Eighth International Conference on The Constructed Environment

Abstract

Solar hot water systems are somewhat unique among sources of renewable energy for homes and small buildings in that they can be financially viable in the US without government subsidies or incentives. Solar heat systems can be used to replace various HVAC processes. However, solar heat is most easily configured as a source of domestic hot water when it is considered for existing buildings. Economic considerations dictate that it is essential that the system is not designed to be too large. While the effect of the amount of hot water used on the desired size of a system is well understood, the effects of timing of water use and uncertainty related to the actual amount of water use is less obvious. A computer model of a candidate solar hot water system with two water tanks is developed, which allows the effects of solar panel array size and water tank size on economic and environmental costs to be determined for specified water use. This program is then used to investigate how timing of the water use throughout the day, as well as uncertainty affect optimal designs. Tradeoffs between economic and environmental concerns are discussed in light of these analyses.