Letters to the editor: volume 17, issue 1

Taming the ‘Wild West’ of home EV chargers

There is much work to be done to help UK householders who want to have home electric-vehicle charging points installed, if my own recent experience is typical. I am not a power engineer but have a telecommunications engineering background. My experience, and that of my approved installer, has been that a ‘Wild West’ situation seems to face EV purchasers as far as arranging home charging is concerned.

A wide range of charging points are openly advertised, but are of varying capability and – apparently – quality of design. My own attempts at making a choice of equipment have fallen foul of the local electricity distribution network operator (DNO)’s rules on load, so that my chosen 7kW single-​phase capable Easee One charging point can only be run at 13A charge current until the DNO conducts a load test before sanctioning an increase. After two months my installer is still waiting for the results. I have found no mention of this load issue in any published guidance. Like me, many people may be lulled into a false sense of security when they see a 100A main fuse next to their meter.

It might have been helpful if the charger had the ability to balance the EV charging load with the measured domestic load, but that functionality on my chosen device is not available in the UK yet. The interaction of the charger control and the vehicle charge-​control system also needs to be thought through. I can well imagine that this will confuse many people as there is no whole-​​system guidance that I have found. I have elected to make the charger dumb and let the car control the charging process through its own app and onboard systems. This works well.

If the user wishes to use off-peak charging tariffs, the allowable charge rate is important because you may not be able to accrue enough low-cost electricity units to cover the more expensive ones, compared to a non-EV tariff, at other times. I currently have a fixed tariff rate that overall is cheaper than an EV tariff because I can only benefit in a limited way from the off-peak cheap electricity units due to the limited load that can be drawn.

There is scope for the IET to publish a short pamphlet or online equivalent that explains all these home charger issues to a non-technical audience, so that they can have a more informed discussion with their installer.

Brian Fisher CEng MIET

By email

The 66-million-year AI project

I fully agree with Rachel Thomas’s comment in ‘Big Tech’s AI Land Grab’ (December 2021) that “innovation comes from doing things differently, not doing things bigger”. We have learnt so slowly, and so little, about artificial intelligence. It has taken 60 years to understand one aspect of the brain – neural networks – but it has many more attributes than the cerebrum.

A little is known about synaptic shrinkage, but very little about synaptic expansion. The cerebellum, which looks after many human biological automatic responses, can be likened to many small apps. The two hemispheres of the brain and the corpus callosum could be partially emulated by time multiplexing artificial neurons. In addition, the folding of grey matter and the gyri and sulcus, which dramatically increase the surface area of the brain, is also not fully understood.

In Excel, for example, not one but many cells have been used to perform a neuron. This dramatically increases the real estate of the spreadsheet displayed. Also, the medulla oblongata and the upper brain stem have been partially emulated in the form of a flow menu. Dramatic improvements have been made when these approaches were adopted in a 10-neuron machine-learning spreadsheet.

Where do we go from here? The best project on the planet has to be the 66-million-year-old development of the human brain. Engineers can learn not only from engineering projects but also from the plethora of other disciplines that we are surrounded by and immersed in. If engineers can’t produce even more dramatic results rapidly then we are not “doing things differently”, and we are definitely not learning fast enough!

Andrew WS Ainger FIET

By email

Britain’s AI false start

Articles in the December 2021 issue of E&T on artificial intelligence and its application to the real world, which has been an ongoing challenge over the last 50 years, prompted me to look again at the Alvey programme, which in the early 1980s was intended to address this problem but in the event achieved little at considerable expense.

Rereading ‘Alvey: Britain’s Strategic Computing Initiative’ by Brian Oakley and Kenneth Owen, I was surprised it made no mention of a previous project that was set up by the National Research Development Corporation with a loan from the government. This brought together the fragmented efforts of major companies in the field – GEC, Plessey and Ferranti. It made excellent progress but the government, rather than pursuing it, set up an expensive and cumbersome programme in Alvey. Had we in NRDC been encouraged to continue I am confident we would have established a stronger position at a fraction of the cost.

Dr Peter Tanner FIET

By email

Beating battery design flaw

In the wake of Christmas, many E&T readers will be faced with battery-powered toys and gadgets that suffer from a basic design flaw. When the device is left on by mistake, or the batteries simply get flat, they leak over the battery compartment. Many is the time I have discovered an unholy mess of corrosive electrolyte, which destroys the battery terminals and leaks into the rest of the electronics, rendering it scrap. You can’t get replacement battery terminals from the manufacturer, and they are often moulded into the plastic to make them totally unrepairable.

Surely it is time for a standard for replaceable battery terminals or modules and leak-proof battery compartments, which the government could mandate for all new electronic equipment. This would be a big step forward on the right to repair.

Peter Negus CEng MIET

London

Upskilling opportunities

In reply to recent letters in E&T regarding home battery systems functioning in power cuts, such systems have been available in the UK since at least 2015. I refer to systems with switching speeds equivalent to a UPS (uninterruptible power supply), which introduces a new problem: the homeowner is unaware of the power cut, so doesn’t know to limit their power and energy consumption.

I suspect that in the cases described in E&T, installers’ knowledge was limited to their suppliers’ catalogue and indeed the level of technical sales support they can offer. But I don’t mean to unfairly put down those electrotechnical roles; the level of complexity available today is a step change from the days when power flowed in one direction. Battery systems are another step up from microgeneration, as they are closed-loop. Next will come coordination of electric vehicle charging and electrical heating to support smart grid capabilities.

This is part of the skills gap, or opportunity, associated with the green revolution. We are going to create opportunities for electricians to upskill to design, install and sell such integrated systems, and then require more electricians to backfill. More skilled jobs – something to be optimistic about.

Bob Hicks CEng MIET

By email

Don’t phase out fossil fuels too soon

During 2021, it was estimated that three million UK households were unable to pay their energy bills – a number that could grow by 392,000 in winter as prices rise by 10 per cent or more. So it beggars belief that the UK’s Climate Change Committee wants to impose taxes on gas before alternative ‘green’ energy sources are available. This will give a further upward twist to fuel poverty, while forcing consumers to spend typically £10,000 or more on installation of a heat pump, supplied from the fossil-fuelled grid.

Gas-fired power stations supply around 40 per cent of UK electricity generation. They, and a declining nuclear capacity, keep the lights on when there is no sun or wind. On some winter days, total solar and wind power capacity can be only around 1 per cent of grid maximum demand.

It will take many years to install enough hydrogen gas turbines to replace conventional capacity – with increased electric vehicle charger and heat pump load – along with the installation of enough electrolysers to produce the enormous volumes of hydrogen needed. The amount of wind and solar capacity required to energise the electrolysers and supply electricity consumers will be more than five times that currently planned. So, we will be using fossil-fuelled power stations to charge EV batteries and supplying heat pumps until well beyond 2030.

The obvious thing to do is to defer the target date for the phasing out of gas boilers, petrol vehicles and diesel vehicles until the grid has been decarbonised.

Roger J Arthur CEng MIET

By email

Benefits of solar backup

Following on from the recent correspondence on domestic solar panels and battery systems, I can report that my house benefits from a fully automatic battery backup system that was installed in May 2020. It comprises PV panels and an inverter, supplying up to 26kWh at 3.6kW peak on a sunny summer’s day, with a Tesla Powerwall battery and Gateway.

In the event of a grid failure, the Gateway automatically manages the switch from grid to battery; no user intervention is required unless we need to isolate the system for maintenance. The system automatically disconnects the house from the grid to prevent islanding. A point to note is that a local earth rod is required for properties like mine with a TN-C-S earthing system that are earthed through the grid connection.

Fully charged, the Powerwall’s storage capacity of 13.5kWh and maximum output power of 3kW could power the house for a whole day at average use levels. We use the battery primarily to store excess solar power and off-peak power during the night for use at other times, but its use as backup during power cuts is a welcome benefit.

This feature came in handy a few days after our system was commissioned when, by coincidence, UK Power Networks came to do some planned maintenance on the power line supplying our village. The grid was disconnected for around five hours, during which time we continued with business as usual at home. UKPN technicians were puzzled to see lights on in our house after they had isolated the local transformer and we enjoyed giving them a guided tour of our installation.

Richard Packer CEng MIET

By email

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