Pages of books on a wall

Letters to the editor: volume 17, issue 11

Image credit: Patrick Tomasso/Unsplash

In the December 2022 issue of E&T, readers discuss how we should assess the success of technological progress, the economics of hydropower, and more.

Judge progress by outcomes

I recently had my credit card cancelled by John Lewis because I was unable to provide a mobile number for two-factor authentication. My argument that using a landline works currently and is more secure, and that in the end the mobile is merely a communication channel, cut no ice with them.

This experience set me thinking that progress should be measured by outcomes, not process. As somebody who has installed and commissioned IT and telecoms systems for around 40 years it is a given to me that technical developments have advanced beyond imagination over that period. However, it is not apparent that services for the ordinary citizen have improved; I would suggest that they have significantly deteriorated. Health, transport, welfare, police and so on are up to their necks in sophisticated systems but as far as the ordinary citizen is concerned we might as well be in the age of Bob Cratchit and the quill pen.

One example of past performance that we would find virtually impossible to emulate today is the construction of the battleship Dreadnought in the government-controlled Portsmouth dockyard. This was a revolutionary vessel, which at a stroke rendered every other battleship in the world obsolete. The keel was laid in October 1905 and the vessel sailed out of Portsmouth Harbour less than a year later. No welding, CAD or project management software, just people who knew what they were doing and did it.

A second example is the evacuation of more than 200,000 children from London in the early stages of the Second World War over a period of four days in chartered trains and buses. I don’t think our current society could manage that in four weeks, or perhaps months, despite the computing power and connectivity that we all have at our fingertips.

These issues feed into the debate on the engineer in society that is a regular feature of E&T’s letters pages. I get the impression that many so-called managers with little technical knowledge drive the agenda in the belief that because they can operate a piece of technology they actually understand how it works, with little realisation of its limitations and benefits, as in the case of my cancelled credit card.

EurIng Mike Matthews CEng MIET

By email

Why heritage hydropower can’t compete

James Walker is right to identify the significant potential for hydropower on old mill sites in the UK (Letters, November 2022). However, the unfortunate reality is that these projects are relatively small and complex, and consequently have a very high installed cost per kW, typically an order of magnitude higher than wind or solar PV at this scale.

It is correct that the lifetime of hydropower is considerably longer – a well-designed and constructed scheme is normally expected to have a lifetime of between 70 and 100 years. However, borrowing and therefore financial viability assessments tend to be on a 10-20-year basis. This means that, rightly or wrongly, the longevity of hydro is not normally a factor in the business case or cost of electricity generated.

As for not worrying about wildlife, attitudes such as this are best consigned to a previous century. Engineers have an obligation to consider the environmental impact of the projects that we deliver. In fact, I would argue that we have a responsibility to identify, and where feasible include, features that provide environmental gain within the scope of our projects. Biodiversity and water quality in Britain’s rivers are only now beginning to recover from the wanton development of the industrial revolution and subsequent activity. This slow improvement has largely come from active regulation, not by leaving things to their own fate.

Being, very proudly, responsible for the recent delivery of the 1.6MW, 5GWh/year Barr River project in Morvern, Scotland which is the UK’s (and possibly Europe’s) largest community-owned hydropower scheme, I am as keen as anyone to see more hydropower development. However, this must be done responsibly and, until there is greater enlightenment in relation to project finance, must make financial sense over a short timescale.

John Heaton CEng MIET

Dunblane, Stirlingshire

Do the maths on energy solutions

I repaired and ran a watermill in our lowland village for many years. With a head of two metres and flow of 300kg of water per second it ran flat-out milling flour. Using ‘g’ in the calculation, the available power was thus about 6kW, subject to sufficient recent rainfall. Mills in upland areas have greater heads but usually smaller flows.

If one considers the average rate of energy usage from all sources over a year for all purposes in the UK for electricity production, heating, transport, manufacturing etc, it would amount to about at least 3kW per citizen, so one mill site would only make up for two people’s equivalent usage.

Another way of looking at this is that 5,000 mill sites would at most generate 30MW, or about one-thousandth of the average UK current electrical demand of about 30GW, and even far less than that for our average total energy needs rate, totalling some 200GW.

The UK does not have the rainfall, topography and land area to make a significant river hydropower contribution. Even our hydroelectric power stations only contribute about 500MW on average.

Biofuels take ten to twenty times the land area that solar energy would, and therefore take much more land that might otherwise grow food. Onshore wind takes negligible land space and offshore none, apart from shore terminals. Modern wind or solar farms can generate on average over a year about 10MW per square kilometre of land or sea area. Nuclear energy provides about 3 per cent of our total energy needs and would be very difficult to ramp up quickly. There could, however, be a useful contribution from tidal power using barrages and lagoons.

I am convinced that the only solution is to massively increase wind and solar power and use it mainly to electrolyse water to make hydrogen to store all year round to cover lulls and cloudiness. Hydrogen can replace natural gas for heating, and coal and oil for heavy industrial processes and transport. Half the volume of town gas made from coal used to be hydrogen. However, battery-powered cars are fine as they do not need to store energy for long periods. We would probably need to import some hydrogen from friendly sunnier countries.

Heat pumps are proposed for domestic heating with the assumption that they will use electricity, but this would require a huge increase in the grid capacity and some sort of electrical storage for the cold months. But if homes already have a gas connection, and if a heat pump is viable for them, they could use ones driven by hydrogen.

Other readers may have different solutions but remember to do the maths!

Dr Robert Stevens CEng MIET

By email

December 2022 Letters section Cartoon

Image credit: E&T

A woman engineer’s story

In reply to ‘Where are the letters from women?’ (Letters, October 2022) here’s one. When I left school in 1944, large numbers of men were still in the armed forces. To replace them in industry, the powers that be organised courses in engineering for girls. I enrolled at the Royal Technical College at Salford on a course designated YWI3, i.e. the third young women’s intensive course. That launched me into a career in engineering. Here I am, in my nineties, still reading E&T, after a very interesting career in technology.

My advice to girls interested in technology is go for it, but you must be competent to avoid the comment ‘just like a woman’. I started as a laboratory assistant at a subsidiary of GEC and ended as a lecturer in electrical engineering at UMIST (University of Manchester).

Rosemary Taylor CEng MIET


Powering an EV from domestic solar

I agree with Ros Eveleigh (Letters, October 2022) that there must be a better way of getting solar power into an electric vehicle.

I envisage using the DC (CHAdeMO) connector with a control box. This controller would be inserted between the solar strings and the house system, with a tee-off to the EV. It would need a DC-DC converter to raise the EMF, and bus connections (CANBUS and start/stop) for control.

But I think that is not going far enough. I see the EV as storage too, with a second DC-DC converter, or the first switched around, to send limitable energy from the EV to the house system as if from solar.

As I’m retired I don’t have the facilities to build and test a prototype, but is there no enterprising manufacturer out there keen to get such a product onto the market?

Geoff Tily MIET

By email

EV aversion is natural

John Wheeler’s pessimism in regard to new technology – in this case EV reliability (Letters, November 2022) – is perhaps a manifestation of the very common ‘loss aversion’ cognitive bias, where we tend to focus on the perceived negative attributes of a change, whilst considering only the positive aspects of the status quo.

Internal combustion vehicles break down. They used to break down a lot, but now less so because we engineers have developed more reliable designs. Combi boilers, aircraft, personal computers etc were all the same. It’s what humans do; we don’t tolerate failure. We always strive to improve designs, to make better. It seems to me our place as engineers is to try to evaluate objectively technological developments, fighting through the cognitive biases and heuristics that introduce subjectivity. We should also remember that many of the technical problems we see today will be overcome tomorrow. We engineers will make sure of that.

James McLellan CEng MIET

By email

Make digital skills compulsory in schools to tackle shortage

Of course there is a digital skills shortage, because for some reason that I can’t fathom, digital skills, computer programming, app programming etc are not taught in schools. Computer science should be a core subject taught at basic GCSE level and beyond. This extends to general use of the internet, an awareness of how to put together a basic web page, HTML, app programming, using Zoom, being able to hook up a PC or laptop for Zoom etc.

These are all basic skills that I found myself having to either re-learn or get to grips with to get my daughter onto the internet and to be able to use Zoom during the Covid lockdown. All the teachers seemed to assume this knowledge would either be taught at home or be acquired via methods using some kind of supernatural communication.

The UK is falling behind its rivals as there is next to no tech taught in schools. When I was at school back in the 1980s we had computer studies at CSE and O Level as an option, as well as the option to carry it on at A Level. Nowadays in this digital age it should be compulsory, as it seems to be abroad.

Recently, I spent the best part of a day digging out my old PC, webcam and microphone and setting them up for a digital thing my daughter had been asked to do remotely. It turns out she was able to do what was required using her mobile phone! However, I was not informed of this until I had spent a good few hours downloading the latest software drivers and taping the webcam and microphone to a flat-screen computer monitor.

Schools, teachers and politicians take note and get computer/digital studies added as a compulsory subject alongside English and maths.

Lorne Mason MIET

By email

Write to E&T at mailto:// We reserve the right to edit letters and to use submissions in any other format.

Sign up to the E&T News e-mail to get great stories like this delivered to your inbox every day.

Recent articles