This document discusses ocean thermal energy conversion (OTEC), which harnesses the temperature difference between warm surface waters and cold deep waters to drive a power cycle and generate electricity. It describes the Rankine, Kalina, and Uehara power cycles that can be used. OTEC has a potential energy supply of 35-168 terawatt hours per year and can also provide desalinated water and other products. The document outlines offshore and onshore plant architectures and modules as well as cost comparisons and preliminary economic analysis of an OTEC system. It also discusses business opportunities in renewable energy, electrochemical processing, desalination, and using deep ocean water.

1. OCEAN THERMAL ENERGY
OCEAN THERMAL ENERGY
Harnessing the stored solar energy in the seas
Vicente Fachina

2. CONTEXT
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TO PROMOTE SERVICE &
FLOW ECONOMY

3. THE RANKINE POWER CYCLE
The Rankine power cycle Upgraded cycles
Warm water
•Water / Ammonia mixture as working fluid
Saturated vapor
working
•To use heat regenerators
fluid
•To use solar heater for the surface sea water
Liquid working
fluid •To use solar super heater for the working fluid
•To use gravity for reducing pumping power
•Rankine upgrades: KalinaTM & UeharaTM cycles
Cold water

4. THE KALINA POWER CYCLE
Saturated vapor
working
fluid
Working
water
Warm water
Liquid working Liquid working
fluid fluid
Cold water
References: http://kalinacycle.net, http://www.globalgeothermal.com

5. THE UEHARA POWER CYCLE
Saturated vapor
working
y 1-y
fluid
Working
water
Warm water
Liquid working
fluid Liquid working
fluid
Cold water
Reference: http://www.otec.ws

6. OCEAN THERMAL ENERGY SUPPLY
35-168 TWh/yr SUPPLY POTENTIAL (WEC, 1994)
Source: esrl.noaa.gov, 2012

7. ARCHITECTURES 1/4
OFFSHORE PLANT - I
Source: Lockheed Martin Corp., 2011

8. ARCHITECTURES 2/4
OFFSHORE PLANT - II
Source: http://www.otec.ws, 2011

9. ARCHITECTURES 3/4
ONSHORE PLANT
Source: http://www.otec.ws, 2011

10. ARCHITECTURES 4/4
MODULES
(w/ sub sea condenser)
Source:http://www.otecpower.com, 2011

11. PRODUCT PORTFOLIO
N2
Deuterium
Ammonia
Methanol Ethanol
CO2 H2 CO2 H2
Source: adapted from http://www.otec.ws, 2012

12. COST COMPARISONS
CEE (2010)
70
60
50
USD/GJ
40
30
20
10
0
OTEC CSP Offshore wind Hydro Biomass
Source (blue columns): irena.org, 2012

13. PRELIMINARY ECONOMICS
70 MW ELECTRICITY SUPPLY @ 90% UPTIME
USD 630-1,350 MM CAPEX, AND USD 15 MM/yr OPEX
0.7 USD/m3 DESALINATED WATER COST
10%/yr INTEREST RATE
Tempos de retorno
20
18
16
Demanda de água potável [m3/s]
No. anos
14
4 5 6 7 8 9 10
12
10
8
6
4
40 60 80 100 120 140 160 180 200 220
Preço combustível [USD/GJ]

14. BUSINESS OPPORTUNITIES
DAILY RENEWABLE ENERGY ROUTE
ELECTROCHEMICAL PROCESSING: OTHER ENERGY
CARRIERS (HYDROGEN, AMMONIA)
DESALINATED WATER, SEA MINERALS, DEUTERIUM
DEEP OCEAN WATER (DOW): MARICULTURE, COLD
WATER AGRICULTURE, CHILLING WATER FOR AIR
CONDITIONING

15. OBRIGADO PELA ATENÇÃO!
Vicente Fachina
vicentefachina@gmail.com