Planet Earth Saves the Day...

Horns Rev. The worlds largest offshore wind farm. www.elsam.com  

Over the last few months we have looked at the Emissions Trading Scheme, at how effective it will be at reducing our Co2 emissions and how that will help the environment. We also considered (last month) nuclear power generation as one way of producing cleaner electricity. As a continuation to this theme, let’s take a look at other forms of power generation, and see what is on offer.  

As part of on-going agreements to reduce Co2 emissions and the overall greenhouse effect, the European Commission has set targets for members to produce cleaner power using renewable power generation. Many European countries are striving towards 12% renewable energy by 2010, while the UK hopes to produce 10% of its power demand also by 2010.  

There has been much speculation about renewable energy over the years, some regarding it with indifference; some see it as ‘not the real thing’. Others however have seen the potential of renewable energy as an ally to fossil fuel generation and have embraced it. The intention of this article is to present to the reader a selection of facts and figures so that a clearer understanding of the potential of renewable energy can be reached.  

There are many different forms of renewable energy on offer to us, requiring exploration and development to enable us to discover the viability and cost effectiveness of each. Over the next few months we will take a look at some of these and how they are starting to make a difference to our world.  

Types of renewable energy  

The types of renewable energy currently available to us are;  

1. Wind
2. Solar
3. Biomass
4. Wave and Tidal
5. Hydrogen
6. Hydroelectric
7. Geothermal

1 Wind  

Of all the renewable energy technologies, wind power is currently the most developed and cost effective. Wind turbines can be situated on rooftops, on land in clumps of ones or twos, or in larger “wind farms”, where there could be up to 100 or more.   Mainly situated onshore, but offshore wind has huge potential and is also being developed as a real source of power generation.  

Wind turbines, which are normally three blades, although some have two, attached to a generator via a gearbox, are mounted high off the ground to catch as much wind as possible. Their uses vary, being an ideal solution to providing electricity to places that are not connected to the national grid, or reducing household bills or generating power directly into the national electricity grid. They also vary in size, from small kilowatt to large multi mega watt and as technology improves their capacity gets larger.  

Wind is the third largest contributor of renewable energy in the UK , which currently operates 1316 turbines, 62 of which are situated offshore, producing 1089 megawatts, saving 2463352 tonnes of co2 emissions. Providing 1.3% of the UK ’s supply by the end of 2005, wind is expected to be the main contributor towards the UK government’s 10% renewable energy target, by 2010.  

But it is not just the UK that is harnessing the power from the wind. The world in general has embraced this form of renewable supply, with Germany in the lead. Installed capacity for Germany totalled 16,649 MW at the end of 2004*, followed by Spain 8,263* and USA 6,750*. These three countries make up 66% of the entire wind energy generated in the world*.
*Source Windforce 12 from www.ewea.org  

The European Commission White paper on Renewable Energy sets a goal of increasing renewable power generation to 12% by 2010. The expectation being that wind will generate around 40 GW of this target. But if wind continues to grow and develop at its current rate, then we can expect to see around 67 GW being produced by 2010. Source European Commission  

But there are problems facing producers wishing to use wind power. Planning permission can be objected to by local residents and turbines are noisy if you live too close to them.  

Offshore  

The new frontier for the wind industry is offshore sites, where in northern Europe alone thousands of megawatts of capacity are planned off the coasts of many countries.  

Average wind speeds are well over 8 metres per second at 60 metres height which will generate an expected 20 – 40% more energy than well placed shoreline sites. And of course offshore sites reduce the effect on the landscape.  

Almost 600 MW of offshore capacity had already been installed by the end of 2004 by Denmark , UK , Sweden , The Netherlands and Ireland , the largest being at Nysted in Denmark with a capacity of 165.6 MW. But the visionaries see much larger projects with capacities over 1000 MW and individual turbines up to 5MW. This being the case, the European Wind Energy Association have set targets of 70 GW to be produced by 2020, and so the race is on.  

Denmark have been at the forefront of the offshore race, with the construction of eighty 2 MW turbines at Horns Rev, about 20 kilometres from the North Sea coast, the largest in the world. Denmark ’s aim is to produce 4000 MW by wind power by 2030.  

The UK currently have three offshore wind farms, Blyth in Northumberland, with 2 turbines and a capacity of 3.8 MW, North Hoyle off the west coast and Scroby Sands of the east, both with 30 turbines each and a joint capacity of 120 MW. Two more are under way; one in Barrow, the other at Kentish Flats. Both will produce 90 MW each when commissioned. Another fifteen wind farms are planned to produce a total capacity of around 7,200 MW. These would provide enough power for four million homes, according to the British Wind Energy Association. The UK expects to knock Denmark off of the number one spot in 2006 as more projects complete and come on-line.  

Germany is proposing developments of more than 60,000 MW of capacity and construction permits have already been granted for 1,200 MW. The German government’s intention is to have 25,000 MW of wind parks in the sea by 2030.  

Ireland erected the world’s first commercial 3.6 Megawatt turbines in 2003 at Arklow Bank. The seven turbines went up in nine weeks and produce 25 MW.  

Other countries are following suite and 2006 is expected to be the year when many schemes around the world will start to take off. There is a current estimation that 150,000 square kilometres of sea would provide enough space for wind farm schemes to provide all of Europe ’s current electricity demand.  

But how do you encourage companies to develop offshore sites? The initial process is more costly than building onshore sites, but public demand will help to change the tide, as it will soon become more popular to build wind farms offshore than on. Also, more power can be generated using larger turbines when offshore, with stronger winds, so production costs can be reduced that way. Governments can also help this process by reducing the charges for renewable energy as it enters the grid, as some are already doing.  

The development of this technology sounds good, but what of the downside, what happens when the wind no longer blows? Many have expressed that thought, but the reality is that when the wind is not blowing in one place, it often is blowing in another, so as more and more turbines come on-line over the next few years at different locations, that should not be so much of an issue. The dash for wind has seen amazing growth over the last few years, but it is not the only form of renewable energy, as listed above. Next month we shall take a look at other renewable technologies and see how they are being developed to help us reach our targets of producing greener, cleaner power.  

Researched and compiled by Paul Cassar.

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