Drake Landing Solar Community - How IT Works

How It Works

There are 52 homes in this subdivision that contain an array of 800 solar panels. These solar panels are arranged on the roofs of garages located behind the homes. During a typical summer day these solar panels can generate 1.5 mega-watts of thermal power. A glycol solution (an anti-freeze solution; a mixture of water and non-toxic glycol) is heated by the sun’s energy and travels through insulated piping underground through a trench system to the heat exchanger within the community’s Energy Centre. This is known as the Solar Collector Loop. The glycol solution then transfers its heat to water located in the short-term storage tanks. The District Heating Loop begins with water being heated in the heat exchanger to a temperature of 40-50°C within the Energy Centre. This lower temperature is more energy efficient, as solar collecting is more compatible with lower temperatures. This increases the total amount of heat available to each home. In the warmer months the previously heated water is taken from the short-term storage tank to the Borehole Thermal Energy Storage (BTES). The Borehole Thermal Energy Storage unit is 144 holes located 37 m (121 ft) below the ground and stretches over an approximate area of 35 m (115 ft) in diameter. The water returns to the short-term storage tanks in the Energy Centre to be heated again in order to complete the circuit. During colder months the water from the BTES passes back to the short-term storage tank and is then directed to each home. Similar to a hot water tank, the heated water goes through a heat exchanger that blows air across the warm fan coil. Heat travels from the water to the air and is directed through the house via ductwork. When the temperature reaches that said on the thermostat, an automatic valve shuts off the heat transfer unit.