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.

12

98 nations with adequate OTEC resource within EEZ

Theoretical Energy Production > 1/3 World Wide Consumption

Source: http://hinmrec.hnei.hawaii.edu