The answer to the question of how many solar panels and what size system you need has changed over the past year. Initially, the advent of overly generous feed-in tariffs in each state meant that generally the recommendation from solar consultants was to maximise the huge investment returns on offer and install the biggest system that would fit on the roof. Over the past year these overly generous subsidies were wound back in Queensland and system sizing was driven by matching the electricity consumption profile of the house to the solar system’s generation capacity.
Just recently, a couple of factors have combined to change thinking on the correct sizing of residential solar power systems in Australia. The substantial decline in the price of solar systems has meant that is it now a good economic outcome even if all a solar system’s production is sold to the grid at the lower feed-in tariffs available (e.g. 8c/kWh with AGL in Queensland).
Of course, it is better if this production offsets purchased electricity (e.g. at 29c/kWh) rather than being sold to the grid at say 12 to 16c/kWh but what this means is even the “worse-case” scenario of a solar system overproducing is actually a good outcome.
What does this mean for sizing a solar system today?
Quite simply you should seek to maximise the investment return available and this means installing the largest system you can fit on your roof, whilst maintaining eligibility for your local Feed-in Tariff (this often means installing an inverter no bigger than 5kW).
Generally you can install up to 6.7kW of solar panels on a good quality 5kW inverter, if this system is designed correctly
Fill in the On-line Enquiry Form, or you can Email or Call Negawatts Electrical to arrange an inspection.
We will arrange a suitable time to meet with you to discuss your current power bills, make suggestions on minimising your bill, and also suggest options on the number of panels and inverter size that will best suits your needs and your budget.