Comments on: The cost of home based Photo Voltaic Solar Power

By: andrewbg

andrewbg — Fri, 22 Jan 2010 05:53:39 +0000

Thanks for your comments Chris.
What timeframe did you base your ROI on?
Also you the ROI will vary greatly depending on how much power you consume.

Obviously if you are consuming, as I do, quite a bit of power per month, then you are only going to see a few hundred dollars a quarter reduction in your bill. Now obviously that would be a welcomed relief at the moment but not so when you consider the capital outlay to begin with.
Even an interest free green loan will require you to outlay $208.33 PER MONTH for 4 years.

A system that I could buy with a $10,000 green loan would not produce $600 odd worth of electricity savings per quarter UNLESS I am only using a very small amount of electricity and can rely on the generous feed in tariffs to be paying me for my excess production without the initial outlay.

As I said in the post, I am close to be being convinced as the 3.4 years to payoff isnt too bad, and it is cream from then on in, but that is only for a small system.

Also, as time goes by there is no way that feed in tariffs can stay so high.

By: Chris LS

Chris LS — Fri, 22 Jan 2010 02:18:09 +0000

If you do a return on investment(ROI) calculation based on the lowest advertised price for a PV system in NSW you will find a 1.5Kw system will return around 40%, a 2Kw 30%, and 3Kw and above 20%. This is based on the current gross feed-in tariff of 60c per Kwh. If you take out the feed-in tariff and calculate on current prices the ROI range is 6-13% depending on the size of the system; still a pretty good return on investment, especially as that return is almost certain to increase as the cost of electricity does. So even if the tariff only last for a few years the ROI is better than most other investments going around at the moment with no downward volatility. The only caveat is if you are planning to move house you may not cover your costs in the sale price premium. With the interest free Green Loans on offer from the Federal Government, now is a unique window of opportunity to install a PV system. I have no financial or other interest in PV installation companies but have had PV panel recently installed on our roof.
Also do be clear that solar hot water systems and solar PV systems are totally different beasts even though they both use solar energy to work.
In terms of technological improvements of solar panels, the most important point is the cost per watt. Typically the more advanced the panel the more expensive it is so that the cost per watt may well be less for a less advanced panel. Where one should consider investing in the latest panel is if roof space is limited. For example a large commercial roof space may choose to use the less efficient amorphous panels because it makes more economic sense.

By: arthur brogard

arthur brogard — Mon, 21 Dec 2009 12:48:00 +0000

Thanks for this. Should be more of it.

You seem knowledgeable regarding electronics generally. Can you say how fair dink the current state of the solar electricity thing is as regards the retail cost of the things, the installation costs, the level of technological sophistication of the current offerings?

Or put it another way: could we do it all cheaper ourselves if we could manufacture solar cells?

And what about the question of ‘Why’? Because, for instance, a mere black plastic hose coiled around your roof would heat enough hot water for some level of demand. i.e. are we needlessly getting too sophisticated in our effort?