The Ministry of New and Renewable Energy of the Indian government has now come forward with its latest draft policy, aimed at repowering old and low-performing wind turbines to maximise the potential of these wind projects.

Out of a total 41.6 gigawatt installed wind energy capacity in the country, more than 25 gigawatt of wind turbines need repowering, as per the estimate made by the National Institute of Wind Energy. However, the country has not been able to move forward in this direction so far.

In 2016, the ministry had issued a similar policy to repower old wind energy plants but failed to achieve the desired result. Now, with some revision and additional provisions in the new draft policy, the ministry is making a fresh attempt to revitalise the wind energy sector.

Repowering means the upgradation of under-performing wind turbines to make them more efficient and ensure maximum utilisation of the wind potential available in the country.

According to experts working in the sector, there are several benefits of repowering inefficient wind turbines and the new policy can prove vital in its overall growth. Deepak Krishnan, associate director (Energy Programme) at the World Resources Institute-India, told Mongabay-India that modern wind energy turbines are better suited for more power production, handling stormy weather conditions besides other advantages. “The new generation wind turbines come with multiple benefits – for example, they are equipped with condition monitoring equipment which can help in integration with monitoring platforms. This will be of great help in operations and monitoring and forecasting among others. They also have control features which help in protection of the blades during severe storms. Also, these turbines are better in load management,” he said.

A wind farm in Tamil Nadu. Open access for green energy could help minimise fossil fuel usage and promote country – wide trade of clean energy. Credit: Narayana Swamy Subbaraman/Mongabay

The new draft policy identifies wind turbines that need repowering. These include turbines below the capacity of two megawatt or those that have completed their design life. This has come as a revision of the older 2016 policy which initially allowed for the repowering of only those wind turbines which are below the capacity of one megawatt.

To make a case for this change in the criteria, the draft policy says, “Since the latest wind turbine technology of three-plus megawatt capacity is being manufactured in the country, the repowering of turbines below two megawatt capacity must be considered.”

There are some similarities between the 2016 policy and the latest draft policy, such as a 0.25% interest rate rebate for repowering projects. The new draft policy adds a special scheme which the Centre or state might launch to give other incentives for the wind power developers if they want to repower their turbines. The draft policy also says that the states where the repowering will take place could be exempted from their Renewable Purchase Obligation compliances during the period when the turbines are being repowered and there is no production of wind energy from such plants. The project developers will have the liberty to sell additional wind power generated after repowering to the incumbent distribution companies (discoms), or, to any other entity through open access (subject to refusal of concerned discoms).

Krishnan claimed that these changes are likely to help in giving an impetus to the proposal.

He said, “The old policy of 2016 was getting stuck mainly on the issue of who will pay for the additional transmission capacity to be added with repowering. The new policy has two key features – it gives additional Renewable Purchase Obligation benefits to the wind power projects undertaking repowering and also has found solutions for aggregators where multiple players apply together for repowering. In my view, repowering can become attractive due to these policy changes. The new policy also raises the limit for re-powering to two megawatt which can bring in a larger set of projects under its ambit.”

The new draft policy also talks about the formation of a new Wind Repowering Committee comprising members from the central and state governments, the Indian Renewable Development Agency, Central Transmission Utility of India Ltd., National Institute of Wind Energy, state renewable agencies and independent members and others. It also defines the increased potential of new turbines to 1.5 times of the aggregate potential of the old wind turbines during the process of repowering.

“Some of the old wind turbines have already completed their design life while some are approaching the end of their design life. These wind turbines are not only inefficient in comparison to the latest technology but also have lower hub heights (in the range of 30- 60 m) in comparison to hub heights of 120- 140 m range being installed these days. The lower hub height wind turbines are not able to harness the higher wind available at higher hub heights. Therefore, it is essential to repower these older, smaller wind turbines with higher capacity and higher efficiency turbines, in order to optimally utilise the wind energy resource available at the respective site,” the draft policy note said.

According to the latest reports, India has till now been able to harness a total of 41.6 gigawatt of wind energy whereas the total installed capacity of renewable energy of India up to September 2022 stood at 118 gigawatt excluding big hydro projects. According to the latest Nationally Determined Contribution document submitted by the Indian government to the United Nations, India aims to achieve 50% of its energy requirements through non-fossil fuel sources by 2030 while it plans to become emission-free by 2070.

Benefits and challenges

Gujarat-based renewable energy consultant Prakash Vora said that with the advancement of technology, the production of wind energy specific yield per square km has improved. Technological advancements, taller towers and the larger swept blade area has supported this improvement.

“When India started its first few wind projects in the early 90s the average turbines had a capacity of as low as 250 kilowatt to 500 kilowatt while these days, large wind turbines have a capacity of more than four megawatt. Now, the same land and sites can produce around double of the power. Old turbines occupy the best wind potential sites but are less efficient. A majority of the modern wind turbines are situated at less potential sites. In India, around 60% wind turbines have completed more than 20 years and are close to their end of life. So it is very logical to replace them with smarter wind turbines through the repowering process,” Vora said.

A report published by the New Delhi-based clean energy think-tank Vasudha Foundation this year claimed that in the early 90s, the Indian government funded several wind projects and used it as demonstrative projects which took a majority of wind rich sites. The report advocated for repowering most of the government-funded old wind projects first to push the process which the private players could also follow later. The report also claimed that newer advanced wind turbines need lesser operational and maintenance costs, have the virtue of monetary benefits from the decommissioned wind turbines, relief from land acquisition, reduced noise levels due to the deployment of more powerful blades, and also reduced anticipation of mortality of Avian creatures due to low speed of larger wind turbines.

However, experts claimed that despite a forward looking policy of 2016, repowering could not take place as it didn’t address a lot of issues which the new draft policy is trying to.

“Our analysis showed that in India there are only 16 states which have released their wind policies and only three states namely Rajasthan, Andhra Pradesh and Maharashtra have repowering elements in their policies. In 2018 Gujarat became the only state to have a dedicated policy on repowering wind energy plants,” Jaideep Saraswat, senior manager with Vasudha Foundation told Mongabay-India.

However, there are also some challenges related to the transition which has often raised apprehensions among the wind power developers in India. “Sometimes there are more than one owner of wind projects with shared infrastructure. For a transition, every stakeholder needs to come on board. There could be multiple landowners whose land were used in such projects and bringing them onboard is another challenge to avoid future litigations. The evacuation of the extra energy produced could be another challenge, if the local discoms are reluctant to take it up or the developers do not want to give it to the bad performing and erring distribution companies,” a private wind developer company representative told Mongabay-India requesting anonymity.

India aims to achieve 50% of its energy requirements through non-fossil fuel sources by 2030. Credit: Vestas/Yahoo/Wikimedia Commons

While talking about the challenges, World Resources Institute-India’s Krishnan said, “Differing ownership across a potential repowering patch is always difficult. Although the new policy provides a solution through Wind Repowering Project Aggregators, it will involve rounds of negotiations. Like, signing of power purchase agreements that satisfy both discoms and wind developers for the additional power to be produced post repowering could be a cumbersome exercise. Similar challenges can occur when a developer seeks the approval from the distribution company before entering into open access sale for the additional power.”

This article first appeared on Mongabay.