By Paul Homewood
h/t Ian Magness
More naive reporting from Matt Oliver:
The promise of underground riches is nothing new in Cornwall. But on Thursday, the region will plumb new depths in the quest to harness Britain’s natural resources.
For the first time, the United Downs deep geothermal power plant will start generating 24/7 electricity at a site near Redruth.
With an output of around three megawatts, enough to power roughly 10,000 homes, the plant cannot exactly be described as game-changing.
Yet experts believe it will help pave the way for similar projects across Britain aimed at tapping into the vast thermal resources below our feet.
The United Downs project, developed by Geothermal Engineering Ltd (GEL), will draw water at temperatures of around 190C from underground reservoirs that sit approximately five kilometres beneath the surface.
It takes advantage of a natural fault line using two wells, one that draws water up and one that pumps it back into the granite rock formations. Water that is brought above ground is run through a heat exchanger which uses another liquid with a lower boiling point to make steam and drive a turbine.
The result is power that is nearly always on – whatever the weather – save for short maintenance periods, says Ryan Law, the chief executive of GEL.
“Once you have done your drilling and the rest of it, the plant then runs 24/7 for about 96pc of the year,” he says.
In renewable energy, these kinds of numbers are virtually unheard of. Utility-scale solar tends to only push 25pc of the year while wind farms tend to land somewhere between 20pc and 40pc.
Full story here.
I’m not sure who these “experts” are. They would not be paid by GEL, by some chance?
The article also contains serious errors, not least the claim that solar power works at 25% efficiency. The true number is half that.
Bot the biggest error is this:
Matt Oliver obviously does not realise that £119/MWh is at 2012 prices! The current strike price is £170.50/MWh, three times the price of gas power:
Economically attractive, he says! What a joke. It is only viable because of the £3 million a year CfD subsidy plus that £1.8 million bung. And all for a miniscule contribution to UK electricity supply. The 3 MW quoted might generate 25,000 MWh a year, compared to total UK demand of 300,000,000 MWh.
But it gets much worse! The process has been causing earth tremors, as Oliver reports:
Like fracking, however, this kind of drilling can cause unnerving mini-earthquakes.
In Britain, ministers effectively outlawed fracking for oil and gas when they limited operations that create tremors of more than a 0.5 magnitude.
There are no such rules for geothermal, even though it has caused mini-tremors that were three times more powerful than this, with the industry instead regulated based on its surface vibrations. Law argues that this is more sensible because it measures the actual effects above ground.
So it’s OK to have earthquakes three times as powerful as from fracking, because geothermal is “good” and fracking “bad”.
FOOTNOTE
I have left comments for Matt Oliver, pointing out his CfD strike price error, but so far, the article still has not been corrected.
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