PV Operated HVAC for Southwest States

This report analyzes energy usage and associated utility capacity requirements for compressor based air-conditioning compared to evaporative cooling supplied by electricity from photovoltaics (PV). Two novel scenarios are presented, two stage evaporative coolers with grid tied PV, and two stage evaporated coolers supplied with direct current (DC) electricity from PV. The two scenarios are complimentary; where a grid tied system can tap DC for air-conditioning purposes (see Figure 1). 8% PV system gains can be achieved by eliminating the inverter for powering such a DC heating, ventilating and air-conditioning (HVAC) system. A PV system directly coupled to high efficiency evaporative cooler can remove the air-conditioner peak demand from a utilities load profile. Typical cities energy comparisons are presented. Incentive and public goods programs are not necessarily designed for this optimized, direct utilization of DC approach.