Zero Energy Houses: Geoexchange, Solar CHP, and Low Energy Building Approach

On March 29, 2006, the World Business Council for Sustainable Development announced in Geneva, Switzerland, that it is forming an alliance of leading global companies to determine how to design and construct buildings to use zero energy from external power grids, be carbon neutral, and be built and operated at fair market values. This paper is a contribution to the many possible Zero Energy House (ZEH) solutions that deserve further attention. The geoexchange, solar thermal combined heat and power (CHP), and low exergy building approach to ZEH is based on select R&D projects that, together, imply several important synergies. Not using “overqualified” energy in the house (i.e., energy quality, or exergy) is a significant step toward realizing a cost-effective ZEH. Most of the energy conversion and energy storage can be obtained through the appropriate use of purely renewable solar energy. However, a fuel reserve is needed to assure all of the building’s energy needs are met 24 hours a day, 365 days a year. The future ZEH implies the production of this fuel, potentially as hydrogen or alcohol, by using CO₂ plus water synthesis, powered by solar heat from concentrating solar power (CSP).