Solar is on a roll in India, and sceptics are increasingly questioning the relevance of onshore wind to the nation’s future energy mix.

As of May 2020, there was 38GW of onshore wind in India, 24GW of which was added in the last ten years. That looks leisurely in comparison to solar, whose installed base rocketed from 4GW to 35GW just in the last five.

Solar is now the cheaper source of new renewable power in India and is spread out across 10 states, as it does not face infrastructure issues faced by wind, which is concentrated in two states.

But it would be wrong to dismiss onshore wind, and there are plenty of reasons for stakeholders to keep faith in a generation source that has led India’s renewable growth to date.

Firstly, the potential for wind-based power in India stands at 697GW, which is comparable to solar’s potential of 750GW.

Out of that 697GW, nearly 52GW of unexploited sites have capacity utilisation factors (CUFs) of >35%, which can be exploited with current 120-metre rotor diameter and 2.X turbine technology that can match the low prices of solar equipment.

It is estimated that total unexploited potential at sites with annual CUFs between 30% and 35% is approximately 150GW.

This potential can be exploited at low costs thanks to innovation and the introduction of larger generators and rotor diameters, and development of ultra-low wind sites. This is contingent on the plans of OEMs to develop projects in line with pricing expectations in the market.

Beyond price-driven installation, wind will play a role in supporting the requirements of integrating renewables on the grid. SECI, the tendering arm of the Indian government, has shown interest in conducting tenders which can provide firm and flexible supplies, with provision of 12-15 hours of continuous supply or round-the-clock (RTC) power, or supply power during peak-hours. Wind can be useful here for two reasons:

Firstly, wind offers a more consistent generation profile as compared to solar, which is available for 6-7 hours in a day. An oversized wind plant combined with solar eliminates, or reduces, the amount of expensive battery storage needed for getting a higher capacity utilisation factor.

Secondly, wind and solar are complimentary in the generation profile in terms of time of the day and season. Wind supplies power during peak consumption hours in a day. Seasonally, solar production is available during the months of November and December when wind is almost non-existent and reverses the role during monsoons.

Wind and PV are complimentary in the generation profile.

These two properties have been exploited in the recent RTC tender by SECI. Developers are expected to achieve lower cost of energy by oversizing wind and solar projects as compared to introducing storage to meet the requirement of 70% monthly CUF and 80% annual CUF.

This arrangement is likely to continue as long it makes economic sense and grid regulations do not require dispatch restrictions.

In parallel, discussions are ongoing within nodal agencies to chalk-out the requirements for grid stabilisation as renewables ramp up. Here, wind power plants are expected to provide uncompensated primary tertiary as per the last discussions on Grid Codes starting April 2022.

This development might pave the way for eventual participation in compensated tertiary frequency-response, creating avenues for new revenue. However, that opportunity is more long-term.

Sidharth Jain is managing director at MEC+