During December 2013, the NZERTF consumed 1198 kWh of electrical energy. The solar electric photovoltaic system generated 481 kWh of electricity during the month. The difference between the energy produced by the solar photovoltaic system and the energy consumed by the NZERTF, 717 kWh, was imported from the electric grid. A graphical representation of the energy consumed and generated is found in the year to date results. The following chart breaks down the total energy consumed by the house into the various end uses. For the month of December the greatest energy end use was for space conditioning, maintaining the house at 70 F +/- 1 F (21.1 C +/- 0.5 C), followed by plug loads, and energy used to provide hot water.
A breakdown of the appliance end use into the energy consumed by individual appliances is captured in the following pie chart. During the month of December 2013 the greatest appliance energy usage was associated with the clothes dryer.