The wider world

24
Aug
2022

How droughts can cause energy shortages

An exposed riverbed rock with carvings of dates visible back to 1616. Some people are resting their bare feet against it.
Image: Libor Elleder (distributed via imaggeo.egu.eu), licensed CC-BY-3.0

Today I learned about “hunger stones“. These are rocks in the River Elbe that are submerged in all but the lowest water conditions. Carvings on them commemorate historical droughts back to the fifteenth century and warn that if the stone is visible, famine will follow. One of the most poignant inscriptions translates as “If you see me, weep”. As Europe faces what may be its worst drought in 500 years, these stones are appearing… and while famine is less inevitable in a world of globalised food supply, it’s interesting to see the knock-on effects on energy.

Shipping companies have been warning for some time that water levels on Europe’s rivers have been approaching a level at which cargo traffic would have to stop. Indeed, when I was sitting by the Rhine on holiday two weeks ago I noticed that the laden barges were sitting higher in the water than usual – that they were sailing with reduced loads to cope with a shallower river. Since then parts of the river have effectively closed as predicted, as shipping companies decide that there is not enough water to operate safely or economically.

The closure of major transport routes is concerning for supply chains in general, but one of the major cargos carried by these rivers into inland Europe is coal, for power stations. So a shortage of water can translate to a shortage of energy.

Over in France, meanwhile, the country’s major rivers are at historically low flow rates… and that, combined with high water temperatures from this summer’s heatwave, has obliged nuclear power stations that rely on rivers for cooling to reduce their output to comply with environmental regulations. With reduced outputs on top of a lot of maintenance shutdowns this year, the country most famous for embracing nuclear power has become an energy importer.

Norway is another nation that is traditionally energy-independent: while they do have a lot of oil and gas, they use little of it domestically because their electrical grid runs almost entirely off hydro power, and on top of the fossil fuels they are usually a net exporter of clean electricity. But without rainfall there’s less hydro power, and with their reservoirs at unseasonally low levels the Norwegian authorities are considering restricting electricity exports to protect their domestic supply.

None of that affects the UK directly: we don’t use inland waterways for cargo, our nuclear plants are all on the coast, and we only have a small amount of hydroelectricity. But the knock-on effects of a worsening energy shortage in Europe will certainly be felt here, in the form of higher wholesale energy prices.

I mention all of these things together because they’re a clear demonstration of the interconnectedness of the systems that we take for granted. Our power and other industrial infrastructure was designed for the time in which it was built, plus forseeable changes – and nobody (a figurative nobody) foresaw parts of the Loire running dry, or the Rhine becoming impassable to coal barges.

This is a part of something sometimes referred to as the “Energy-water nexus“: the idea that energy supplies depend on water, and water supplies depend on energy, and that developing more of one usually requires more of the other. It’s interesting to think about whether this interdependence might be weakened by increasing use of renewable energy. Wind and solar probably rely on water less than thermal plants do… but in the future, will we see drought-related curtailment of freshwater hydrogen production?

Posted by simon in The wider world
14
Nov
2021

After Glasgow

I haven’t been following the negotiations at COP26 very closely. And I haven’t examined the eventual agreement in great detail, instead following the insight of commentators I trust. It seems, from what I’ve read, that while there are some incremental steps forward in the detail – strengthening of language, and so forth – mostly the parties have agreed to kick the can down the road another year. If readers have better insight and want to contradict that, they are most welcome to do so, but I think it’s fair to say that any climate summit that ends in its president apologizing and breaking down in tears is not what the world wanted to see.

On social media people have noted that the commentators who, two weeks ago, were talking about a “last chance for humanity” are now praising the small steps forward. Greta Thunburg has, of course, summed up her view with eloquence:

The #COP26 is over. Here’s a brief summary: Blah, blah, blah.

@GretaThunberg / Twitter

Twelve years ago, before I had even started studying renewable energy, I wrote a blog post on another site entitled “After Copenhagen”. That was the first COP that was a mainstream media event, and the first one – thanks partly to Barak Obama’s involvement – that felt as though it might get somewhere. In the end it achieved little for various reasons, and there was a temptation to give up. I did a lot of thinking back then, and this is what I concluded:

“I’ve spent a certain amount of time thinking “If I think that the cause is hopeless, why am I wanting to work in the renewable energy and/or energy efficiency fields?”. The answer is that… every little still helps. Yes, low-lying countries are almost certainly doomed. Yes… wars will be caused and exacerbated, many will starve or die of disease… but for every bit that we can reduce our emissions, less of this will happen. The fact that the situation is so terrifying, depressing, and hopeless, even to those of us who probably won’t suffer the worst (or at least the first) of the direct effects, doesn’t mean that we can’t try to lessen it.”

I still believe this. We missed the 350ppm and 400ppm targets that were talked about at Copenhagen. It seems very likely that we will miss the 1.5°C target that is increasingly believed to be important. But it’s still worthwhile to make things better than they otherwise would be. If global efforts get us to 2.6°C, as is suggested by the current NDCs, that’s bad, but it’s better than it could be. As I wrote in some internal training materials recently, under the heading “A note about missing targets”,

“It’s too late to prevent climate change – it’s already happening. It’s probably too late to keep to 1.5°C, and 2°C looks hard as well. But this isn’t a binary thing: it’s wrong to say “we missed the target, may as well give up”. 3°C is better than 4°C, which is better than 6°C. Some harm is locked in, but we can minimise how much more.”

That’s the thought that keeps me going now, as it does on a regular basis away from the COP cycle. In the words of Mary Heglar, “home is always worth it“.

Posted by simon in Reflective, The wider world
27
Sep
2021

Fuel shortage and EVs

As UK readers will know, much of the country is currently suffering a fuel shortage. While there is, as I understand it, a small supply deficit due to a lack of tanker drivers, the main problem is that when people heard about that deficit they all filled up their cars at once, causing a large spike in demand (which will be balanced by low demand for a couple of weeks as everybody has full tanks).

I’m not here to talk about Brexit, HGV drivers, or fuel crisis management. I’m not even here to be smug about driving a partly electric car. What I want to point out is the light that this throws on an argument we sometimes see against EVs:

Sometimes one hears people saying that if everybody in the UK went electric, the grid couldn’t cope because of the load of all the cars charging at once. And that would be a reasonable concern, if we were talking about first-generation EVs that needed charging every night.

But to within a factor of two, today’s EVs have the same range as petrol cars. Most petrol cars aren’t filled every day, and there’s no reason that most EVs will be either. The grid doesn’t have to be able to cope with this eventuality, and this is demonstrated by the evident fact that the petrol network also cannot cope with this eventuality.

Posted by simon in The wider world
05
Sep
2021

Decarbonising domestic heating

There’s a… not quiet, but also not mainstream, debate raging at the moment, about how we’re going to heat our homes in the future. Actually it’s about how people who live on the gas grid will heat their homes, but that is the majority, and it includes most journalists.

An important caveat

I’m not an expert here – if I was, I would be writing a journal article rather than blathering on my blog – and I haven’t done the maths. I welcome correction by people who have.

From 2035 (earlier for new builds) people won’t be allowed to install new natural gas boilers in homes in the UK. There are a few possible ways of replacing them.

One approach, as with most things, is “electrify it, then use low carbon electricity”. In the case of the UK the answer to this is electric heat pumps, which are basically air conditioners run in reverse, to move heat from outside the house to inside it. They’re more common on the continent than here, but they’re reasonably common here in commercial premises and are becoming better known as a domestic option. Heat pumps are stupendously efficient[1], doing between 2.5 and 4 times better than a basic electric heater.

There are some disadvantages to heat pumps: firstly, that they’re not a direct drop-in replacement for a boiler. You need to find somewhere to put the unit that goes on the outside of the building, and because they don’t deliver water at such a high temperature as a boiler, poorly-insulated houses will need to be insulated better. In some cases they may need to have larger radiators fitted. The UK has a lot of poorly-insulated houses, although many would argue that insulating them better is one of the first things we should be doing anyway… Another difficulty is that we’ll need more low carbon electricity to power all these heat pumps, and we might need some grid reinforcements to deliver that power to where it needs to be.

The other approach that’s being talked about is using hydrogen, produced using electrolysis with renewable electricity. Replace gas boilers with hydrogen boilers – at worst a drop-in replacement, at best a simple adjustment – run hydrogen through the old gas pipes, and bingo, low carbon heating without much cost or disruption, and because we’re still sending the energy via the gas grid there’s no need for electricity grid reinforcement.

There are a couple of downsides to this plan. One is that it’s much, much, less efficient. The total amount of energy needed to produce the hydrogen and transport it is (very roughly) 4x the amount you’d use in a heat pump that was doing the same job.

Image: ICCT

The second problem is that renewable energy is a scarce resource. We’ll struggle enough to find enough to power all those heat pumps in the short or medium term, so we’ll struggle even more to find four times that much to electrolyse all that water into hydrogen.

And this is where it gets controversial. Instead of finding enough renewable electricity to produce hydrogen by electrolysis (so-called “green hydrogen”), we could make it from natural gas. The “blue hydrogen” concept is to continue extracting natural gas, and split it into carbon and hydrogen when it gets ashore. Put the hydrogen into the gas grid, and bury the carbon back under the North Sea using carbon capture and storage (CCS). It’s quick, relatively cheap, and uses existing infrastructure. It’s not forever, of course, because both natural gas and carbon sequestration space are finite resources, but it’ll tide us over until we can produce enough green hydrogen. Right?

The strongest proponents of this plan are, unsurprisingly, the natural gas industry (fascinating scholarly report from UKERC). The next strongest are politicans who have good relations with the natural gas industry, and would like to minimise disruption. There’s a lot of lobbying power there, and this is a tempting proposition. Some people look at this and say “it’s a way for the natural gas industry to keep going with business as usual, and lock us in to a whole new gas infrastructure in the process”. Blue hydrogen champions say “but what choice is there? You can’t build renewables fast enough otherwise”. They’re usually using a straw man of building renewables fast enough for green hydrogen, rather than simply electrification, but they might be right about that too – I’m no expert on build-out rates and supply chain limitations.

But if they’re right, and if they’re speaking in good faith, then surely there’s a way to get the same stopgap benefit as blue hydrogen without locking us into the hydrogen route in the long term? Use natural gas, and use CCS, just like with blue hydrogen – but when the gas comes ashore, don’t make hydrogen with it. Burn it in a CCGT power plant, with carbon capture, and then supply electricity. Sure, you lose 2/3 of the energy in the power station, but the efficiency gains in using heat pumps rather than boilers roughly cancel that out. In the future it’s easy to let renewables replace the CCGT+CCS, at which point we’re left with a much more efficient system. And in the short term the gas companies get to keep extracting – but without locking us in for the long haul.

I don’t see anybody recommending that. Maybe it’s because it still leaves the supply chain “problem” (people will argue problem vs opportunity), in how quickly we can get homes converted to heat pumps. Maybe it’s because it will still require electrical grid reinforcement. Maybe because the whole argument for blue hydrogen is being made in bad faith.

I honestly don’t know which. It could be all of the above! Or it could be something that I haven’t thought of.

[1] Pendants and physicists are correct that this isn’t actually an efficiency, it’s a Coefficient of Performance – and hence it doesn’t break any laws of thermodynamics for it to be over 100%.

Posted by simon in The wider world
14
Aug
2020

The A-level results mess

GoT meme: "Brace yourself: Results are coming"

I should caveat this post by mentioning that I know nothing of secondary education, and am not involved in undergrad admissions for my university – so this is purely the view of an uninformed layperson.

As most of my readers will know, there’s a row in the UK at present about A-level results. A-levels are the exams that people sit at age ~18, at the end of secondary school, and are key to getting into universities. As of a few years ago, thanks to the views of Michael Gove on how education should work, they contain no modular exams or coursework and are judged entirely on one set of exams at the end of the year. And this year, thanks to COVID-19, those exams didn’t happen.

Students apply to universities long before they know their A-level results, and so their applications are based on predictions made by their teachers of what grades they will probably get. The universities then make “conditional offers” that commit to providing a place to the student so long as they achieve a given set of grades at the real exams. This has a host of problems that have led some to campaign for years for a change to the system, but that’s a different story.

Thanks to the lack of actual exams this year, students’ final grades have been based on their teachers’ predictions. But for various (mostly sensible) reasons, teachers tend to be generous / optimistic in their predicted grades, and so simply using these would have led to what the government and the tabloids call “grade inflation” – more people getting high grades this year than usual. To avoid this, the regulatory body OfQual was charged with adjusting the predicted grades using a statistical approach. As near as I can understand it, the grades of students in each school were adjusted according to how students from that school usually do. Many have been downgraded from their predictions, leaving them surprised to find they are rejected from their chosen universities. Some smaller number have presumably been upgraded, though we don’t hear about that, and though that won’t impact them as much as they are unlikely to have conditional offers above their predicted grades.

Of course, students are disappointed every year. But there’s a huge difference between being predicted good grades but then failing to achieve them through your own efforts in an exam, and being predicted good grades and then having them reduced because a government algorithm said so – however accurate that algorithm may be when validated through hindcast. One is, ultimately, down to individual performance (albeit in a single exam, which nobody except Michael Gove thinks is a good way of assessing ability), while the other is something that the individual in question is unable to affect.

The task that OfQual were set was clearly impossible to do with any sense of justice. They have probably succeeded in producing a set of national marks which in a big-picture, statistical, sense, reflects what this year’s cohort of students would have achieved. But however good their statisticians, there’s no way that they could achieve that while remaining fair to individuals. As somebody beautifully put it on Twitter:

So given a choice between the problem of “grade inflation” and the problem of arbitrary-seeming marks for students, I find myself asking… is grade inflation really a problem? If, for one year only, the aggregate student body does better than usual, what harm does that cause? This entire year is inherently a set of mitigating circumstances, and there doesn’t seem to be any gain in punishing students even more for the year in which they happen to turn 18.

Sure, an excess of high grades would cause some trouble for the most prestigious universities, as they may not have room to take all the students they gave conditional offers to (I say “may”, because they’ll have lost international numbers this time around). But given how keen these universities usually are to increase recruitment, I’m sure they can find inventive ways to deal with that. Maybe some of the students are even asked to defer to the following year. That feels like much less of a problem than effectively telling a generation of new adults, “What you do doesn’t matter, you will be assigned a place in society according to the school that you come from”.

Given the situation all around us, would it really be so terrible to be kind?

Posted by simon in The wider world