It's time to invest in the hydrogen economy
I am sure Paul Spare is right in outlining problems in generating electricity for the grid with such a hugely varying water power as the Severn barrage (Your Voice, Professional Engineering No 1, 2022).
May I suggest that a way of overcoming many of the difficulties is to use the electricity generated to convert this to hydrogen by electrolysis. We urgently need hydrogen for heating and transport.
Hydrogen is also a good storage medium when connected to tanks and would help alleviate fluctuations in energy supplied to them. It could also be used to supply heating to Bristol, taking over from pipelines for natural gas. This in turn could feed domestic boilers with a small adjustment.
Hydrogen could be pressurised and bottled to meet transport needs, maybe feeding internal combustion engines or fuel cells.
Harry Rosenbaum, Matlock, Derbyshire
Bullied and intimidated
Last year, I cancelled my Institution membership after 16 years as a mechanical engineer. This was done with a phone call, no questions asked. I wonder why the IMechE would have so little interest in why a member would leave.
I had two reasons – overwork and sexism. On overwork, all the companies I worked with are understaffed. Engineers want to do their best, and companies take full advantage.
On sexism, I would not recommend any woman to go into mechanical engineering, and certainly not to work in any office where the number of women is very low. I have never been sexually harassed, but I have had my fair amount of bullying, intimidation and discrimination. I have generally always been the lowest paid at my grade, expected to do more hours, and judged more critically than male counterparts. I worked for six companies and left every one because it has been made clear that I will never be allowed to advance, or be provided with training and mentorship to attain that advancement.
I have worked with some great people, but I have also worked with people who have made my life extremely difficult, and I can no longer put up with it.
I am retraining to be a plumber – the hours and pay are better, and I can work for myself.
Helena C Whittaker
Flawed nuclear decisions
I am an engineer retired from a British AGR nuclear power station. I remain to be convinced that the EDF Hinkley C and Sizewell C stations are the answer to future electricity demand.
EDF seems to be following the 'bigger is always best' approach at huge cost. About 37 years ago small modular PWRs were being proposed but no one was listening. It has taken Rolls-Royce all these years to get their voice heard and even then their current proposals may come to nothing.
The most recent generation of AGRs was chosen by the then generators as the way forward but these have turned out to have a more limited life than forecast, largely as a consequence of graphite core life issues. Other, less-favoured AGR designs of only a few years before seem to have achieved longer predicted lives. This may show that the design decisions made in the early 1980s were flawed.
Can we expect any better from our new decisions bearing in mind that EDF seem to have been evolving their EPR design despite it supposedly being eligible for full-scale build – think about the long delays in EDF getting the design on stream in other countries. Only China seems to have managed better with the EDF design.
Sizewell B seems to be the British success story, essentially using American technology, but there again not being replicated despite the then Central Electricity Generating Board proposing just such. British ability to build cost-effectively is historically littered with un-replicated models.
So I remain to be convinced that Hinkley C will be the answer or maybe just a super-expensive way of generating electricity. Just look at all those companies that have withdrawn from building any nuclear power station in the UK, it seems on the grounds of cost.
Gavin Robertson
Getting into a spin out in space
I wonder how many engineers remain puzzled as to how the SpinLaunch spinning rocket launch system really works without destroying itself (Weird Engineering, Professional Engineering No 1, 2022).
The release of the first stage at high speed will inevitably induce a massive out-of-balance force within the machine that ought to destroy itself. Is it similar to a self-balancing spin drier?
Could other masses closer to the centre of the spinning and balancing arms be released at the same time so that they are guided outwards along the arms, inducing a rebalance plus a massive de-acceleration due to the Coriolis effect?
Furthermore, as the first stage effectively accelerates in the launch direction from zero to launch velocity over a distance equal to the spin arm radius, would more tolerable accelerations be permitted by some sort of linear accelerator or cannon that could be much longer than the radius?
Denis W Oglesby, Bingley, West Yorkshire
Concrete argument
In the article “Plus points for printing,” I was shocked to read concrete being described as naturally sustainable (Professional Engineering No 1, 2022).
It is estimated that concrete is responsible for 8% of global CO2 emissions and is one of the world’s largest sources of carbon emissions. There is no way that it can be described as sustainable.
I agree that 3D printing has potential to improve the construction industry’s woeful environmental performance by reducing energy usage and waste. However, it can only truly be a sustainable solution when alternative materials are used instead of concrete.
P Taylor, Lancashire
Bumpy road to sustainability
Battery-electric vehicles (BEVs) have a role to play in transport and we should expect them to get better in the future. However they are not a zero-emission solution. The embedded CO2 in battery manufacture is large and is unlikely to improve much till all the mining and manufacture uses low-carbon energy.
The health impacts associated with mining are serious, and worse than for conventional cars.
Modern internal combustion engine (ICE) vehicles will have negligible particulate emissions as the use of particulate filters spreads; NOx levels can also meet the most stringent requirements. Then particulates from tyre wear will become the dominant source of urban air pollution and BEVs will be worse for this because they weigh more.
There are many other serious material availability, economic and infrastructure issues to be solved if BEVs are to replace all ICE cars and this will require over a 200-fold increase in globally available battery capacity.
All available technologies, particularly partial electrification through ‘self-charging’ hybrid electric vehicles and alternative fuels, have to be used and improved to address the sustainability of transport. Banning ICEs from 2035 will be an environmental and economic disaster. If indeed BEVs turn out to be so much better, they will naturally take over without such a ban!
Professor Gautam Kalghatgi, Oxford
Electric cars are just a stopgap
I must take issue with the views of Dr Ray Bacon (Your Voice, Professional Engineering No 1, 2022).
Whilst electric vehicles carry no flammable fuel, the energy to drive them is stored in a fundamentally dangerous manner. A battery is analogous to a coiled spring. There is nothing to prevent, in the event of a mishap, all its stored energy being released at once. There have been some spectacular fires associated with crashed electric vehicles.
The availability of materials for battery construction, together with the environmental impact of their production, is a major concern. This, coupled with problems associated with range, charging times and end-of-life processing of batteries mean that electric vehicles can only be a limited and transient solution to the problem of emissions.
The future of clean transport lies with a hydrogen economy. An internal combustion engine can run on hydrogen.
R T Holmes, Cheltenham, Gloucestershire
We need affordable options
As I prepare to enter my ninth decade on this planet – and the privilege of Institution membership for six of them – I understand Dr Ray Bacon’s enthusiasm for electric cars (Your Voice, Professional Engineering No 1, 2022).
They may well be the future – but he offers the Mercedes EQS as an example of long range between charges, and this car has a list price of almost £100,000. I wonder if he has taken into account the economic reality with which most people grapple when choosing their car.
The most I can spend on a vehicle is £1,500, which three years ago bought me a nice 18-year-old Volvo V70, which I shall probably hang on to until I meet St Peter at the Pearly Gates… my earthly record will be on his hand-held device.
As the second-hand car market outsells the new car market about four to one, most people will be buying fossil-fuelled cars for the foreseeable future – and, although range is one concern with electric cars, battery life, rare-earth component sources, and charging infrastructure are also considerations.
David Simmons
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Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.