tag:blogger.com,1999:blog-1782071132773305341.post1133521453416333878..comments2023-07-01T05:09:27.649-04:00Comments on Schaller Eco Home: A Case Against GeothermalUnknownnoreply@blogger.comBlogger3125tag:blogger.com,1999:blog-1782071132773305341.post-42292157659196737612010-09-08T00:50:53.851-04:002010-09-08T00:50:53.851-04:00I agree that too often geothermal systems are cons...I agree that too often geothermal systems are considered the only way to do a NZE home, because it is an electric heating system that you can run off a PV system to generate the energy you need for the home. While it uses less power than direct electric, it still takes a lot of power to run that compressor and water pump. You have shown that it is not the only way. People should be thinking of Geothermal systems as a heat pump (i.e. reversible central AC system) with a better condenser than the usual air-cooled outdoor box. The ground water is always cooler than outdoor air in summer and warmer in winter, but as with any central heat pump it will be a big energy user (although not as bad as an air-cooled type). Solving that issue with a really big PV array is not very cost effective, as you point out, with the present high cost of PV systems.<br /><br />If you build a super-insulated shell as you did and you can take care of domestic hot water needs with solar thermal, the problem becomes finding a heating system that is small enough for the tiny heating load. Conventional boilers are way too big and most people can't have their own gas well to fuel it. That ductless split system mentioned by a previous poster is one of the only systems that is that small and it is very simple mechanically, and will run off a PV array. It may require a simple open floor plan to effectively heat the entire house with only 2 or 3 of the wall-mounted units. Surprisingly, electric radiant ceiling systems use less energy than air-cooled heat pumps and might be acceptable. You have charted a third path using a solar thermal radiant floor system. The best way to decide is to run a simulation model to compare operating costs and installation costs. But that's rather costly for a residence, but maybe necessary to get to Net Zero.Gene Dejoannisnoreply@blogger.comtag:blogger.com,1999:blog-1782071132773305341.post-41740381394757968032010-08-16T14:54:59.124-04:002010-08-16T14:54:59.124-04:00The 2010-11 Zero Energy Challenge will use a more ...The 2010-11 Zero Energy Challenge will use a more comprehensive scoring criteria that will include among other things, an "affordability index". This will allow less expensive homes (i.e., homes with fewer expensive, renewables) to compete on an equal playing field with homes that may be more efficient but are financially beyond reach for typical home owners. Also, while many of the Challenge homes include geothermal systems, those systems are generally much smaller (and therefore less expensive) than standard, conventional heating systems. Some Challenge homes incorporate ductless heat pumps which have a very low life-cycle cost because of their low installation cost.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1782071132773305341.post-46857056476184320682010-08-10T08:00:18.011-04:002010-08-10T08:00:18.011-04:00You obviously don't understand how Geothermal ...You obviously don't understand how Geothermal works. Using a refrigeration cycle Geo leverages one unit of electricity into 4+ units of heat.<br />I am using Geo to leverage energy from my PV, wind, and soon microhydro to attain Net Zero.Peter Cannnoreply@blogger.com