Electric car owners will lose money feeding power into the National Grid Vaccines for under-18s

sir – It is proposed that electric car owners could connect their cars to the National Grid and allow the energy in their batteries to take some of the load at peak times (report, July 28). But such use would seriously compromise battery life.

A typical lithium-ion battery has a life of about 1,000 cycles. For a car like a Tesla S, a 100kwh battery costs about £10,000. So each charge cycle costs £10 – or 10p per kwh – in battery wear and tear alone.

This sum of 10p per kwh is nearly twice the current wholesale price of electricity. Unless car owners are prepared to bear the extra wear on their batteries without compensation (and who would?) the price of electricity would have to increase very significantly.

Secondly, it is said that ministers are currently drawing up rules to make all public charge points have smart charging – in other words, they will only work in off-peak periods.

Does this mean that if I am driving from London to Manchester, and need to recharge at Birmingham, I will have to make an overnight stop?

Andrew Chantrill

St Mawes, Cornwall

sir – Your timely report on the possibility of blackouts because of electric car charging quotes a suggestion that smart charging will solve the problem.

But smart charging currently is just a vision and does not accomplish the huge changes required to make an all-electric car future viable. Changes must be made to the generation and distribution of electric power, as well as to our expectations of driving.

Assuming that the 30 million or so vehicles on the road today were all electric and were all plugged in at 6pm for overnight charging, then, if they were using standard 3.7kw chargers, there would be an instantaneous demand on the grid of 111 gigawatts. That is just over the equivalent of 34 Hinkley Point Cs – or the total electricity generating capacity of the United Kingdom in 2019. What mechanism – apart from electricity blackouts – will stop this happening?

The National Grid’s annual Future Energy Scenarios has for a few years talked about “demand management”. The 2020 edition often mentions “societal changes”.

Anyone who thinks that in a decade or so we’ll all be carrying on as normal, driving around whenever we feel like it in nice, clean electric vehicles, is living in a fantasy world.

Dermot Flaherty

Southampton

sir – I see that the transport select committee has highlighted the disparity in pricing between home and public charging of electric vehicles.

Before castigating the charging providers, they should have a word with HM Revenue and Customs, which has just ruled that public chargers must apply VAT at the full rate of

20 per cent rather than the domestic rate of 5 per cent.

Malcolm Benson

Beckenham, Kent

sir – My daughter turns 18 in just over three weeks. Despite the Government’s announcement that 17-year-olds within three months of their 18th birthday can be vaccinated, she is unable to find anywhere that will do so until she is 18. Why?

There are reports in the media of a low uptake of vaccinations among the young and of vaccines being thrown away as they are not being used. This is crazy. My daughter is planning on going to university in September and I want her to be as protected as possible.

Boris Johnson also says he is considering stopping students attending lectures unless they are fully vaccinated. It is a bit short-sighted for the Government not to realise that some students will have been unable to obtain their vaccinations by the time university starts.

R M Day

Billingshurst, West Sussex

sir – A study has found that shielders were eight times more likely than the general population to test positive for Covid (report, July 28).

This is catastrophic news for those like my wife and me, and their families. Clinically extremely vulnerable people have endured 16 months of what amounts to voluntary house arrest, shunning all human contact and hardly ever leaving the premises. In the belief that we are minimising our risk, we have continued this non-lifestyle even as the rest of the population begins to return to normality.

However, the study seems to suggest that what we have had to endure has been a waste of effort. Can anyone offer me a crumb of reassurance?

ACJ Young

Egerton, Lancashire