Posted on

Home Battery Storage – the Basics

Renewable energy Queensland has produced a really to the point video summarising the basics of using home solar PV systems, with home battery storage:

Home battery systems are about self-consumption of Solar power

Many home owners who have solar power installed, are looking to install a home battery system, to store and self-consume solar power, rather than feed back into the grid to get the often low FIT rate credit. The issues can be framed as follows:

  • Solar PV energy stored in a home battery system can be used at night when the sun is not shining
  • However, storing Solar energy in batteries means you will not receive a “feed-in” tariff credit while charging
  • When you self-consume solar energy, instead of feeding it to the grid, however, there is a cost saving to you
  • Self-consumption saves the higher cost of grid power at night, which costs around 25c/unit (kWH)
  • So instead of paying the 25c/unit for power at night, you use battery stored solar power, but don’t receive the approximately 10c/unit, not selling that stored solar energy
  • Put more simply, if you store solar in a home battery system during the day, you lose the 10c feed-in tariff for that energy, but you don’t have to pay the full rate of 25c for power at night
  • You save 15c per unit of power you store in a home battery system, and self-consume at night, or at times of high demand

For well matched battery, solar system, and home energy use, the ideal is to self-consume your solar power, so that there is a net zero exchange of power between the grid and your home.  If you can achieve that closely matched system, the savings you make over time, can effectively mean payback of a home energy storage system, within 3-7 years.

See ecoCool’s Solar Insight Excel spreadsheet to do a quick calculation to see how to create that ideal system match with your solar PV and home energy use scenario.