Last week, PM Rishi Sunak made a speech on the UK’s net zero policies. The BBC described it as an overhaul of the government’s green commitments, designed to meet net zero targets the UK has made internationally.

Rishi himself has been quick to make clear that nothing in these changes reduces his commitment to reach net zero by 2050, however. Despite one of the stand out policies being a delay to the end of petrol and diesel car sales in the UK from 2030 to 2035 (moving to be in line with the EU), motor industry sources have been informed that government plans to force manufacturers to meet minimum targets for selling electric cars will still come into effect from next year.

In other words, the changes appear to be more about presentation than a fundamental shift in Government policy. It is clear that the policy will require significant lifestyle changes if it is to be achieved.

Let’s take the example of the electricity grid.

National grids have to provide electricity at a set frequency. In the UK it is 50hz; the USA, 60hz. Maintaining a consistent electrical frequency is important because multiple frequencies cannot operate alongside each other without damaging equipment. If the exact amount of electricity being used minute by minute (demand) is not matched by the energy generated minute by minute (supply), it alters the frequency of the electricity on the grid. This is very difficult to control, as power supplier Drax explains in this excellent article:

To make matters more delicate, there’s a very slim margin of error. In Great Britain, anything just 1 per cent above or below the standard 50Hz risks damaging equipment and infrastructure.

To be explicit. If the frequency is not kept within 0.5hz of 50hz all of the time, the transmission grid and your kettle, TV and refrigerator will go kaput.

In a world where electricity is generated by burning gas or coal (or even modern nuclear plants), maintaining a steady frequency is relatively easy. The grid simply dials up and down the amount of electricity generated to meet demand.

In a world where more and more electricity is generated by renewables, however, this becomes increasingly more difficult. This is not only because when the wind doesn’t blow and the sun doesn’t shine, there isn’t any electricity generated at all. When the wind blows too much or the sun shines too strongly, renewables generate too much electricity, which the grid cannot cope with.

The grid is forced to turn off wind turbines and solar panels when supply exceeds demand and, under our current system, pay the providers to do so. These are called grid balancing costs. To give you some idea of the scale of these costs, they have risen from a few tens of millions before renewable capacity was added to the grid to £506m in 2015, £794m in 2019, £1.3b in 2020 and £2.7b in 2021. They will keep rising as the proportion of renewables in our energy mix rises.

I don’t want to concentrate at the moment on the additional costs involved in this shift (important as they are), but on the lifestyle changes they will require.

The national grid produced this excellent piece in July 2023 on future energy scenarios. It looks at four potential future scenarios in the race to net zero. Note the scenario labelled “Consumer Transformation”. It states:

The net zero target is met in 2050 with measures that have a greater impact on consumers and is driven by higher levels of consumer engagement. They will have made extensive changes to improve their home’s energy efficiency and most of their electricity demand will be smartly controlled to provide flexibility to the system. A typical homeowner will use an electric heat pump with a low temperature heating system and an Electric Vehicle (EV). The system will have higher peak electricity demands managed with flexible technologies including energy storage, Demand Side Response (DSR) and smart energy management.

You will have noticed the phrase “Demand Side Response (DSR) and smart energy management”. It sounds benign, but what does it really mean?

We have a clue from this pilot that Octopus energy and UK Power Networks trialled this week in Essex. During a two hour window (12:00 BST and 14:00 BST) when it knew renewable electricity supply would exceed demand, it offered customers free electricity. The BBC headline was “Free electricity: Is it really fair?”, and the article concentrated on how people outside the pilot missed out.

What the BBC should have concentrated on is the pilot’s true aim — which was to measure how much demand they could shift from peak times to low demand times. That is, from times when renewable supply is in arrears of demand, to times when renewable supply exceeds demand.

Yes, that means periods of cheap or even free electricity. For every two hour window of cheap or free electricity, though, there will be many more windows when the converse applies. Electricity prices will be so high (in order to reduce demand) that ordinary people will not be able to afford to use it.

We know that the periods where electricity prices will be higher, rather than lower, will be more frequent because we have the data on how often wind and solar farms generate electricity.

The industry term for this is “load factor”. Essentially, this means the per centage of time that electricity is generated. For nuclear, for example, the load factor is 93 per cent. So, 93 per cent of the time nuclear is generating electricity. The comparable figure in the UK for solar is nine per cent. For wind, it is 25 per cent.

To be explicit, that means for over 90 per cent of the time, solar does not generate the maximum amount of electricity it can generate. For wind farms, 75 per cent of the time they do not generate the maximum amount of electricity they can generate.

Energy use returns to the pre industrial age: dependent on the weather

These are average figures, averaged over the year. That means there are plenty of days in the year when wind and solar generate much lower or even absolutely no electricity at all.

In my recent interview with Climate Debate, I explained how the plan to deal with the intermittency issue of renewable electricity generation was to manage demand to meet supply. Only months ago, this idea was derided as conspiracy theory.

Yet there are clues that this is indeed the plan, in these quotes from Ian Cameron of UK Power Networks. He said the grid needed consumers to “step forward and engage with the energy system”. Mr Cameron added, “The peak period for electricity demand is between 17:00 BST and about 21:00 BST. Drawing 15 per cent to 20 per cent away from that period “makes a significant difference”.

“The best opportunity, rather than trying to store it for later use” was encouraging customers to be “flexible”. “For example, electric vehicles — can we get them to charge? Could we have our heating on at a different time of the day?”

People should be completely clear what this means. We are looking at a world where energy use returns to the pre industrial age: dependent on the weather. People may not be able to have a cup of tea or a shower when they want. Watch the TV when they want. Wash their clothes when they want. Put the heating on when they want. People may have to run their lives around when the wind blows or the sun shines. It could take society back to a time when the weather ruled over our energy use and life choices.

Sunak may be making presentational changes to his policies, but the plan is still the same. He claims he wants to be honest with people about what the plan means. If so, he should start by telling people the truth — that the dash to net zero before the technology exists means significant changes to the way people live their lives.

Is that what you want? What you voted for?