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Solar cells still don’t add up

At least, as far north as London they don’t add up:

My annual consumption of electricity is 5500 kWh. So assuming I consume all the electricity produced over the 10 year warranty period my cost per kWh is ~25p kWh. At present I pay 13p kWh for a green tariff.

26 thoughts on “Solar cells still don’t add up”

  1. Part of this is the excessive price of a product recommended by Sadiq Khan and part of this is due to the latitude and cloudiness of London (in 2004 they were economic in southern California).
    But solar water heating panels *are* economic in the UK (and have been for 40 years, so the latest versions should be profitable) and what Dr Bayley should recommend to those concerned with “saving the planet” is that those who have a south-facing roof should install solar water-heating panels.

  2. “…should install solar water-heating panels.”

    Do these use a closed circuit with antifreeze, and pump & heat exchanger to warm the domestic water, or is the domestic water piped through the panels?
    In either case, how much to budget for freezing related damage every winter?

    I once fooled around with solar heating on the garage roof, to warm swimming pool water, but one deep freeze winter spell destroyed it. And flooded the garage.

  3. Between mid-April and mid-September, during the hours of sunlight, my solar panels make more electricity than I can use. Overnight and from mid-September to mid-April the panels make less electricity than I need. My estimate is that the ‘deemed’ export rate of 50% is about right.

    I generate about 42% of the electricity that I consume. I can’t see any economic way of improving on that. Without Gordon Brown’s insanely lavish Feed In Tariff payments, I would not have bothered with solar panels at all.

  4. I think I pay around 13p for leccy and 2p per gas. I think I am getting a good deal now. Us consumers never had it this good.

  5. &Tim the Coder

    “to warm swimming pool water”

    What do you use currently? I’ve searched in vain for a pool heater that burns old car tyres and asbestos sheeting.

  6. What is missed in this sort of cost/benefit analysis is that it is the intention of the the State to charge ever more for electricity. So the ‘what I pay for electricity’ portion needs to have a substantial ‘inflation’ portion added.

    I fear that in ten years – on current trends – it will seem a pretty good deal to have electricity at 25p/Kwh….

    It’s not (necessarily) that electricity will become fundamentally more expensive, but that the Idiot Greenery will require you to reduce your carbon footprint (or whatever the trending stupidity is) and as is frequently pointed out if you want to have less of something used then up the price. So the price will go up. This is accelerated by the Idiot Greens killing nuclear power along with gas heating…

  7. The reason for the high price for solar powered electricity is the high capital cost. One reason for the high capital cost is the high tariff on Chinese solar cells (88-110%) imposed to protect German manufacturers. Get rid of the tariff and a lot of the capital cost goes.

  8. Talking of carbon tax, I found this on Judith Curry’s blog. The main article talks about ‘Uncomfortable Knowledge’ – knowledge that TPTB ignore because they don’t want to face the consequences. However there is a paragraph that makes an argument as to why a carbon tax is the wrong solution:

    In “What Would Hayek Do About Climate Change,” Sagoff takes aim at neoclassical economists who argue that the problem is the result of a “market failure” that can be solved by pricing carbon. The claim misunderstands what markets and prices actually do. “Markets are for discovery, not utility,” Sagoff argues. Prices convey information, not value.
    “If the American Economic Association (AEA) had its way, it would set prices in terms of its calculus of the social cost of carbon,” Sagoff writes. “Entrepreneurs would then plan not around market prices but around AEA ‘prices,’ which float in the doctrinal and political winds. This turns investment into speculation — bets on what the next administration or central committee will do.”
    Hayek, Sagoff speculates, would have understood climate change not as a problem of market failure but as one of information, discovery, and innovation. He would not have objected to government acting as investor and venture capitalist, or even paying more for nascent clean energy technologies. But he would have objected to government attempting to fix markets by setting prices.
    “By chanting a ritual ‘market failure’ abracadabra over social problems,” economists, Sagoff argues, “would replace a free-market economy with cost-benefit analysis, the better to achieve a figment of their mathematical imagination, i.e., welfare, being better off, or utility, which they expect to be paid to measure.”

    Unfortunately the author quoted, Sagoff, is not averse to government subsidies, but we are now seeing the consequences of such a policy on the integrity & availability of our electricity supply networks.

  9. Thanx for that, TG. It’s what I’ve been trying to get into TimW’s head since he embarked on pumping a CT. There isn’t a “cost of climate change” to discover in advance of it occurring. So a CT to reflect the externalities cost of carbon emission ends up being whatever the PTB want it to be. And I don’t accept Pigou taxation is anything other than economic theory. Unless someone can demonstrate a real world example of one working as per the theory. The revenue neutral bit. Governments will tax to the point where higher taxes lose them votes. So a “popular” Pigou tax will just be a way of getting the voters to accept a higher level of overall taxation.

  10. And governments have never shown a propensity to tax for what they need, but to tax for the maximum they can get.

  11. Bloke in Spain: ‘There isn’t a “cost of climate change” to discover in advance of it occurring’. That’s a very strong concentrated sulphuric acid argument there that will dissolve any policy proposal in comes in contact with. Absent such costs, no climate policy – of either any change whatever or Business As Usual – could make rational sense.

    But actually, there is such a cost – how could there not be such a cost? It might be as low as 0.01p per degree C, but there will be a cost… though working out what it is, is pretty difficult. But once you have decided on say, $100/tonne (as opposed to $10 or $1000), you’ve done all you need to. That is the point TW keeps making. After all, how precise do we need to be?

    Yes, you are right, TPTB will just use it to extort more money, as jgh rightly points out. But the CT – or any Pigou tax – will leave us no worse off, will it? They will already tax us as much as they can.

  12. @ Tim the Coder
    The former. I had never heard of one freezing until I read your post.
    I get a regular service visit every five years to check if anything has gone wrong (usually not, but I did have a problem with CaCO3 deposits after 20 years because I live in an exceptionally hard water area).
    My budget for freezing damage is zero.

  13. Dogleg: That’s the Precautionary Principle in spades. And not a good argument for doing anything. All we know at present is that the CO2 concentration in the atmosphere is going up. We surmise it’s because we are burning fossil fuels. We also further surmise, based on a lot of shonky models that refuse to agree with each other, that the average global temperature will rise in the future. However their current predictions run well hotter than the outturn, and the models don’t/can’t include all the feedbacks that take place. What we do actually know is that the world is considerably greener than it used to be, especially in marginal areas like the Sahel, so what is the net benefit – it could easily be positive currently, and we’ve no good info that would allow us to predict reliably that it would go negative in the future.

    What we also know is the current panic induced by not very well-meaning people is pushing politicians into unwise decisions like screwing our electricity supply network. I, for one, have been very happy living in a society with reliable 24/7 electricity since the late 50s, and I don’t relish the thought of going back to regular power cuts like we had when I was a little kid. Call me selfish if you want, but I don’t think my desires are particularly out of line with a lot of people in UK, Europe, USA & other parts of the civilised world. I also think that our current trajectory is not going to help the 3rd world one whit, even if we do pay them the Paris Agreement geld they want.

  14. Dogleg:

    “But actually, there is such a cost – how could there not be such a cost”

    Because there is no such cost?

    Onset of next glaciation = not so much a cost, rather a threat to most of the population.

  15. ‘Call me selfish if you want, but I don’t think my desires are particularly out of line with a lot of people in UK, Europe, USA & other parts of the civilised world. I also think that our current trajectory is not going to help the 3rd world one whit, even if we do pay them the Paris Agreement geld they want.’

    I can only agree with you TG.

  16. Landfill tax. Brown specifically reduced employer NI to balance the new tax.

    Of course, a few years later then he reversed that…..

  17. That’s actually getting “market failure” wrong.

    Everyone’s reading it as “markets have failed here” which isn’t, in fact, the technical meaning. Rather, it’s “we have failed to have a market here”. So, create a market, or crowbar the thing into markets, we’re solved.

  18. Yes but Tim, markets are natural animals. They arise spontaneously when people interact to swap stuff. Creating an artificial market where none arises naturally is an exercise in futility. In the long term it will fail. In the short term it will keep needing fixups to paper over the poor design. Look at attempts in the UK – railway privatisation and the wholesale electricity ‘market’.

  19. Re CO2 & what we know:
    1. Current CO2 around 380 ppm.
    2. CO2 dropped to around 250 ppm at end of little ice age.
    3. Plant respiration stops & plants die around 170 ppm.
    4. Dutch greenhouses boost CO2 to around 1000 ppm for growth.
    5. Biologists confirm plants start to suffer when levels are below 500 ppm.
    6.Banana & Avacodo etc ripening facilities show plant and fruit damage when levels go above 1% or 10,000 ppm.
    Conclusion: 400 ppm is still dangerously low and leaves insufficient buffer on the low side, all life om earth would be much safer with levels around 1000ppm which leaves a decent buffer either side.

  20. @AndrewC
    “What do you use currently? “

    Mains gas. The boiler was cheap, and a stainless steel heat exchanger about £150. I did most of the work myself, only getting in the Corgi where I had to. As a bonus, a large Myson fan convector, for another £100, keeps the whole outbuilding safe in the winter and nicely toasty on usage.

    I looked at heat pumps, but at £8k upwards, the capital cost was huge, and the difference pays for loadsagas. Now about 25 years old, so still working well.

    If they ever ban gas boilers, and survive the lamposts, I guess the warm water days are over, but I’ll be long in my box by then, so unlikely to be too concerned.

  21. Dogleg

    There’s no apriori reason for climate change to have a **cost**.

    True, any change may change costs, but there’s nowt to say that the costs must increase. They can reduce.

    A greening world sounds a pretty neat plus.

  22. Tim the C: The tale I heard was that one of the problems that led to the Texas stuff-up was that, below a certain temperature, heat pumps are inefficient and need resistance heating back up. This huge increase in demand naturally occurs when everything else needs more power too.

    Since the UK is always cheering about the way its lovely GREEN electricity supply is becoming ever GREENER, I’d say you should stick to the gas as long as you can.

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