Just over a year ago, I pointed out that holes were starting to appear in the net zero tapestry and I wondered how long it would be before politicians and other fans of renewable energy would start to jump ship.
Since then, the Tories have softened their stance and the UK’s two big oil companies – Shell and BP – have pulled back on renewable energy investment.
It has been difficult for Labour because (a) as the party of government it has the ability to do more than just talk, and (b) Energy secretary Ed Miliband is a net zero fanatic and any retreat will cause ructions in the Cabinet.
However, help may be at hand in the shape of Trump’s trade war. Already we hear rumours that targets for EV cars might be eased and that the Chancellor’s “fiscal rules” might also go out of the window to allow more economy-boosting borrowing. All this will be done under cover of the changes wrought by Trump’s tariffs.
Don’t be surprised if John Maynard Keynes line “When the facts change, I change my mind – what do you do, sir?”‘ is trotted out to justify whatever U-turn is proposed.
>If net zero is abandoned or downgraded it will be entirely beneficial because, whatever propaganda the renewables industry puts out, we simply don’t have the technology to decarbonise our electricity system without subjecting the economy to serious harm.
Old Grumpy’s attention was captured by two recent Pembrokeshire Herald articles on electricity storage.
The first a couple of weeks ago reported: “Project manager Victoria Williamson said RWE wanted the Pembrokeshire site to be “at the forefront of South Wales’ low-carbon future,” the battery facility providing storage of excess electrical energy from the grid, contributing to a consistent energy framework by storing energy at peaks and making it available for periods of higher demand.”
And more recently we had Westminster wannabe Sam Kurtz calling for an easing of planning regulations in respect of battery storage facilities in order to secure our electricity supply “when the wind doesn’t blow and the sun doesn’t shine”.
While battery storage might have uses for balancing the grid, the idea that it can keep the lights on during periods of calm is nonsense.
Below is a screenshot of gridwatch templar, Sheffield University’s National Grid tracking website. It is a wonderful tool for understanding how our electricity generating system works because if you visit the site and hover the cursor over any of the dials an explanation of the method of generation appears.
This screen grab was taken at 9.30 on the morning of 27 January and shows wind generating a measly 1.2 Gw or 0.28% of the UK’s needs. To be fair, it was a bit early in the morning for mid-winter solar which is weighing in at 0.79% while CCGT (gas) is providing the bulk of the power at 61.87%.
This illustrates the problem with renewable generation: its intermittency.
One of the bits of knowledge which I hold with a fair degree of confidence is that, despite all the talk of a cost of living crises, food banks and child poverty, we UK citizens are among the richest people who have ever walked the planet. And the reason for all this wealth is that we have access to massive amounts of affordable energy.
In his book “Renewable energy without the hot air” Prof David McKay calculates that the energy consumption of a typical Western human is the equivalent of having a small army of servants at their disposal. From memory, I think the number was seventeen, but if you think how many big strong men (or women) would be required to push your car from Milford to Haverfordwest at 30 mph, you get some idea of the size of the beast.
So, when I take up the cudgels against those who tell us we can replace fossil fuels with windmills and solar panels, it isn’t because I have shares in Shell and BP, or that I dislike progress – it is because I believe that, as things stand, such developments will lead to a much diminished standard of living – particularly for the least well off.
And, although she didn’t quite come straight out with it, it seems the Chancellor of the Exchequer’s recent pronouncements on economic growth might suggest that she agrees with me. So don’t be surprised if, sometime in the fairly near future, Ed Miliband is seen heading along Downing Street clutching his P45. If the overseas aid budget can be chopped in half at the drop of Donald Trump’s hat, anything is possible.
At the moment, UK industry is being crippled by the highest electricity prices in the developed world and if someone comes up with a way to either generate cheap reliable renewable energy, or store the unreliable sort, I will be the first to cheer.
However, because electricity generated by so-called renewables is intermittent – under favourable conditions the system produces more electricity than consumers require and on calm, dark days the opposite is true – it requires expensive backup from gas. The remedy for this is to find ways to generate renewable electricity that are not weather-dependent, or to devise affordable methods for the storage of surplus energy in times of plenty for use in times of famine, much as we do with food and water.
Anyone interested in a technical discussion on the subject of storage might care to visit this site written by an American physicist.
Below are some popular ideas for overcoming these problems together with the reasons why, given present technology, they don’t work:
Batteries
Electricity is dynamic which makes it difficult to store. It is not like water or gas which can happily sit in the pipe waiting for someone to turn on a tap. Electricity has to be generated and used more or less simultaneously and while the pressure of gas and water might drop off a bit at times of high demand without causing serious problems, electricity frequency has to be maintained within a few percentage points of 50 Hz per second to avoid damage to delicate electronic equipment.
While gas is relatively easy to store, coal even easier, present day battery technology is simply not up to the task of providing a buffer for a modern electricity grid.
As the excellent Paul Homewood has observed on his website “Not a lot of people know that”, we could scrap all the UK’s windmills and still generate enough electricity to keep the lights on, but if we scrapped all the gas fired power stations we would be in semi-permanent darkness.
It is not easy to find information about grid-scale, conventional battery storage probably because it is so puny as to be laughable.
Such a facility was up for consideration at a recent meeting of Pembrokeshire County Council’s planning committee. The report on the application contains much talk about balancing supply and demand, but I can’t find any mention of how many Gw or Mw hours this battery will hold.
When you do manage to track down some hard figures, you usually find the capacity of these batteries expressed in Mw, whereas the important unit of measurement is Mw hours i.e. the duration of the supply.
I did manage to find a site where this information was available. Under “What we do” we can see that Eelpower’s battery at Dunsinane in Scotland has a capacity of 50 Mw hours – enough to power the National Grid for about ten seconds.
No doubt batteries can provide valuable services to the grid, but, with present technology, keeping the lights on for a couple of weeks during the calm, dark days of winter is not among them.
Pumped storage
This is the clever technique of employing two lakes at different levels as a form of battery.
During the night when renewable electricity is plentiful and cheap, water is pumped from the lower lake to the upper and at times when electricity is in short supply it is released through turbines to the lower reservoir.
The largest such facility in the UK is the civil engineering masterpiece at Dinorwig in North Wales.
The difficulty is the UK’s lack of suitable sites and the need for massive capital expenditure to get such facilities up and running.
To give an idea of the scale of the problem you can consider that, when full, Dinorwig can generate 1.8 Gw for six hours, which comes to 11 Gw hours; roughly what passes through the National Grid in 20 minutes.
For comparison, Pembroke Power Station (PPS) has a capacity of 2.2 Gw (1 Gw = 1,000 Mw) which, breakdowns and maintenance shutdowns aside, can generate for so long as gas is available.
There are plans for a much larger pumped storage facility using two Scottish lochs, but even that will be a mere pinprick when compared to the gridscale storage needed to see us through a prolonged period of calm.
Rivers
The sight of torrents of water pouring over the weir outside County Hall was the inspiration for ex-Cllr Ken Rowlands’ suggestion that a turbine could be installed to prevent all that energy going to waste. After all, give or take a few percent for efficiency losses, the quantity of energy that could be collected is in the same ball park as that required to pump a similar quantity of water back up over the weir.
And, according to Ken, all this lovely free electricity could be used to save the taxpayer a fortune by being used to power County Hall.
You often read of enterprising greenies going off-grid by installing a turbine in the stream that runs past their remote cottage in the hills.
Unfortunately, when the calculations for the Haverfordwest scheme were done, the amount of electricity produced didn’t cover the cost of the machinery.
However, the Cleddau at Haverfordwest is not a very good example, because, when the tide is in, the required head of water is not available so it would be out of commission for large parts of the day.
A much better prospect is the mighty River Trent and, just as it happens, the UK’s biggest “run-of-river” generator is at at Beeston, near Nottingham.
You can read all about Beeston Hydro here, but don’t get too excited because it only generates 1.66 Mw (1 Gw = 1000 Mw) so more than 1,200 such contraptions would be needed to equal the 2Gw capacity of Pembroke Power Station.
Wikipedia tells us: “The power generated [at Beeston] supplies enough electricity (1.5 MW) for two thousand homes, a total of 5.26 GWhours annually(my emphasis).
Running flat out, Pembroke Power Station can generate 5.26 Gwh in less than three hours.
Tidal
A couple of years ago, there was a great deal of publicity surrounding a proposed tidal lagoon at Swansea. Tidal energy has all the advantages of wind and solar (it’s free) with the added benefit that it’s as regular as clockwork. However, when a thorough evaluation was carried out, it turned out that tidal energy is not all it’s cracked up to be. Firstly, the capital cost of building the lagoon doesn’t compare well with a gas-fired power station. Second, because a certain head of water is required (about 2 metres) to turn the turbines, they only generate for about 14 out of every 24 hours and there are also issues with silting up, fish-kill and loss of habitat for wading birds.
Details of the 340 Mw facility (one-sixth of the capacity of PPS) can be found here.
It may be that something along the lines of the Severn Barrage could make a serious contribution to our electricity needs, but, despite their love for renewable green electricity, environmentalists find that a difficult pill to swallow because of the loss of valuable wetland habitat that such a development would involve.
As Milton Friedman observed: “There’s no such thing as a free lunch”.
Hydrogen
Another favourite is hydrogen. Indeed, PCC’s Chief Executive William Bramble and Deputy Leader Cllr aul Miller can often be found holding forth on the subject of Pembrokeshire’s “Energy Kingdom” where the Universe’s smallest element occupies the throne.
While the “hydrogen economy” slips easily off the tongue, the snags are many and difficult to overcome. The big advantage of hydrogen is that it can be used to directly power cars, ships, planes and electricity-generating turbines. So it could step straight into the shoes presently occupied by petrol and diesel.
There are several ways of producing hydrogen – the cheapest and most common is the steam reformation of methane.
However, as this produces much the same amount of CO2 as burning the methane in the first place, it is a pointless exercise in terms of saving the planet from greenhouse gas-induced global warming.
The “clean” method of producing what is known as “Green Hydrogen” is the electrolysis of water using electricity generated by wind or solar. This has the added advantages that it can use the excess power generated during times of plenty and the hydrogen can then be liquefied and stored to generate electricity during calm, dark periods.
However, the difficulty arises from the fact that the round-trip efficiency of the Green Hydrogen pathway is under 30% i.e. the energy required to produce, liquify and store the hydrogen is three times that produced when it is used to generate electricity.
Fans of hydrogen point out, with some justification, that, because the electricity consumed by the process is the excess that would have to be dumped during windy, sunny times, this efficiency gap is not a serious problem.
One further drawback is that being the smallest atom in the Universe means that hydrogen is difficult to confine and in addition it embrittles steel pipes leading to the risk of mechanical failure.
The pro and cons of green hydrogen can be found here.
P.S. When discussing these matters it is important to keep in mind the difference between capacity and output.
We often read that such and such a wind farm can generate X Mw, enough to power Y thousand homes. The operative word is “can” because what is referred to is the output in ideal conditions. An onshore wind farm will have a capacity factor of about 30% i.e. it will only produce about 30% of its nameplate capacity. Offshore is better at 40-50%.
This leads to some interesting arithmetic. It would take 400 x 5 Mw wind turbines to equal the 2 Gw capacity of PPS, but, as PPS has a capacity factor of 80% compared to wind turbines at 40%, you need 800 windmills to match its electricity output.
A comprehensive account of the pitfalls of relying on wind energy can be found here.