Free Electricity from PV Solar – Trick or Treat?

”Free electricity,” Said the householders for the sixth time. The phrase was being repeated like a mantra throughout the testimonial for their PV solar installer. “It was up and running in just one day, and now we can enjoy ‘free electricity’” (seventh time.) There was no mention of the feed in tariff subsidy: perhaps the deal they got involved the installer keeping the government handout. In that case the householder was left with just their ‘free electricity’ and this, after all, is how solar PV will be marketed post government subsidy. So pleased with their system were these particular householders that they were now going to set their washing machine to come on during the day rather than at night – and they were having a cooked meal in the middle of the day rather than in the evening – to take advantage of all that ‘free electricity.’

Hang on here, wait just a minute. The washing machine is going to take 1kwh per cycle and that oven is going to eat up another 1.5kwh with up to another 1kwh if they use the hot plates. So exactly what have these people got on their roof? Well it turns out that all this free electricity is coming from a 4kwhp 16 panel PV system. Note that ‘p’ in ‘kwhp’ is for ‘peak.’ Perhaps they had better make sure all that cooking and washing is done while sun is directly overhead in the middle of July.

Yes, PV installations are being oversold: most of us are well aware of this. The market will continue to bubble even after feed in tariff subsidies are withdrawn. A glut of PV panels dumped onto the market and companies willing to buy business, just to keep the cash going around, will maintain the illusion of ‘free electricity’ for some time to come. But eventually the dust will settle...

PV was born of an age when something had to be done and PV was a very visual and relative quick way of doing something. Feed in tariff subsidies made some sort of sense for countries with their own PV silicon industries. For the UK it made no economic sense. People already in fuel poverty were charged more for their electricity so that more wealthy households could be paid to put PV solar collectors on their roofs. The money handed over for the installation went overseas to support the PV manufacturers in China, Germany and Japan. It temporarily created a labour shortage in the installer sector driving up the cost of fitting double-glazing and insulation, or building a conservatory – all building improvements that reduce the cost of heating a house.

There has also been an unintended consequence of handing over £1500 per year to a householder while at the same time telling them they suddenly have access to ‘free electricity.’ In the age of the gadget the householder will take that windfall and spend it on a wide screen television – why not, after all they can power it with all that ‘free electricity.’ The problem is that the sun stops shining around the time the wide screen TV is switched on. The solution to that problem is electrical energy storage – a perfect answer for the gadget age. Except of course electrical energy storage will focus the consumer’s attention on exactly how much electricity those PV panels on their roof are producing. If the householder is asked to spend a significant part of their feed in tariff windfall on equipment to store not very much at all in terms of kilowatt-hours they may well not do this. They may well ask what was the point of the PV panels in the first place.

It was technology push on the part of the silicon industry that brought us to this point. This industry has received a multi billion dollar boost from government panic measures designed to do something about climate change and oil dependence. For its part the silicon industry has been unable to reproduce the magic it performed in the high tech sector. Faced with a bust in the PC market the silicon producer came back with a new bag of tricks – most involving more compact and powerful devices. But PV has yet to produce the great leap forward in efficiency the microprocessor industry comes up with from time to time. And with the scarce minerals needed to turn silicon into PV the industry itself appearing environmentally as well as economically unsustainable.

’Free Electricity’ is just the sort of magic the PV industry needs to keep the householder on their side. It must be hoping that magic is not merely an illusion.

Peter Kruger

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