Friday, July 18, 2008

80% Savings on Air Conditioning With Sea Water

Deep cold seawater can be a practical and economically viable source of cooling in a centralized air conditioning system. A seawater air conditioning system (SWACS) uses cold sea water from approximately 2000 ft depth to cool (via a heat exchanger) a centralized fresh chilled water distribution loop serving multiple buildings. At ideal coastal sites, SWACS power savings can approach 80% compared to conventional chillers. _IEEE
Anywhere on Earth with easy access to seawater roughly 2000 ft. deep can save 80% to 90% on its energy expenditure for air conditioning. It is being done in Hawaii
The water will travel through the pump system to an onshore station where it will cool fresh water that circulates in a closed loop through customers’ buildings in downtown Honolulu. Once the cold seawater has done its job, it is pumped back into the ocean at a shallower level, going through a diffuser to ensure proper mixing and dilution to the surrounding sea. _Ecogeek
A similar project is being carried out in Curacao.
The pipeline will reach 6 kilometres out into the sea, going south out from the Marriot Hotel, down to a depth of 850 meters, fetching up seawater at a temperature of 6°C at half cubic meter per second. The SWAC system operates with a temperature differential (ΔT) between the water it takes in and the water it lets out of about 7°C, and the return water will go into the sea again at 100 meters depth to avoid any substantial environmental impact. _OTECNews
On an island, fuel must be shipped in, and is very expensive. Saving 80% on energy costs of air conditioning in a tropical island environment means a very large reduction in fossil fuel consumption. The main costs for such a seawater chiller system are electricity for pumps and routine maintenance.

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Friday, May 16, 2008

Combining Land Conservation w/Biomass Energy

The largest questions about the future of biomass energy involve concerns about ample feedstock supply combined with land area requirements and impact on land quality.
Rentech, Inc. (AMEX:RTK) announced today that it has entered into an agreement to collaborate with the Wilds, one of the largest and most innovative wildlife conservation centers in the world, to study the effect on the entire ecosystem of growing and harvesting biomass and non-food energy crops.

The collaboration, which will also include Ohio State University, will be conducted on reclaimed mine lands at the Wilds in Cumberland, Ohio. The study will also examine the utilization of marginal landscapes for the production of perennial, non-food based biofuels, and the potential for bio-sequestration of carbon and other environmental services on reclaimed land. __Source
Large areas of wild lands are prolific producers of biomass. The waste biomass from forests and wilderness is plentiful, but requires energy to harvest. Questions about impact of biomass harvesting on wildlife and ecosystems are also involved in the long term viability of the use of wilderness and reclaimed land for biomass production.

Studies such as the one above involving a prestigious university and a respected land conservancy organisation, should go a long way toward answering some of these questions.

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