I use this blog as a soap box to preach (ahem... to talk :-) about subjects that interest me.

Tuesday, October 5, 2010

Photovoltaic Panels Update

At the end of the post titled “Photovoltaic Panels” of September 8th, I talked about my intention to extend my PV system. I did, and here is a new picture of my roof showing the new array.

I then wrote:

The price of the panels is going down. Solar Online Australia sells our panels for $890 each, and Energy Matters for $1,088. If we buy six panels, add $200 for delivery and $300 for installation (figures out the hat), we reach a very rough price estimate of $7,000. Those panels would add to our current capacity 1/3 of what we are currently producing. Therefore, at the end of twenty years, they would give us a return of $69,200/3 = ~$23,000. If we kept the $7,000 and locked them up in a term deposit at 6%, we would get 63,000/26,600*7,000 = ~$16,600 in interests. And all this without even considering taxes. It definitely pays to expand the system. We could probably integrate into our system more modern and cheaper panels, which would further enhance our earnings.

We did buy six new panels from Solar Online for $890 each. Including the mounting kit for a tiled roof and shipping, the total cost added up to $5,913. The installation costed us $759, more than twice the $300 I had estimated, but it was in part compensated by the delivery of the panels, which was $33 instead of $200.

Therefore, all out, the new panels costed us $6,672, not far from the $7,000 we had budgetted.

But there was something I had not considered in my previous calculations that reduces the price of the new panels. When you buy and install a PV system, you are entitled to create Renewable Energy Certificates (RECs, see orer.gov.au/publications/rec-system.html). You can then sell them on the open market. The only complication is that you have to register with the government to be able to create them, and it is increadibly bureaucratic. The alternative solution is to assign your entitlement to an organisation already registered (an agent). They can then create the certificates on your behalf and buy them from you. Obviously, your return is reduced, but you certainly have it much easier.

When you download from the ORER website the list of registered agents, you are confronted with twenty pages of names, corresponding to about 140 agents. Some of them don’t handle PV certificates because they are only interested in hot water systems; some only operate in a single state; and some only handle certificates for the system they sell...

After removing the agents who were not suitable, I was still left with more than seventy. I checked out some websites and saw that Green Energy Trading Pty Ltd published the prices they were going to pay for the certificates. I liked that, and as their prices were not much lower that the spot prices listed by Green Energy Markets, I decided that they would do.

The number of RECs one is entitled to depends on the state/territory and on the power rating of the system. With my addition of 1.05kW in the ACT, I can create to 21 RECs. The government supports the generation of green energy by authorising the creation of five times more RECs for the first 1.5kW, but I took advantage of that when I installed the initial system.

Green Energy Trading is going to pay me $672 for the entitlement to create my 21 RECs. This means that the effective cost of the six new panels is going to be exactly $6,000.

The system was off-line for less than a day. Since September 23rd, when the expanded system started generating, I have already seen more than once the amount of energy generated in a day reach 27kWh. In Summer, I expect it to reach a maximum of 30kWh and hope to see even 31kWh. In any case, the energy fed into the grid, for which I get paid, is always between 5.6% and 6.3% less than the energy measured by the inverter.

The maximum power has risen from the 4.695kW I had recorded before the expansion to 5.258kW. Theoretically, the peak power should exceed 6kW, although the inverter Fronius IG60 is rated to produce a maximum output of 5kW.

Time will tell...

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