Solar Gen March ’14

At last, when it’s not been positively cold and wet it’s been rather splendid. You can see the variety of awfulness and splendidosity in the graph below… up and down like the proverbial ‘ores drawers! Daffodils have replaced crocus, dandelions are replacing daffs… buds are beginning to firm up ready for bursting out all over, and Sol has taken to shining at least some of the time.

Solar Generation March 2014ce
Solar Generation March 2014ce


This is the first month that we’ve had the solar diverter installed, and truth to tell it’s worked very well indeed, with some caveats regarding its compatibility with the Owl Intuition metering logger. I’m still running the gas for ten minutes in the morning, just in case the water is a bit cool – I like a scalding hot shower – but it’s off for the rest of the day. The water in the evening is absolutely scorching (I have the electrical element set to 80 degrees C, rather than the 65 degrees C of the gas boiler). With a reduction in central heating – well, apart from a couple of really nasty cold and wet days – the gas consumption has gone down significantly… only 87 units on the meter. The  twelvemonth to last October used 1380 units and the winter sixmonth used 1130 of those. Generally then, we seem to have saved about 100 units of gas.

In energy terms that’s (100 units x 39.10 Calorific Value x 1.022640 Volume Correction) / 3.6 = 1110 kWh saved this month.
In cash terms that’s 1110 kWh x 4.15p = £49.95 saved this month!!! Can that be right??? Time will tell. The gas savings are very hard to predict, as I wasn’t recording the gas meter before this month. However, on to the main event…


Solar Units Generated = 292 kWh
Electricity Imported = 417 kWh

In cash terms that’s
Feed in Tariff = 292 x 14.9p = £43.50
Export Payment = 292/2 x 4.65p = £6.09
Saving on Import = 292 (minus 20kWh we actually exported), 272 x 12.45p = £33.86

Total Saving for March 2014ce = £83.45

It’s about the time expected for SSE to confirm my FiT account and ask for my first meter reading… they said 12 – 15 weeks (although the gods only know why it should take that long!) and it’s just twelve weeks since I filed my application. Watch this space. I await my cheque with some interest – have I got the calculations right (have they?)…


According to the Carbon Trust, the 292 units generated by the roof were worth  130 kgCO2e, the 1110 kWh of gas was 204kgCO2e, meaning the solar roof and diverter combined saved 334 kgCO2e this month. That’s the equivalent of driving nearly 2500 miles in my Toyota Auris Hybrid. Sadly, that’s about what I did drive over the last month. Hey ho.

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