Wind power will set a new record for new installations in 2023, with 110 gigawatts of new capacity added in one year. More than half of the new capacity will be installed in just one country, China, underlining that most of the world is still far from the pace needed to meet climate goals. Although we will soon see 1 million megawatts of installed wind capacity worldwide, the world will need to at least triple wind capacity by 2030 – as many governments have proposed in the run-up to the UN COP28 climate conference. This means that annual installations will also need to more than double in the coming years.
In the now more than 40 years of modern wind turbine history, not only have installations grown exponentially, but the technology has also progressed enormously. Twenty years ago, turbines with a rated capacity of 1 megawatt were common; today, the largest wind turbines are in the range of 5 megawatts, with the world record being held by China’s Mingyang with 18 megawatts – and a 22 megawatt model is under development.
In many countries where wind power was developed early, such as Germany or India, many wind farms have been in operation for 20 years or more, using technology that is no longer state of the art. Old turbines are often no longer eligible for feed-in tariffs, and operating and maintenance costs increase significantly. The maintenance costs of old wind turbines are often so high that, together with the expected higher overall yield, it may be economically viable to replace old turbines with new ones.
Benefits of repowering
Replacing old wind turbines with the latest technology brings many tangible benefits:
- The first wind farms are often located in excellent, very windy locations, and new technology can exploit these resources much more effectively.
- Repowering wind farms is resource-efficient because it can also make use of existing infrastructure, such as roads, grids, substations and transmission lines, requiring sometimes expansions.
- There is little or no need to develop new sites, minimising the impact on people and the environment – the environmental factors at an existing site are known.
- Repowering can multiply the available capacity while reducing the number of wind turbines.
- New turbines are usually more grid friendly and contribute to grid stability.
- New turbines have a lower environmental impact: they usually produce less noise, and larger turbines mean fewer rotations and less flicker.
- As a result, repowering can help improve community acceptance of a wind farm.
- Fewer wind turbines also mean lower monitoring and maintenance costs.
- Ultimately, repowering can reduce the cost per kWh, benefiting both electricity consumers and investors.
In several countries, repowering is already part of the normal wind development that started years ago. Some governments have even set up support programmes for the repowering of old wind farms.
How repowering works in practice
In Germany, for example, more than 2 gigawatts of wind power is coming out of the 20-year feed-in tariff every year and will either have to face full market risk, be decommissioned or be repowered. Many wind farms have already undergone the repowering process, such as Düngstrup Wind Farm in Lower Saxony, where eight 1,3 megawatt turbines were replaced by four new 3 megawatt turbines on the same site. While the old wind farm produced 12 gigawatt hours per year, the new turbines produce 35 gigawatt hours. At another wind farm in Dardesheim, 2-megawatt turbines will soon be replaced by 5,5-megawatt machines, quadrupling the existing output. In general, repowering projects can be expected to multiply by a factor of four in terms of power output and by a factor of three in terms of installed capacity.
Wind power multiplied by 3/4
Of course, quadrupling wind power output is not only good for the wind farm operator, it also makes it easier for countries to meet their renewable energy targets – especially densely populated countries with a limited number of viable sites. So repowering is obviously a win-win-win for the operator/investor of the existing wind farm as well as for the local communities and the country in general.
However, there are some barriers that make repowering a challenge for wind farm operators:
Of course, the technology itself is usually not a problem, but the main hurdles lie in regulatory issues, namely permitting rules and remuneration schemes.
In some cases, repowering projects are no longer subject to statutory remuneration schemes, which increases the financial risk of such investments. The global trend towards auctions is also a negative factor for such projects, as older wind farms are often owned by small or medium-sized companies that may not be able to cope with the risk of not winning a public auction. Such market uncertainties, e.g. caused by auction systems, may exclude early movers and investors from participating in the market for new wind farms and receiving the necessary remuneration.
Therefore, wind farms should have easier access to fair remuneration after repowering.
Similarly, regulatory rules often hinder the replacement of older wind turbines with new ones:
Permits for wind farms are usually not valid for new turbines, and in some cases it may not be possible to build a new wind farm on the site of an existing one. In some cases, there are no rules at all and the authorities simply do not know how to deal with the situation.
In general and as a new paradigm, legislation should explicitly allow repowering in order to take advantage of the large additional potential that can result from repowering wind farms.
Permitting procedures for repowering should be simplified. This will still be in line with environmental and other standards, as a proper assessment of the relevant factors has usually already been carried out.
Global repowering potential
The potential to increase global installed capacity through repowering is huge: 15 years ago, global wind capacity was around 100’000 megawatts. Assuming a repowering factor of three to four, this could add 200’000 megawatts of installed capacity – or 20% of current capacity. If we consider the wind capacity installed ten years ago of around 350’000 MW, we could add capacity equivalent to the current total installed wind capacity and more than double the wind power output.
Looking at the big picture, repowering of existing wind farms has the potential to increase the share of wind power in the electricity supply in a very efficient way. It should therefore be a key component of any country’s renewable energy and climate strategy.
About the author:
Stefan Gsänger is Secretary General of the World Wind Energy Association with head office at the UN Campus in Bonn/Gemany. He has managed WWEA since its foundation in 2001. Under his direction, WWEA has become the voice of the wind sector worldwide, with members in more than 100 countries. Stefan Gsänger holds various other positions, including co chair of the Global100% Renewable Energy Platform as well as chair of the IRENA Coalition for Action Community Energy Group. He has supervised and co-chaired 21 World Wind Energy Conferences on all continents, and has been an invited speaker at conferences in more than 40 countries. He has published numerous articles and studies on wind power and renewable energy.
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