our solar moves

photo soon to be replaced by one of our first solar hws

On the news just now on Radio National – but I believe it’s old news – I heard that householders in South Australia will be paid for sending excess solar energy back into the electricity grid, thereby enhancing the state’s ability to deal with peak load. Of course, photovoltaics, that’s to say complete solarisation, is still a distant dream for La Luna.

The state has a rebate scheme for solar hot water systems that apparently comes to an end on June 30, so that many providers are being inundated with orders as the deadline approaches. La Luna Co-op has just ordered its first solar HWS from a Victorian company, and we’ve been lucky to get in ahead of many others, even though the rebate deadline doesn’t affect us! As a co-op we’re ineligible.

What we are eligible for is Renewable Energy Credits [RECs]. On this system, costing $4095, we’re eligible for 42 RECS at $49 each, for a total rebate of $2058, a little more than half the cost price. Installation will be between $1600 and $2000 on top.

From July 1 2008, SA will have new greenhouse and flow rate standards for residential HWSs. A major aim appears to be the phasing out of electric hot water systems. Alternatives are gas, solar and heat-pump systems. Apparently up to a third of residential greenhouse gas emissions come from residential water heating, and electric systems have the highest greenhouse impact.

I don’t know the precise situation regarding our own properties [we have at least one electric HWS], but there may be increased pressure now regarding who gets solar next. Even making decisions on the basis of properties rather than tenants could be tricky.

The two panels we bought were TINOX [titanium-oxy-nitride] coated, which has increased their efficiency. Comparisons between TiNOX and black chrome coatings have shown that there is less thermal loss with TiNOX. It all sounds good, and has increased our RECs score. The only more efficient system is the vacuum tube system, which is apparently rare in Australia.

I’ve made enquiries to our maintenance officer to get the low-down on our water heating systems [I’ve little idea even about my own system, except that it’s gas, as were the systems at Exeter Tce], and whether any others need replacing. At this price [$4000 at most, in the wash-up], and with some 14 properties to be turned to solar, we’re talking more than $50,000. Our surplus this year will be around $10,000. If we did two a year, we’d all have solar hot water systems within seven years. We’ll need to check out the systems being put in place in our new houses too – what will the government install? I doubt if it’ll be exactly state-of-the-art.

As far as I know, two of our houses, at Browning Street, already have solar hot water systems, but I’ve heard nothing about their efficiency and cost. That’s another thing I’ll have to research. There’s also the possibility of upgrading from solar hot water systems to a more comprehensive use of solar power in our properties.