Grassroots action boosts renewable energy
I work as a certification surveyor in the oil industry for DNVGL, but in my spare time I also serve voluntarily on the board of directors for two local renewable energy community groups – the Wester Derry Wind Co-Operative and Aberdeen Community Energy (ACE).
Last month we completed the installation of the UK’s largest-diameter Archimedes screw at ACE, Donside Hydro, for our 99kW fish-friendly scheme. The 17,350kg Landustrie Archimedes screw is suspended through sealed eco-bearings at 13 to 20rpm and has a drop of 2.5m over its entire length.
Shaft power is stepped up through a Landy coupling and gearbox and into the 180kW ABB generator at up to 1,478rpm. The power is then sent through ABB drives and into the SSE 500kVA grid transformer for export.
The build for this fast-track project has gone without any showstoppers over 14 weeks, thanks to the commitment of the men and women in the team. The local community has been excited by the project and has been very involved. Its £1,250,000 cost was partially paid for by £500,000 of shares raised in just over three weeks.
The project has been supported by Local Energy Scotland and Sharenergy, who support and encourage ordinary people to take on industrial-sized renewable projects such as hydro, wind and solar power for community benefit. The Scottish government’s Community and Renewable Energy Scheme also helped by providing seed grants and commercial loans.
The project is currently completing its finance with a bond issue – at the time of writing there are less than £400,000 worth of 4% fixed rate bonds left for sale.
I would encourage engineers across the country to diversify and contribute to their community Sharenergy renewable projects. By investing you can be part of a local solution, having your own say in the running of your green energy co-operative, helping to offset climate change while making a sound financial return.
It’s a rewarding way to use your expertise for the benefit of the local community that I’d highly recommend.
Mark Bragg, Aberdeen
Tide and tested technology
The installation of wind turbines continues even though their output is erratic and unpredictable. By contrast, the daily and seasonal variations in the tides can readily be predicted, but this resource remains largely neglected and some of its attributes unmentioned.
By building tidal lagoons in pairs rather than barrages, it is possible to have power derived from tides available when it is most wanted and to store the power from wind turbines generated when it is not wanted.
One lagoon would be designated as the high-tide pool and the other as the low-tide pool. Flow from the high to the low could then be independent of the tide at a time when power is most needed. Power could also be generated by flow into the low and out of the high pools when permitted by the tide.
Surplus power could be stored by pumping from the sea into the high pool. The best time to do this is at high tide when the least head is required and a gain in energy available is achieved by use at low tide. The low pool can also be used for storage by pumping it down at low tide and generating at high tide.
A tidal lagoon is proposed for Swansea. The government instituted a review into tidal lagoons in February. The energy minister of the day in referring to the Swansea scheme said: “Tidal la-goons on this scale are exciting but as yet untested technology.” I am left wondering what part of the scheme has untested technology.
In contrast, with a new PM and new energy minister, we have signed up to a very large nuclear station with an unproven reactor design, where two such stations under construction have suffered large overspends and delays due to ongoing technical issues.
John Carter, Ottershaw, Surrey
Pleasing the customers
Your article about JCB (“A family affair,” PE September) reminded me that in the early 1990s I went to the company to advise them on investing in advanced manufacturing technology.
I was impressed by the way they had looked at what customers wanted and designed their machines to suit. I was pleased to see in your article they had kept this idea up-to-date.
Dr Peter Primrose, Malpas, Cheshire
Keep HS2 debate on track
The statement by Lee Horwich that the sole output of High Speed Two will be to reduce journey times by 10 minutes undermines his credibility as it seems to suggest ignorance of the actual proposals, which have been in the public domain for years (Letters, PE October).
As a supporter of the project I acknowledge that – as one would expect for any major infra-structure investment – there are valid arguments against it, so I do not understand the apparent need among HS2’s opponents to put forward invalid and contradictory ones! An earlier anti-HS2 letter asserted that the capital’s terminus would be “in a field”, in flat contradiction of Horwich’s “cripplingly expensive” last few miles into central London.
I could continue by rebutting Horwich’s arguments, but would rather make a general plea for accuracy in contributions to the debate on HS2 and, indeed, any other subject.
Caspar Lucas, Stourbridge, West Midlands
Equality for all
Your experience listening to Yassmin Abdel-Magied’s presentation reminded me of candidate interviews in the past (Editor’s comment, PE October).
To me the most important questions were: “Could they do the job?” and “Were they team players?”.
Their religious belief, political views, ethnic background or sexuality were of no importance.
Deleting such references would I hope help us to remember that we are all basically human beings.
I seem to remember a recent article on alternative types of nuclear reactors. Molten salt springs to mind. Could we please have an update on this type and other alternatives to the hugely expensive and complex reactors currently in favour?
As we shut down coal-fired power stations, it would appear more sensible to have a larger number of less complex and expensive reactors on these sites, which already have grid connection. Thus producing a distributed and less vulnerable baseload generation system.
When joining consulting engineers Binnie & Partners in the late 1980s I remember seeing drawings of proposals for the Severn barrier scheme. Since then there has been a “Mulberry harbour construction” variation of a full barrier, together with the concept of tidal lagoons. To say nothing of endless debate, cost and inaction.
Could we therefore see the latest thinking on this and similar projects? Tidal lagoons grab my support due to non-interference with river transport, reduction of ecological concerns and flood risk, and possible attenuation of peak flow impact.
Marcus Field-Rayner, Hundon, Suffolk
Who was in the wrong?
The results of the 8 Questions readers’ survey on ethics in engineering and Martyn Maynard’s letter analysing the available information on Dieselgate make interesting reading (PE October). However, there is still an unanswered question. Why did Volkswagen not defend their actions?
The development engineers were faced with an interesting pair of interconnected problems. They had to provide minimum emissions at given operating conditions and maximum performance and fuel efficiency throughout the operating envelope. In the old days with a simple carburettor and distributor a compromise was achieved and accepted.
Now, with all the electronic gadgetry available, these two requirements could be separated and then met individually. This was done successfully and the solution put into production. The resulting performance was found acceptable by everyone who drove the cars.
In a similar situation where a lawyer found a way to circumvent or bypass a regulation the profession would have praised and lauded them. However, when engineers achieved the feat of solving an almost impossible task, the lawyers ganged up and condemned them in an excessively vitriolic manner. I will not be buying a car from the VW group, not because of the widely publicised actions of the engineers but because of the failure of the management to defend and support them.
John S Moore, Holywood, Co Down
An added dimension
In 2014 I wrote to Model Engineer magazine complaining about the poor standard of dimensioning on the drawings supplied to engineers from various sources, and how such ignorance can lead to a waste of time and materials.
Afterwards I was invited to give a lecture on the subject by the Society of Model and Experimental Engineers (SMEE), as the subject is not taught in universities.
My own understanding has let me produce machinery “straight from the drawing board”. In one case I only did the general arrangement of a special-purpose machine and detail draughtsmen did the rest, and the machine still assembled (“fell together” to quote the work-shop foreman) and worked without adjustment. This seems to be a rarity whereas it should be a commonality.
I gave the lecture on the subject of dimensioning and presentation to 60 SMEE members in April 2014. There were drawings to check and score-cards to mark. Despite the members all being experienced engineers, out of a maximum of 70 marks the highest score reached was 48 and the lowest eight.
Afterwards I was asked whether there was a book available about it. I replied I knew of no such book.
I’m pleased to say that my work Understanding Dimensions and Tolerances is now available as an e-book. I would be prepared to present the lecture should any branch desire it.
Geoffrey Johnson
Memorable museum
Thank you for including the Hovercraft Museum in the Worth a Detour series (Back Page, PE March). Indeed, it is worth a detour. My wife and I thoroughly enjoyed it.
The museum hangs together through the efforts of dedicated volunteers. They are doing a great job of preserving engineering heritage and are somewhat up against it. They are wholly reliant on charity and custom.
This is a great day out and I very strongly recommend it.
Simon Shaw, London
On the up and up
When there is any debate on energy demand, it is claimed that increasing energy efficiency will come to our aid. It is a myth that increasing efficiency will cause a reduction in consumption.
There is abundant evidence that higher efficiency increases consumption. Higher efficiency will reduce the cost per beneficial unit, hence it attracts marginal consumers – stimulating greater use.
Evidence can be found in the 2016 Digest of UK Energy Statistics. After several years of reduced consumption following the 2008 financial crisis, there was a 2.9% increase from 2014 to 2015 in the consumption of transport fuels, as the economy returned to pre-crash levels. Jet fuel also increased.
Internal combustion engine efficiency has improved significantly over recent years, but higher efficiencies have permitted drivers to get the same consumption with larger engines. Average engine size has increased, with a growth in vehicles with 3- and 4-litre engines.
Planning for lower carbon emissions has to recognise that human nature will not always align with environmental policy.
Paul Spare, Davenham
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