The Alexandra District Energy Utility uses ground source heat pump technology to extract heat (renewable geothermal energy) from the ground via a network of vertical pipe loops—in cooling mode during the summer months, the energy flow is reversed and heat is pumped into the ground. ADEU enables building owners to conserve energy and improve operating efficiency, thus protecting the environment. The Phase 3 & 4 expansions added capacity through the addition of a second large geo-exchange field, two cooling towers and three boilers; connecting new residential buildings, and for the first time, new retail developments to the ADEU system. To meet demand needs for the commercial connections, Air-Source Heat Pumps were installed and incorporated into the ADEU system as low carbon solutions that maintain competitive annual energy costs. The ADEU is the first system in North America to connect a Wal-Mart store to a civic district energy system.