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!

5 Responses to “Next solar update”

  1. narf77 Says:

    A most excellent way to get creative about finding benefits ma’am! 😉 Still working how best to utilise our hard saved dollars (when we get some 😉 ) for summer hot water production. At the moment we have winter (all 6 months of it 😉 ) sewn up with Brunhilda but the remaining 6 months needs to be sorted with electricity being so expensive here in Tasmania (apparently “clean green” electricity is expensive…). So far this summer we have had a lot of rain, a lot of grey overcast days and if we had solar I would be spitting chips. I am still inclined to think about a personal wind turbine to generate power because its a rare day where some form of wind or other is absent from Serendipity Farm (and Tassie in general). So glad that your power is working out for you and all of that heat is starting to finally pay off! A few years ago you would have been twitching with 40C days, now you will be whooping with joy because of all of those free ray hours 😉


  2. L from 500m2 in Sydney Says:

    Thank you SOOO much for the update. You were definitely responsible for getting me over the line with solar, and now I’m dying to have my system installed.
    Like you, we have off-peak hot water and I’ve also been assured that I won’t lose that – so I’m looking forward to when you get a bill so I can see how it works out for you. Our systems are very similar in size, too so hopefully my outputs will be similar.
    Do you have any winter shading?


    • foodnstuff Says:

      Apparently, whether you get to keep off-peak hot water or not depends on the whim of your energy distributor, but don’t quote me on that. It is all so complicated and no-one tells you anything!

      We have a lot of trees on our north side, so will surely get winter shading. I noticed that in late September/early October there was some shading as the afternoon sun moved into the north-western sky, then this disappeared as it moved further south. So I’m expecting that to start happening again in March and then continue through the winter.

      I expect it will take a full year to see the real effects. You will do a bit better than me as you are so much further north. Hope you will keep updating your blog about it; it is so useful to see what others are achieving.


  3. Gavin Webber Says:

    Great update! When I first installed solar in 2007, the only metering they had was electromechanical (the one with the wheel). I used to gain great delight from standing in front of the meter and watching the wheel spin backwards for most of the day.

    Since the introduction of smart metering, it is much easier to read how much solar I have pumped back into the grid, but not as exciting.

    FnS, Have you thought of installing solar hotwater? The savings are incredible, especially if you don’t get to retain your off-peak tariff! Our SHW system paid itself off in three years. Now it is all free.

    Gav x


    • foodnstuff Says:

      Hi Gav,

      Yes, I have thought of solar hot water. My HWS is 14 years old and I’m told they don’t last much longer than that, so when it conks, I’ll definitely consider solar.


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