Next solar update

I’ve been thinking I should do another solar update post and have been spurred on by reading that 500m² in Sydney is just about to put in a PV solar system. I’m sure she’ll love it!

When I last wrote I said:

“(Note that when the energy supplier FINALLY comes out and reconfigures the meter to show what has gone to the grid, I’ll be able to read it directly from the meter; no messing around with the spreadsheet).”

Well, the meter was finally reconfigured on 1st November and the first thing I noted was that the total amount of power exported to the grid was now showing on the display. I’d been saying that I thought I wouldn’t get a credit for it until it WAS showing, but it must have been metering all along. I had thought that when it began to show on the meter that it would start from zero, so I was rapt to find the amount was 482 kWh, which meant I already had a credit of just over $38!

The other, not-so-good thing I discovered was that separate metering of off-peak hot water had disappeared and was now reading zero. The amount that had previously been showing had been ADDED to the normal household metering, which is charged at peak rates. Not good. I’ve rung the energy distributor and retailer several times and they say I still have off-peak hot water, but no-one can explain why it’s not being metered independently as it used to be. The energy supplier hasn’t updated the retailer with details of my system yet and I think they’re just parroting out what used to exist in the belief that it will continue to exist. I’ve been following energy forums on the Net and there seems to be a feeling that energy suppliers won’t allow separate off-peak hot water metering once you’ve got solar. If I have to pay peak rates for electricity used between 11 pm and 7 am, then fur is going to fly. I’m told that it will all come out in the wash when the paperwork is finally done (I thought we had computers to do that now). My next electricity bill isn’t due till late January, so I’ll wait to see what that is before I start putting bombs under people!

Anyway….I now have figures on my spreadsheet for the whole of November and it’s looking good. Below are daily average figures.

Power imported from the grid = 5.4 kWh  (about half what it used to be pre-solar)

Cost of imported power = $1.37  (I’m using peak tariff rates to calculate this; it will be less if some is off-peak)

Power exported to the grid = 15 kWh  (we’ve had lots of nice sunny days)

Credit earned on exported power = $1.15  (@$0.08 per kWh)

Actual generation from the system = 18 kWh  (which means 3 kWh was actually used in the house)

Net cost with credit = $0.16  (if you’re wondering why this isn’t just  = cost of imported power ($1.37) minus credit on exported power ($1.15), this is because on some days I actually sent more to the grid than I took from it)

Total cost with supply = $1.08  (adding supply charge @$0.92 per day to net cost with credit)

So what I’m seeing is that for November the all up cost of power was $1.08 per day. The nice sunny weather has a lot to do with it. Winter will be a different story.

Some final comments.

There are a number of ways of looking at the savings from solar power. Firstly, there’s a reduction in power taken from the grid, so there are savings to be had there. Secondly, there are the credits earned by exporting excess power to the grid. That comes off the bill.

But I discovered another way of looking at it.

My system cost a tad over $5600. The money was sitting in a bank account earning 4% interest. That works out at an income of about 61 cents per day. But for November, I earned $1.15 per day for power exported to the grid. That $5600 isn’t in the bank any more, it’s sitting up on my roof and it earned me an interest rate of 7.5%. You won’t get that from a bank!

Oh…and the maximum solar generation so far was 27.1 kWh on 7th December. Love those sunny days!