The true cost of net zero? Ruinously high bills, for decades

rishi sunak
Peak electricity demand is estimated to treble, despite Rishi Sunak’s decision to roll back net zero initiatives - JUSTIN TALLIS/REUTERS

Household electricity bills will rise relentlessly and then stay high if Britain sticks to its net zero ambitions.

This is the inevitable consequence of the shortcomings of all current means of generating clean electricity – and demand for electricity is certain to soar if we scrap gas boilers and force people to buy electric cars.

The Government has committed to net zero carbon dioxide emissions by 2050 and this pledge survived the Prime Minister’s recent watering down of the Government’s green agenda.

One of the pillars of emissions reduction is a continuous increase in the use of zero-carbon electricity.

There are four large-scale sources of zero-carbon electricity: nuclear, hydro, solar and wind. All are technologically quite mature, so we can judge how well they will be able to meet the country’s need for zero-carbon power.

It’s important to understand that electricity is a carrier of energy, not an energy source, and is currently not storable at grid scale at affordable cost. To give an example, the largest grid-storage battery in the world would power Britain’s peak demand for two minutes and 24 seconds.

Now to those four sources of green power.

Nuclear power is very, very expensive. To build plants safe enough by today’s standards, construction costs have rocketed, and the result is that no new nuclear plants are being commissioned without heavy subsidies. Nuclear power is too expensive to be competitive with other sources.

On the plus side, nuclear power plants supply continuous, reliable energy. It is not easy to adjust their output quickly, but modern economies have a base load that can be well served by nuclear plants.

Hydro-electricity has many attractive characteristics, but Britain has very few sites (mostly in Scotland) with sufficient height gradients to allow the construction of dams, and most of these already have hydro in operation. There is little opportunity to increase hydro capacity in the UK.

Moving to solar, central southern England sits at a latitude of about 52 degrees north, which means that sunlight falls at a very slanting angle for much of the year.

We also live in a cloudy country. The result is that solar is not competitive without subsidies. Solar also cannot be turned on at will; it supplies energy randomly, but more in the summer when it is least needed.

Finally wind, currently seen by the Government as the principal route to the decarbonisation of the grid.

Wind-generated electricity is now a very well established technology and wind farms can be built more quickly than nuclear stations, but their major drawback is that they don’t supply power on demand.

Wind generation cannot be relied on to supply electricity when it’s needed, and electricity generated when it’s windy cannot be stored with current technology.

This creates a major problem. With an ever-increasing wind fleet, Britain is experiencing long periods when wind dominates electricity supply.

Gas-fired generators, which currently make up the supply/demand gap, are forced to continuously adjust their output, and can often be idle. Increasingly this is rendering gas an uneconomic generation method.

The result is that gas generators are retiring their fleets, only recently the mainstay of Britain’s generation capacity, or recovering their much higher costs by increasing significantly the price at which they sell electricity to the grid in times of wind shortage. But while gas produces half the carbon of oil or coal, it is not zero-carbon.

Without gas, and with the near extinction of coal and oil generation in Britain, how are we going to get continuous zero-carbon electricity? Doubling, trebling or even multiplying by 10 the number of wind turbines cannot solve the problem, since a much larger wind fleet still cannot fill the supply-demand gap when there is no wind.

Here’s an example. At 9am on December 12 last year, a very cold, grey, still winter morning, electricity demand was (predictably) very high at 42GW. 60pc of that demand was met by gas, 14pc by nuclear, 2pc by wind, and nothing from solar. The remainder was from biomass, hydro, hydro storage or coal, or imported.

Since with current technology we have no means to store electricity at grid scale, how can we keep the lights on if we abandon gas? Gas, the ideal transition fuel, is currently the sponge that soaks up supply and demand changes and, given the intermittency and unreliability of wind and solar, there needs to be enough “on demand” capacity to supply all peak demand.

But if we also have enough renewable capacity to fully supply the grid when the wind is blowing and the sun is shining, we will need to have nearly twice the capacity we actually require to keep the lights on when they’re not. This is going to enormously and permanently increase the cost of our electricity.

If gas is to be replaced by electricity to heat homes and offices, and if petrol and diesel vehicles are to be phased out, peak electricity demand is estimated to treble, even if Rishi Sunak has now delayed both initiatives.

The scale of this rise will require not only a huge increase in electricity supply but also a complete upgrade of every single transmission cable, including those to our homes, and of the associated equipment, plus double or treble the current number of pylons.

And still we will face the problem of a grossly inadequate supply of reliable zero-carbon energy sources to convert into electricity.

So net zero by 2050 for Britain’s electricity supply is so difficult as to be practically impossible with current technology.

If net zero remains the goal, the price of energy will be forced to rise and rise, and stay at ruinously high levels, as electricity generating capacity is massively increased to at least twice what we need on average, and then underused.

Neil Record is a former Bank of England economist and chairman of Net Zero Watch

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