THE WINDS OF CHANGE: Getting to know the resource
By Anagha Bhambri
Mankind’s tryst with wind power began with the use of sailboats, which had an important role to play in the development of water pumping wind mills as well as those used for grinding grain. Countries like Argentina and Australia still operate wind mills for water pumping. Interestingly, these were all vertical-axis wind mills. But that was then. Wind mills have now grown in size and structure to deliver power at competitive rates in comparison to fossil fuel-based power plants.
In a bid to now further popularise the concept of wind energy, especially in developing countries, LIFE Academy held the second phase of its SIDA-sponsored programme on “Wind Power Development and Use” for the 25-member group from Africa, Asia and Eastern Europe. Spanning three-and-a-half weeks, the programme was conducted in Sweden in the months of August and September 2009. The programme, which kicked off at the LIFE Academy premises in Karlstad, involved week-long visits to different cities of southern Sweden: Stockholm, Falkenberg and Malmo.
The underlying essence of the programme was to empower people in the developing countries with knowledge on wind power and prepare them to work as information soldiers for the promotion of the resource.
The Swedish experience
The training programme began with a detailed introduction to the Swedish energy system which primarily relies on hydro power due to the country’s huge water resources, as well as nuclear energy. Currently, hydro power fulfills almost half of Sweden’s total electricity needs.
It would be interesting to know that in the year 2002, Sweden produced 70.3 TWh of electricity from renewable energy sources, of which about 90 per cent was in the form of large-scale hydro power.
To support the expansion of electricity production from renewable energy sources and peat, Sweden introduced an electricity certificate system in May 2003. The objective behind the mechanism was to increase, by 2016, the production of electricity from renewables by 17 TWh relative to the production level in 2002. This was part of the country’s overall aim to move Sweden towards a more ecologically sustainable energy system.
In respect of wind energy, research and development started in Sweden in the 1970s following which the first wind power plant was set up. Although wind power today meets only 2 per cent of Sweden’s total electricity requirement, it has the potential to supply a considerably greater proportion making it an area of political priority. In Bill No. 2001/02:143 Cooperation for Reliable Effective and Environmentally Friendly Electricity production, the Swedish Parliament has set a national planning target of 10 TWh of electricity from wind power by 2015.
Instructed by the government, the Swedish Energy Agency has proposed a new planning target of 30TWh (20 TWh onshore and 10TWh offshore) of wind power production by 2020. However, according to the country’s national grid operator Svenska Kraftnat, to be able to integrate 30 TWh wind power with a large share located in the Northern part of Sweden, the grid network will have to be revamped and extensive grid reinforcements will be required in North-South Sweden.
The Global Perspective
The tremendous growth of the global wind energy sector in the last two decades was the highlight of the programme. During the last 20 years wind turbines have literally got a new lease of life in terms of bigger size and better technology. Horizontal-axis wind turbines completely dominate today’s market and come in a variety of types.
Technologically speaking: Ten years ago most turbines used passive stall control, with blades that could not be rotated. The dominant turbine type these days has a rotor (the blades) which turns at a variable speed, with the output limited if necessary by pitching the blades so they are out of line with the wind. As the turbines have grown in size, the rotors are higher above the ground. Hence, the wind speed is higher, resulting in an increased annual output for a given rotor surface area.
With the advent of technology, wind turbines are designed for specific situations. The main considerations are the mean and maximum wind speeds and the turbulence. Other factors include whether the turbine is freestanding or part of a wind farm.
The lectures at KTH (the Royal Institute of Technology) in Stockholm provided a deeper insight into wind power technology. The visit also involved practical information in wind measurement and data analysis. Working on two wind power assessment computer models – RETScreen and Homer – was an important part of the technology curriculum.
Also part of the syllabus was the subject of open electricity market in Sweden. After the electricity reform in 1995-96, mobility increased on the Swedish electricity market. The reform also changed the roles as well as number of players. Currently, the market consists of many independent players, these include: Electricity producers, network owners, the system operator (Svenska Kraftnat), electricity traders, market places, and electricity consumers.
The fundamental principle behind introducing the open electricity network is that the players should pay for the right to input or output electricity at a single connection point. This way they obtain access to the entire network system and the entire electricity market. This means that producers and consumers connected to a local network pay their network fees to the owner of this network. They can then trade in electricity with any one of the other players across the entire open network system.
Growth of small wind turbines: Taking cognizance of the fast developing small wind turbine segment, which is propelling growth in the US wind industry as well as in several other developed and developing countries, a brief session was held on the limitations and advantages of such systems including a checklist for new investors.
Europe boasts of having the world’s best offshore wind power market. And this fact is testified by the aggressive offshore wind power industry of the United Kingdom. In fact, the British government recently gave the go-ahead for offshore wind farm development in new areas.
Though Sweden comes a long way down the list of top wind power producing nations of the world, the renewed targets set by the government has ignited interest in favour of the resource among the Swedes. The wind farm on Lake Vanern, the largest lake in Sweden and the third largest in all of Europe stretching a total size of 5,655 km. sq., is one such project. The unique part of the project is that it is the first time a wind farm has been built on a lake. Comprising ten wind turbines, the project turned into reality after almost 10 years of research and development efforts, and has had positive effects for local business as well as created new jobs. It is a joint venture with a broad base of owners. The two main owners comprise both private companies and economic associations. The annual power production is estimated to be around 90 GWh, enough for 20,000 Swedish households.
During a trip to Malmö – the third most populous city in Sweden after Stockholm and Gothenburg, and with its own share of Scandinavian history – we got to learn about the country’s biggest offshore Lillgrund wind farm and one of the largest in the world. Put up by Vattenfall, the wind power plant (having 48 wind turbines) is located around 10 km off the coast of southern Sweden, just south of Öresund Bridge. The wind velocity here is 8-10 m/s, which is ideal for wind power, and the wind farm generates 330 GWh annually. Vattenfall is a power company wholly owned by the Swedish government and one of the leading energy producers in Northern Europe.
The Öresund Bridge is a combined two-track rail and four-lane road bridge-tunnel across the Öresund strait. It is the longest combined rail and road bridge in Europe and links the two metropolitan areas of the Öresund Region: the Swedish city of Malmö and the Danish capital of Copenhagen. Interestingly, the quaint city of Malmö has about 10 per cent population working in Copenhagen.
Europe is also known for the unique wind energy cooperative model, popular in Denmark, Germany, the Netherlands and Sweden. Today, it is the leading form of wind turbine ownership in Denmark.
These wind power plants are partially owned by local landowners and other community members, and often take the form of “wind turbine cooperatives”. The electricity so produced from these plants fulfills the requirement of the owners, that is, the local community depending on their respective shares in the turbines.
However, the role of wind turbine cooperatives is not limited to a single turbine. A quick visit to Copenhagen brought us to the 20-turbine strong Middelgrundens offshore wind farm in the Øresund region. When it was built in 2000, this was claimed to be the world’s largest offshore wind park.
It was developed in cooperation between the Middelgrundens Windpower Cooperative and the local utility Copenhagen Energy, which was later acquired by Dong Energy. The cooperative is by far the largest worldwide with 8,600 shareholders, each holding 5 shares on average, and each equivalent to an estimated average production of 1,000 kWh a year.
Remarkably, the production from the wind park is 100GWh/year, which covers 4 per cent of the electricity consumption in Copenhagen.
The cooperative model has been quite successful in most places. It has been even been credited for helping local communities become energy-independent as well as more environment-conscious.
The European experience provided a stream of innovative ideas – each leading to a more refined and mature approach to understand wind power development. The inexhaustible information that we all had tried to grasp during the programme had finally led us to the conclusion – That this was just the start.