Wednesday, 20 March 2019

Kickstarting a hydrogen economy

Battering batteries

There's a lot of interest in battery electric vehicles at present; they're popularly viewed as the future of transport. But there are several problems with the widespread adoption of battery electric vehicles.

  1. The battery techologies required (currently) rely on large quantities of rare minerals, involving substantial environmental and social costs in their extraction;
  2. The batteries themselves are quite heavy, leading to heavier vehicles which have more kinetic energy in a collision and therefore higher propensity for injuries and damage, and, additionally, cause more damage to road surfaces leading to increased need for maintenance (although to be fair battery vehicles are no worse in this regard than conventional SUVs);
  3. Batteries have limited range and take longer to recharge than petrol or diesel vehicles to refuel;
  4. Batteries are inherently quite expensive (although the vehicles have many fewer moving parts and consequently lower manufacturing and maintenance costs than conventional vehicles);
  5. To distribute electrical power to the many charging stations which widespread adoption of battery vehicles would require would need substantial and expensive new grid infrastructure.
But, we urgently need to decarbonise transport (as well as the rest of our economy), so we need to adopt them... but what if there was another technology which would equally decarbonise transport and had none of these problems?

Well, there is.

But before we get to it, let's have a wee digression on Scotland's energy economy, and a glaring inefficiency in it.

Blow wind, and crack your cheeks

Scotland has wind. Scotland has a lot of wind. After only Patagonia, Scotland has the second highest average windspeed in the world. Capturing energy from that glorious surplus of wind should be a no-brainer.

Scotland's electricity grid, which forms part of the UK national grid, was designed essentially as a collection of interconnected hub and spoke networks. Generation was expected to be at the hubs, consumption at the periphery. The revolution in wind power turns that on its head, putting generation at the periphery, and the grid cannot cope. Also, wind blows inconsistently and inconveniently, generating power when it's not needed and not generating power when it is. So in practice, the average Scottish wind turbine spends a lot of its time 'curtailed', which is to say, switched off; chiefly because the radial grid connections which would take its power to consumers are overloaded.

So, in times of strong winds, turbines are often not generating, the energy that they could have generated is being wasted, and the return on the investment which built them is not being returned. But, what if there was a way to embody that energy into something physical which could be conveniently stored and transported?

Well, there is.

The maker of water

Scotland has water. Scotland has a lot of water. After only Norway, Scotland has the second highest average rainfall in Europe.

Take a bucket of water (other containers are available), stick an anode and a cathode into it (these are fancy names for copper rods, although you can use other things), put an electrical potential difference across the anode and cathode, and hydrogen will bubble off at the anode, oxygen at the cathode. Obviously it's desirable to put separate cans over the anode and cathode to collect the gasses separately, since left to themselves they tend to go with a bang, but that's simple, too. If you have surplus electricity and surplus water, you can electrolyse hydrogen virtually for free (you could also make use of the oxygen as a by-product, but I'm assuming for now you simply vent it off to the atmosphere).

Hydrogen can be stored, fairly easily, in fairly inexpensive tanks. Those tanks can be transported. It is flammable, of course, just as petrol is flammable; but industries which have experience of transporting and storing petrol should be able fairly easily to adapt to transporting and storing hydrogen.

This is all simple plant; consequently, it's relatively cheap to make and Scottish engineering industry can easily make it.

Hydrogen passed through a tetraflouroethylene membrane doped with platinum recombines with oxygen from the atmosphere to make pure water, and in the process generates an electric current; the device in which this happens is called a fuel cell. This is, literally, rocket science, but it's not beyond the wit of Scottish manufacturing.

We can dae this.

So, why don't we?

The kicker

There's no market for hydrogen as a fuel, because there are no vehicles on the roads which use it. There's no vehicles on the roads to use it, because you can't conveniently get hydrogen as a fuel. And meantime, most of our wind turbines spend an awful lot of their time doing nothing.

What policy intervention could kickstart this?

A potential answer seems to me very simple. The government could mandate that planning permission would only be given to new windfarms above a given size, provided that the installation included a hydrogen electrolysis plant capable of capturing the entire output of the farm when it would otherwise be curtailed.

Suddenly, windfarm owners would have a lot of hydrogen which they'd want to market; and because there was a lot of it (and it didn't cost much to make - simple plant and otherwise-waste energy) it would be extremely cheap fuel.

The availability of extremely cheap, zero carbon fuel would encourage people and businesses to invest in vehicles which could make use of that fuel (and some government intervention would help here). Such vehicles exist; Honda, Hyundai and Toyota will happily sell you one here in Scotland right now. River simple, from Wales, will lease you one (although at present this is still a prototype scheme).

As adoption of fuel cell vehicles ramped up, the market for hydrogen would expand, motivating owners of existing windfarms to install electrolysis plant.

So what's the downside?

To go back to the beginning:
  1. Batteries require rare minerals. Fuel cells require platinum, which is rare; but not more platinum than is currently used in existing motor vehicle exhausts, and the platinum is easily recyclable. So adoption of fuel cells does not create an additional demand for rare minerals.
  2. Fuel cells are relatively light. Hydrogen storage tanks may be relatively heavy, but not to the extent that it makes the whole vehicle heavier; a fuel cell car should be lighter than an otherwise equivalent battery car.
  3. Hydrogen is a gas, and refuelling should take no longer than LPG refuelling and very little longer than liquid fuel refuelling.
  4. Fuel cells should be very substantially cheaper than batteries.
  5. Hydrogen does not need complex new infrastructure to distribute; on the contrary it can be distributed in tankers just as petrol or LPG are at present.
Obviously, we need to move away from widespread use of private cars. Obviously, we need to move more journeys onto public transport, and to replace much existing physical commuting with tele-commuting. Replacing all existing cars with fuel cell cars would substantially reduce our carbon emissions, but it needs to be part of a much wider revolution.

But in so far as we do still need vehicles, I honestly cannot see a downside to hydrogen.

Nevertheless, this is an area where Scotland is uniquely placed to make a lead.

We can dae this.

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