Photovoltaic Solar Panels

The 1.5kW solar panels were installed in January 2008 after a number of quotes over several years. Even then, we did not have a handle on all the factors and advice was somewhat variable. It was important for me to see how the panels were operating so we added the optional wireless display. This cost ~$600, but added massively to my understanding and daily appreciation of the system.

Output has averaged 5kWh over the year, varying substantially over the months. While not our
original intention, we now are a net exporter to Origin Energy and are in credit. Although

Origin are probably the best company around, we have had issues with every bill since installation. For example, even though we were exporting to them, we were still being charged for 20% Greenpower.

The panels make up about half of the average daily savings we have made - but cost $10,000 (the new feed-in tariff will help here). The new fridge contributed 15% and cost ~$700. Using the dishwasher less and the clothes washer on a different cycle contributed 8%. A small toaster oven to supplement the electric stove and other bits and pieces cost around $100 and contributed 6%. The real ‘no brainer’ however, was simply reducing standby power of appliances - saving 20% for no cost and generally little effort. It needs to be emphasized that installation of the solar panels was absolutely critical in raising our awareness to bring about this action. It all adds up.

We were initially disappointed with the panel output – the peak power rarely exceeded 1.2kW compared with the rated 1.5kW and the daily average output seemed less than the 5.8kWh quoted. It took time to build trust in the system and understand the factors at play. For example, variation in the sun’s path was a revelation with trees unexpectedly blocking morning sun in summer and winter. The monthly maximum output (assuming at least one sunny day per month) indicates that our maximum output is in Autumn/Spring - influenced not only by the trees, but also lower output in higher temperatures and a panel elevation of 32° optimized for mid season.