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Renewable Energy Sources for the United States Virgin Islands
15 Megawatts+ Today the average retail cost of electricity generated via utility scale PV system ranges between $0.21 and $0.25 kWh. By 2015 (seven years from now) technological innovation and improved manufacturing efficiency are projected to lower the retail price to near $0.10 to $0.15 kWh. This means that electricity from utility scale PV systems will soon be on par with or less expensive than electricity generated by fossil fuels (coal, natural gas, oil). This parity in generation costs may be hastened by upcoming carbon tax legislation for fossil fuels which will make them more expensive. Advantages • 1.5 to 2 years to bring online. • Service life of 30+ years. • No fuel costs or increases.• Peak production matches peak day time electric usage.• Solar energy is uniform and abundant throughout the Virgin Islands.Disadvantages • Intermittent production (day time only).• No production of water as a by product.• Uses land.
Distributed generation from solar PV & Wind 15 Megawatts+ Private investment in grid-connected solar PV installations should be dramatically expanded through net-metering and other incentives. In addition to distributed generation by residential homeowners, there is substantial potential for “co-generation” by hotels and other commercial businesses. Privately owned solar PV for residential and commercial buildings connected to the grid can reduce mid-day peak energy demand on WAPA, and represents conservation of WAPA-generated energy, not energy generation from mini Independent Power Producers (IPPs) selling electricity to WAPA.
Wind Farms 20 Megawatts+ Today the average retail cost of electricity generated via utility scale wind farms ranges from $0.06 to $0.12 kWh. The wind resource in the Virgin Islands can be classified as moderate to good depending on location. Virgin Islands topography and road conditions present challenges to the siting of large (1 to 3 MW) wind turbines. East and south on St. Croix are large shallow water shelves that would allow for theoffshore siting of a significant number of large scale turbines. Windstorm insurance can be obtained for larger machines and smaller tilt-down turbines can be used to reduce the risk of damage (see recently installed 10 MW Butoni wind farm on Fiji). Advantages • 2.5 to 4 years to bring on line• Service life of 25 years.• No fuel costs or increases.• Land or sea platform loca tions may be used.• Hurricane insurance or small machines (.25 MW) mitigate hurricane insurance issue.Disadvantages • Intermittent production (only when wind blows).• No production of water as a by product.• Potential mpact on birds and bats.• Visual impact.
Ocean Thermal Energy Conversion (OTEC) 10 Megawatts+ OTEC technology is being used in power generation today. Examples are a Sumitomo steel mill power plant (operated since 2000), a Fuji Oil power plant in Japan (operating since 2006), and a power plant using geothermally heated water in Husavik, Iceland (operated since 2000). The technology for building and deploying the large diameter pipelines (10-12 ft) required for OTEC has been designed by Makai Ocean Engineering. OTEC has the desirable feature of producing electricity day and night, regardless of wind speed or whether it is a cloudy day. It uses the temperature difference between deep cold ocean water and the heat that is stored in warm surface ocean water. No fossil fuels are required for its operation, and there are no gases emitted that can influence climate warming. The cold water discharge is costs, waste disposal fees, and other local factors. Air emissions must to be managed with state-of-the art air quality control equipment. Advantages • Producing electricity 24/7, rain or shine, hurricane or no wind.• Potable water production.• Water for agriculture.• Nutrient rich water for mariculture operations.• No fuel costs or increases.• No fossil fuels required for operation.• No release of greenhouse gasses.• Seawater cooling (A/C) for nearby buildings.Disadvantages • Mitigation of shore impact.• Estimated 4 years to full operation.
10 Megawatts+ Waste-To-Energy (WTE) is a combustion technology which uses trash (now sent to a landfill) as a fuel to generate electricity and/or potable water and steam. More advanced WTE systems recover recyclable materials and create construction materials from the ash in addition to generating power. There are more than 700 WTE systems operating throughout the world, especially where land is at a premium and energy costs are high. The most economically sound WTE facilities require about 1,000 tons of waste/day and can produceelectricity between $0.10 kWh to $ 0.20 kWh. Successful smaller scale WTE facilities of 200-600 tons/day exist (waste profile of the Virgin Islands). The economics and electricity price for these smaller systems are generally higher and are dependent on land cost, equipment and construction costs, waste transport costs, waste disposal fees, and other local factors. Air emissions must to be managed with state-of-the art air quality control equipment. Advantages• Generates electricity 24 hrs/ day with waste currently sent to a landfill.• Produces a variety of resources – electricity, steam, potable water, and construction materials.• Minimizes the need for landfills and their associated greenhouse gases.• Reduces land needed to manage solid waste.• Reduces use of imported fossil fuels.Disadvantages • Produces CO2 and other emissions that must be controlled with appropriate air quality control equipment• Ash produced during the combustion process must be managed properly.• Ensuring sufficient solid waste for reliable delivery of power above 10MW.
50-130 Megawatts Geothermal energy technology uses hot water in the earth to produce steam that is sent to a turbine for the production of electricity. The use of geothermal power began in 1904 and today there is over 9,000 MW of geothermal production in 27 countries.The geothermal power proposed for St. Thomas and St. Croix would come from the islands of Nevis and/or Saba. Nevis has capacity to provide 300 MW of power with a potential of 900 MW. Saba has the capacity to supply 100 MW with a potential of 3,000 MW. The electricity would be transported by submarine electric cables from the geothermal power plants on those islands to St. Thomas and St. Croix. These cables have been in use for over 50 years all over the world. The longest submarine cable is the Baltic Cable between Norway and Latvia which carries 600 MW over 500 miles. This cable has been in operation for over 15 years. Geothermal is base-load power that operates 24 hours a day, 7 days a week, 365 days a year. It has an availability factor of over 98%. The geothermal power energy charge will be between $0.12/kWh and $0.15/kWh plus a fee for the cable usage, depending on the amount of power purchased. The cable will have a capacity to supply a minimum of 50 and a maximum of 130 MW of power. The more power purchased the cheaper the energy charge and the cheaper the cable usage fee per kWh. Since the power plants are not located in the US Virgin Islands, environmental impact to the US Virgin Islands is limited to impacts related to the construction of facilities located on St. Thomas and/or St. Croix, e.g., a converter station and switch/transformer yard which would use approximately 5 acres of land on each island (at a cost of about $25 million for both islands). The principle discharge from Geothermal power generation to the atmosphere is water vapor. Geothermal projects can produce emissions, but they can be 35 times lower than the cleanest fossil-fuel power plants of comparable size.Advantages •Proven renewable continuous base load power used worldwide. •No environmental impacts on the U.S. Virgin Islands. •Not effected by fuel price or availability fluctuations. •Can grow with the growth of the US Virgin Islands electricity needs. Disadvantages •Not available until 2012. •Foreign source of energy. •Dependence on base-load energy delivered via a 100-mile long cable transiting a seabed subject to earthquakes. |
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Solar Electric-(PV) 
Waste to Energy (WTE) 
Geothermal
VIREO * 5032 Anchor Way, Suite 3, Christiansted, St. Croix VI 00820 * 340.773.1989 * www.virenewableenergy.org
Hispanos Unidos * NR Electric * Quad State Solar Inc * RenewCo VI, LLC * St. Croix Alliance for the Protection of Utility Rate Payers * St. Croix Environmental Association * Solar Delivered * Sustainable Systems & Design International * Virgin Islands Conservation Society
