Hybrid renewable energy projects combining solar and wind power generation are gaining traction globally and now appear to be winning favor with the Solar Energy Corporation of India and several state governments.
Although the nation has only 100 MW of hybrid facilities at present, analyst Crisil predicts around 15 GW of combined wind and solar capacity will be installed in India over the next five years. Of the new project capacity, around 10 GW is already under construction or being tendered – and will start feeding the grid by 2024.
Co-locating solar and wind plants reduces the variability of generation and improves grid security, overcoming the reluctance of electric distribution companies to act as renewable energy offtakers. Combining the two technologies also offers developers the chance to maximize returns, even on sites with sub-optimal solar and wind resources.
A Crisil report into hybrid projects states pricing will be critical to even wider adoption. The analysts estimated wind-heavy facilities will be able to produce electricity for tariffs of around Rs2.80-2.90/kWh, compared to Rs2.50 for solar and Rs2.80-2.85 for wind.
“The [hybrid] tariff can be brought down by another Rs0.10/kWh if the co-location clause (necessitating the wind and solar components to be located at the same place) is removed,” said the analysts.
For wind-solar hybrid-plus-storage projects, Crisil estimated a weighted average tariff – including on and off peak periods – of Rs4.04-4.30 could be reached, as witnessed in recent auctions. Such a power price would be competitive with equivalent thermal power prices of Rs4.40/kWh.
Lack of transmission infrastructure at sites with suitable solar and wind resources was cited as a potential hurdle to hybrid project deployment, as well as grid balancing technical concerns.
Some 3.9 GW of hybrid generation capacity has been proposed in India, with a further 4.5 GW which will be associated with energy storage. In addition, 1.1 GW of hybrid capacity is expected as part of the 5.4 GW envisioned under the round-the-clock (RTC) scheme introduced by the Ministry of New and Renewable Energy to even out intermittency concerns by bundling clean energy generation with coal-fired power. The RTC program mandates a 51:49% ratio of renewables to thermal facilities.
“Since wind-solar hybrid projects with energy storage systems (ESS) can cater to peak and RTC power demand, they can reduce the country’s dependence on gas-based and pumped hydro-based peaking plants,” wrote the Crisil analysts. “They can also improve the role of RE [renewable energy] in providing grid ancillary services on the generation side. Moreover, they can spur ESS demand by [encouraging the] building [of] an effective storage ecosystem.”