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By E&T Readers

In the November 2022 issue of E&T, readers discuss a potential unexploited energy source for the UK, the implications of China’s ambitious plans for electric vehicle adoption, and more.

The BBC’s ‘Countryfile’ programme recently covered the Archimedean screw hydro-​turbine set into the weir on the River Thames at Windsor, which supplies the Castle. The question this raises is why every weir on all our rivers isn’t being equipped with this ancient piece of technology, coupled with more modern generating equipment.

There are dozens of disused mills all over the country with the basics still in place – a wheel housing and wheel house, the infamous mill pond, usually the size of a small reservoir and with close access to the local electrical infrastructure.

The obsession with planting thousands of acres of high-​quality farmland with solar PV cells that by their very nature have short life spans and are high maintenance – they need cleaning at least once a year, or else their output drops even more than just their ageing process – is just nonsense. Similar issues affect wind turbines – high maintenance cost and never near the infrastructure. Don’t forget if the sun don’t shine and the wind don’t blow neither of these systems looks very good, but ‘Old man river just keeps rolling along’.

This and tidal generators are a far better answer than wind and solar. Don’t worry about wildlife, they have already learnt how to deal with man-made weirs and in most locations fish runs are in place.

James Walker IEng FIET By email

Alpitronic’s large-scale environmental testing facility in the Italian Tyrol is clearly a useful, indeed essential, piece of kit across a whole spectrum of applications that involve extreme environments (‘Blizzard in a Box’, October 2022). However, I’m afraid that the introductory paragraph claiming that until recently, the only way to find out what happens to anything in extreme cold or heat was to “take it somewhere suitably extreme...” is inaccurate.

To quote from a 1968 British Aircraft Corporation advert: “The worst weather in the world occurs in Weybridge, to order.” This referred to the Stratosphere Chamber facility, which operated at that time at the company’s Brooklands site in Weybridge (now an excellent museum). It was designed and built by the then Vickers-Armstrong company’s R&D department in the late 1940s and was operational from 1951 to 1982.

As its name implies, its primary purpose was aeronautical. However, it was used for many other research projects, including assessing icing of ships, radar scanners, vehicles and Antarctic clothing.

In some ways it appears to have been superior to the Alpitronic facility. The first is physical size. To this day, it contains the front fuselage section of a large Vanguard airliner and could accommodate whole helicopters. The test chamber is cylindrical, and at 15m x 7.5m has roughly double the volume of Alpitronic’s 12m x 6m x 5m cube. Minimum possible temperature of -65°C compared to -40°C is likewise greater, and it had a unique appendage: a small-scale supersonic wind tunnel.

My first reaction upon visiting this amazing place a few years ago was one of awe. This was replaced by sadness that it fell into disuse at all; I was informed by a museum guide that it owes its present state to the familiar British syndromes of short-termism and knowing the price of everything but the value of nothing. Apparently, it would have been demolished years ago but the cost of demolition exceeded the scrap value, so only ‘cost-effective’ component parts went that way.

My final mood after a pleasant day at Brooklands was one of depression, as the chamber, previously unknown to me, joined the ranks of other similarly successful, currently useful, but abandoned British achievements: Harrier aircraft, Black Arrow satellite launchers and Advanced Passenger Trains to name but a few.

Kenneth F Rusby CEng MIET Prudhoe, Northumberland

The October 2022 issue of E&T reports a study which found that China is “leading the pack” in its infrastructure preparation for the rollout of electric vehicles, noting that “China retains the top position when it comes to progress toward an electric vehicle future”.

China is by far the leading country in digging coal out of the ground (4.07 billion tonnes last year) and burning it in its growing fleet of power stations. The country is already estimated to emit over 10 billion tonnes of carbon dioxide per year. Locally, the move to EVs will shift China’s energy demands away from imported petroleum sources to dirty, but indigenous, coal. Increasing China’s demand for coal-fired electricity is surely not the way to reduce global carbon dioxide emissions.

Sophisticated systems for the home charging of electric vehicles (‘Two-Way Street’, October 2022) will likely involve a number of independent computers, probably running AI algorithms that no one understands, trying to optimise the use of the car battery for grid support while implementing demand-side grid management, planned – one hopes – around the owner’s use of the vehicle, and using electricity supplied through a smart meter.

I hope that the designers will bear in mind the plight of someone who, coming out in the morning to do their round of supporting aged people in their care, finds that their car won’t go anywhere. Unless this problem is addressed from the start, my guess is that they will have a frustrating day even trying to find someone to contact, let alone someone who can explain what went wrong.

Maybe in reality our vehicles will no longer be a dependable means of getting to the airport, hospital appointments or dependent relatives. If that is what we are facing, society needs to be prepared for it, because for some communities this will be a serious problem.

John Wheeler Middleton St George

I enjoyed the October 2022 issue of E&T, with its focus on electric vehicles, but I am left thinking – really? I am a university student, but over the summer I worked in a company that sells plant, machinery and fuel tanks all over the UK and Ireland. I have seen first-hand the need and demand for diesel and petrol, even in today’s culture of reducing your carbon footprint.

The UK’s desire for a complete ban on diesel and petrol car sales raises some questions. Why is electric seen to be the solution to our problems? We are aware of the issues with lithium supply and production. How does, for example, a quarry operator charge their 90-ton digger at the bottom of the pit when it could take over an hour to move the machine to the top of the site to charge it? This is lost production time; the machine needs to be at the rock face, not being transported for two hours a day.

I believe the solution is electrofuels, also known as e-fuels or synthetic fuels, which will allow the existing infrastructure to be used without the need for costly infrastructure changes. It allows the current fleet of vehicles on the road to be viable with no changes needing to be done to the engines to run on such a fuel.

I can see benefits of electric vehicles for small vehicles, but it seems a little unfair that this seems to be getting such media interest, and therefore investment, compared to other solutions such as e-fuels.

In his editor’s letter in the October 2022 issue of E&T, Dickon Ross writes about how, living in London, he’s managed without owning a car for ten years.

The majority of people who reside in the UK do not live or work in London and enjoy the city’s fantastic public transport system of overground trains, underground trains and buses. Also, I expect that the streets of London will be the first city/location in the UK which will be littered with adequate charging points for electric vehicles.

Surely, we all care about the environment, global warming, climate change and what kind of planet we are going to leave future generations. Living in rural Leicestershire, and being an old age pensioner, I try my best to use my free bus pass on as many occasions as possible, hence cutting down the number of journeys made in my internal combustion engine car.

For people living outside London, doing away with an internal combustion engine car is a pipe dream and not a practical option.

FW Fisher MIET By email

Dickon Ross replies: This is a fair point and one I did consider myself. London has a good public transport system of underground, overground, buses and light railway. The distances also tend to be shorter. I also feel safer cycling in London than the countryside because of the cycle paths, but also because London drivers are more used to cyclists around them. I am surprised when I come to the IET’s Futures Place building in Stevenage and see how little the town’s incredible network of cycle paths is used.

I am surprised that Ros Eveleigh’s electrician mentioned the DC from solar panels as a reason not to install an external 13A socket (Letters, October 2022).

To be able to use the output from the panels an inverter is essential to regulate their supply. I have 8kW of panels and can interrogate them via an app. Last night at dusk the inverter output was only 50W and the panel DC voltages – there are two strings – were 204V and 206V. Just now, though overcast with 2.50kW output, they were 231.46V and 231.81V.

If the panels are producing more than the car’s charging current, then they will run the car’s charger. If less, the difference will be made up from the mains, and of course, there will be no output at night when one might want to charge the car for the following day.

After my panels were installed, the power the house draws from the mains dropped by 50 per cent, justifying my investment. Most days, during daylight, the smart meter reads 0 and the panels are running the house. If it’s a bright day, I put the washing machine on.

Tony Meacock CEng MIET By email

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