Last month, we had a solar system installed on our roof in QLD. The system cost us $6,000, and we expect to return ~$3,000 in bill credits/ saved energy costs each year for 5-10 years. The bill credits can be refunded as cash (tax free).
I am no expert in solar systems, but I can run the numbers on an investment, and rather than make my regular contribution to a company’s shares or an ETF, I’ve decided to invest in solar.
This post intends to show my expected benefits, and I will also update this post as live data starts coming through.
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The Numbers
Lets start with the numbers.
We went with a large 10 kW system, much more than we consume, to improve the return on investment and the carbon credit rebates.
Equipment
- 10.5kw Jinko Cheetah 330w*32 Mono Perc Black split cell Panels (why “Chinese panels”? Because during a CSIRO/Choice study, the Jinko panels performed 2nd with 90%+ efficiency, outperforming much more expensive rivals)
- Sungrow 8kW Inverter with WIFI Monitoring
- Sungrow Energy Meter for Consumption Monitoring
- CEC approved retailer
- Installation by CEC approved installers
Costs - $6,000 after ~$6,000 carbon credit rebates
Output
Take the follow example in August where 44.7 kWh was generated. At a feed in tarif of $0.20 and purchase cost of $0.24, this relates to roughly a $10 day. Summer is expected to return as much as 60 kWh. There is an added complication for my state (SE QLD) where feed in is capped at 5kW for single phase, we tend to hit that every day by 11am on sunny days, but through daily consumption we can still get up to 7.5kW use out of the panels.
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Returns
The return you get from a solar system is a combination of the money you save not paying for electricity during the sunlight hours, and the amount you get for feeding in excess power to the grid. The retailer will produce a report like this, I belive generated from nearmap (a great company I am a shareholder of).
Actual Results
So far, one month in, our average in August has been 45kWh, about 8% less than what was forecast by the retailer. This should give us a monthly credit on our bill of around $100, rather than owing $200.
Taking 8% off still leaves us with over $3k of yearly benefit, putting this at under a two year pay back, a great return on investment.
Disclaimer
Where I live – QLD, Australia, with a north facing roof, is great for solar. Your results may vary. The equipment is complex so can fail, but there is 10 years warranty on the panel and inverter to alleviate some of that risk. There is also a risk that the Feed In Tarrifs are reduced, or that power companies abandon the scheme. No risk no reward!