000 876,000 876,000 876,000 876,000 876,000 876,000

Annual fuel consumption****** 468,449 1,616,236 7,008,000 35,040 0 0 1,100,000 0 0

Annual cost of fuel (M$US) $21.08 $155.16 $24.53 $1.96 $0.00 $0.00 -$89.10 $0.00 $0.00

Annual cost of Maintenance (M$US) $3.69 $1.80 $1.80 $10.43 $8.90 $11.78 $12.86 $10.79 $3.69

Op Cost (Annual): Cost of fuel + maintenance (M$US) $24.77 $156.96 $26.33 $12.39 $8.90 $11.78 -$76.24 $10.79 $3.69

30 year cost (M$US) $1,034.74 $4,819.94 $884.56 $1,046.67 $2,598.03 $2,005.86 -$1,255.58 $573.90 $356.20

2nd level ranking 5 9 4 6 8 7 1 3 2

With Standby Power to Provide 90% Capacity Coal Oili Natural Gas Nuclear Solar Windii WTE - trash Geothermal Hydro

30 year cost $1,034.74 $4,819.94 $884.56 $1,046.67 $2,598.03 $2,005.86 -$1,255.58 $573.90 $356.20

Capacity Difference from Nuclear (0.9) 0.05 0.03 0.03 - 0.65 0.56 0.07 -0.02 0.38

Cost of gas as standby power (M$US) $44.23 $26.54 $26.54 - $574.97 $495.36 $61.92 -$17.69 $336.13

30 year cost (M$US) $1,079 $4,846 $911 $1,047 $3,173 $2,501 -$1,194 $556 $692

3rd level ranking 6 9 4 5 8 7 1 2 3

24

When considering the total 30 year cost plus the cost of natural gas as standby power, WtE still comes in

first as the most affordable at -1.2 B$US, with geothermal and hydro in second and third at 556 M$US

and 629 M$US. In last place is oil at 4.8 B$US, solar at 3.2 B$US, and wind at 2.5 B$US. The addition of a

gas fueled generating unit to provide standby power is important to incorporate into final costs, but this

factor did not significantly affect the ranking order of the technologies.

Some other important considerations are as follows:

To take advantage of solar energy, it is recommended that commercial and residential rooftop space be

utilized, especially in Hawaii where land is limited and expensive. A brief rooftop PV feasibility study was

conducted as part of this research and found that an estimated 330 acres of rooftops on Oahu are

available (between Kahala and the airport) for solar PV installation, which could provide a total of 60

MW of power (Appendix B). Although this would help a bit with land costs, the main issue with solar is

its high cost due to its low capacity factor.

Expanding WtE not only generates electricity with an alternate source, but it also reduces landfilling,

which is a growing problem on Oahu. With three boilers and approximately 90 MW generation, WtE on

Oahu is taking advantage of almost all of its municipal waste production. An option is to import trash

from outer islands like Kauai and Maui and to burn it on Oahu for power production. Barges often return

to Honolulu from outer islands empty. With the expansion of a WtE plant, it is recommended that a

sophisticated materials recovery facility (MRF) be ordered to increase the efficiency of the sorting

process. It is important to note that if the desired expansion of WtE capacity far exceeds 100 MW, then

Oahu and the outer islands may not generate enough trash to fuel the plant. One consideration is to

import trash from California, which has banned incineration and has limited landfill space (GTC, 2013).

This would continue the financial benefits associated with receiving trash, and would continue to supply

Oahu’s electricity needs. Further research should be conducted to assess the impacts of incineration by

WtE plants because, although they burn cleaner than fossil fuel plants, they are not zero emission

technologies like solar and wind.

25

CONCLUSIONS

Deriving 90% of its primary energy resources from oil (9), Hawaii is the most heavily dependent state in

the nation on petroleum for its needs such as electricity generation, ground transportation, and

commercial aviation. With 75% of Hawaii’s electricity production based on fuel oil, the average

residential electricity price in Hawaii in the first quarter of 2013 was nearly $0.35/kWh; over 300%

higher than the national average (DBEDT, 2013).

With growth in population, tourism, and the economy, there has been a significant and growing demand

for energy in the commercial, industrial, transportation, and residential sectors. Additionally, with

lifestyle improvements and a high standard of living, a growing market for electric vehicles (EVs) and

plug in hybrid vehicles (PIHV), the potential rail installation, and the retirement of old oil burning units,

there is a growing demand for energy that needs to be met by alternative energy sources.

The objective of this research was to address Hawaii’s energy dependence on fossil fuels by investigating

the cost effectiveness of options for the next 100MW alternative energy power plant for Oahu. Nine

different energy sources (coal, oil, natural gas, geothermal, hydroelectric, photovoltaic solar, on-shore

wind, waste-to-energy (WtE), and nuclear) were compared and analyzed.

Most individual power plant specifications (capacity factor, construction cost, needed acreage, etc.)

were retrieved from online corporate power plant profiles and from online periodicals and government

energy-related sources. Plant construction costs were equalized 2012 dollars using historical

Construction Cost Indices (CCI) provided by Engineering News Record (ENR). The U.S. Energy Information

Administration (EIA) provided data for national electricity generation pie charts; national historical

power plant development charts; and the values necessary to conduct the 30 year power plant

comparison analysis (i.e. capacity factors, costs of fuel, MWh generated per unit of fuel used, etc.). The

Hawaii Department of Business, Economic Development and Tourism (DBEDT) provided data for local

electricity generation pie charts, and for Hawaii energy trends. The EIA, the United States Department of

Energy, and the National Renewable Energy Laboratory (NREL) provided information for energy source

profiles and national energy trends.

The results of this study indicate that WtE is superior (in terms of cost) to any other technology. Because

fuel for WtE is municipal solid waste, it is the only option that profits while providing electricity. Ranking

2nd and 3rd are geothermal and hydro technologies, respectively, but these resources do not exist on the

island of Oahu. Ranking 4th is natural gas, and although is not a renewable energy source, it is a much

more affordable and cleaner fossil fuel option than oil and a reliable baseload provider that can assist

intermittent power generation from wind and solar energy sources. Ranking 5th in affordability is coal,

but its use is counter-intuitive to the Hawaii Clean Energy Initiative (HCEI) goals of reducing fossil fuel

dependence, especially since coal produces the most pollution of all fossil fuels. Ranking 6th is nuclear,

but the average capacity of nuclear power plants in this study was 2,000 MW and current installations

scale down to 500 MW but not to 100 MW. Additionally, approval for nuclear power generation in

Hawaii given its constitutional prohibition is a long and intensive process that will likely take over a

decade to accomplish if it is ever pursued. Ranking 7th and 8th is wind and solar, respectively. High costs

26

for construction and standby energy are associated with their low capacity factors. Ranking 9th is

petroleum largely due to the high price of the fuel. This is unfortunate because oil-fired power plants

currently generate the supermajority of Oahu’s electricity. In turn this explains the high cost per MWh in

Hawaii which is 300% of more above US mainland average.

In the long run, fabricating a society and economy that is less dependent on imported energy will

benefit future generations. In the short run, it will provide greater security in the case of a natural

disaster or war-time complications that could easily discontinue our imported supply of petroleum.

Either way, this issue is of critical importance and must be addressed in a timely fashion.

FUTURE WORK

As can be seen in Fig. 19, this study did not produce the same levelized costs as the EIA for each

technology. The main contribution to this discrepancy is data variation as well as Hawaii-specific costs

that favor some technologies and penalize others. For example, the big discrepancy in WtE results is that

our estimate is Oahu-specific using the actual (high) tipping fee on Oahu, whereas the EIA cost comes

from biomass. Hawaii solar and wind estimates are high and part of the reason is the high cost of land

per acre in rural Oahu.

Figure 20. Levelized Cost for Power Production: This study vs EIA averages

-200

-100

0

100

200

300

400

500

Co

al Oil

Nat

ura

l Gas

Ge

oth

erm

al

Hyd

ro

Sola

r

Win

d, o

n s

ho

re

WtE

-tr

ash

Nu

cle

ar

Nat

ual

Gas

se

t to

10

0 a

nd

sca

ling

the

re

st

Levelized Cost for Power Production

UHM.CEE 30 yr Estimates

US Average, EIA.gov

27

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Accessed on 4/10/13. (http://www.eia.gov/energyexplained/index.cfm?page=nonrenewable_home)

31. U.S. Energy Information Administration (EIA6) (2012). “Energy Explained – Renewable Sources. “Accessed

on 4/10/13 (http://www.eia.gov/energyexplained/index.cfm?page=renewable_home)

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http://www.eia.gov/state/?sid=HI#tabs-1

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Annual Energy Outlook 2013" (http://www.eia.gov/forecasts/aeo/er/electricity_generation.cfm)

34. U.S. Environmental Protection Agency (EPA) (2011). Shale Gas Development, Responsible Stewardship

and Environmental Protection. Accessed on 4/10/13.

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(http://www.wyretidalenergy.com/tidal-barrage/la-rance-barrage)

29

APPENDIX A. Additional Tables

Table A.1. Constants used to Calculate Values for Table 2 and Table 3.

i Low construction cost ii. Wind turbine lifespan = 12 yrs * 220 acres in Kahuku for sale for 6.5 million USD… rounded down to 25K per acre ** EIA (2012). "Levelized Cost of New Generatin Resources in the Annual Energy Outlook 2013"

(http://www.eia.gov/forecasts/aeo/er/electricity_generation.cfm) *** lb for coal, 1000 ft^3 for natural gas, bbl for oil, lb U3O8 for nuclear, and ton of trash for WTE **** EIA (2012). “Frequently Asked Questions: How much coal, natural gas, or petroleum is used to generate a kilowatt-

hour of electricity?” Accessed on 4/10/13. (http://www.eia.gov/tools/faqs/faq.cfm?id=667&t=2) ***** EIA (2012). "Levelized Cost of New Generatin Resources in the Annual Energy Outlook 2013"

(http://www.eia.gov/forecasts/aeo/er/electricity_generation.cfm) Coal price: EIA (2012). "Coal Explained". Accessed on 4/10/13.

(http://www.eia.gov/energyexplained/index.cfm?page=coal_home#tab2)

Petroleum price: EIA (2012). "Oil: Crude and Petroleum Products Explained". Accessed on 4/10/13.

(http://www.eia.gov/energyexplained/index.cfm?page=oil_home#tab2)

Natural Gas Price: EIA (2012). "Natural Gas Explained". Accessed on 4/10/13.

(http://www.eia.gov/energyexplained/index.cfm?page=natural_gas_home#tab2)

Nuclear Price: EIA (2012). "Nuclear Explained". Accessed on 4/10/13.

(http://www.eia.gov/energyexplained/index.cfm?page=nuclear_home#tab2)

Tipping Fee: Coney, S. (2012) "The Economics of Recycling in Hawaii." Hawaii Business Magazine. Accessed on

4/10/12. (http://www.hawaiibusiness.com/Hawaii-Business/August-2012/The-Economics-of-

Recycling-in-Hawaii/)

Variables (all costs in 2012 USD) Coal Oili Natural Gas Nuclear Solar Windii WTE - trash Geothermal Hydro

Plant cost per MW (M$US/MW) 2.47 0.96 0.82 6.05 5.72 2.24 8.55 2.28 1.17

Land productivity (acre/MW) 0.39 0.26 0.08 0.87 4.36 1.07 0.62 1.07 4.29

Value of farm land* (M$US/acre) 0.025

100MW at 100% capacity (Mwh) 876,000 876,000 876,000 876,000 876,000 876,000 876,000 876,000 876,000

Capacity Factor** 0.85 0.87 0.87 0.9 0.25 0.34 0.83 0.92 0.52

Cost of Fuel ($US)*** $45.00 $96.00 $3.50 $56.00 $0.00 $0.00 -$81.00 $0.00 $0.00

MWh generated per unit of fuel used:**** 1.87 0.542 0.125 25.00

Maintenance Cost ($/MWh)***** $4.21 $2.05 $2.05 $11.90 $10.16 $13.44 $14.68 $12.31 $4.21

30

APPENDIX B. PRELIMINARY ROOFTOP PV ESTIMATES (ACRES)

Table B.1. Honolulu Area Rooftop Study for PV Potential

Figure B.1. Usable roof space in downtown Honolulu area.

Figure B.2. Iwilei Costco utilizing roof space for solar PV.

ROOFTOP STUDYDowntown

& Chinatown

Ward, Ala Moana

& Kaka'akoWaikiki

Sand Island

& NimitzTotals

Total roof area (acre) 26.95 51.37 18.90 130.47 227.70

Total solar panel area (m2) 49,731 94,802 34,884 240,768 420,186

Total Capacity (Mw) 7.06 13.46 4.95 34.18 59.66

Land productivity (Mw/acre) 0.26 0.26 0.26 0.26 n/a