Pathway to energy security
It was good to see an article discussing options for the long overdue decision on how to dispose of the UK’s extensive and expensive stockpile of safeguarded plutonium (“Waste not, want not,” PE May).
There is a longer-term strategic consideration to take into account. Established wisdom is that a reasonable estimate for the duration of usable reactor fuels is of the order of 100 years based on a ‘once through’ cycle before disposal. However, full fuel recycling has the potential to increase this period by at least a factor of 10, leading to the potential for more than 1,000 years of nuclear power generation.
The current price of virgin fuels indicates that fuel recycling is unlikely to be economically advantageous for some time but we should expect that shortages of readily accessible ores will eventually result in price increases as the world demand for low-carbon energy grows.
Whatever option we take to resolve the short-term issue of the safe storage of plutonium, and other irradiated reactor fuels, we owe it to future generations to ensure that we don’t do anything which would preclude the safe and economic recovery and recycling of these valuable materials when the economic conditions are right.
We should also take action to preserve and protect the extensive knowledge base that the UK has amassed during many years of Magnox and AGR fuel reprocessing for the benefit of future generations.
Tim Chittenden, Workington, Cumbria
MOX waste overlooked
I read the “Waste not, want not” article expecting, from the ‘best thing since sliced bread’ tone, a new approach to nuclear waste management and reduction (PE May).
As usual with nuclear discussions, the article failed to address the issue of long-term waste from the featured MOX process. It failed to critically analyse the suitability of this process for the UK and whether the various stages involved can really mean that MOX counts as low-carbon energy.
Vince Matthews,
Thetford, Norfolk
Energy costs and benefits
In the discussion of future energy supply, the elephant in the room that very few people seem to be talking about is energy returned on energy invested (EROEI). At its inner-most core, the economy is a measure of surplus energy, not of financial wealth.
In PE April, there was an article entitled “Hail shale,” and there have been comments in the letters section on the fracking debate. In February the IMechE hosted a pan-industry event aimed at providing a “more technically literate discussion about hydraulic fracturing”.
Whilst I agree that a more technically literate discussion is vital to all parts of the debate regarding our future energy mix I was staggered to find not a single mention of EROEI in any of the material on the subject of fracking.
If the average EROEI of our energy system falls below a critical threshold, then our society will be at serious risk of collapse, because the governing energy equation is reciprocal: the higher the proportion of our currently available energy supply that we spend on obtaining our future energy supply, the lower the proportion of our currently available energy supply that remains available for everything else that society wants to do with it.
EROEIs for early conventional onshore fields were in the region 100:1 and have been falling ever since – slowly for many decades but now rather more quickly. We have taken the easy conventional options, and are now left with the unconventional options. When the ratio has fallen to 1:1, there will be absolutely no point in spending current energy to obtain future energy. The critical tipping point may be somewhere in the region 10:1 to 5:1.
My understanding is that the EROEI from US shale gas is worryingly low, perhaps well below the 10:1 ratio. If this were correct, then serious questions should be asked regarding whether it should be pursued as a physically viable option, let alone commercially viable option.
Regardless of the financial costs, the energy cost of the energy – which is fundamentally more important – would be too high.
The presentation The Technical Realities of Fracking by Tiffany Parsons at the IMechE event skirted around the issue of EROEI. Some graphs showed rapidly depleting production rates from US experience; there was some commentary around the need to drill more and more wells to maintain a constant output – a 50% reduction even after just one or two years.
This suggests to me that the EROEI for shale gas is indeed worryingly low.
I would like to see the IMechE supplement its material on shale gas by including data on the EROEI from the US, along with any technically robust justification for how and why the UK may expect to achieve different (better?) results.
James Croftson,
Falmouth, Cornwall
Misguided policy
I have read how Tesla is to introduce home batteries to store solar power. It is an expensive solution in search of a problem. The ‘problem’ is caused by idiotic governments choosing to subsidise expensive solar and wind power because of a mistaken belief that they can make a big reduction in carbon dioxide. They cannot.
A 10kWh battery – without installation and inverter – costs $3,500, or $350/kW. It has a life of about 1,000 cycles so each cycle costs $0.35. It has an efficiency of 80% so you need to put in 1.25 units to get one unit out. So the overall cost of stored energy is $0.50 per kWh (Electricity from solar cells or the mains costs about $0.15 in the US but much more in European countries due to idiot policies on carbon dioxide reduction.)
The simpler, cheaper and safer option (the batteries have a risk of fire) is nuclear power, gas or coal. And if you do need to store energy, hydro pumped storage can do it cheaper and better.
Bryan William Leyland, Auckland, New Zealand
Opportunity missed
Regarding your survey on nuclear power (PE March). It is a quarter of a century since I was given early retirement from Nuclear Electric, as it had become, after 27 years of working for the Central Electricity Generating Board on power station construction. My last appointment was to PWR power projects in the Knutsford design office and for the last couple of years I was working on the design of the Sizewell B follow-on stations, Hinkley Point C, Wylfa B and Sizewell C.
The Hinkley C public inquiry was complete and awaiting the entirely satisfactory report, we were well into the environmental statement, site planning and the like at Wylfa, besides working on replication of documents, repeat orders and other ways of speeding things up and reducing costs.
Cancellation was not for planning or safety reasons, nor was it because of technology, construction time or capital cost. A side effect of privatisation and the associated competition between electrical distribution companies meant that the cost of any large station would have to be written off in too short a time to be viable. Hence the ‘dash for gas’.
A number of contracts had to be cancelled with associated costs. By now we could have had at least 3,500MW more clean energy available with minimal global warming impact. And even now EDF has still to start building.
It is good to see, from the survey, that 90% of the engineers who responded support new build, and I continue to enjoy my retirement. But I despair of financiers, of much of the green lobby and of politicians of all persuasions.
J G Taylor, Lingfield, Surrey
Climate certainties
It was with some disbelief that I read some of the responses to the Soundbites question “should we access the 100 billion barrels of onshore oil?” (PE May).
It is a sad reflection of the level of debate about climate change that there should still be professional engineers who either believe “the scientific evidence is overwhelming that there is no man-made climate change” or that having a carbon-neutral economy means living in conditions similar to the Stone Age.
The scientific evidence for the anthropogenic causes of climate change are clear and unequivocal and I would challenge readers of a different view to find a single peer-reviewed article in a reputable scientific journal over the last couple of years which says otherwise. Similarly clear is the fact that, globally, we have around three times as much fossil fuel reserves as we could possibly use and still stay within the generally accepted limit of 2°C average temperature rise. This calls into serious question the rationale for any continued exploration for further reserves.
As for going back to the Stone Age, even the government believes that the UK can achieve an almost carbon-neutral economy by 2050 with no reduction in living standards, and probably with increased global competitiveness. The most cursory glance through any recent issue of PE will highlight game-changing technologies on the near horizon that support this ideal.
The vision of the IMechE is encapsulated in the phrase “Improving the world through engineering”, and I believe that as engineers we all have a moral responsibility to seek to understand the facts of what is becoming one of the defining issues of the 21st century.
The impact of emissions and the carbon economy affects the whole world. Engineers need to be at the heart of the matter, providing the expertise, knowledge and advice to help governments implement solutions to this most pressing of challenges.
Ken Mitchell,
Alveston, Bristol
How to make an impression
As I am currently placed on a Formula E internship, I wanted to let other readers know the importance of work experience for young people looking to make it in the ‘real world’.
Whether you have just finished college, or you’re part-way through your degree, consider taking some time off, but don’t waste this time by doing meaningless part-time jobs that aren’t relevant to your desired career path.
Internships are the way forward. Yes, you might not earn a great deal. Yes, you might be expected to make more than your fair share of tea. But a whole year with a company is a huge amount of time to make an impression. It will be more than noticeable on your CV.
If you use a gap year as an opportunity to fulfil an internship or placement, it will give you a chance to get your name known, as well as a chance to network with potential future employers and colleagues. Make connections and stay in touch once you have finished your time there.
Make sure people remember you. Maintain contact throughout your remaining studies and keep your connections updated with your progress.
If you don’t make the effort once you’ve finished your placement, you risk the chance of your connections forgetting who you are. Internships are an incredible opportunity to gain valuable experience and make important relationships which will help you in your search for a career.
Don’t feel you have to complete your degree in the immediate years once you’ve finished A-levels or college, so you can get out into the world of work as quickly as possible. Take the time to get necessary experience within your chosen industry, so that when you have completed your studies you are equipped with knowledge of a real workplace and relevant experience.
Charlotte Tolley, London
No green gain
Nowhere in the article about hydrogen-fuelled vehicles is there mention of where the hydrogen comes from (“The green gas,” PE May).
It does not grow on trees (unlike oxygen!) and if it is produced by electrolysis it will rely on some form of electricity generation and even if that is ‘green’ electricity there is no net gain because that electricity could be used for other purposes, such as battery-energised buses.
On a different subject, I must point out that the first Formula One mid-engined car was not the Cooper T43 of 1957 but the 1955 Bobtail Cooper of Jack Brabham, which I helped to build (“Sporting chance,” PE May). It looked like a sports car but was a central-seater, so qualified as a Grand Prix car.
Michael Tucker, Thurso
Image problem
A well-chosen picture will say something about the text. What then does the title picture to “Engineering abroad – India” say (PE May)?
What, especially, does it say to young people leafing through the magazine? Here are some suggestions:
“Uncle Tommy is an engineer. I guess he spends all day welding bits of angle iron.”
“Doesn’t anyone care if Indians catch fire?”
“Dad always uses a welder’s mask when he’s welding in the garage but he needn’t bother – he could just use tinted safety specs.”
“I hate the way the techie teacher makes us use jigs and clamps when we’re doing a welding project – that fella doesn’t need ‘em.”
C’mon PE – ‘P’ stands for ‘Professional’.
Stuart I Brown, St Andrews