Monkeying around with DIY solar.

SOPRAY exhibitor Gina


Ever since setting up the off grid solar system at Three Dams Estate, I've been pretty obsessed with the potential of solar PV to create free energy from the sun. Earlier this year being the renewable nerd that I am, I attended a Solar and Renewable Energy trade show here in Melbourne and was able to acquire some solar panels from the Chinese Sopray exhibitor. Gina on the stand said it was too expensive to ship the panels back to China and offered to sell me the 4 panels (250, 260, 295, 140 watt) for 0.60c per watt ($600).

I didn't have an intended purpose for the new panels but had seen those cheap "plug and play" grid tie inverters on EBay and wondered if I could try and set up a small PV set up on the house we rent here in Melbourne. In researching the feasibility of this, there was some doubt if theses small inverters would actually work with the new digital smart meters we have here in Melbourne now and whether in fact the power generated by the panels would actually be measured as a "load" and subsequently billed as "usage". I decided to give it a try and purchased 2 x 350 watt inverters on EBay for about $80 each.

The next step was to construct a simple array frame to secure the panels to the rear patio roof and run the cabling in through the laundry window and connected to the back of the inverters. I needed up using a separator inverter for each panel as the panels were different (polychrystalline and monochrystalline) and of different power ratings. With identical panels one 600watt inverter would have done the trick.

The panels have been up for 2 months now and as we are coming through Spring with more decent sunlight, the results so far are very encouraging. On a good sunny day between the hours of  about 9am and 4pm the panels generate enough power to put our power consumption at neutral (see graph below). I'd highly recommend this time of basic install to anyone with a bit of DIY nouse. The whole set up cost no more than around $600. Feel free to contact me if you have any queries.