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by Jan Rocha

Brazil’s indigenous harness the wind

May 11, 2013 in Development Issues

EMBARGOED until 2301 GMT on Friday 10 May

Mount Roraima, inspiration of The Lost World Image: Paulo Fassina

Mount Roraima, inspiration of The Lost World
Image: Paulo Fassina

By Jan Rocha

While Brazil’s Government tends to favour a one-size-fits-all approach to energy provision, an indigenous group in the far north has come up with its own more sustainable solution, as our São Paulo correspondent reports. 

SAO PAULO, 9 May – A few years ago I lay in a hammock in a mud and wattle hut in a Makuxi village, shining my torch on the walls to look for spiders, listening to the BBC World Service on my radio (I learnt that Labour leader John Smith had died). There was no light – the noisy diesel generator which provided a few hours energy each day was turned off at night.

The Makuxi, one of Brazil’s largest indigenous communities, with about 19,000 people and 140 villages, inhabit an area of savannah and sierras in the far northern state of Roraima, sharing  borders with Venezuela and Guyana.

Their land, which was offically recognised by a Supreme Court ruling only in 2009, after years of conflict with invading goldminers, cattle ranchers and rice farmers, stretches to the foothills of the imposing Mount Roraima, a table top mountain with sheer cliffs rising 9,000 feet (2,750 m) high.

This was the mountain that inspired Arthur Conan Doyle to write The Lost World, published one hundred years ago. In the book, prehistoric creatures still roamed the plateau of a remote table mountain. The Makuxi, however,  are more concerned with today’s problems than yesterday’s myths.

After the illegal occupiers had been expelled, they began the task of  restoring land and rivers contaminated by years of  pesticides. And they are now looking for ways to replace the old diesel-powered generators with renewable sources of energy. The nearest power grid is 185 miles (300 kms) away.

Planning for sustainability

 

The Brazilian Government has a programme to bring electricity to rural communities which is called Light For All, and it is considering building a number of dams inside the Makuxi reserve.

But the Makuxi have come up with another idea. The Brazilian Atlas of Wind Potential shows that the northern region of their reserve, Raposa-Serra do Sol, enjoys some of the strongest winds in the country, with speeds of up to 11 metres per second being registered, and an average of six to nine metres.

So in February three towers were installed to measure the winds over the period of  a year, in order to calculate the potential  for generating  energy. The project is the result of a three-way partnership between the Indigenous Council of Roraima (CIR),  the Socioenvironmental  Institute (ISA), one of Brazil’s largest NGOs, and the Federal University of  Maranhão (UFMA).

The towers were installed by the Makuxi themselves. They also plan to map the energy needs of each family in their communities. A team of 14 indigenous researchers is travelling round the villages with GPS equipment and questionnaires.

They hope the energy to be generated will be enough, not only for domestic consumption, but also for the agricultural activities they are also preparing, as part of their plan to develop their reserve sustainably.

Too many helpers

 

The Makuxi do not want to repeat the experience of the other large indigenous community in Roraima, the Yanomami. Several years ago the German Government’s development agency donated solar panels for a health post and other buildings in their area. But none of the Yanomami were trained to maintain them.

Carlo Zaquini, an Italian missionary who has worked with the Yanomami for decades, told me what happened: “Over the years the panels developed problems, but because none of the Yanomami knew how to repair them, every visiting outsider, whatever his speciality, has had a go at tinkering with them, so now they don’t work at all.”

Once they have the results of the wind speed study the Makuxi hope to persuade the Government that harnessing the region’s powerful winds will be a more sustainable solution than hydropower, which researchers now conclude also produces carbon emissions.

The Makuxi’s extraordinary wind power potential, favoured by their terrain of savannah and mountains, is probably unique among Amazonian indigenous populations.

Solar energy – with local people trained to maintain the equipment – seems a much more feasible solution for rainforest communities. So far the Brazilian Government, committed to a gigantic programme of  dam building, has shown little interest in these more modest solutions. Backing from NGOs is probably the only way to make them happen. – Climate News Network

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Avatar of alex kirby

by alex kirby

China ‘moving to lead on climate change’

April 28, 2013 in Mitigation

EMBARGOED until 1401 GMT on Sunday 28 April

That was then... China is cleaning up its act fast Image: High Contrast

That was then… China is cleaning up its act fast
Image: High Contrast

By Alex Kirby

The world’s two greatest emitters of greenhouse gases, China and the US, earn high praise for their efforts to tackle climate change from an Australian report. But it says much more radical global action is urgently needed.

LONDON, 28 April – Both China and the US, the world’s two principal emitters of greenhouse gases, have been making significant recent progress on tackling climate change, a report by an influential Australian advisory group says.

Its report, The Critical Decade: Global Action Building on Climate Change, has particular praise for China, saying its efforts “demonstrate accelerating global leadership”.

The other “energy giant”, the US, is also commended for showing “a new commitment to lead”. The report says the US “appears to be gaining momentum with President Barack Obama outlining his strong intent to address climate change…”

The report is the work of the Australian Climate Commission, an independent body set up in 2011 to provide authoritative and trustworthy information on climate change science and solutions.

Its authors are Professor Tim Flannery, chair of the Commission, Gerry Hueston, former CEO of BP Australasia, and Roger Beale, an economist and former Secretary of the Australian Department of Environment.

The report says China and the US, the world’s two largest economies which together produce about 37% of world emissions, are both on track to meet their international commitments on climate change, something they said in this month’s “historic agreement” they would tackle together. “Today the energy giants are undoubtedly on the move, which will fuel global momentum.”

Halving electricity demand

 

China earns praise for several reasons. It is reducing its emissions growth, and in 2012 cut the carbon intensity of its economy more than expected. After years of strong growth in coal use, the rate of growth has declined substantially. It is also “the world’s renewable energy powerhouse”.

Professor Flannery says: “China has halved its growth in electricity demand… [and] is quickly moving to the top of the leader board on climate change.”

Emissions have also been declining in the US, which is on track to meet its goal of cutting them by 17% on 2005 levels by 2020. The authors note that the economic downturn and a shift away from coal to gas have helped here.

Global progress on renewable energy Image: Climate Commission

Global progress on renewable energy
Image: Climate Commission

The report says every major economy is tackling climate change, introducing policies to drive down emissions and encouraging renewable energy.

But in a section headed “This is the critical decade for action”, it says the significant progress made so far is not enough. “Globally emissions are continuing to rise strongly, posing serious risks for our society. This decade must set the foundations to reduce emissions rapidly to nearly zero by 2050.”

The scale and the pace of the changes needed to reduce emissions as drastically as that – something which many scientists insist is vital – is a huge challenge, and many countries appear on present trends very unlikely to meet it.

A report in the Sydney Morning Herald on 26 April, headlined “Japan turns back to coal-fired power plants”, included this observation on the country’s post-Fukushima prospects: “…with the government considering the closure of much of the installed nuclear capacity over the medium term, the spotlight is back on coal as the cheapest energy source, notwithstanding plans to cut carbon emissions.

“A commitment to slice 2020 carbon emissions by 25 per cent from their 1990 level will be revised by October, according to Japanese newspaper reports.”

Action needed now

 

The Australian report’s praise for China and the US commends their recent performance – or at least their stated intentions – in comparison with their past records. But they will need to do far more than show the relative improvement the Commission recognises.

If the Earth is still to have any chance of staying below the 2°C global average temperature rise which most governments say is essential to prevent dangerous climate change, the energy giants (and the rest of the world) will have to make vastly greater absolute progress.  – Climate News Network

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Avatar of Paul Brown

by Paul Brown

Solar link will bridge Mediterranean

April 16, 2013 in Energy

EMBARGOED until 2300 GMT on Monday 15 April

Concentrated solar power in Hawaii: New technology is opening doors for renewables Image: Xklaim

Concentrated solar power in Hawaii: New technology is opening doors for renewables
Image: Xklaim

By Paul Brown

Renewable energy is rapidly becoming a much more serious possibility, as novel technologies come of age and offer the prospect of a new relationship between Africa, the Middle East and Europe.

LONDON, 16 April – The world’s largest concentrated solar power plant opened in March in the middle of Abu Dhabi’s western region, amid the country’s giant oil fields.

The $600m plant’s hundreds of mirrors direct sunlight towards pipes full of oil to drive steam turbines that in turn provide enough electricity for thousands of homes.

In a country whose vast wealth is generated by oil, adopting a new technology that produces only 100 megawatts of power – about a tenth the amount of a large coal-fired plant – may seem a mere token, but it is part of a much larger industrial strategy for the region.

Serious money and political clout in Europe, the Middle East and North Africa is aimed at building hundreds of similar plants. The potential is so great that all the electricity requirements of these desert countries – and a good slice of Europe’s – could be met by 2050.

European companies are now putting serious investment into a scheme to bring electricity from North Africa across the Mediterranean to their shores.  Algeria, Egypt, Libya, Morocco and Tunisia are among the Saharan countries that could provide all their own power and much of Europe’s.  Morocco and Tunisia are already building plants, and Morocco has an electricity connector to Spain.

It has long been known that harnessing the power of the sunlight that shines on a few hundred square miles of desert would be enough to provide electricity for all of mankind’s needs. How to collect the power and transport it was the problem. Now both technical barriers to development have been solved with a variety of schemes.

The Abu Dhabi plant that uses mirrors is one of a number of similar ideas that arrange reflectors to concentrate the Sun’s rays to make electricity. Several have now been proved to work commercially – and the price of power continues to come down. These plants are in operation in many sunny parts of the world including California, Spain and Australia.

Night light

 

Photo-voltaic cells that make electricity direct from sunlight are even more prevalent, with the price of panels also continuing to fall. Add to the power of sunlight the fact that many desert areas are also windy, and the potential for power production is huge.

A factor that has previously worried investors is that even in the desert the Sun does not shine at night, when much of the electricity is needed. To get round that a system has been developed to store excess heat in molten salt and use it to generate electricity after dark. The wind turbines in the desert built alongside the solar arrays would of course continue to pump out power at night.

The next problem – how to transport electricity from isolated areas with low populations to the cities that need it – is also solvable. Modern super-conducting cables using direct power can transport electricity across 3,000 kilometres, losing only 3% of their power per 1,000 kilometres.

These cables, developed in Europe, are not theoretical: they are already in use in China. Super-conductors could be laid across the Mediterranean so that North African sunshine could power Europe.

The organization that aims to create a super-grid across North Africa, the Middle East and Europe to utilize this resource, Dii, accepts that the problems are not just technical but also political.

Some of the countries with the greatest solar resource that would need to be connected to each other to make maximum gains from the technology are not good friends.

Local use comes first

 

This would make a super-grid difficult to construct, and electricity supplies liable to disruption if disputes broke out. Power plants would also be easy targets for terrorists.

There are other political sensitivities. The European Union, and particularly Germany, which is very keen on the idea of exploiting this renewable resource, are anxious that Africa and the Middle East should feel ownership of the projects rather than that they are being leant on to cooperate.

European politicians feel it is important that these countries should also be the first to get the benefit of the solar power stations with the electricity being used locally, and only surpluses exported across the Mediterranean.

There are now 36 partners in the Dii project, with most of the money and expertise coming from Germany and other large European manufacturers. According to the German Aerospace Centre, investment would need to be €400 billion by 2050 in plants and transmission lines to realize the dream of providing the entire electricity supply for North Africa and 15% of Europe’s needs.

Studies have shown that even with transmission losses it is cheaper to construct solar plants in North Africa than in southern Europe. This is partly because the Sun shines from 3,000 to 3,500 hours a year, with greater intensity than in Europe, but also because there are large tracts of unused land for the construction of fields of mirrors or lenses to concentrate the solar rays.

Lack of water to clean the mirrors, and for cooling, is one of the technical problems still to be overcome. But like all newer renewable technologies, the cost of concentrated solar power is expected to fall because of mass production and to be considerably cheaper than rivals like nuclear power. What is needed is the political will to make it work. – Climate News Network

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Avatar of Tim Radford

by Tim Radford

Renewables burn a little brighter

April 13, 2013 in Energy

FOR IMMEDIATE RELEASE

Not just portable power, but storable as well: A step forward for renewables? Image: Foncesoulstudio

Not just portable power, but storable as well: A step forward for renewables?
Image: Foncesoulstudio

By Tim Radford

The prospects for some forms of renewable energy look brighter after scientists said they had found ways to store excess power and to take carbon dioxide straight from the atmosphere to make fuel.

LONDON, 13 April – Researchers in North America claim to have found two new ways to deliver power to the people – and reduce the global carbon footprint.

One team hopes to produce a low-cost, efficient technique for storing the surplus energy from wind power, or the solar panels on the roof. The other team hopes to deliver biofuels from the carbon dioxide in the air without even troubling the photo-synthesising plants that have, for the last half a billion years, taken on the task.

The first advance is from chemists at the University of Calgary in Canada, who report in the journal Science that they have found new catalysts that could convert electrical energy, which cannot be simply stored, into chemical energy, which can.

This is a serious problem for renewable suppliers. On a sunny day, photo-voltaic cells deliver generous quantities of power, but on a sunny day, fewer people need to turn on the central heating or use the electric lights.

Wind turbines can generate whenever there is wind, but on a still, frosty day, they deliver little or nothing to shivering households. If the turbines could pump water that could be used later for hydro-electric power, that would be a solution, but if the consumers already had generous hydro-electric sources, they wouldn’t need wind turbines anyway.

But Curtis Berlinguette and Simon Trudel at Calgary have thought of another way of using water. Fuel cells use electric current and catalysis to drive a reaction that splits water into hydrogen and oxygen that can be stored separately as fuels and then reconverted back into water at any time, delivering generous quantities of energy that can be turned into electricity.

There would be no exhaust, and no pollution, no carbon dioxide emissions and, in theory, no loss of water in the process.
The catch so far has been that catalysis has depended on rare, expensive and toxic crystalline minerals.

The Calgary team report that they have driven a successful reaction using a new family of electro-catalysts made out of cheap, safe, amorphous mixed metal oxides of iron, cobalt and nickel (an oxide of iron, of course, is also known as rust: never a rare commodity). These, they say, perform as well as any catalysts now on the market, but are a thousand times cheaper.

Still to be proved

 

“We are essentially showing, even with our first generation of catalysts, we are equal to or better than anything that’s sold commercially right now after 30 years of development”, says Trudel. The duo have patented the process and created a university spin-off company called FireWater Fuel Corporation.

They foresee small household energy systems no bigger than a home freezer, running on a few litres of water. They hope to be testing a prototype before 2015.

These are large claims, yet to be tested in the marketplace. An even bigger claim, and still a very long way from the marketplace, comes from the University of Georgia in Athens in the US, where Michael Adams and colleagues have developed a micro-organism that absorbs carbon dioxide and generates stored energy in the form of tissue.

They report in the Proceedings of the National Academy of Sciences that they have genetically manipulated a new strain of Pyrococcus furiosus that lives on carbohydrates in superheated ocean waters near geothermal vents.

They have adjusted its metabolism to make it capable of feeding on carbon dioxide at much lower temperatures. They believe that they could use it to generate other useful products, including fuel, from carbon dioxide.

Anyone who burned biofuel would be putting back into the atmosphere only the carbon dioxide that had been recently removed from it and stored in the organism’s tissue: that is why ethanol fuel from sugar cane or maize husks is described as carbon-neutral.

“What this discovery means is that we can remove plants as the middle man”, said Adams. “We can take carbon dioxide directly from the atmosphere and turn it into useful products like fuels and chemicals without having to go through the inefficient process of growing plants and extracting sugars from biomass.” – Climate News Network

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Avatar of Tim Radford

by Tim Radford

Wind power ‘has inescapable limits’

April 9, 2013 in Energy

EMBARGOED until 2301 GMT on Tuesday 9 April

A little too close for comfort? Wind turbines need space Image: Stan Shebs

A little too close for comfort? Wind turbines need space
Image: Stan Shebs

By Tim Radford

Wind power is undoubtedly valuable for generating electricity, but researchers say they have found evidence that the more you use the resource, the less of it there is.

LONDON, 9 April – The wind blows almost everywhere, but its power to turn turbines may have been overestimated, according to US scientists.

Amanda Adams from the University of North Carolina and David Keith of Harvard suggest that large-scale wind farms may create conditions that would ultimately limit their capacity to fulfil demand.

The problem, they warn in Environmental Research Letters, is not one of economics, or engineering: it is one of atmospheric physics. When a steady wind slams into a blade and keeps it turning, it transfers energy to the blade, and thence to the turbine. That slows down the wind.

Because each turbine carries a “wind shadow” beyond it, wind farm entrepreneurs have to compromise: they need to space their turbines as far apart as possible, given that it makes sense to erect as many turbines as possible on the limited land available.

That is, output is going to depend on calculations involving both capacity and density. The usual rule of thumb is that a wind farm could sustain production rates of 2 to 4 watts per square metre. Over a square kilometre, that is 2-4 megawatts.

Adams and Keith calculate that, in wind farms bigger than 100 square kilometres, generating capacity is more likely to be limited to one watt per square metre, because of the local drag on winds. In effect, harvesting the resource also reduces the resource.

There are other problems. Wind farms change the natural wind shear and produce turbulence; they also – consistent with the logic of thermodynamics – affect local temperatures.

“It is easy to mistake the term renewable with the term unlimited when discussing energy”

She and Keith based their findings on a series of simulations involving modest, medium-sized and very large notional wind farms studded with hypothetical turbines at varying intervals, in various regions of the US, and using global forecasting system final analysis data over specific 10-day periods in winter and summer to provide the wind levels.

The results showed that, for large wind farms, it would be difficult to sustain wind power production with a power density of much more than 1.2 watts per square metre.

“It is easy to mistake the term renewable with the term unlimited when discussing energy,” said Adams. “Just because you can keep generating new energy from a source does not mean you can generate energy in an unlimited amount.”

These cautious conclusions run counter to a much more hopeful scenario reported by Climate News Network in January – that, in theory at least, renewable sources could provide more than 99% of American needs.

They are also countered by some positive findings from Germany in the last few days. And the Earth Policy Institute recently reported that Iowa and South Dakota in 2012 got almost 25% of their electricity needs from wind power. Wind provided at least 10% of electricity generation in seven other states.

The US, says the institute, now has 60,000 megawatts online, enough to meet the needs of 14 million homes, and developers scrambled to complete wind farm construction before the end of 2012, to qualify for federal wind production tax credits that were scheduled to expire in December. – Climate News Network

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Avatar of Paul Brown

by Paul Brown

Linked renewables avoid blackouts

April 4, 2013 in Energy

FOR IMMEDIATE RELEASE

Solar power in Spain: Linked systems mean renewables can deliver Image: Koza1983

Solar power in Spain: Linked systems mean renewables can deliver
Image: Koza1983

By Paul Brown

 German researchers have found a way to overcome one of the problems with renewable energy – the fact that it is not always available – by linking different options in a unified system.

LONDON, 4 April – Critics of renewables have always claimed that sun and wind are only intermittent producers of electricity and need fossil fuel plants as back-up to make them viable. But German engineers have proved this is not so.

By skillfully combining the output of a number of solar, wind and biogas plants the grid can be provided with stable energy 24 hours a day without fear of blackouts, according to the Fraunhofer Institute for Wind Energy and Energy System Technology (IWES) in Kassel.

For Germany, which has turned its back on nuclear power and is investing heavily in all forms of renewables to reduce its carbon dioxide emissions, this is an important breakthrough.

The country has a demanding industrial sector that needs a large and stable electricity supply, and some doubted that this could be achieved in the long term without retaining nuclear or large fossil fuel plants.

Solving the problem is becoming urgent. The latest figures show that on some days of the year the electricity being generated from sun, wind, biomass, water and geothermal production already accounts for more than half of the load required in the country.

The research is funded by the German Federal Ministry of the Environment and is aimed at showing that the entire electricity grid could be run on renewable energy.

Dr. Kurt Rohrig, deputy director of IWES, said: “Each source of energy – be it wind, sun or biogas – has its strengths and weaknesses. If we manage to skillfully combine the different characteristics of the regenerative energies, we can ensure the power supply for Germany.”

The idea is that many small power plant operators can feed their electricity into the grid but act as a single power plant using computers to control the level of power (see our story of 20 January, Renewables: The 99.9% solution).

Sharing the load

 

Scientists linked together 25 plants with a nominal power output of 120 megawatts. Surplus power could be used for charging electric vehicles and for pumped storage (pumping water uphill into a reservoir to produce hydropower later).

When many small producers work together, then regional differences when the wind blows or the sun is intermittent are balanced out in the grid and can be boosted by controllable biogas facilities.

If there is too much surplus energy then the power can also be used to create and store thermal energy to be used later.

Kasper Knorr, the project manager for the scheme, which is known as the Combined Power Plant2 research project, says the idea is to ensure that the consumer is supplied reliably with 230 volts at a frequency of 50 Hertz.

The current system of supplying the grid with electricity is geared to a few large producers. In the new system, with dozens of small producers, there will need to be extra facilities at intervals on the system to stabilize voltage. Part of the project is designed to find out how many of these the country will need.

The project has the backing of Germany’s large and increasingly important renewable companies and industrial giants like Siemans.  Researchers will be demonstrating the system at the Hanover Trade Fair from April 8 to 13. – Climate News Network

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Avatar of alex kirby

by alex kirby

Africa’s energy ‘can drive its growth’

March 18, 2013 in Energy

FOR IMMEDIATE RELEASE

Mobile needing a charge? Here's the answer, Burkina Faso-style Image: Nathalie Bertrams

Mobile needing a charge? Here’s the answer, Burkina Faso-style
Image: Copyright Nathalie Bertrams

By Alex Kirby

Paying Africa’s people to produce all the renewable energy they can would give the continent a huge economic boost, spurring development and the growth of democracy, researchers say.

LONDON, 18 March -  Africa can go a long way towards lifting itself out of poverty and ending its chronic shortage of energy by using its own resources, a report says.

The report, entitled Powering Africa through Feed-in Tariffs – advancing renewable energies to meet the continent’s electricity needs, says renewable energy feed-in tariff policies (REFiTs) can unlock renewable energy development in Africa.

REFiTs encourage investment in generating renewable energy – by individual home owners and communities as well as institutional investors – by guaranteeing to buy all the electricity produced from renewable sources.

The report is based on analysis of existing and planned REFiT policies in 13 African countries (see end for list). It is the work of the World Future Council and the Heinrich Böll Foundation, with the support of Friends of the Earth UK.

It says that, when tailored to local conditions, REFiT policies successfully increase the overall energy production of areas both on and off the electricity grid.

Their decentralised nature, it says, provides an opportunity to empower communities and to revitalise local democracy and self-governance by allowing for alternative models of ownership and governance. And, of course, they do not cause emissions of harmful greenhouse gases, being based on technologies like wind and solar power.

The authors say REFiTs have helped to increase the use of renewable technologies worldwide, with 65 countries implementing some version of the policy by 2012.

The golden thread

 

Most of the installations that have resulted are in industrialised countries, particularly in Europe, but the report says Africa still has significant untapped renewable energy potential.

World Bank research has shown that fewer than 25% of households in sub-Saharan Africa have access to electricity, with the figure falling to 10% in rural areas.

The UN Secretary-General Ban Ki-moon has described renewable energy as “the golden thread that connects economic growth, social equity and a climate and environment that enables the world to thrive”.

Many of the countries examined in the report have low levels of electrification and rural populations which are widely dispersed. But the report says REFiTs can serve decentralised mini-grids, which also encourage greater levels of democratic control and ownership.

Referring to one of the countries featured in the report, Ansgar Kiene, director of the WFC Africa office, said: “Tanzania had already opened its electricity market to independent power producers back in 1992.

“Its experience with mini-grids in particular should be seen as an advantage when it comes to drafting supportive frameworks for accelerated renewable energy production. However, the lack of long-term, low-interest financing has been, and remains, a key challenge.”

The authors acknowledge that broader problems can complicate the adoption of REFiTs. One is the need of developers for access to affordable financing options and to locally available technical expertise.

Welcome for subsidies

 

Governments must balance the need to keep energy prices low with the requirement to offer sufficiently profitable tariff rates to attract private investment.

The report identifies a number of national and international measures that can help to shift financial resources towards renewable energy uptake. These include levies on fossil fuels and contributions from the United Nations’ Green Climate Fund.

It says high-level political support for REFiTs is essential, and urges models of South-South co-operation to overcome obstacles. Civil society coalitions can help to produce policies which will be resilient to political change.

The report urges policy makers to be very clear what it is they really want to achieve, as REFiTs offer more than one benefit. It says subsidies for low-income households are important, and that rich and energy-intensive users of the schemes should cross-subsidise affordable tariffs for the poor.

Kulthoum Omari, sustainable development programme manager of the Heinrich Böll Foundation Southern Africa, said: “REFiTs are most successful when they are an integral part of a country’s wider development strategy.

“High-level political support and strong buy-ins from civil society and the private sector are crucial factors for the successful development and implementation of a REFiT.” – Climate News Network

Countries included in the report are: Algeria, Botswana, Egypt, Ethiopia, Ghana, Kenya, Mauritius, Namibia, Nigeria, Rwanda, South Africa, Tanzania and Uganda.

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by alex kirby

Offshore wind at risk from wave power

March 2, 2013 in Energy

EMBARGOED until 0001 GMT on Saturday 2 March

Going up: But might it come down too soon? Image: Jamie R Mathlin

Going up: But might it come down too soon?
Image: Jamie R Mathlin

By Alex Kirby

Offshore wind turbines are vulnerable to sudden and catastrophic destruction in moderately stormy seas, according to new research.

LONDON, 2 March – Wind turbines are at constant but unpredictable risk of being snapped in pieces like matchsticks by medium-sized waves, a researcher has found.

“The problem is, we still do not know exactly when the turbines may break”, says Professor John Grue from the Department of Mathematics at the University of Oslo, Norway.

In 1989 Grue, a leading wave researcher, discovered a phenomenon called ringing, which is a type of vibration that occurs when choppy waves strike marine installations.

So far scientists have studied ringing only in small and large waves, but it now appears to be more common in medium-sized waves.

For marine turbines with a cylinder diameter of eight metres, the worst waves are those that are more than 13 metres high and have an 11-second interval between them. These waves occur in even small storms, which are fairly common off the Norwegian coast.

The ringing problem may increase significantly, because there are plans to build tens of thousands of offshore turbines.
“If we do not take ringing into consideration offshore wind farms could lead to financial ruin”, Grue told Apollon, Oslo University’s research magazine.

The largest offshore wind farms are off the Danish and British coasts, though these are small scale compared with installations planned in the area of the Dogger Bank, out in the North Sea.

Oil industry also at risk

 

So far it has not been possible to use an actual turbine to measure the force exerted by ringing. But Grue says laboratory measurements show the biggest vibrations occur just after the wave has passed, not when it strikes the turbine.

Immediately after the crest of the wave has passed, a second force hits the structure and it’s this which creates the ringing. “If that resonates with the structural frequency of the turbine, the vibration will be strong… This increases the danger of fatigue”, says Grue.

Estimates of the damage caused by ringing are not yet reliable enough to allow an accurate calculation of the material fatigue that it produces, says Grue. “Ringing is very difficult to measure -  there is great uncertainty.”

Scientists also need to consider whether the turbines are in deep or shallow water. “The structural frequency also depends on conditions on the seabed. You can compare it with a flagpole in a storm, which vibrates differently depending on whether it is fixed in concrete or in soft ground.”

Ringing does not harm wind turbines alone. It is already a big problem for the oil industry. The designers of one oil platform did not take ringing into account, and lost NOK 12 billion (US$ 2.1 bn), says Grue.

“It’s possible to build your way out of the ringing problem by strengthening the oil rigs. But it doesn’t make financial sense to do that with turbines.”

Many advocates of wind power argue in favour of siting turbines offshore, where they tend to attract less opposition and there’s space to place wind farms far apart (see our story of 27 February, Wind power ‘may be less than thought’. Professor Grue’s research suggests that siting farms at sea could give rise to serious problems. – Climate News Network

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by alex kirby

Wind power ‘may be less than thought’

February 27, 2013 in Energy

EMBARGOED until 0001 GMT on Wednesday 27 February

Danish turbines: wind farms need plenty of space Image: Mariusz Paździora

Danish turbines: wind farms need plenty of space
Image: Mariusz Paździora

By Alex Kirby

The world may have to revise downwards its expectations of the contribution wind energy can make to to a less carbon-reliant world, a study says.

LONDON, 27 February – Wind power may in some conditions manage to produce less energy than its supporters believe it can, two US researchers suggest.

In the latest contribution to the debate over wind’s potential,  they say they have found evidence that some of the largest wind farms may cause effects which substantially reduce their generating capacity.

The research, published in the journal Environmental Research Letters, suggests that the generating capacity of large-scale wind farms has been overestimated.

Each wind turbine creates behind it a “wind shadow” in which the air has been slowed down by drag on the turbine’s blades. The ideal wind farm strikes a balance, packing as many turbines onto the land as possible, while also spacing them far enough apart to reduce the impact of these shadows.

But as wind farms grow larger, the researchers say, they start to interact, and the regional-scale wind patterns matter more. This means we may not manage to obtain as much wind power as scientists had thought.

The authors are David Keith, professor of applied physics at the Harvard school of engineering and applied sciences and Amanda S. Adams, assistant professor of geography and earth sciences at the University of North Carolina at Charlotte.

Professor Keith’s research has shown that the generating capacity of very large wind power installations (larger than 100 square kilometers) may peak at between 0.5 and 1 watts per square meter. Previous estimates, which ignored the turbines’ slowing effect on the wind, had put that figure at between 2 and 7 watts per square meter.

“One of the inherent challenges of wind energy is that as soon as you start to develop wind farms and harvest the resource, you change the resource, making it difficult to assess what’s really available”, says Professor Adams.

Recognising limits

 

“If wind power’s going to make a contribution to global energy requirements that’s serious, 10 or 20% or more, then it really has to contribute on the scale of terawatts in the next half-century or less”, Keith adds. A terawatt (TW) is one trillion watts. In 2006 energy use worldwide amounted to about 16 TW.

Keith says: “Our findings don’t mean that we shouldn’t pursue wind power – wind is much better for the environment than conventional coal – but these geophysical limits may be meaningful if we really want to scale wind power up to supply a third, let’s say, of our primary energy.”

“The real punch line is that if you can’t get much more than half a watt out, and you accept that you can’t put them everywhere, then you may start to reach a limit that matters.”

To stabilize the climate, he estimates, the world will need to find sources for several tens of terawatts of carbon-free power within a human lifetime. In the meantime, policymakers must also decide how to allocate resources to develop new technologies to harness that energy.

Keeping their distance

 

In doing so, Keith says: “It’s worth asking about the scalability of each potential energy source – whether it can supply, say, three terawatts, which would be 10% of our global energy need, or whether it’s more like 0.3 terawatts and 1%.

“Wind power is in a middle ground. It is still one of the most scalable renewables, but our research suggests that we will need to pay attention to its limits and climatic impacts if we try to scale it beyond a few terawatts.”

Apart from debate over wind’s fitfulness and inconstancy and claims that it is environmentally more damaging than acknowledged (to birds and landscapes, for example), scientists differ on the contribution it can make to a low-carbon economy.

But this latest study, funded by the Natural Sciences and Engineering Research Council of Canada, chimes with the conclusion recently reached by other US researchers (see our story of 20 January, Renewables: The 99.9% solution.

Consistent wind power can be obtained, they said, if the turbine fields are dispersed at distances greater than 1,000 kilometres. – Climate News Network

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by alex kirby

‘World can end poverty and limit warming’

February 24, 2013 in Sustainable Development

EMBARGOED until 1800 GMT on Sunday 24 February

Clean, modern energy is essential to end poverty Image: A Davey

Clean, modern energy is essential to end poverty
Image: A Davey

By Alex Kirby

A United Nations scheme intended to guarantee everyone access to clean energy could help to keep global temperature rise below 2°C, researchers say, although it would not achieve this without sharp cuts in emissions of all the main greenhouse gases.

LONDON, 24 February – Eradicating poverty by making modern energy supplies available to everyone is not only compatible with measures to slow climate change, a new study says. It is a necessary condition for it.

But the authors say the scheme to provide sustainable energy worldwide will not by itself be enough to keep the global  average temperature rise below the widely accepted international target level of 2°C. While the scheme can help measures to tackle climate change, it cannot achieve that by itself.

The scheme, the UN’s Sustainable Energy for All initiative (SE4All), if it proves successful, could make a significant contribution to cutting greenhouse gas emissions, according to the analysis from the International Institute for Applied Systems Analysis (IIASA) and ETH Zurich.

The study, published in Nature Climate Change, shows that reaching the three energy-related goals of SE4All would cut GHG emissions and is achievable.

“Achievement of the three objectives would provide an important entry point into stringent climate protection”, says Joeri Rogelj, ETH Zurich researcher and IIASA-affiliated scientist, who led the study.

It found that the short-term goals, due to be reached by 2030, would help achieve long-term climate targets. But to ensure stringent climate objectives were reached, SE4ALL would need to be matched by other measures, the researchers say.

SE4All ‘necessary – but not sufficient’

 

SE4All’s objectives include providing universal access to modern energy, doubling the share of renewable energy globally, and doubling the rate of improvement in energy efficiency – all by 2030.

While the objectives do not explicitly address climate change, sustainable energy is accepted as vital for cutting GHG emissions: 80% of CO2 from human activities comes from the global energy system, including transport, buildings, industry, and electricity, heat, and fuel production.

“Doing energy right will promote the Millennium Development Goals and at the same time kick-start the transition to a lower-carbon economy”, says IIASA researcher David McCollum, who also worked on the study. “But the UN’s objectives must be complemented by a global agreement on controlling GHG emissions.”

SE4All has global goals, but the researchers say action at regional and national levels will be essential to achieving them. IIASA’s energy programme leader Keywan Riahi, a co-author of the study, says: “The next step for this initiative is already under way, with a large number of national plans that underpin the global objectives.”

They analysed the likelihood of the world limiting global warming to target levels if each or all of the SE4All objectives were achieved. Using a broad range of scenarios, they found that if all the objectives are met, the likelihood of keeping temperature rise below 2°C will be more than 66%.

Many variables

 

If only the renewable energy goal is met, chances of staying below 2°C will range from 40 to 90%, they say, while achieving just the energy efficiency goal will improve the chances to between 60 and 90%.

But the researchers warn that this result depends strongly on what future economic growth is assumed. They say the  likelihood of reaching climate targets within the scenarios depend on a range of other factors, including energy demand growth, economic growth, and technological innovation.

The study also found that providing universal energy access by 2030 will not hinder long-term climate goals, thanks to the marked gains in energy efficiency that will result. “Sustainable development and poverty eradication can go hand in hand with mitigating climate risks,” says Rogelj.

He told the Climate News Network: “To ensure effective climate change mitigation, a global treaty on greenhouse gases should enforce a cap on global emissions which limits emissions from all sources.

“With such a cap SE4ALL can help to limit emissions from the energy sector, but other measures will have to tackle those from other sources like deforestation, or other gases, like methane from agriculture and waste, or facilitate an even quicker decarbonization of the energy sector, like carbon-capture and storage.”

The new work also quantified the potential costs of reaching the SE4All objectives, which would amount to increasing energy investment by between 0.1 and 0.7% of global GDP. The authors’ estimates account for the substantial savings in energy use and reduced fossil energy investment that would result from promoting more sustainable energy technologies and lifestyles. – Climate News Network

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