Energy Self-sufficiency

Given that solar generation only occurs when the sun is shining, a solar system will not enable you to be independent of grid-supplied electricity. Without extensive investment in battery storage, plus a back-up generator, solar alone will not enable you to go “off grid”.  Solar will, however, reduce the quantity of grid-supplied energy that you need to purchase.


Does having a solar system help during a power outage?

If you have a distributed generation system, you will have an inverter that is ‘tied’ to the electricity network. During a power cut, for safety reasons, your inverter will automatically shut down, as required by the Australian and New Zealand standard for solar inverters AS/NZS4777.  This stops the flow of solar electricity to your home - which is worth knowing if protection from power cuts is a crucial reason to you when considering installing a solar energy system.

More sophisticated battery installations with battery management systems can maintain supply during an outage, provided there is sufficient charge in the battery. However, they usually have a limited rate of discharge, meaning that just the bare essentials can be supplied - for example, boiling the kettle has a higher power requirement than many residential battery set-ups can meet!



Summer generation & household load

Solar Generations graphs-02click on graph to enlarge


Winter generation & household load

Solar Generations graphs-03click on graph to enlarge


Solar Generation Data

Solar generation forecasts are based on projected average monthly sunshine irradiance levels (W/m2), with assumed solar generating efficiency of 92%. The summer curves represent forecast average generation for the period of November to February, and the winter curves for the period of May to August.

Energy Use Data

Household energy use profiles are based on a sample of 750 Hawke's Bay residential properties, on a 24-hour uncontrolled tariff.