A new scientific study has found there is wind energy in abundance to power the needs of the world with near zero emission electric power several times over. The world currently utilizes about 18TW (TeraWatts) of power. The study identified that the lower geophysical limits for energy harvested from surface turbines (supported on towers on land and sea) was over 400TW. If turbines could be flown by kites to capture the more reliable high altitude winds, more than 1,800TW of power could potentially be extracted throughout the atmosphere.
The authors warn that extracting wind energy near the upper physical limits would have substantial climate effects on temperature and precipitation. But at current global demand and as long as turbines were spread out and not clustered in a few regions the climate impact on surface temperatures would be about 0.1 degree Celsius warming and a decrease in global average precipitation by about 1%.
This must be weighed against the substantial reduction in greenhouse emissions that would occur, the substantial health gains from wind power phasing out the health problems associated with coal mining and power production. Reduced carbon pollution would also slow the rate of ocean acidification which is contributing to a great marine extinction event.
Researcher Ken Caldeira said "Looking at the big picture, it is more likely that economic, technological or political factors will determine the growth of wind power around the world, rather than geophysical limitations,"
The study was led by Kate Marvel of Lawrence Livermore National Laboratory, although much of the research was done at the Carnegie Institute for Science. It was published in Nature Climate Change.
Wind turbines create drag, or resistance, which removes momentum from the winds and tends to slow them. As the number of wind turbines increase, the amount of energy that is extracted increases. But at some point, the winds would be slowed so much that adding more turbines will not generate more electricity. This study focused on finding the point at which energy extraction is highest.
Of course in developing the renewable energy economy energy from wind power will be just one substantial source from many. Large scale Concentrating Solar Thermal (CST) with storage systems plus solar photovoltaic panels will also play a substantial role. Some coastal areas may be able to extract significant power from waves, currents or tides. Geothermal and biomass may also be possible significant sources.
Scientists have estimated that A carbon neutral solar and wind powered world is possible in 20 to 40 years. Beyond Zero Emissions here in Australia have calculated it is achievable with current technologies to transform Australia's stationary energy to zero emissions by 2020.
A separate study by researchers Mark Z. Jacobson, a professor of civil and environmental engineering at Stanford, and Cristina Archer, associate professor of geography and physical ocean science and engineering came to a similar conclusion that there is a lot of potential in the wind - hundreds of terawatts. But like the Marvel et al paper found that there is a saturation point where building new turbines would plateau, reaching a level in which no additional energy could be extracted even with the installation of more turbines.
"Each turbine reduces the amount of energy available for others," Archer said. The reduction, however, becomes significant only when large numbers of turbines are installed, many more than would ever be needed. And that's the point that was very important for us to find," Archer said. That saturation point is likely to be at more than 250 terawatts, much higher than we would ever need.
The authors then calculated how many turbines would be needed to meet half the world's energy power demand by 2030 - they estimate about 5.75 terawatts. They calculated that about 4 million 5MW turbine towers 100metre high would be required which would have a capacity of 7.5 terawatts of power without a significant affect on climate. Jacobson pointed out it is still early days, "Today, we have installed a little over 1 percent of the wind power needed," Jacobson said. "The careful siting of wind farms will minimize costs and the overall impacts of a global wind infrastructure on the environment," said Jacobson. "But, as these results suggest, the saturation of wind power availability will not limit a clean-energy economy."
The Jacobson and Archer paper - Saturation wind power potential and its implications for wind energy (Full Paper PDF) - was published in PNAS.
Political constraints on wind power in Australia
Of course here in Victoria we are well aware of the political constraints placed on the development of wind power with draconian planning regulations placed on new wind farm development by the Baillieu Government. The planning controls pander to a vocal group of people who maintain wind turbines generate ill effects but with no scientific research to support their opinions. (See Four Corners Against the Wind 25 July 2011)
There are similar draconian planning constraints on wind farm development in NSW introduced by the O'Farrell government.
"Victoria now has the toughest wind energy planning guidelines in the world. The anti-wind energy laws have already cost Victoria thousands of jobs and millions worth of investment in the renewable energy economy and must be repealed," said Cam Walker in a media release by Friends of the Earth Melbourne which attacked the Baillieu government's introduction of the draconian planning regime and the lack of funding afforded to the nascent wind industry in the state.
According to the Friends of the Earth report - What is the real cost of Ted Baillieu's Wind Energy Policy (PDF) - the strict planning regulations have caused the collapse of wind farm projects in the state, causing the cancellation of up to 204 turbines and 408MW of generating capacity. This amounts to some $887 million of lost or stalled investment, the loss of 650 jobs in construction, 54 ongoing jobs and 1408 indirect jobs. Well done Ted! These wind turbines would save some 1.6 million tonnes of carbon emissions per year.
Much investment in wind farms has subsequently moved west to South Australia where last week wind energy produced 57.9% of demand on Tuesday and 55% total demand on Wednesday. Wind energy projects pumped $5 billion into the South Australian economy last financial year and created over 2,000 jobs, according to this report in the Weekly Times.
Is it any wonder the coal barons are so keen to develop coal and maintain coal burning technologies, the technologies that are so last century, while they are being supported and compensated by our politicians who ensure the legal frameworks and planning operate to the benefit of a few.
But the climate change numbers are clear. Globally we can only afford to emit 565 gigatonnes of carbon (see Global Emissions Gap Scoreboard) to stay below the 2 degree celsius increase in global temperature limit. But there is five times that amount of fossil fuel reserves easily accessible. And those who own the rights to mine - the Clive Palmers, Gina Rhinehearts, and Twiggy Forrests of this world don't want to lose the money to be made even if it sends the world to hell.
- Carnegie Institute for Science Media release, 10 September, 2012 - Enough wind to power global energy demand
- Kate Marvel, Ben Kravitz, Ken Caldeira. Geophysical limits to global wind power. (Full Paper) Nature Climate Change, 2012; DOI: 10.1038/nclimate1683
- Friends of the Earth report (2012) - What is the real cost of Ted Baillieu's Wind Energy Policy (PDF)
- Stanford University News, September 10, 2012 - Wind could meet many times world's total power demand by 2030, Stanford reseachers say
- Mark Z Jacobson and Cristina L. Archer, Saturation wind power potential and its implications for wind energy (abstract, Full Paper PDF) Published online September 10, 2012, doi: 10.1073/pnas.1208993109 PNAS September 10, 2012