Wind – Walker Engineering

Grain of Salt: Wind farms can cause climate change

Wind farms can cause climate change, according to new research, that shows for the first time the new technology is already pushing up temperatures.

Wind farms can cause a rise in temperature, found a study in Nature.

Wind farms can cause a rise in temperature, found a study in Nature. Photo: Alamy

Read the entire article, related articles, and updates directly off the original site http://www.telegraph.co.uk/earth/earthnews/9234715/Wind-farms-can-cause-climate-change-finds-new-study.html

I included some of the article here so that you can get the gist of the study.

Usually at night the air closer to the ground becomes colder when the sun goes down and the earth cools.

But on huge wind farms the motion of the turbines mixes the air higher in the atmosphere that is warmer, pushing up the overall temperature.

Satellite data over a large area in Texas, that is now covered by four of the world’s largest wind farms, found that over a decade the local temperature went up by almost 1C as more turbines are built.

This could have long term effects on wildlife living in the immediate areas of larger wind farms.

It could also affect regional weather patterns as warmer areas affect the formation of cloud and even wind speeds.

It is reported China is now erecting 36 wind turbines every day and Texas is the largest producer of wind power in the US.

Liming Zhou, Research Associate Professor at the Department of Atmospheric and Environmental Sciences at the University of New York, who led the study, said further research is needed into the affect of the new technology on the wider environment.

"Wind energy is among the world’s fastest growing sources of energy. The US wind industry has experienced a remarkably rapid expansion of capacity in recent years,” he said. “While converting wind’s kinetic energy into electricity, wind turbines modify surface-atmosphere exchanges and transfer of energy, momentum, mass and moisture within the atmosphere. These changes, if spatially large enough, might have noticeable impacts on local to regional weather and climate.”

The study, published in Nature, found a “significant warming trend” of up to 0.72C (1.37F) per decade, particularly at night-time, over wind farms relative to near-by non-wind-farm regions.

The team studied satellite data showing land surface temperature in west-central Texas.

“The spatial pattern of the warming resembles the geographic distribution of wind turbines and the year-to-year land surface temperature over wind farms shows a persistent upward trend from 2003 to 2011, consistent with the increasing number of operational wind turbines with time,” said Prof Zhou.

However Prof Zhou pointed out the most extreme changes were just at night and the overall changes may be smaller.

Also, it is much smaller than the estimated change caused by other factors such as man made global warming.

“Overall, the warming effect reported in this study is local and is small compared to the strong background year-to-year land surface temperature changes,” he added.

The study read: "Despite debates regarding the possible impacts of wind farms on regional to global scale weather and climate, modelling studies agree that they can significantly affect local scale meteorology."

Professor Steven Sherwood, co-Director of the Climate Change Research Centre at the University of New South Wales, said the research was ‘pretty solid’.

“This makes sense, since at night the ground becomes much cooler than the air just a few hundred meters above the surface, and the wind farms generate gentle turbulence near the ground that causes these to mix together, thus the ground doesn’t get quite as cool. This same strategy is commonly used by fruit growers (who fly helicopters over the orchards rather than windmills) to combat early morning frosts.”

Prototype wind turbine condenses 1,000 liters of water a day from desert air

If you live in or travel through a desert region, having access to clean water is always going to be an issue. If you can’t carry enough for your journey, you have to ensure your route allows for a few water bottle refills. But the lack of water in deserts and other arid locations may soon be a thing of the past if a new wind turbine system is implemented on a large scale.

Marc Parent, founder of Eole Water, realized that he could extract water from the air after noticing how much water an air conditioner unit collected. He decided to combine a green energy source with the necessary components for condensing water directly from the air. The end result after 10 years of R&D is the WMS1000 wind turbine, capable of condensing and storing up to 1,000 liters of water every day.

The 34 meter tall turbine requires 15mph winds for its 13 meter diameter rotor to turn and generate sufficient energy. It then produces 30kW of power for the system to function. Air is drawn in through vents in the nose of the turbine and a generator heats it producing steam. That steam is then fed through a cooling compressor to form moisture that gets condensed into water. The resulting liquid is piped into a storage tank at the base of the turbine after being purified.

As long as an area meets the wind speed requirements this is a completely self contained system. It effectively allows mass water storage in some of the most arid places on earth.

The Eole Water wind turbine isn’t just an idea. A prototype unit was constructed and erected in Abu Dhabi 6 months ago and has consistently produced up to 800 liters of water a day. With that test proving the system works, Eole is now working with a number of manufacturers to produce the turbines

Although the desert example shows off the potential of the system, the turbines can be deployed anywhere. Eole believes they can be erected anywhere that is isolated, does not have a reliable water source, in disaster areas, and as a source of wtare for organic farming where a low impact on the environment is highly desirable.

Wind farms ‘have major economic benefit’

From The Independent. Read the article directly and check out the links provided to related articles. I have copied some of the article here just for reference.

Onshore wind farms, recently under attack from leading conservationists for damaging the countryside, can bring significant economic benefits locally and nationally, as well as contributing to the fight against climate change, a new study claims.

Onshore wind supported 8,600 jobs and was worth £548m to the UK economy in 2011, says the report, by consultancy BiGGAR Economics. Of this figure 1,100 jobs were created at local authority level, with £84m of investment.

Looking at 18 case studies of wind farms of different sizes drawn from across the UK, the study analyses the contribution of wind farm development, construction, operation and maintenance to the economy at a local, regional and national level. It suggests if onshore wind is deployed at a scale suggested in the Government’s Renewable Energy Roadmap, the economy could benefit by £780m by 2020, with around 11,600 jobs being supported.

From its beginnings 20 years ago, Britain’s wind industry now has 3,176 large onshore turbines, with 568 turbines in the sea, according to RenewableUK, the wind industry trade body.

The onshore wind farms together can produce about 4.5 gigawatts of electricity, roughly the equivalent of four large conventional power stations, with another 1.5GW coming from offshore turbines. But the growing presence of turbines in the landscape – there are nearly 3,000 more in the planning process – has led to criticism from conservationists, and last week the Campaign to Protect Rural England broke ranks with other environmental groups who have hitherto been united in support for wind energy for the contribution it can make, with other CO2-free energies like solar and tidal power, to cut carbon emissions that cause climate change.

The CPRE said the countryside was being caught in "a hurricane of new wind turbines" and local communities were "struggling to safeguard valued landscapes" which were being industrialised by the presence of wind farms. Shaun Spiers, its chief executive, said his group accepted onshore wind in the right places as part of the mix required to meet the UK ‘s carbon reduction targets, "but we are seeing more and more giant turbines sited in inappropriate locations".

The Government and wind industry stress the benefits wind farms can bring. "Rather than feeling wind has been imposed on them, people across the UK recognise the benefits of having wind in their backyard," said RenewableUK’s chief executive Maria McCaffery. Energy and Climate Change Secretary Ed Davey said: "Wind power provides secure, low carbon power to homes and businesses, and supports jobs and brings significant investment."

Wind tops 10 percent share of electricity in five US states

Earth Policy News reports that a new picture is emerging in the U.S. energy sector and wind-power is remarkably on the rise.

According to Paul Ray, renowned sociologist and coauthor of The Cultural Creatives: How 50 Million People Are Changing the World, “these growth rates for wind are the kinds of numbers that alternative energy experts, including me, have been waiting to see for decades. This all means that wind and solar can take their place as solutions to the climate crisis. Wind power is now becoming part of the grid. On the other hand, the most dangerous energy source, coal, is in steady decline. (The 36% annual growth rate for wind reflects the very small base of the percent to start with.) Most important is wind’s growing share of net electrical generation in the second graph. The other key benchmark is mentioned at the end: Germany’s leading wind power provinces have wind at 40% of electrical supply–the top US states should be able to equal or exceed that because they are far better wind territory. That shows the size of the potential.”

Engineers enlist weather model to optimize offshore wind plan

From Stanford School of Engineering, WEngineering is interested in the application of modeling to modern issues.

Using a sophisticated weather model, environmental engineers at Stanford have defined optimal placement of a grid of four wind farms off the U.S. East Coast. The model successfully balances production at times of peak demand and significantly reduces costly spikes and zero-power events.

By Andrew Myers

Politics aside, most energy experts agree that cheap, clean, renewable wind energy holds great potential to help the world satisfy energy needs while reducing harmful greenhouse gases. Wind farms placed offshore could play a large role in meeting such challenges, and yet no offshore wind farms exist today in the United States.

In a study just published in Geophysical Research Letters, a team of engineers at Stanford has harnessed a sophisticated weather model to recommend optimal placement of four interconnected wind farms off the coast of the Eastern United States, a region that accounts for 34 percent of the nation’s electrical demand and 35 percent of carbon dioxide emissions.

“It is the first time anyone has used high-resolution meteorological data to plan the placement of offshore wind grid,” said senior author Mark Z. Jacobson, a professor of civil and environmental engineering. “And this sophistication has provided a deeper level of understanding to the grid plan.”

The team started with 12 randomly selected energetic locations (in magenta) between Long Island, New York and a shallows about a hundred miles to the east of Cape Cod, and narrowed their recommendation to four optimal locations, highlighted in red, with a total capacity of 2000 megawatts. Map: Mike Dvorak, Stanford School of Engineering

Beginning with 12 energetic potential locations, the engineers winnowed down the sites to four optimal sites. Total maximum capacity of the interconnected grid is 2000 megawatts, roughly equivalent to the yearly capacity of one-and-a-half conventional coal-fired power plants. Each farm would have approximately 100 turbines, delivering an individual maximum capacity of 500 megawatts.

“Two thousand megawatts and four farms are somewhat arbitrary figures. The sizes and locations could be adjusted for economic, environmental, and policy considerations,” said Jacobson.

“An offshore grid as an extension of the onshore grid in this region will improve reliability, while reducing congestion and energy price differences between areas,” said Mike Dvorak, the lead author of the study and a recent PhD graduate in civil and environmental engineering at Stanford.

Optimizing the grid

The optimized grid was located in the waters from Long Island, New York to Georges Bank, a shallows about a hundred miles to the east of Cape Cod. The nearshore locations take advantage of consistent sea breezes that occur naturally due to the daily difference in temperature between land and sea. The offshore farms experience stronger, though less regular, frontal storm activity. The four farms would be interconnected to help balance output across the grid.

“Until recently, large scale wind resource assessments have neglected the aspect of time. We matched peak productivity with peak demand at specific times of day and year,” said Dvorak. “Our analysis matches production to demand.”

Wind farms on land, for instance, tend to see daily peak output at night, when demand is lower. Seasonally speaking, demand usually spikes in the late afternoons of summer when air conditioning needs are high, but this time of year is also known for a dearth of storms and a meteorological phenomenon known as the Bermuda High, a high-pressure center that affects winds along the entire coast.

“In some areas, like Massachusetts, the Bermuda High boosts sea breezes,” said Dvorak. “But south of Long Island, NY, where one offshore grid has been proposed, the Bermuda High has the opposite effect and often hinders sea breezes.”

The nearshore locations take advantage of consistent sea breezes that occur naturally due to the daily difference in temperature between land and sea. Image: Sergiy Serdyuk

Balance of power

Beyond matching production and demand cycles, the researchers had to balance several technical challenges in their models.

“The farms had to be in waters less than 50 meters deep to allow use of bottom-mounted turbines and near urban load centers like Boston and New York,” said Jacobson. “And, we wanted to smooth power output, ease hourly ramp rates and reduce hours of zero power.”

The engineers took a novel approach, choosing to interconnect the offshore farms. Offshore wind farms in other parts of the world today are connected individually to the onshore grids.

“The goal is to even out the peaks and valleys in production,” said Dvorak. “In our model, expensive no-power events — moments when individual winds farms are producing zero electricity — were reduced by more than half from nine percent to four by connecting the farms together.”

In the final analysis, the interconnected grid was able to yield a year-long capacity factor of over 48 percent, meaning that the grid could reliably produce close to 1000 megawatts on average over the course of a year.

“Generally, with wind farms, anything over 35 percent average capacity is considered excellent,” said Jacobson.

Location. Location. Location.

Among its findings, the Stanford model recommended a farm in Nantucket Sound, precisely where the controversial Cape Wind farm has been proposed. The Cape Wind site is contentious because, opponents say, the tall turbines would diminish Nantucket’s considerable visual appeal.

By that same token, the meteorological model puts two sites on Georges Bank, a shallows located a hundred miles offshore, far from view in an area once better known for its prodigious quantities of cod. The fourth site is off central Long Island.

The researchers last looked at the economics of installing their offshore grid, which they said would have the advantage of sharing costs across several states, potentially increasing political support for the plan.

“This paper should be seen as a tool for energy planners to better inform their renewable energy decisions across a densely populated area,” said Jacobson. “It is an opportunity to collaborate on a shared system that reduces costs while benefitting a large and important center of electrical demand in the U.S.”

This research was supported by the Charles H. Leavell Graduate Fellowship and the US Environmental Protection Agency and the Otto Mønsted Foundation. The NASA Advanced Supercomputing (NAS) Division and NCAR Computational & Information Systems Laboratory (CISL) provided access to computational resources and global weather datasets, respectively.