Power

Electricity Generation and Supply in the UK

The First Problem

Everyone agrees that we need to meet the peak demand for electricity, which occurs when several situations coincide, the two principal ones being:

  1. The deepest UK-wide freeze. This only ever happens in UK-wide still-air conditions, thanks to our island position surrounded by warmer oceans fed by the Gulf Stream, which means that there might be little contribution at that time from wind-farms, anywhere.
  2. Late afternoon week-days in the winter. Industry will still be working, street and internal lights will be on, electric kettles will be going on everywhere, and children will have returned from school and switched everything on in their homes. In these circumstances there would not be enough sunlight for solar arrays to produce anything, so there will be no contribution from solar energy, either. Later in the evening, countless vehicle batteries will be plugged into their chargers and electric cookers will be on.

Its Conclusion

However many wind farms and solar arrays we commission we cannot thereby afford to decommission a single alternative source of electricity. We must be able to meet our peak demand without recourse to either wind or solar energy.

The Second Problem

There is public pressure to make all motor transport in the future rely on electricity rather than on petrol and diesel fuel. The inevitable consequences of such a silly policy have not been honestly evaluated.

From published Government figures, our total motor fuel consumption in 2016 was 12 million tons of petrol and 24.6 million tons of diesel fuel. Even ignoring losses, replacing this with electricity would require a battery recharging capacity (smoothing out the peaks and troughs in demand) averaging an extra 48 Gigawatts. Extra to what? A good question! The UK's electricity generation and consumption in 2016 averaged only 35.3 Gigawatts (smoothing out peak demands) It would clearly have to more than double!

The solution

We must start by maximising our power generation from sources which do not rely on the combustion of fossil fuels.

These include:

  1. Conventional Hydroelectricity. The power output from a conventional hydroelectric generator is proportional to the product obtained by multiplying together the water flow rate and the pressure drop across the turbine, the technical term for which is the 'Head', meaning the height difference between the turbine and the water surface of the reservoir supplying it. In my mountain wanderings in the Scottish Highlands I have come across several locations which could be exploited for hydroelectricity, even though they will degrade the beauty of the surrounding landscape in the eyes of many.
  2. Other Hydroelectricity. Power could certainly be generated by harnessing the many strong tidal flows around our coast.
    (a). Conventional water turbines are probably out of the question, since the only way to get a sufficiently high pressure drop across the generator (aka a 'head') would require the construction of barrages, which would be unpopular with mariners and the fishing community, as well as pushing up the capital cost.
    (b). Water vanes similar to those used above-ground on windfarms are undoubtedly the only viable option. For safety reasons, their tops must lie blow the keel level of any expected ships, and they probably kill fish, but they are currently being planned.
  3. Bardsey
    Planned for off Bardsey Island, Wales

  4. Nuclear Fission. Nuclear power has to be considered as an essential source of power throughout the future. Perhaps though, instead of very large nuclear generators such as that proposed for Hinckley Point, we should exploit British technology and build many more smaller nuclear generators such as those used to power our submarines. Thorium might well be the optimum fuel, in preference to uranium.
  5. Nuclear Fusion. The challenge facing those advocating Nuclear Fission as a viable energy source is the need to produce more energy than is used to create it. This is impossible since it would mean completely overturning the universally accepted First Law of Thermodynamics. The Second Law goes on to add that neither can you break even, since there are losses in all energy conversion processes. [The total gravitational energy needed to create a star must therefore be greater than the energy released from that star in its lifetime.]
  6. Hydrogen. Hydrogen has been widely promoted as a future source of power for vehicles. As the Laws of Thermodynamics dictate, it would use up more energy to create the hydrogen, presumably obtained electrolytically from water, than would be provided to the vehicle. As Wikipedia confirms: “Hydrogen is produced as a by-product of industrial chlorine production by electrolysis. Although requiring expensive technologies, hydrogen can be cooled, compressed and purified for use in other processes on site or sold to a customer via pipeline, cylinders or trucks. The discovery and development of less expensive methods of production of bulk hydrogen is relevant to the establishment of a hydrogen economy.” Not nearly enough hydrogen could be exploited as a bi-product of electrolytic chlorine production, so very many more electrolysis plants would be needed, all soaking up more energy than they end up producing in vehicles.

Nevertheless, conventional thermal power generation by the combustion of fossil fuels is essential if we are to avoid severe power shortages, even though this is far from ideal. Gas, oil and coal all have a place to fill at the current time. The problem of greenhouse gas emission cannot realistically be tackled by the UK setting the rest of the world a good example, unless they can be persuaded to follow our example. Until then, since we are such a small player, we are damaging ourselves financially without any significant reward for either the planet as a whole or the UK in particular.

What might well concentrate the minds of the idiots responsible for our current policies would be to insist that in the event of any power shortages, then the first load to be shed on every occasion, and the last load to be reinstated shall be the City of Westminster. Leaders should lead from the front.

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