A Myth Dispelled (Sort Of)

The problem with wind and solar power, so we’re led to believe, is that because both are dependent on weather conditions, neither is a “reliable” source of electricity. The big question has always been “What if there isn’t enough wind?”

But, do we ever ask “What if there is too much wind?”

High winds will cause wind turbines to automatically shut down, but what happens if wind speed is within operable parameters over a very large region for an extended period of time?

According to a recent Calgary Herald article, that’s what happened in Germany on July 24 this year. The country’s wind turbines generated so much electricity that some utilities paid consumers to use it.

And that’s happened more than 30 times this year. And not just in Germany.

With calls for increased renewable power, and more and more wind farms and solar parks being constructed, one can almost foresee a time when coal and gas-fired electricity form the peaking load and not the base load.

So what if the wind doesn’t blow and the sun doesn’t shine? With widespread distribution, that may be rare.

HAWTs and VAWTs

There are two basic types of wind turbines defined by the orientation if the axis or drive haft that turns the generator – horizontal axis wind turbines (HAWT) and vertical axis wind turbines (VAWT).

Horizontal axis wind turbines are the oldest, most efficient and therefore, the most common of the two types. They consist of two or more vertical blades (three is the most common) attached to a hub which is in turn attached to the horizontal drive shaft and the generator. This whole assembly sits on top of a tower. The blades face into the wind on the windward side of the tower to avoid any disturbance the tower may create. The tower is designed to elevate the blades into the strongest and most consistent wind. Currently, the longest blades are 82 metres long (269 feet) and the tallest towers reach 180 metres or 590 feet.

There are many different vertical axis wind turbine designs, ranging from the Darrius “egg beater” configuration to bladed turbines. Like HAWTs, vanes or blades turn a shaft connected to a generator , although in this case the shaft is vertical and the generator on the ground. There is no tower, and VAWTs  are generally much shorter than HAWTs, The prime advantage of  VAWT configuration is that it faces always faces into the wind, and is therefore better suited to areas where the wind is continually changing direction. Because of their more compact design, VAWTs are commonly used for microgeneration by home, cottage and small business owners and farmers to provide power for their own use or to sell back to grid.

A new development combines a VAWT with solar cells to provide electricity from wind power and solar power at the same time.

Ontario Pours Cold Water on Offshore Wind Farms

Offshore wind farms are viewed as one answer to wind turbine noise, unsightliness, and danger to bats. Makes sense? – put them where no one can hear or see them. As well, offshore winds are far more consistent and reliable than onshore winds. There are more than 40 offshore wind farms in China, Japan and 10 European countries. Their total combined capacity at the end of 2009 was almost 2,000 megawatts. So the question is why aren’t there offshore wind farms in Canada?

The answer is obvious for Alberta and Saskatchewan – neither have an offshore. Sure there are some big lakes but those are well off the grid and the costs of transmission infrastructure and transmission itself would be prohibitive.

British Columbia may soon have an offshore wind farm. On March 17, 2011 NaiKun Wind Energy Group was “granted a federal screening decision, confirming that Canada’s first offshore wind project can be constructed with no significant environmental, social or health effects.”  The project will be located in Hecate Strait Haida Gwaii and Prince Rupert and will comprise up to 110 turbines will a combined installed capacity of 396 megawatts.

Image: Naikun Wind Energy Group

While Ontario doesn’t have a sea coast, it does border on three great lakes: Ontario, Erie and Huron. Until recently four offshore projects were planned, but in February, the Ontario government decided to impose a moratorium “until the necessary scientific research is completed and an adequately informed policy framework can be developed.”  The ministry also said “Offshore wind power development in freshwater lakes is relatively new and presents technical challenges that do not exist in a saltwater environment, such as the need to manage potential impacts to drinking water and the effects of ice build-up on support structures.”

The action be the Ontario government seems to be counter to its previous assertions that wind power will be a more and more important source of electricity as the province’s coal-fired generating stations are phased out.

There is one other example of a wind farm in fresh water, the Vindpark Vänern on Lake Vanern in Sweden. Located 6.5 kilometres off shore and consisting of 10 three-megawatt turbines, the project went on line in May 2010.

While New Brunswick, Prince Edward and Nova Scotia currently do not have offshore wind farms, all three provinces are investigating the possibility.

Wind on a Global Scale

As with pretty much every great discovery, the initial use of wind power was probably accidental. Someone standing on a raft put out their arms, the air current caught their cloak and presto, the wind had been harnessed.

Initially, using the wind was more a case of redirecting it – into sails for transportation, through ducts and pipes for ventilation. Later, some enterprising person figured out how to power machines, like water pumps and grain mills with the wind.

It wasn’t until 1887 that a Scotsman named James Blyth first used wind-generated electricity to light his summer home. Later the same year, Charles F. Brush made a horizontal axis wind turbine that powered his house and laboratory in Cleveland, Ohio.

Left: James Blyth’s vertical axis wind turbine   Right: Charles Brush’s horizontal axis wind turbine.

Wind powered generators grew in popularity, primarily on farms or isolated buildings not connected to the grid. Capacities of these early generators was usually in the range of five to 10 kilowatts.

In the late 1970s, capacities increased to 20 to 30 kilowatts and the market expanded, especially in Europe. In 1980, the first wind farm was built in New Hampshire and comprised 20 30-kilowatt turbines. However, the project failed because of design errors. Never the less, it paved the way for successful projects soon after. The largest on shore wind farm in the world is the Bigelow Canyon Wind Farm in Oregon. The project consists of 217 wind turbines with a combined installed capacity of 450 megawatts. The site covers 100 square kilometres.

The first offshore wind farm was constructed at Vindeby, Denmark. It consists of 11 450-kilowatt turbines with a combined installed capacity of 4.95 megawatts. The largest offshore wind farm is Thanet, off the southeast coast of England. Covering 35 square kilometres, it comprises 100 three-megawatt turbines with a combined installed capacity of 300 megawatts.

Thanet Offshore Wind Farm Image: Vattenfall

The total global installed capacity is more than 200,000 megawatts, and individual turbine capacity has risen to seven megawatts. The top five producers are the United States (28.3 per cent), Germany (14.4 per cent), Spain (13.9 per cent), China (10.0 per cent) and India (6.1 per cent). Canada ranks 13 overall with 1.4 per cent.

In Denmark, wind generation accounts for 18.7 per cent of total electricity generation. Portugal ranks second with 15.5 per cent and Spain ranks third with 12.6 per cent. In Canada, wind power contributes less than one per cent of total electricity generation.

Wind – The Other Solar Power

Wind is just moving air. We all know that. But, what causes the air to move? The sun.

Solar radiation hits the surface of the Earth, and because the Earth is composed of different materials, the solar radiation is absorbed unevenly, creating warmer areas and cooler areas. The air over the warmer areas heats up and rises, creating an area of low pressure. The air over the cooler areas is cooled and sinks, creating an area of high pressure. Air always moves from high pressure to low pressure, so cooler air moves in to replace the rising warmer air. Hence, wind.

For example, during the day, land heats up faster than water, so warm air over land rises to be replaced by cooler air from over a lake or ocean. Conversely, at night the land cools faster than water, so the wind reverses and moves from the land to the sea.

Image: PhysicalGeography.net

On a larger scale, the regions closer to the Earth’s equator receive more heat from the sun than the polar regions, creating atmospheric winds that are also influenced by the Earth’s rotation.

Wind turbines generally operate at wind speeds ranging from about 13 kilometres per hour to 90 kilometres per hour. The number of revolutions per minute, depending on the type of turbine, ranges from 4.5 to about 30. The blade tip speed varies with blade length and revolutions per minute. The maximum blade tip speed for an 82 metre blade at a maximum 12.1 revolutions per minute is almost 375 kilometres per hour.

Energy BOT Squad’s Newest Member

This week we’re taking wind energy for a spin with WindBOT, the breeziest BOT around. And with this BOT’s use increasing across the country, she’s not just turning blades, she’s also turning heads.

Wind turbines can come in a variety of sizes — from towering turbines to small-scale turbines that can be installed on the roof of an average home — and shapes — turbines can be mounted on either a horizontal or a vertical axis. In Canada, wind producers are represented by the Canadian Wind Energy Association (CanWEA), which promotes wind energy across the country. And across the country, there’s more than enough to promote.

There are more than 100 wind farms in Canada, boasting over 2,200 individual turbines producing a combined output of 1.6 terra-watt hours. (That’s about two per cent of the country’s electricity needs.) And, just as it is around the world, wind power use in Canada is growing — in 2010, Canadians added more than 690 megawatts of installed capacity to the country’s electricity grid. Add in the projected 1,000 MW to be added in 2011 and it won’t be long before WindBOT’s flying as one of Canada’s most important renewable energy sources.

Wind energy is one of the world’s fastest growing sources of renewable power, increasing globally at a rate of around 30 per cent every year. So you know that as WindBOT takes off in Canada she’s also joining an airstream that’s going around the world. What a breath of fresh air.

Totally Renewable – and Renewed – by 2030?

In our recent post on the World Future Energy Summit, we discussed the need for policy change in order to achieve current climate change targets. Two scientists in the United States have taken that one step further. Mark Z. Jacobson, professor of civil and environmental engineering, Stanford University and Mark A. Delucchi, research scientist, Institute of Transportation Studies, University of California, Davis; believe that all that is needed to achieve a totally carbon free, totally renewable, wind, water and solar (WWS) based energy system by 2030 is political will.

Well, maybe a bit more than that. We’ll also need:

• 490,000 tidal turbines, each with an installed capacity of one megawatt
• 5,350 geothermal plants, each with an installed capacity of 100 megawatts
• 270 additional hydroelectric plants, each with an installed capacity of 1,300 megawatts
• 3.8 million wind turbines, each with an installed capacity of five megawatts
• 720,000 wave powered turbines, each with an installed capacity of 0.75 megawatts
• 1.7 billion rooftop photovoltaic systems, each with an installed capacity of three kilowatts
• 49,000 solar focusing steam power plants, each with an installed capacity of 300 megawatts
• 40,000 photovoltaic power plants, each with an installed capacity of 300 megawatts

Basically, to achieve a totally renewable WWS energy system, we’ll have to totally renew the existing system. And that includes building a new, super-interconnected electricity transmission grid. It also involves scrapping all internal combustion engine vehicles and replacing them with electric or fuel cell vehicles.

And the cost estimate is only about $100 trillion.

The most fascinating aspect of this theory is that it might just be doable.

The U.S. Energy Information Administration predicts that by 2030, world energy demand will be 16.9 terawatts (TW), or enough to power 47 60-watt light bulbs for every person on earth. But Jacobson and Delucchi point out that in a carbon-free world there would be no internal combustion engines, and internal combustion engines are far less efficient than electricity, so the actual requirement drops to 11.5 TW.

And if you think 3.8 million wind turbines is a lot, consider that auto manufacturers make 73 million cars per year. Also consider that much of the world’s electricity generation and transmission infrastructure is aging and will have to be replaced in the not too distant future anyway. And without all the transportation-induced air pollution, medical and environmental costs would decrease significantly.

As far as reliability of the system is concerned, a thoroughly interconnected grid will be able to re-route surplus electricity to wherever it is needed. Jacobson and Delucchi point out, perhaps a little simplistically, that if it’s raining in one place, it’s sunny someplace else, or if there’s no wind, it’s probably sunny. In other words, electricity will be generated somehow, somewhere.

The authors have determined that the only technical barrier might be the availability of rare-earth metals needed for batteries, solar films and fuel cells. But if we recycle old batteries and buildings, we should have ample supply of steel, concrete and things like neodymium and indium.

Which means the real barrier is political will, which ultimately means getting everyone onside. Most of us agree there’s a problem, but maybe it’s a little far fetched to try and achieve all this by 2030. Maybe it’s more realistic to try for 2050. Implement a more gradual shift, replacing old infrastructure as needed with new wind, water and solar generation. Maybe people will be a little more comfortable with that and a little more willing to put one of the 1.7 billion photovoltaic systems on their own roof.

Read the paper in the journal Energy Policy, Part 1 (600KB PDF) and Part 2 (680KB PDF)

Via Green Tech, cnet News

Wind Matters from the Canadian Wind Energy Association

Noticeable in the recent CanWEA newsletter is the geographic diversity of both the wind industry and the energy companies that are investing in wind power in Canada.

In Toronto, Bridgepoint Group has helped secure financing for a 200+ MV Ontario wind farm. Northland Power Income Fund has sold its 54 MW wind farm in Quebec to Burlington’s NextEra Energy Canada.

Ontario has almost 40 per cent of Canada’s installed capacity for wind-generated electricity. The Conference Board of Canada has reported that development of the offshore wind industry in Ontario could add between $4.8 and $5.5 billion to the province’s economy.

Hydro-Quebec has recently accepted bids for a dozen small-scale wind energy projects totalling just under 300 MW of installed capacity.

On the prairies, SaskPower is assessing the economic and environmental benefits of self-generated power projects. Wind turbines are being installed at municipal ice arenas as part of the demonstration projects.

TransAlta, located in Calgary has recently commissioned wind facilities in Alberta and New Brunswick. Greengate Power, also located in Calgary is planning to build a wind facility just outside of the city in partnership with Edmonton’s Capital Power Corporation.

Via CanWEA

Wind Matters from the Canadian Wind Energy Association

In Ontario the Gosfield Wind Project has opened. Owned by Brookfield Renewable Power, the project (a 50MW facility) will produce power for the Ontario Power Authority. Close on its heels is the construction start of another Brookfield project. Its new Comber Wind farm (a 166MW facility)is expected to be on line in a year. Together these two projects will power over 70,000 average Ontario homes.

Also in Ontario, the government is seeking public input into its long term energy plan. Log on and share you thoughts.

In Nova Scotia the Nuttby Mountain Wind Farm (a 45MW facility) is powering up. If you’ve never had the change to visit a facility, have a look at the pics below. They’ll give you a good sense of scale and better understanding of what’s involved in building a project like this. The green colour bands on the posts are new – nice idea. Thanks to Nova Scotia Power for the slide show.

Eye of the Wind

Look up, look waaaay up. Yup, that right. There’s something new at the top of that wind turbine.

Grouse Mountain Resort has installed a wind turbine (1.5MW installed capacity) that is capable of supplying up to 25 per cent of the resort’s power needs. Including presumably, the elevator inside of the turbine tower. In under a minute, you and 35 of your closest friends can be on top of the world, or at least on top of the turbine in its one-of-a-kind viewing pod.

The construction was an international affair – the blades were made and transported from Europe as was the viewing pod – made in France, shipped across the ocean and then transported by train across Canada. The tower was made in Washington State and trucked up the west coast to Vancouver.

If you’re in the viewing pod on a windy day, the blades will start up when wind speeds are just under 10 km per hour and cut-out at 90 km per hour. You’ve got to admit it would be pretty cool to be in the pod with the wind howling. And if that isn’t exciting enough, you and your buddies could jump up and down on the glass floor section, in the pod, in the howling wind…

Next Page »