Prepared by Haim R. Branisteanu

7th International Renewable Energy Conference Eilat-Eilot Israel, November 2016

The presentation is also available on LinkedIn

Ramko Rolland Associates

Energy Storagefor “Smart Cities” with renewable energy resources.

Presentation of Conceptual Projects of electrical energy storage that can be part of

the Electrical Network • Due to the intermittent nature of renewable energy of all types:

solar, wind, sea wave, there is a need to store the excess energy generated for the time the energy source is not available or not in the anticipated amount by using stored energy with controlled release and, in addition, as a stabilizing element of the electrical grid, in a distributed energy resources (DER) configuration.

• In general there is a need for short term storage and long term

storage.

• The economic viability aspect of any energy storage medium is to be comparable in cost to the electrical generation from NG on a LCOE basis.

• NG combined cycle efficiency is 170 to 180Kwh @ $2 to $3 per million cubic feet or $11 to $18 Mwh.

• US combined cycle power plant LCOE is $57 to $58 Mwh. According to NOAA, NG Pollution expenses can add up to $25 Mwh in cost. For PV it is at $58 Mwh net power to the grid (as per last report). Israel on average has 20% more solar irradiation

100% Renewable Grid – is Feasible? – The answer is YES“We found that all experts agree that a 100% renewable grid will be reliable and stable, as long as it uses an appropriate mix of renewable generation sources, energy storage and upgraded infrastructure,” said the paper’s author. “This grid would be robust, with smarter renewable generators and batteries automatically injecting extra electricity when required for grid stability. Similarly, smart appliances would detect disturbances in the grid and independently adjust their power level to compensate.” (prices in $AUD)

Wind and Solar Are Our Cheapest Electricity Generation Sources, Now what we do?

Some venues for storage of energy in their various forms are:

• Electrochemical energy usually in batteries with various chemistries

• Electrostatic energy usually in modern super capacitors which are catching up in storage

• Calorific or heat energy storage taking advantage of the latent heat of salts or other materials including metal oxides, sand, gravel, stones

• The use of solar panel excess heat storage for HVAC application

• Potential gravitational energy storage, similar to pumped hydro for long term storage.

There are two basic principles to take into account in renewable energy storage systems: (i) simplicity and (ii) abundance of raw materials to achieve competitive cost and

volumetric weight per kwh of storage which differs from system to system.

Maximizing the efficiency of stored energy in its various forms

In any energy storage system, the storage and the conversion unit should be integrated and if possible the electrical output “network interconnected”

Secure distributed commercial and residential-neighborhood “micro-grid networks” with the integration of thermo-solar panels (instead of the present solar water heaters) and battery storage in connection to a neighborhood storage system for mutual peer to peer consumption* and inter-connected to the grid.

Architectural integration of CdTe solar panels or “solar-paint”** and storage in fire-retardant batteries within the office buildings structures in special designated bays *** as part of the micro grid or a “virtual power plant” (VPP)

The implementation of at least 3 to 4 GW peak installation is warranted as Israel enjoys solar irradiation of around 2,000 Kwh/sq. meter/year

* This will establish a virtual “localized electrical power plant” a/k/a Thomas Edison **“solar-paint” in R&D phase very cheap, made of perovskite, quantum dots, nanoparticles ***Example: is a Zinc (Zn) Bromide (Br) battery with a fire-retardant gel in development

To the question is “Renewable Energy waiting for storage” the simple answer is a resounding NO as economically viable solutions are currently available and implemented

The present cost accounting validates the economic viability of installing even on the residential level thermo-solar panels in conjunction with available battery storage, power supplies and net metering systems, in a integrated distributed energy resources (iDER) setup. See slide #21 for present situation Savings of $A450 a year per average household (or around 1,300 Shekels)

The return on investments (ROI) varies on situation, from 5 to 8 years with a 10 year guaranty which justifies bank financing of the system.

Due to the anticipated decline in pricing in solar panels, battery storage, converters networked in a fiber optic system within a micro grid configuration, would make the installation of those systems highly beneficial, and will, not only improves energetic security but also lower the cost of the national electricity distribution system and reliability of the whole system, * and enable the establishment of a VPP from the iDER assets within a city.

* lowering the expenses on grid transmission lines and transformers as explained below

In the following 3 slides I present the results of a “behind the meter” solar and battery installation, which provides substantial savings by reducing both usage and (peak)

demand of cost of electricity charges and lowers network connection costs

Blue is the building demandDark Blue the net demandYellow solar energy

Diagram outlining the actual electricity demand from the grid with solar and batteries installed. The blue line is the electrical consumption of building. The gray line the consumption from the grid

This presentation describes how a California project electrical demand savings from battery installations paired with a solar installation by relying on actual performance data. Specific to California there is a need to understand how an electricity bill is calculated. The electricity costs are calculated based on the rate schedule applied to each utility electricity meter.

$72,782+ $5,303$78,085

$8,267 $2,385$10,652

Each solution mentioned, is suitable for specific situations; storage is not a one solution solves it all type of setup.

The electrochemical storage solution as related to batteries; The anticipated cost within the next few years will drop to around $100 to $160 per Kwh of storage for a life expectancy of 15 years ($160/5,500 cycles=$0.03/day/Kwh).

The most readily available batteries for introduction within as year or two are Magnesium–ion batteries with double volumetric capacity, as the Mg ions have 2 electrons to exchange versus 1 in lithium ions.

It is estimated that the batteries based on magnesium with, higher capacity and lower cost to the present popular lithium-ion will supplant the Li-Ion batteries.

At present time lithium-ion @ $190 - $225 Kwh, are the most popular but with many drawbacks and restrictions, which is the impetus for new developments

Electrochemical storage prices where falling precipitously during last few years

* According to the BEE study, the current price (12/2016) of second use batteries, which includes their reconditioning, is around €150/kWh or $166/kWh. A 13MWh facility in the final stages of development by Daimler AG, The Mobility House AG and GETEC in Lünen, which will also be used to deliver reserve control to the German grid (the pack will have lower performance of a new pack).

This is an example of a lithium transition oxide with a spinel structure revealing the complexity.

Within the structure of those batteries the familiar cylindrical packed batteries are popular and the pouch batteries similar to those enclosed in most cellphones. The most popular format is the Lithium-Ion battery cell “18650”.

Due to more storage demand Panasonic and Tesla developed the new “20700” cell format which is still cylindrical 20x70 mm but claims double the energy storage. BMW/Samsung use a different packaging.

The costs, are already below $200/kWh for cells and $215/kWh for the entire battery pack. GM/LG expects batteries @ $145 for cells $190 per pack

Lithium-Ion battery storage

The schematic above describes the principle of in Xn- ion batteries, whereby the ions migrate from the positive to the negative electrode, where they become embedded in the porous electrode material (in many cases also carbon) in a process known as intercalation, which is a common process in each ion based battery.

Other metals/materials used in the anticipated batteries would be based on zinc ion, al ion, calcium ion, magnesium ion, potassium ion or sodium ion, etc, each well suited for a specific range of uses for their stability, temperature range, etc., based on the ability of intercalation within those compounds which are complex materials having a formula CXm where the ion Xn+ or Xn− is inserted (intercalated) between the oppositely charged layers.

Schematics of a cylindrical battery

Storage Batteries trends and theoretical volumetric storage limitsThe graph below indicates storage batteries trends and anticipated developments. There are more than 200 various development programs.

Recent R&D developments and academic researchAs mentioned before the most realistic new battery to market will be the Magnesium (Mg) based battery due to the attractive metallic anode material . Development of Mg batteries started already in 2010. The main advantage is the Mg 2+ ion compared to the Li 1+ ion (one electron) in Li-ion batteries and lack of dendrite accumulation as in Li-ion.

BMW cell pack above – Toyota is expected to A illustration represents a computer model bring to market a Mg battery within a year or two. that shows how the orange magnesium ion

is coordinated by only four nearby ions in the electrolyte (2*2=4).The Dept. of Chemistry, U of Cambridge, claim to have developed in laboratory environment the most powerful battery of Li-O2, by - Cycling Li-O2 batteries via LiOH formation and decomposition, by solving the problems with Li-air batteries and by this achieving the searched after goal of volumetric “gasoline energy” content (as is IBM).

The U of Cambridge laboratory claim, was achieved by demonstrating a lithium-oxygen battery which has very high energy density, is more than 90% efficient, and, to date (Oct. 2015), can be recharged more than 2000 times. Lithium-oxygen, or lithium-air, batteries have been touted as the ‘ultimate’ battery due to their theoretical energy density, which is ten times that of a lithium-ion battery which is today around 200+Kwh/kg. Such a high energy density would be comparable to that of gasoline. http://www.cam.ac.uk/research/news/new-design-points-a-path-to-the-ultimate-battery

In general terms, to increase the storage capacity of a battery with a specific chemistry, it is active surface dependable, - more surface is needed for more electrical storage, to enable the intercalation of electricity carrier ions.

An important development in the structure of anodes or cathodes in batteries, are the internal changes in the structure which transcended from foil like anode and cathode to a 3 dimensional foam/sponge structure or like that of fullerenes, CNT (carbon nanotubes), nanowires, nanoribbons.

This foam/sponge like structure brought to the fore the ability of changing the packaging structure of the battery cell on higher and wider surface areas.

The pictures below visualize the structure of what is called a 3D/Foam battery

(a) Schematics of the “Layer by Layer” process used to assemble 3D devices in an aerogel and (b,c) cross-section SEM images of the first Polyetherimide/CNT electrode (left column), the PEI/CNT electrode with separator (middle column) and the full device (right column). Scale bars, (b) 50 μm and (c) 2 μm.

Example of 3D/Foam/sponge batteries and their structure and advantagesThe Prieto battery is being developed

The ability of 3D foam/sponge batteries and supercapacitors to change physical dimension and endure compressibility as illustrated below. This induces the probability of changing the packaging of the sponge like batteries and super capacitors, from rolled in round encasing or pouch, to flat and sizable batteries of different thicknesses as the active area increases with the physical thickness of the 3D/foam /sponge and is not only two dimensional as in present cylindrical or pouch batteries. One of the problems concerning rolled up sheet like batteries is the dissipation of heat from charging and discharging. By designing flat big surface area battery cells, vast surface area enables the dissipation of the heat by convection.

Energy Storage from Solar panels for HVAC use Solar Panels reach during summer temperatures of up to

75C to 80C Power output falls from 240W@25C to 190W@70C on a

typical panel The proposed addition to the solar panel collects the excess

80% solar radiation, lowers the panel working temperature & increasing output.

The 80% excess of solar radiation is collected as heat in a storage tank to be further used in HVAC system @ 50C to 70C at the user choice.

The energy differential can be used for heating or cooling.

In temperate climate the graph is representing changes in temperature year round

In exchange of pumped hydro storage, surplus electrical energy can be stored at temperatures above 550°C in insulated structures or insulated caverns

The heat energy generated by electricity stored in various salts or materials like iron-oxides, sand, gravel stones can be extracted later by generating steam.

The ideal system to generate “dry steam” for industrial use, as steam, will be based on the latent heat of iron-oxides* & sand or gravel

Other use of the thermal storage facility would be adjunct to a combined cycle power station with the steam generated feed into the main steam turbine feed or activate their own steam turbine, which Siemens is now developing. Total efficiency is relatively low (below 50%)

The high temperature heat exchange facility will be similar to those exiting now in electrical power stations generating the steam for their steam turbines, best suited for enterprises which need hot steam in their manufacturing process.

*iron oxide sintered into building blocks, specific heat of is 920.0 J·kg−1·°C−1, its density is 3,900 kg·m−3, and its thermal conductivity is 2.1 W·m−1·°C−1. “Feolite” can be used up to 1000 °C. Silicon and alloys like pozzolan have potential for heat storage

High Temperature Thermal Energy storage for steamin utility size power generation

Effects of overload on electrical transformers due to the hysteresis curve pulse as a result of temporary overload which can be mitigated by battery stored energy

The accepted rule of thumb is that the life expectancy of insulation in all electric machines including all transformers is halved for about every 7°C to 10°C increase in operating temperature, this life expectancy halving rule holding more narrowly when the increase is between about 7°C to 8°C in the case of transformer winding with cellulose insulation

Small dry-type and liquid-immersed transformers are often self-cooled by natural convection and radiation heat dissipation. Large transformers are filled with transformer oil that both cools and insulates the windings.

Transformer oil that cools the windings and insulation. It is estimated that 50% of power transformers will survive 50 years of use, and that the average age of failure of power transformers is now about 10 to 15 years.

About 30% of power transformer failures are due to insulation and overloading failures.

Prolonged operation at elevated temperature degrades insulating properties of winding insulation and oxidizes the dielectric coolant, which not only shortens transformer life but can ultimately lead to catastrophic transformer failure.

We can provide a solution of extending network transformer's useful life

The newest economic analysis for residential PV+ battery+ grid in Australia

The chart shows that the combination of PV + battery + grid, taking advantage of the best grid offer, is $A123 per year cheaper than the cheapest grid-only offer ($A1,645 per year) & $A449 lower than the median grid-only offer ($A1,971), as of November 2016

In other words, our typical 4,800 kWh household in Adelaide can beat all contemporary grid-only offers by installing a PV + battery system and selecting the best retail offer to provide their residual grid consumption and to export their PV production surplus.

For solar PV, the median installed price of a 5kW system (data from Solar Choice) and assume a 20 year life with zero residual & 20% purchase premium for on-going maintenance. For battery. The indicative installed price ($A10,300) assuming a 10 year life with zero residual.

This comparative advantage is reflected in payback periods for PV + battery that I estimate to be between 5 years (assuming the alternative was that the customer selected the most expensive grid-only retail offer) and 10 years (assuming the alternative was that the customer selected the cheapest grid-only retail offer) and 8.5 years for the median offer.

In Israel, the potential transaction volume of the battery storage proposal

Investment Assumptions; - preliminary figures to be tested in a market research, as prices fall consistently.

Cost of Storage Batteries today is estimated at $200 to $250 Kwh with a price slide which is expected to be around $100 to $160 in 3 to 8 years. The batteries charge discharge economic viability of presently installed batteries will end in 10 to 15 years.

To enable the proper leveling off, of peak electrical demand a capacity of around 2.5 hours is needed @ a discharge rate of around 30% which will cover 6 to 7 hours. A partial recharging possibility of the batteries, would be at the lowest rate of electrical power.

Depending on the shape of the load, of a municipal or cooperative utility, it may be possible to use a less costly 2 or 3 hour storage solution. To summarize our 2016 comparison, it will require a high degree of selectivity, but storage economics can be much better than some conventional NG Turbines even at 2016 projected storage costs.

Therefore, investment cost in batteries would be $450 - $700 per kw of solar panels

Installation and engineering cost are $160/kw+$90/kw = $250/kw as the DC/AC inverters are already installed within the solar panel (PV) farms.

Total cost of “PV + batteries” is $700-$950 per kw or $700K - $950K per MW, cost of land not included. The present investment cost is 30% - 40% cheaper than the cost of combined cycle NG turbine. Maintenance of PV +batteries us substantial cheaper than the cost of NG

Related to Energy Storage as heath based on latent heath of gravel or sand, for steam for electrical generation by steam turbines in combined cycle setup please contact me

Same for thermo-solar panels for HVAC in commercial

setups

Same for substitute of pumped hydro storage based on gravel

Thank you for watching

SUMMARY AND CONCLUSIONS - GUIDE TO PROCUREMENT OF FLEXIBLE PEAKING CAPACITY: ENERGY STORAGE OR COMBUSTION TURBINES?http://www.energystrategiesgroup.com/wp-content/uploads/2014/10/Guide-to-Procurement-of-New-Peaking-Capacity-Energy-Storage-or-Combustion-Turbines_Chet-Lyons_Energy-Strategies-Group.pdf (report prepared in 2014)

Lower cost solar PV and its rising penetration in all market segments will have a profoundly disruptive effect on utility operations and the utility cost-of-service business model. This has already started to happen. Storage offers a way for utilities to replace lost revenues premised on margins from kilowatt hour energy sales by placing storage assets into the rate based and earning low-risk long-term regulated returns on capital.

Because solar PV is highly distributed, simply overlaying storage on a central station basis won’t maximize grid performance or cost reduction. Storage enables more PV while mitigating stability problems at the distribution circuit level. Availability of cost effective and technically proven distributed storage will further accelerate the shift toward distributed power grid architecture. The central station approach utilities have used to meet peak power requirements is on the verge of a paradigm shift. Central station topologies will give way to distributed grid architecture.

By 2017 Capex for a 4-hour storage peaker of “Zink Iron Redox Flow” battery (my proposal is for 2.5 hours) is projected to be $1,390. With added benefits from locating storage on the distribution grid, in 2017 storage will be roughly competitive with many CTs conventional assuming mid to higher range CT (NG Combustion Turbine) costs. For CTs at the high end of the cost range, 4-hour storage will be a clear win.

By 2018 the cost of ViZn Energy’s (http://www.viznenergy.com/) 4-hour storage solution is essentially identical to that of a conventional simple cycle peaker. Given the added benefits of installing storage in distribution, by 2018 storage will be a winner compared to a typical mid-range cost for a conventional simple cycle CT and generally disruptive for higher cost simple cycle CTs.

Visualization of a 1-MW/2.8-MWh Grid Storage Solution installation in Japan. The project was commissioned in March 2014 and is being used

for peak shaving and demand charge management.

By 2018 the cost for a 4-hour storage resource – that translates to $244 per (installed) kilowatt-hour of capacity. Given the added benefits of installing storage in the distribution network. By 2018 storage will be a winner against the mid-range cost for a simple cycle CT (Combustion Turbines) and clearly disruptive compared to higher cost simple cycle CT.

Tank you for watching !

Prepared by Haim R. Branisteanu –proprietary