Turbine trouble: How does a windfarm affect the local microclimate?
Tell us the cost and risks of energy storage technologies
Thank you for your excellent resumé of storage systems that could provide the missing link for more effective utilisation of the unpredictable renewable energy generators (“Whatever the weather,” PE May).
While you provided a clear description of the technologies, it would be useful to understand associated costs and potential environmental issues. For example, I believe that lithium and lead-based batteries pose significant disposal issues. And what does the overall energy balance look like when you include the energy required to make, support and dispose of these storage devices?
We keep referring to renewables as ‘free’ energy. There is no such thing as a free lunch yet there is little research being undertaken to understand the consequences of removing energy from a natural cycle that has matured over millennia.
There is evidence from the US that windfarms not only result in reduced wind speeds and altered prevailing wind directions downstream but also an increase in the ground temperature as a result of the turbulence created by the turbines. I believe that Plymouth University is also studying the impact of wave-energy systems on surfing.
While the energy removed by human intervention may be small, the number of systems being deployed could have a significant impact on microclimatic conditions as enjoyed by areas such as Cornwall.
Dr Ben Dobson, Newquay, Cornwall
Turn up the heat
It was very good to see the IMechE producing such a useful report on the vital issue of energy storage (“Whatever the weather,” PE May). Energy Storage: The Missing Link in the UK’s Energy Commitments emphasises that the country’s energy demand is 40% heat, 33% transport, and 27% electricity. So let’s think about heat energy.
Given the limitations of biofuel, perhaps the easiest route to switch to non-fossil-fuelled transport is to synthesise fuels that can be burnt in internal combustion engines using high-temperature heat sources directly rather than electricity. (Ammonia is one favoured option not included in the report.) Transport fuels are already expensive because of taxation so perhaps there is room to absorb additional production costs.
If we can generate heat near where it is needed (district heating systems, chemical and other industrial plants), we can eliminate the inherent inefficiency of conversion to electricity. This would make small modular nuclear reactors even more economically attractive when compared to renewables.
With regard to electricity demand, surely any objective reading of the report indicates that the storage options mentioned are far too small and costly for ‘wrong time’ electricity generation from renewables to be viable on a significant enough scale to have much of an impact on climate change.
I hope that a follow-up report includes an assessment of Ambri’s liquid metal batteries. If Professor Donald Sadoway of the Massachusetts Institute of Technology is right, these may have the potential(!) to make renewables a viable option for isolated communities.
Jon Michaelis, Buxton, Derbyshire
Miracle methane
You described the production of hydrogen for storage in the gas grid and claimed that the 360kW Thuga plant is Europe’s largest pilot project for the technology (“Pipe dreams,” PE May).
The article also claimed that the gas grid could be a huge hydrogen tank, despite admitting that the hydrogen content could be only 0.1 to 3%. However the Audi e-gas plant at Werlte has an electrolysis plant of 6MW, and was opened last July. Here the hydrogen is combined with CO2 from a biogas plant to produce methane for the gas grid, so avoiding the leakage and blend-limit issues of hydrogen.
Methane can be used directly in gas-fired power plants and CNG vehicles, and the electrolysis and methanation conversion losses harnessed for heating the biogas plant, as at Werlte, and buildings, as at the Prenzlau power-to-gas plant.
By combining wind turbines with gas-fired plants using power-to-gas methane, the electricity system could reach zero carbon, along with significant contributions to transport fuels and heat.
Gordon Taylor, Ingatestone, Essex
Stop scaring us
Throughout history, science has advanced in three stages, firstly by observation of phenomena, secondly by suggesting a theory to account for the observations, and thirdly accepting the theory if its predictions are correct. If not, the theory is rejected and new theories have to be sought.
With man-made global warming, the first two stages have been completed but its predictions have proved 100% wrong. The theory predicts a steady global temperature rise with increasing carbon dioxide levels. For the last 15 years there has been no rise in temperature in spite of rising carbon dioxide.
Historically, its prediction seems to fail insofar as until two million years ago CO2 levels were 20 times higher than they are now, but the earth has been much hotter and much colder than now, so clearly carbon dioxide is not a major player in controlling the earth’s temperature.
There is anecdotal evidence that in medieval times the temperatures were higher than now, with the Romans growing grapes in the north of England, and farming in Greenland.
If there were not such a great vested interest and scare stories associated with man-made global warming, the theory would have been rejected long ago. How long will it take for us to accept that global temperatures, like the weather, is a chaotic system?
Martin Beaney, Shaldon, Devon
Leave fewer footprints
I was very distressed to read that half of the respondents to your 8 Questions survey are not concerned about their carbon footprint when they fly (PE May).
Even more distressingly, the reason most quoted was that individual actions are “irrelevant in the overall scheme of things”. Does that mean they don’t bother voting either?
Can I please refer them all to read David MacKay’s excellent book Sustainable Energy – Without the Hot Air, which proves that flying is one of the biggest consumers of energy (and producers of CO2) in our western lifestyle. You really are making a big difference when you don’t fly.
The book also outlines other things that individuals can do to make a difference. Finally, I would like to throw in my own recommendation: switch your electricity to a 100% renewable tariff. I was pleasantly surprised to find I saved by switching.
John Anthony, Oxfordshire
Devolve some power
Having returned from spending seven years in Australia, three of them volunteering for the IMechE, I am intrigued by some recent comments about making the institution international.
If the IMechE is to be truly international, a change in the manner in which it conducts its business needs to be examined. My three-point plan is this: devolve subscriptions, professional interviewing and prizes to the branches.
An overseas member has to pay their subscription in pounds sterling to the UK. It is held in central funds and a proportion is sent back to the branch to use as required. Apart from being administratively intensive, this causes some heartache. A member has to pay an international money transfer fee. And the money the branch gets back for them is pitiful.
In Australia the branch gets sufficient funds to buy each member four cups of coffee a year. With this funding, the branches are expected to carry out events and competitions to the same level of excellence as the rest of the institution.
If subscriptions were devolved to branches they could be paid in local currency. This would remove the need for administration from the institution and the international transfer fees. In return, branches would pay a retainer to the IMechE to cover administration and online libraries.
At present, the paperwork for a prospective member goes to the UK, where it is analysed by some members, before being sent to the branch for an interview to be organised. Following the interview, the paperwork, endorsed now by UK members and the overseas interview team, goes back to the UK to be endorsed again by more UK members who have not met the candidate, before the candidate gets told whether they have been successful.
It’s ridiculous. The involvement of the UK is superfluous. It has created a perception that members within the membership teams in the UK are greater than the lesser mortals doing the interviewing.
Why does a committee which has not met the candidate have to check the work of the interviewers and the original paperwork analysis team? I would ditch the committee’s function and let the interviewers on the day decide.
IMechE prizes are controlled by the UK. If subscriptions were devolved to branches, prizes could be given in local currency, and there would be the opportunity to develop more prizes for competitions suited to the local scene.
Chris Hoskin, York
Railway worry: The electrification programme could be derailed by the skills shortage
Switch on to railways
I read “Wiring up the network” with great interest as I am one of the nine conversion engineers mentioned in the article (PE May). The scale of rail electrification work to be delivered over the next 5-10 years is staggering. This work will only be completed successfully if the right people with the right skills are in place, and lots of them. At present, in terms of engineering resources, there are gaps everywhere one looks, whether in design, project delivery, or maintaining the assets after they are built.
The back-up and training provided by Network Rail and its suppliers through the conversion scheme is first-rate, and I believe huge opportunities exist for any engineers who may want to make the leap from another industry.
My worry is that this is not being marketed effectively by the rail industry. The very word ‘electrification’ may be enough to put some off that may be ideally suited, wrongly assuming that an electrical background is required to work with the overhead catenary equipment, which is essentially a mechanical system mounted on steel structures.
Much more needs to be done to recruit the engineering skills we desperately need.
Tim Nichols, Droitwich Spa, Worcs
Export opportunities
Working in a UK aircraft company in 1980, following analysis of the potential of producing wind-power generation systems, it was concluded that they would be quite uneconomic in operation. The company dropped the idea.
Hydro-power, however, was seen to be much more effective and economic and has far less environmental problems. Water is 1,000 times more dense than air and so will produce 1,000 times more power from the same flow rate. It is more reliably available.
It is not necessary to completely barrage-off a river. A lagoon formed on either side, containing modular-mounted bi-directional-flow turbines, is all that is needed. The gap between, spanned by a road bridge, would allow shipping to pass.
If, as in the case of the Severn estuary, it is desirable to incorporate flood prevention measures for the upper reaches, a removable barrier such as in the Thames could be incorporated.
In vulnerable coastal areas, flooding protection measures could be combined with hydro turbines. The UK is served by plentiful supplies of tidal water. Let us make good use of it.
Such systems, made in the UK, could be exported to the benefit of our economy.
Also in the 1980s, the UK pioneered unmanned aircraft, proven to meet civilian airworthiness requirements, and demonstrated them successfully in civilian applications in several countries. Thirty seven of those countries wished to purchase them. Unfortunately, export was prevented by UK authorities.
Yet another opportunity for British industry was wasted.
Reg Austin, Bracknell, Berkshire
Time for a pay rise
We should not be surprised over the lack of guidance regarding engineering as a career (Training and Education News, PE May).
It is much harder to qualify as a chartered engineer than it is to become a fully registered medical doctor or a lawyer. In addition, the status and respect given to engineers is far behind that awarded to doctors, lawyers, dentists and many more professionals.
Engineering salaries, at all levels, are so low that advertisers are loath to show them (not one of the job adverts in the May issue of PE states a salary).
As a district councillor, I am fully aware of the salaries paid to local government middle managers, let alone the higher managers. There are many jobs around for which no formal qualifications are required, but which pay grotesque salaries.
Last year, having started out as a graduate back in 1963, I received a certificate from the IMechE recognising my 50 years as a member. I did not however get a letter saying that, in recognition of that long service, I would no longer have to pay my membership fee!
All of this confirms my belief that I should have entered another profession and not engineering. Why choose to become an engineer?
Terry Mullard, Dymchurch, Kent
Catch them young
Your recent editorials have struck a chord with me. I echo calls for more engineers and scientists to try to get more youngsters into the profession.
Many companies encourage staff to do so and give them time in which to volunteer. There is nothing more satisfying than seeing science and engineering generate a spark of interest and excitement in younger children.
I would like to draw readers’ attention to the Stemnet network which is sponsored by government and has centres covering the UK. It organises contact between volunteer engineering ambassadors and schools, and deals with training and DBS certificates that are needed for working with children.
My local centre is now at the University of Reading but previously the role was held by Surrey Satro which is a charity funded by local industry. I have volunteered with them for 14 years. I have focused on trying to interest children at primary school level in science and engineering.
The range of activities that can interest children is wide, including water rockets, fruit batteries, wind-driven land yachts, and electric circuits. I specialise in bringing the wonders of pulleys and cranes to six-year olds, who find they can lift quite heavy weights, and sometimes their teacher. They can be introduced to computer programming with the Lego Dacta equipment.
With every class, I make sure they understand what an engineer does, and all the important things they would not have if there were no engineers – cars, bikes, TVs, computers, and so on.
Tony Kimber, Wraysbury, Staines