The ‘where’ approach to sourcing green hydrogen…

So, can we import lots of green hydrogen from places with abundant renewable electricity potential, but no market within cable-laying distance – what I call the ‘where’ solution? The short answer is much the same as for making hydrogen from curtailed renewables here in the UK, i.e. yes we can but it’s likely to be quite expensive, so its niche will be restricted to those areas with very little other option to decarbonise.

There are various ways that hydrogen could be transported, the main ones being:

  • Pipeline
  • Compression
  • Liquefaction
  • Convert to ammonia or methanol
  • Lock into metal hydrides or liquid organics

Since hydrogen is literally the least dense form of chemical energy in the universe, transporting it is inevitably going to be difficult. The following article does a good job of explaining those difficulties in detail –

I’m not technically qualified to attest to its accuracy, but even if the specifics can be debated, the broad picture is clear – moving hydrogen over long distances entails additional energy losses and significant capital costs. Just to recap the key points in brief:

Pipelines – hydrogen is a very small molecule that will leak through any sort of plastic pipes, and makes most types of metal pipe brittle and thus more likely to crack. Its low energy density means using a lot more energy in pumping a given amount of energy through a pipeline compared to natural gas.

Compression – very high pressures needed, lots of energy used in compression, and hoop stress limits the size of individual cylinders. Simply not practical for large quantities.

Liquefaction – hydrogen liquefies at -249degC (only 24 degrees above absolute zero), and has a reverse Joules Thompson effect, so that it warms when it expands at temperatures above -200degC. It therefore has to be pre-cooled with liquid nitrogen before final cooling via expansion. The whole process is very energy intensive, and boil-off rates are high.

Convert to ammonia – this releases heat at the point of production (which will probably be wasted as that’s where you have cheap energy) and requires high grade heat to convert the ammonia back to hydrogen at the destination. Ammonia is also poisonous in general, and poisonous to the catalysts in hydrogen fuel cells in particular.

Convert to methanol – as with ammonia, methanol is a useful product, or a fuel, itself, and as a liquid at room temperature is relatively easy to store and transport. The major problem is that it requires a supply of CO2 (and that CO2 will be released when the methanol is burned or turned back into hydrogen). If one has a source of non-fossil CO2 available, either from an AD plant, direct air capture or other, the question is whether it would be better to just bury it rather than make and transport the ethanol?

Lock into metal hydrides or liquid organics – this approach may well have a niche, but in both cases (as with ammonia) heat is needed at the destination to release the hydrogen, and the weight of the carrier has to be transported in both directions, so again round-trip efficiency is low.

So, should we conclude that this is just a non-starter? Well, apparently not. At the ITT Hub show last week I visited the Air Products stand, where they were talking up their plans to make green hydrogen, and convert it to ammonia, in Saudi Arabia, then ship it to a terminal in the UK to turn back into hydrogen. Saudi Arabia may have the world’s largest oil reserves, but it also has huge potential for wind and solar power, and a lot of ready capital to invest. I for one will be watching the development of this project closely to see whether it’s just Saudi greenwashing or whether the economics really stack up.

It’s also worth noting that the world’s second largest shipping line, Maersk, has bet on methanol as its route to decarbonising its ships. They will burn the methanol directly though, rather than converting it back into hydrogen. (I’ll write another post in a few weeks about this.)

Ultimately, I would broadly agree with the conclusions of the article I quoted:

  • Firstly, before we start finding other uses for green hydrogen, we need to make sure we replace all the grey hydrogen we use right now.
  • Second, rather than trying to move hydrogen long distances, we should move some of our industries to the hydrogen supply. An obvious example is to use hydrogen in Western Australia to process Australia’s iron ore and make low carbon steel – then export the metal rather than the hydrogen. All our fertiliser should be made in similar places.

Cheap electricity for hydrogen production – a few more thoughts on the ‘when’ approach

So, a couple of people have responded to my last post and prompted me to take a deeper look at the ‘when’ approach – i.e. using curtailed renewable electricity to make hydrogen. The main source I’ve taken a look at is the latest version of National Grid’s ‘Future Energy Scenarios’ report. They model the whole energy system of the UK, across all sectors, and offer four different scenarios out to 2050, three of which assume we hit net zero (plus one ‘business as usual’ comparator).

The number one consideration in thinking about the role of hydrogen is what we’re going to do about heating. Overall our energy demand for heating is about several times larger than what we use for surface transport (road plus rail). Historically, in the winter peak the gas grid has delivered up to seven times the amount of energy per day that the electricity grid delivered – most of which was going to gas boilers.

On the face of it, winter heating demand suggests that to switch to mostly renewables would require an awful lot of spare capacity in the summer in order to meet the peak in the winter.  The suggestion is that using spare summer capacity to make hydrogen as a balancing mechanism is cheaper than battery storage (which isn’t viable over a timescale of months anyway).

As it turns out though, there are a number of other factors that will work to lower the winter/summer capacity imbalance. Specifically:

  • Improving building insulation and thus reducing heat demand is a key part of any serious strategy
  • Heat pumps are considerably more efficient than gas boilers, which will also lower the winter energy peak in the future
  • The wind blows more in the winter than in the summer
  • As the climate warms, we’ll want to use more air conditioning in the summer (which we’ll have if we install heat pumps, because they can also deliver AC)

Despite these factors, there will still be a capacity imbalance on a longer timescale than can be addressed by demand response like smart charging of EVs overnight.

Interestingly, only one of the three main scenarios suggests much hydrogen going into surface transport. That’s the ‘system transformation’ scenario, which models a future in which government makes big investments in things like making ‘blue’ hydrogen (i.e. steam reforming natural gas with carbon capture and storage), alongside nuclear etc. In this scenario, consumers resist changes like heat pumps, so the energy system is transformed upstream and hydrogen plays a big role.

In the other two scenarios, hydrogen is mainly made by electrolysis, and most of it goes to industry, aviation and shipping. Relatively little is stored to turn back into electricity, presumably because storing hydrogen is quite hard (salt caverns are the main proposal) so it makes more sense to turn it into industrial products (fertiliser) or fuels (methanol, ammonia) and store those instead. In these scenarios almost no hydrogen goes to fuel cell road vehicles or trains.

So, what do I conclude? Well, I still think hydrogen will have a significant role to play. But, unless we have more of a ‘command and control’ approach to the energy system than recent governments have had an appetite for, it looks like the energy models agree that the hydrogen we do produce as part of balancing the grid will still go to uses where there are no other alternatives, rather than widespread use of fuel cell vehicles. Its use in road transport will remain expensive compared to batteries and therefore confined to a few use cases.

Of course I could be wrong… Next, the ‘where’ approach – could cheap hydrogen imports make its use more widespread?


How are hydrogen producers going to get their hands on lots of cheap electricity?

First of all, let me make clear that I’m not ‘anti’ hydrogen – I absolutely think we’re going to need it for some applications. For a start, we’ll have to replace all the ‘grey’ hydrogen we currently use to make fertilisers, and we’ll probably need a lot of hydrogen for steel-making. In applications like that, where there is not really any other zero carbon choice, the question is not whether to use non-grey hydrogen, but how best to do it.

So my question about hydrogen is really about using it where there are competing options – such as in vehicles. Where does the line get drawn between turning electricity into hydrogen and then back into electricity, vs just using the electricity? Physics says that the hydrogen option is always going to need a minimum of twice as much energy compared to using the electrons directly, so for hydrogen to compete, it has to use electricity that is half the usual price, or less.

As far as I can see, there are two possible options for finding cheap renewable electricity to make hydrogen – either ‘when’ or ‘where’. The ‘when’ option is to use curtailed renewables – wind power generated in the middle of the night for example. And the ‘where’ option is to hook up an electrolyser to a wind turbine out at sea or a solar farm in the Australian outback (rather than lay a cable).

Let’s look at the when option first (I’ll tackle ‘where’ in the next post). At the moment, in the UK, if the wind is blowing in the middle of the night, some wind farms get paid to switch off rather than damage the grid, so the electricity price is effectively negative. I can see why people get excited about hydrogen when looking at this. However, I had a client who asked me to assess the feasibility of producing hydrogen from curtailed power, and for now the numbers don’t stack up. The problem is that electrolysers are a big up front cost, so an operator needs to run them continuously in order to generate a return on investment – only running them when there’s excess electricity on the grid is not good enough for investors.

Even if the price of electrolysers falls significantly, my guess is there won’t be enough curtailed power to supply them, for two reasons. One, we are rapidly moving towards a smart grid in which consumers and energy companies collaborate to match demand to supply. And two, we are seeing exponential growth in electric vehicles, which will be left on overnight to be charged at the discretion of the smart grid whenever power is cheapest. Effectively, all those EV batteries will be soaking up the cheap electricity leaving none to make hydrogen.

I would really welcome comments on the above from anyone who has more detailed modelling of the UK electricity grid. My thoughts are purely qualitative, so maybe the scale of renewables we need to meet peak demand is such that we’ll have a huge amount of curtailed power even with EVs and a smart grid. But my suspicion is that the market will match the two, and not leave much for hydrogen production. So what about the where option? That’s for my next post…

The reality of self-driving cars is a lot closer than you think

Google got itself all over the media last week when it put up a video of people trying out its new self-driving car. It’s a great story, and the commentators who are into techy stuff waxed lyrical about how it could give mobility to the elderly or disabled, and just generally free up time for us all. But I’ll bet most people were thinking ‘yeah, but…’ – that’s years away, because who’s going to trust a computer to drive a car, given how often the ones on our desks crash?

What fewer people pointed out was that the driverless car won’t be a leap of faith, it’s a series of small steps – and we’ve already taken a lot of them.

Driver and smartphone

“Alright, you’re so smart, you drive!!”

Get on a motorway, and plenty of people put on cruise control. Increasingly that’s augmented by systems that warn you if you’re going out of your lane, and now systems that stop you getting too close to the car in front. A European Union-funded project is working on using similar technology to allow ‘platooning’ of lorries, i.e. allowing them to follow each other very closely, thus saving a large amount of fuel.

OK, so a motorway is a simple driving environment, but at the slower end, a number of cars will now park themselves for you. And several companies are working on systems that will take over the car to prevent collisions (Volvo being the main one, of course).

Software reliability is an issue, of course, but it’s one the automotive industry has been dealing with for years. The engine of every modern car is entirely reliant on computer hardware and software to run, and failures in that software could cause serious accidents, but it doesn’t. That’s because, let’s face it, you apply a very different set of criteria if a crash is, well, a crash, rather than if it’s just an inconvenience.

It won’t be long before a significant proportion of drivers have experienced vehicles that pretty much drive themselves, at least for some of the time. It’s not hard to envisage a time when motorway driving could mean hitting cruise control, and then getting out a good book. And urban driving will soon involve a super-satnav guiding you precisely around the streets, safe in the knowledge that if you don’t spot that cyclist, the car won’t let you hit her anyway.

As we drive down the current road, we’re just steadily handing more and more control over to the car. Eventually, the reality will be that the car looks like it does now, but the manual controls are really just there as a back-up, for us to take over if something does go wrong, or just if we feel like it. The biggest barrier to a lot of this, and particularly removing the steering wheel altogether (as in Google’s car), will be legal, given laws such as the Geneva Convention on Road Traffic (1949) which states that drivers “shall at all times be able to control their vehicles”.

However, our technology is getting better at an exponential rate, while human drivers… how to be charitable… are certainly not improving as fast. So whether the legal issues to allow self-driving cars take years, or more likely decades, to sort out, eventually the really tough question will be this. At what point will we view humans controlling cars as the really risky option?



Google’s YouTube video here:

Longer article exploring the legal issues here:

The UK is spending £500 million on ‘Ultra Low Emission Vehicles’. Is it money well spent?

Earlier this week, the government announced the elements of its £500 million package to promote ‘ultra low emission vehicles’ (ULEVs), by which it mostly means electric cars. They will continue to subsidise EVs by £5,000 each, will spend £100 million on R&D, £32 million on infrastructure like rapid chargers, and £20 million on ULEV taxis, amongst other things.

£500 million is a lot of money, but is it worth it, and is it enough to make EVs mainstream?

Well, as for whether it’s worth it, the government estimates the ULEV industry is worth £11.2 billion to the economy. I’ve no idea how that figure is arrived at, but I’ve been attending a lot of automotive events recently, and there’s no doubt that the global car industry is serious about EVs. And I think it’s fair to say that the UK has the engineering expertise to make it a major player.

A few years ago I was involved in a government funded programme to test EVs on the road. I worked with four UK sports car makers who were developing electric sportscars – the idea was to show what an electric car could do, and dispel the ‘milk float’ image. The great thing was that the market for sports cars is not so price sensitive, and has a lot of enthusiasts who want new toys, so these guys could develop vehicles with the latest motors, batteries etc and really show off the engineering.

None of those cars has made it into significant production, but that wasn’t the point. They showed that the UK has loads of engineering talent, they developed the state of the art, and they blew the socks off anyone who drove them! Fast forward three years, and in 2014 we have a couple of really interesting developments – on the track the FIA’s ‘Formula E’ series is finally happening in a big way, and on the road, the Tesla S is pushing the boundaries of what an EV can do.

A few weeks ago, I finally got the opportunity to drive a Tesla S (on a sunny day around the Silverstone track, doesn’t get better than that). This is a car with a 300 mile range, luggage space under the bonnet as well as in the back, and an option to have a couple of extra (foldaway) seats in the boot so you can seat seven people in it – so a pretty practical family car. However, it’ll do 0-60 mph in 4.2 seconds and beat an Aston Martin Rapide in a drag race – at Silverstone I flew effortlessly past all the other cars on the track. Tesla basically can’t make them fast enough, with every car so far pre-sold.

Tesla Model S

Tesla Model S – popular in Norway

Tesla’s success brings me neatly back to the second question about the government’s £500 million plan to get us all driving EVs – is it enough? In Norway, in March, the Tesla S broke the all-time record for sales of any one model of car in any one month, getting 10.8% of all new car sales. And EVs in general got 20.3% of new car sales, with the Nissan Leaf and BMW i3 doing well too. That’s mainstream, so how did they do it? Well, they tax car sales heavily, but have zero tax for EVs, plus EVs are exempt from congestion charging in a number of cities, get free parking and free charging at a network of fast chargers all over the country.

So will the UK emulate Norway? Probably not just yet. Yes, we’re building a fast charge network, but the UK has more drivers and more roads to serve than Norway. Yes, EVs are exempt from the London congestion charge, but we really need to see congestion charging in a lot more places, and that’s proved politically challenging. But the real stumbling block is still price. GDP per capita is about 50% higher in Norway than the UK, meaning a lot more disposable income – allowing an £80,000 car like the Tesla S to top the sales charts.

Is this £500 million well spent? Spending money to create jobs is always a gamble by government, but if that’s the goal, I think the ULEV industry is a better bet than most. Is that money going to help us address our transport problems, especially climate change? Well, in the long term it will be part of the picture, but only if we get on with the other stuff that needs to happen right now, like building more renewable electricity capacity, changing travel behaviour and looking into other fuels for the vehicles we can’t run on electricity. I’m still waiting for equally serious commitments on those fronts…


Government announces £500m support package for ULEVs including Plug-in Car Grant extension:,government-announces-500m-support-package-for-ulevs-including-plugin-car-grant-extension_2981.htm

Electric car breaks all sales records in Norway:

Tesla Model S takes on the Aston Martin Rapide:


Air quality and health – a few thoughts now the dust has settled

Last week a cloud of Saharan dust swept across the UK, and as a result stories about air quality settled with similar ubiquity across the country’s media. As soon as we could see the choking cloud in front of our faces, we all wanted to talk about a problem that has in fact been with us every day for decades. No metaphor could have made the point more clearly that ‘out of sight is out of mind’.

Woman coughingJust last week, the World Health Organisation (with perfect timing) released new data suggesting that one-in-eight deaths around the world can be linked to air pollution. There’s no need for me to re-hash arguments made very well in the better quality media last week (see John Vidal’s piece in the Guardian, ref below). The one thing I’d like to pick up on is just what all those people in the WHO data are dying of, and perhaps why we and our politicians seem incapable of seeing the problem except when it paints the streets red.

The media reports during an air pollution ‘episode’ like the one we just had invariably focus on coughing, asthma, stinging eyes – the sort of thing you’d expect. I saw one paramedic interviewed on the BBC saying, ‘Yes, we’ve seen a 14% rise in cases of acute respiratory illness over the last two days.’

The thing is, if you read the WHO report, it summarises the deaths linked to outside air pollution by cause, and this is the run-down:

  • 40% – ischaemic heart disease;
  • 40% – stroke;
  • 11% – chronic obstructive pulmonary disease (COPD);
  • 6% – lung cancer; and
  • 3% – acute lower respiratory infections in children.

That’s 80% caused by heart disease and stroke, before you get to the ‘obvious’ stuff, the ‘lung’ stuff. I’ll be honest and admit that it made me sit back and think. So I went looking for a little more explanation, and found some great references from the American Heart Association (hardly radical) and then the penny dropped, because they reference the many studies on second-hand cigarette smoke.

We all know smoking is bad for us, and we know that it massively increases the risk of heart disease and stroke, two of our society’s biggest killers. And we’ve enacted smoking bans in public places because we realised that inhaling smoke puts you at risk even if you’re not a smoker.

Step out onto the street in London, and the air may not be pleasant, but you’re not immediately thinking about people dying from it. You may well know someone with breathing problems, or asthma, but they probably manage it. But I’m guessing most of us have been touched by the death of a friend or relative from stroke or heart disease, and not necessarily a smoker. Was the air they were breathing the final straw? Quite possibly.

Our current controls on smoking have taken decades to enact, and smoking is regarded as much more of a choice than the presence of buses, trucks, taxis and cars on our streets. In the case of smoking, it took a culture change – the public had to internalise the evidence of health risk, and the politicians reacted (eventually) to that change, some of the braver ones even helped it along.

Action is being taken on air quality, but much too slowly (another post on that soon). If we want a quicker pace of change, I think one component will need to be a greater recognition of the true health impacts, and just how much the invisible cloud is affecting us, our friends and our relatives.

So here’s a thought – next time you step outside in a major city, look at the traffic and picture every exhaust pipe as a giant cigarette. I’m talking about a six-foot Gauloises, smoked by an elephant with a 200-a-day chain-smoking habit. See if that changes your perspective on air quality.


WHO press release:

John Vidal’s piece in the Guardian:

Information from the American Heart Association: