Page 47 - Zero Net Energy Case Study Homes-Volume 2

Control Systems
The house does not have a special “smart” control system, but simply relies on individual control apps for each system accessible through a laptop computer.
Construction
Construction required one year and was completed in February, 2018, although the owners moved back in from their temporary rental in November, 2017. The owners acted as general contractor and hired a building contractor to act as a construction consultant for a fee.
Renewable On-Site Energy Supply
The on-site solar PV system consists of sixteen (16) Sunpower panels at a maximum output of 360 watts, facing a few degrees east of due south and installed directly on the roof, which slopes at an angle of 24°. The total size of the system is 5.6 kW.
Twelve panels are dedicated to the house energy use and four additional panels were added as an estimated energy supply for an electric vehicle (EV) based on anticipated daily use.
The entire system is also connected to one Tesla Powerwall battery with storage potential of 13.5 kWh. This battery provides an energy source in the evening when the energy consumption tends to be high and there is no power being generated by the solar PV panels. It is a means of “load shifting” so that the renewable energy that is normally sent to the utility grid during the day is instead stored on-site at the battery for use later to supply the house.
PERLITA PASSIVE HOUSE
CASE STUDY NO. 7
Zero Net Energy Case Study Homes: Volume 2
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PHOTO: LAWRENCE ANDERSON
(Left) Sixteen solar PV panels provide 5.6 kW (DC) power for the house and one electric vehicle (EV). The EV is gener- ally charged in the afternoon directly from the PV panels af- ter the battery is fully charged.