How large a solar pv system should you install ?
The optimum size is dictated by the usage associated with your common property areas between approx 7.00am and 3.00pm, i.e when the solar pv installation is operating. Any electricity produced beyond the OC’s requirements has to go somewhere, and in the absence of batteries, is exported back to the grid.
Electricity exported will earn your OC just 8 cents per kWh credit on the electricity bill, whereas the electricity saved through “Own Consumption” of your home produced power might be saving the OC 25 cents per kWh in reduced charges.
You can see how sizing a system according to the OC’s daytime needs might give you a 20% return on investment (say payback in 5 years), whereas producing for “export” might return the OC just 7% ( say a payback period of 15 years)
So really getting into the business of selling your surplus solar pv isn’t attractive even before you start thinking about the tax and other financial complications mentioned by Jimmy, (as well as additional technical requirements for systems exceeding 30 KW)
Blessed as you are with an abundance of rooftop space ( for most this is the limiting factor ). You could consider
- Reconfiguring your building so that individual lot owners could make use of solar pv for their private electricity needs. You might allow (by Special by-law) lot owners to place their own solar pv units on the roof or you could extend the OC’s installation so that it services all apts through an embedded network owned by the owners corporation but with benefits flowing back to lot owners in the form of reduced electricity rates
- Looking at investing in battery storage (cost, space and safety considerations here ) so that the OC could generate more solar pv during the day and store the surplus for night time use.
We hope this is helpful
S T R A T A A N S W E R S PTY LTD practical solutions for strata living
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http://www.strataanswers.com.au.
Email: Solutions@strataanswers.com.au. Tel: 0418 797 470