Hawai’i National Marine Renewable Energy Center (HINMREC)
Hawai’i Natural Energy Institute (HNEI)School of Ocean and Earth Science and Technology (SOEST)
University of Hawai’i (UH)
http://hinmrec.hnei.hawaii.edu
September 16, 2011
Hawaii National Marine Renewable Energy Center
Facilitate development of wave energy Conversion (WEC) systems;
Support Development of Ocean Thermal Energy Conversion (OTEC) technologies
2
Hawaii Electricity Demand: Contribution Potential
Island Wave Farm Challenge OTEC Challenge
Oahu < 17% Siting: requires all shoreline segments;
Storage: intermittent resource
>> 100% No prototype operational data
Maui < 75% “ >> 100% “
Hawaii < 150% “ >> 100% “
Kauai < 300% Siting: requires 30% shoreline segments;
Storage: intermittent resource
>> 100% “
Molokai < 2000% Storage: intermittent resource
>> 100% “
3
Environmental Impact Studies
Goal: inputs to EISs required for permitting and licensing of WEC & OTECWorked with federal regulatory agencies (FERC, BOEM,
and NOAA) to define differences between ocean energy systems and already established regulated industrial activities:
OTEC key differentiator: return of large amounts of deep seawater (“plume”) below the photic zone
4
Environmental Impact Studies
OTEC plume impact can not be determined a priori;
Must monitor operations through an “Adaptive Management” Protocol;
UH greatest contribution would be to design such Protocol.
5
OTEC Operations: Environmental Parameters
Nutrients & Biological CTD Carbonate Cycle
Nitrate *Temperature Dissolved Inorganic Carbon
Phosphate *Salinity *pH
Silicate *Dissolved Oxygen Alkalinity
*Chlorophyll a
6
*Monitor at: (i)Plume Neutral Buoyancy Depth (“known”); (ii)Far Field (TBD)
7
\ Seasonal Concentrations of Nitrate + Nitrite, Measured at Station Kahe, Oahu, 1989-2001
-0.5
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
Spring Summer Fall Winter Spring Summer Fall Winter Spring Summer Fall Winter
50-75 100-150 150-200
Depth (m)
Co
nce
ntr
atio
n (
ug
/m3)
Mean Seasonal Chlorophyll a, Measured at Kahe Point, Oahu, 1989-2009
0
0.05
0.1
0.15
0.2
0.25
0.3
Spr
ing
Sum
mer
Fal
l
Win
ter
Spr
ing
Sum
mer
Fal
l
Win
ter
Spr
ing
Sum
mer
Fal
l
Win
ter
Spr
ing
Sum
mer
Fal
l
Win
ter
0-50 50-75 100-150 150-200
Depth (m)
Co
nce
ntr
atio
n (
ug
/l)
Annex
8
9
RREESSOOUURRCCEE PPRROODDUUCCTT
RREESSOOUURRCCEE Transfer Function PPRROODDUUCCTT
T (C)=T 20m–T 1000m Public Domain kWh; H2O, AC
Ocean Volume 24/ 7
Transfer Function
Ocean Thermal Energy Conversion
Ocean Thermal Energy Conversion (OTEC)
10
Resource: Baseload energy production potential of at least 30% world wide consumption in tropical oceans around the world. Ninety-eight (98) nations have adequate OTEC resource within EEZ with direct application in Hawai’i and 5 US Trust Territories
Technology: Uses temperature difference between warm surface water and cold deep water (1,000m) to generate electricity
Technology status: - Electricity generation and simultaneous desalinated water
production has been demonstrated 24/7 at experimental scale (~ 250kW)
Industry technology development needs: Economic models indicate scale of > 50 MW needed in USA to be economically
viable; Low cost manufacture and long-term testing of critical components, such as heat
exchangers (HXs); Deployment and testing of a pre-commercial OTEC plant (5 to 10 MW) to determine
realistic costs, survivability, and environmental impact; Sustained and substantial government support through pre-commercial
demonstration is a critical requirement.
Two Year (July 2007-June 2009) Average Temp. Difference {T20m – T1000m}
Hawaii Ocean Time Series Kahe Station : T Daily Averages Change 1°C in T 15% change in Pnet.
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98 nations with adequate OTEC resource within EEZ
Theoretical Energy Production > 1/3 World Wide Consumption
Source: http://hinmrec.hnei.hawaii.edu
