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Solar System Update – November 2017

Its been a while since i updated readers on the performance of our 5 Kwatt solar system we installed in October 2012.

The system consists of 20 x 250 watt Kyocera brand mono solar panels. The question everyone wants to know is how much does the system actually save us in terms of cutting our power bills and what kind of reliability does it offer, year round.

Savings From The Solar System – October 2016 to October 2017

I am fairly adept and on the ball when it comes to keeping records of our household expenditure. This has proven invaluable in assessing the real savings we are making from the solar system. Below is a breakdown of the figures and the savings the system is returning. I have used a calendar one year period for the analysis. The figures look like this:

Electricity Costs For Period 1 October 2011 to 1 October 2012 (when system was installed) = $3980

Electricity Costs For Period 1 October 2016 to 1 October 2017 (solar system operating during this period.) = $885

Savings Over One Year = $3095

Discussion:

Ok, firstly lets look at the electricity costs in 2011 (ie – from ETSA). According to my old electricity bills the ‘average’ electricity cost was $0.23 / Kwh. In 2017 the average cost is $0.26 / Kwh. So, in reality, the savings are even greater, to the magnitude of around 10 percent (roughly).

Payback Period. The Kyocera solar panels used were expensive in 2012 – approximately $1.10 / Kw. The totaol solar system cost, including an SMA inverter and a properly done installation came to $14,400. Still,  using an ‘average’ yearly saving of, say, $3000 per year on electricity bills, we can see that the so called ‘payback’ period for the system will comfortably come in in under 5 years.

Solar system pricing in Adelaide has dropped, i estimate, by around 20 to 30 percent, since the time we installed our system (October 2012). The same 5 Kwatt solar system using equivalent quality solar panels, could now be installed for around $10,000 to $12,000, possibly less. Therefore, the payback period could be down to 3.5 years!

Important Assumptions When Looking At ‘Payback’ Periods For Solar

The figures i am quoting are based on an important factor – that is, our electricity usage is relatively high during daylight hours and low at night time. This is because Jan and i both work from home. We are (very) early risers and generally are in bed by around 8pm. This means that our night time usage of grid supplied power is minimal – this may NOT be the case for the majority of Adelaide people!!! Looking at our power bills, our average night time power consumption is less that 3 Kwh per day – some days it really is negligible.

Conclusion. My thoughts are that solar, for us at least, is an absolute winner. You MUST consider your patterns of electricity usage when considering the viability of solar for your circumstance.

Phil Paul – November 2017