Measured and Simulated Performance of a High Solar Fraction District Heating System with Seasonal Storage
Abstract
The Drake Landing Solar Community in Okotoks, Alberta, Canada utilizes a solar thermal system with borehole seasonal storage to supply space heating to 52 detached energy-efficient homes through a district heating network. Figure 1 is a photograph showing the community on a summer day. Several systems of similar size and configuration have been constructed in Europe, however, this is the first system of this type designed to supply more than 90% of the space heating requirements with solar energy and the first operating in such a cold climate (5200 degree C-days). Solar heat captured in 2293 m2 (gross area) of flat-plate collectors, mounted on the roofs of detached garages, is stored in soil underground and later is extracted and distributed through a district system to each home in the subdivision, when needed for space heating. Independent solar domestic hot water systems installed on every house are designed to supply more than 50% of the water heating load. Annual greenhouse gas emission reductions from energy efficiency improvements and solar energy supply exceed 5 tonnes for each house.