A friend who is an airline pilot tells me that the addition of winglets to the wingtips tips civil airliners reduces fuel consumption by 5%. Now the fact is that all modern airliners do sport winglets, and the airline operators are not going to add them just to make their planes look good. They are designed to reduce the tip vortex, which is a cause of induced drag.

I can see no reason that the same considerations should not apply to wind turbines. Has the addition of winglets to turbine blades been tried already? Is there some fundamental reason that it doesn't work with turbine blades? It is hard to see what this might be.

It could even be that reducing the tip vortex would reduce bat kill from smaller turbines, since bats might be mistaking the vortex for clouds of insects.

So I took this question to the Wind energy group on LinkedIn, and this is what I picked up:

There are winglets on Siemens 2.3 MW turbines.   They have been introduced in Enercon turbines in different shapes since 1994. If you see the good CP values ( up to 50 %) of this blade design and the low noise values of this turbine types the application of winglets make sense. One  figure given is that winglets increase yield up to 6 %.

Efficiency is very important in wind energy because 1 % yield plus makes approx. 3-4 % revenue plus in wind economics.

Winglets make sense and do improve performance on turbine blades, in a similar manner as on an aeroplane wing, so a number of turbine manufacturers do include them now, though the design is somewhat different to those on aeroplane blades. 

Historically winglets were not included because the flow around a turbine blade tip is highly complex, i.e. due to the radial and turbulent components being relatively large. Another point would be that aircraft blade lengths are constrained by airport infrastructure, so you need to get maximum performance from a fixed blade length. Windturbines on the other hand can achieve improved performance by simply making the blades longer, which might well be the more cost-effective.

Noise reduction is a side effect of good controlled vortex from the winglets. There is a general rule among blade experts, if you hear one blade to be noiser than the others (lightning damage or equal deformation close to the blade tip) you lose approx 1-2 % yield. 

I estimate the effect of winglets to be 1.5-3 dBA in noise reduction . 

Approximately 80 % of the total noise of a turbine is erodynamic born.

So thanks to all on the list who shared information. Very shourtly after setting the question, I noticed winglets on a turbine visible from the Paddington-bristol rail line, ? at Didcot.
 

So wind turbines generally have a 5% inprovement in efficiency to come.

Incidentally, there was an anti-wind troll on the list, who seems possibly to be thought disordered. I am impressed by the frequency anti-wind and climate change "sceptics" show this feature.

The key significant accusation they bring about wind is the low load factor - the poor match between production and consumption. The answer to this is to increase power spread through HVDC lines, and power storage capacity through pumped water, compressed air, batteries (distributed as electric vehicles) and through electrolysis.

Don't Let Osborne Break Wind!

Osborne plans to cut subsidies to wind farms by 25% according to the Observer. This will, of course, kill the UK wind industry, what is left of it, stone dead.

This is an insane decision, and it must be stoppped.

Osborne is aiming a wrecking ball at house our children are going to live in. We must draw a line in the sand over his general destructiveness. His plan is unacceptable. It is economically and ecologically illiterate. He has no concept of investment, of putting money into a project today so that the project will give more money back to you in the future. I wouldn't trust Osborne to run a street party, let alone a national economy.

By killing off  UK wind energy development, Osborne is making certain that in the future, we will be dependent on foreign companies for all aspects of wind energy development.

This will make our balance of payments (ratio of imports and exports) worse than it actually is - and that's bad.

Osborne as Chancellor should know this, so either he is badly informed, unable to comprehend what he is told, or is deliberately trying to sabotage the UK economy. Take your pick.

The fact is that we have the biggest wind resource in the EU. But now that the idiot Osborne is taking anti-windpower propaganda seriously, it is time for us, the Green movement, to force him into another U-turn. Here is the authoritative counter to windpower myths.

There are two strands to the anti-windpower movement. One is that it is a branch of the AGW denial lobby, Quixotically (or psychotically) tilting at windmills because they are a visible manifestation of the low carbon economy. The second strand, exploited by the lobby, is the natural NIMBYism of people in the vicinity of wind farms. This second strand is easily managed by introduction of compensation schemes for neighbours of wind farms. They get lower electricity prices, dependent on how close they are. It's a fair deal, compensation for loss of amenity, that is, for noise and visual intrusion, and is a standard instrument of environmental economics.

Osborne's ill thought out slash at the UK wind industry is a symbol of his total incomprehension of the ecological situation that we are in. He must be stopped. 

Is Nuclear Power cheaper than renewable energy?

This is a letter from the excellent Gerry Wolff in response to yet another claim that nuclear power is cheap, this time in the Sunday Times


THE HIGH COST OF NUCLEAR POWER

Contrary to the often-repeated claim that nuclear power is cheap (“Saving Britain's economy: ditch expensive wind farms”, 6 November), it is one of the most expensive ways of generating electricity. It only seems cheap if we make wildly optimistic estimates of the cost of building nuclear plants, or assume that capital costs have been paid off, and if we ignore the enormous subsidies enjoyed by the nuclear industry all around the world.

Connie Hedegaard, the EU climate change commissioner, says that nuclear power is more expensive than offshore wind power.

The Economist has written that "More than half of the subsidies (in real terms) ever lavished on energy by OECD governments have gone to the nuclear industry."

A report by the Union of Concerned Scientists says that "Government subsidies to the nuclear power industry over the past fifty years have been so large in proportion to the value of the energy produced that in some cases it would have cost taxpayers less to simply buy kilowatts on the open market and give them away."

A report by the Insurance Forum, Leipzig, a company specialising in actuarial calculations, shows that, if the nuclear industry was required to insure fully against the cost of accidents, the price of nuclear electricity would rise by a range of values—€ 0.14 per kWh up to € 2.36 per kWh—depending on assumptions made.

Reports by the Energy Fair group show that nuclear power in the UK today benefits from 7 main types of subsidy, and the Government is proposing more.

Around the world, the average annual growth of wind power in the last 5 years has been more than 27% and the annual growth in solar power has been about 30%. In 2010, the worldwide growth of solar power was a whopping 70%. There is now abundant evidence that renewables can provide robust and reliable supplies of power, they are cheaper than nuclear power, and they can be built very much more quickly than nuclear power.

Instead of clinging to a failed technology of the past, we should be grasping the huge opportunities opening up in the clean, green technologies of the future.

Sincerely,

Dr Gerry Wolff PhD CEng

Energy Fair

www.energyfair.org.uk, 

PriceWaterhouseCoopers endorse Supergrid plan

Europe could meet all its electricity needs from renewable sources by mid-century, according to a report released Monday by services giant PricewaterhouseCoopers.

A "super-smart" grid powered by solar farms in North Africa, wind farms in northern Europe and the North Sea, hydro-electric from Scandinavia and the Alps and a complement of biomass and marine energy could render carbon-based fuels obsolete for electricity by 2050, said the report.

The goal is achievable even without the use of nuclear energy, the mainstay of electricity in France, it said.

Over all, about 50 percent of Europe's energy demand is met with imported fuels.

Under so-called business-as-usual scenarios, that share could increase to 70 percent in coming decades, according to several projections.

The switch to renewables is more than a matter of energy security, said the report, backed by research from the Potsdam Institute for Climate Impact Research and the European Climate Forum, both based in Potsdam, Germany. "Substantial and fairly rapid decarbonisation... will have to take place if the world is to have any chance of staying within the 2.0 degree Celsius (3.6 degree Fahrenheit) goal for limiting the effects of global warming," the report said.

10 African countries threatened by sea storm surges

On this, Dr Stephen Salter tells me in an email that there is evidence that wave power technology, by extracting energy from the sea, tend to resist coastal erosion and even cause beaches to build up. Although the wave power machines are designed to let storms pass over them, it is still the case that by building up beaches, wave power technology will reduce the damage caused by storm surges.

Restoration of the mangroves will also help to protect the seashore. In th eglobal greens' Conference lat year I met a Senegalese guy who had planted thousands of mangroves successfully, aided by his children aged 7 and 8.

!IRIN, the humanitarian news and analysis service of the UN Office for the Coordination of Humanitarian Affairs report that World Bank researchers have crunched population, economic, and elevation maps to analyse which countries are most at risk from storm surges, assuming a one metre rise in sea level (due to climate change).

"A Comparative Analysis of Impacts in Developing Countries, reveals "very heavy potential losses. [which] further strengthen the case for rapid action to protect endangered coastal populations".

The 10 countries with the largest increases in at-risk land area are:

Mozambique - http://www.irinnews.org/Africa-Country.aspx?Country=MZ

Madagascar - http://www.irinnews.org/Africa-Country.aspx?Country=MG

Nigeria - http://www.irinnews.org/Africa-Country.aspx?Country=NG

Mauritania - http://www.irinnews.org/Africa-Country.aspx?Country=MR

Senegal -

Guinea-Bissau -

Cote d'Ivoire -

Gabon -

South Africa -

Somalia -
"

Hope rears its tousled head at Green Party Conference

At Green Party Conference in Blackpool. Got policy through on the financial crisis, conversed with 1000 people, and brain is now unable to process any more information.

There is room for hope. Presentations on energy showed that the human population can meet all its energy needs from the sun, by covering about 2% of the world's deserts with Concentrated Solar Power installations. This is going to mean a bit of an argy bargy with the Desert Preservation Sociey, but I can live with that.

Greens backing Nuclear Power??

I see the Independent has lined up four Greens - Chris Smith, Stephen Tindale, Mark Lynas and Chris Goodall, as converts to the cause of boiling water through splitting uranium atoms.

Would you rather have your electricity from coal, or from nuclear is like the old question, would you rather die by being boiled in a vat of sump oil, or die by lying in the road and have a spiked harrow dragged over you?

The correct response to both questions is "No thanks", or, for non idiot people, "Let us re-frame the question".

It is not a straight choice between coal and nuclear, both of which are as deadly as each other, each in its own special way. There is a third option - a Europe-wide grid of High Voltage Direct Current lines which can distribute renewable energy, from arrays of offshore windfarms the North, to assays of Concentrated Solar Power in the South.

Every day, the sun gives us about 200,000 times as much energy as we humans actually use. Our task is to stop dithering and get busy tapping into that energy. This process, combined with energy conservation (basically, insulation work) will provide a sufficient stimulus to power us out of the recession, provided Government stops fiddling around with bailouts for the investment bankers and grants for the banks motor car industry.

There are 10 strong arguments against using nuclear power to decarbonise our economy. The one that never gets mentioned is that nuclear power stations are not insured, unlike your average motor car. You'd think they would insure them, but the cost of insuring them would make it more expensive than renewables, so they don't.

I am sure that Chris, Mark, Chris and Stephen will be working on a little insurance package for the industry.

Here is my letter to letters@independent.co.uk

While I respect the decision of Green activists who have come to the awesome decision that they must accept nuclear power, I hope they will use their 2p of influence to ensure that the new stations have the cost of insuring the power stations built in to the equation. At the moment, they are insured for less than 1% of the cost of a Chernobyl-type accident, which creates an uneven playing field, since sustainable forms of energy have to carry full insurance against accidents.

Red tape and cuts see householders give up on green grants, MP says | Environment | The Guardian

Red tape and cuts see householders give up on green grants, MP says

Slash Gordon Leaves Planet Earth

"The 2% of our total energy that now comes from renewables is much less than in many other European countries. In the Energy White Paper we announced plans to triple the amount of electricity from renewables by 2015. But as the urgency of tackling climate change and achieving energy security increases, the case for more reliance on renewables has become more compelling. And that is why at the European Council this year Britain led the way to an agreement that by 2020 one-fifth of all Europe's energy should come from renewables, a near threefold increase.

The UK worked hard to get agreement to this target and let me make it absolutely clear, we are completely committed to meeting our share. The European Commission will, as you know, come forward with their proposals for how the overall target is to be divided between member states in January. A final decision is expected in early 2009. We do not yet know therefore what the UK contribution will be but it is clear that over the next decade and beyond Britain will need to raise very significantly the proportion of our energy from renewable sources and we must start planning for this now." Gordon Brown PM 19 November.

And the assembled hacks solemnly enter his words into their spiral bound notebooks, all unaware that this is the Gordon whose Government spend April capping the Low Carbon buildings Programme to £2500 per domestic property, thus slashing the take up of domestic solar heating and PV. His ignorant Government is also resisting a feed in tariff, which is the means used in Germany who have 100 PV domestic cells for every one in the UK?

Alistair's Darling Little Lies

Hooray. The Energy White Paper is out. In it Rt Hon. Alistair Darling MP writes "...we are strengthening our support for renewable electricity...".

So that's why he has slashed the subsidy for domestic photovoltaics by 50-75% then.

Thanks Alistair.

Alistair Darling is an anagram on "Ar, it is Al, dang liar".