hummingbird212

In response, Clark wrote: "Interesting analogy with the odometers, but Links of London not clear on the basis of the conclusions. For example, you state that, ? utility meter tells how many kilowatt-hours were used, but not how many source British thermal units were used to make and transport the electricity.' However, the source-site ratio for electric energy (which actually is a measure of the efficiency of that energy and is dependent on the fuel being burned and the equipment being used to burn it) has been established on a national level by the U.S. Environmental Links of London Y Charm Agency and the U.S. Department of Energy through their Energy Star program. For electric energy purchased off the grid, that factor presently is 3.34. So, the value in source British thermal units of a kilowatt-hour consumed is: "1 kwh (site) ? 3.413 ? IO3 Btu per kwh ? 3.34 (source-site ratio) = 1.14 ? 104 Btu "The comments regarding the distinction between capacity reduction and efficiency reduction are interesting. As stated in the article, the chillers are compound (low stage and high stage), with 3,000-gpm-percell cooling towers - in other words, water-cooled centrifugal chillers, not air-cooled screw chillers. In ice-building mode, the input power to a chiller at rated capacity of 2,000 tons is approximately 1,700 kw, resulting in an efficiency of 0.85 kw per ton (1,700 kw divided by 2,000 tons). The same chiller in 'day mode' has input power of 1,458 kw at its full-load capacity of 2.300 tons, resulting in an efficiency of 0.634 kw per ton (1,458 kw divided by 2,300 tons). As Links of London Black Friendship Bracelet suggest, this does not address the efficiencies from the cooling towers seeing lower ambient air temperatures that should be achieved during ice building, which is presumed to be primarily at night. However, that is addressed early in the article. "I am glad you agree with the need to explore ways to store energy and reduce our fossil-fuel consumption and dependence. It's not just conservation and stewardship: it's a vital national-defense imperative." "EnergyGod" writes: "My firm makes ice by cooling 100 percent water to 29°F under pressure (water freezes at a lower temperature under pressure). We then release the sub-cooled water to an atmospheric (sealed) tank, where it forms a slush - the ice floats to the top, and the 32°F water goes to the bottom, where it is recycled. "Because we are operating at a much higher temperature, cool night temperatures yield a compressor loading virtually equal to Links of London Charm Bracelet daytime chiller performance, so no additional energy is required.