The Ministry of New and Renewable Energy (MNRE) has announced the new wind solar hybrid policy which aims at providing a framework for the expansion of grid-connected wind-solar photovoltaics (PV) hybrid systems in the country.
The main objective of the policy is to provide a framework for promotion of large grid connected wind-solar PV hybrid system for optimal and efficient utilization of transmission infrastructure and land, reducing the variability in renewable power generation and achieving better grid stability. The policy also aims at encouraging new technologies, methods and way-outs involving combined operation of wind and solar PV projects.
The wind solar hybrid policy hinges on the idea that hybrid renewable energy projects will reduce the intermittency of the power sources. Studies revealed that in India, solar and wind resources are complementary to each other and the hybridization of these two technologies would help in minimizing the variability apart from optimally utilizing the infrastructure including land and transmission system.
MNRE had issued draft National Wind-solar Hybrid Policy in June 2016. The policy has now been finalized after detailed consultation with the stakeholders.
Superimposition of wind and solar resource maps shows that there are large areas where both wind and solar have high to moderate potential. The existing wind farms have the scope of adding solar PV capacity and similarly there may be wind potential in the vicinity of an existing solar PV plant.
- Under the category of wind-solar hybrid power plants, Wind Turbine Generators (WTGs) and Solar PV systems will be configured to operate at the same point of grid connection.
- There can be different approaches towards integrating wind and solar depending upon the size of each of the source integrated and the technology type.
- In case of fixed speed wind turbines connected to grid using an induction generator, the integration can be on the HT (high current) side at the AC output bus.
- In case of variable speed wind turbines deploying inverters for connecting the generator to the grid, the wind and the Solar PV system can be connected to the intermediate DC bus of the AC-DC-AC converter.
- A wind-solar project will be considered a hybrid project if the rated power capacity of one resource is at least 25 percent of the rated power capacity of other resource.
- The power procured from the hybrid project may be used for fulfilment of solar RPO and non-solar RPO.
- No additional connectivity or transmission capacity charges will be levied by the respective transmission entity for the hybridization at existing wind or solar projects.
- In case the capacity margins are available at the receiving transmission sub-station of respective transmission entity, at which the existing wind/solar projects is connected, additional transmission capacity or access may be allowed, subject to its technical feasibility.
- In case of AC integration, the assessment of solar and wind power injected from the hybrid project in to the grid will be worked out by apportioning the reading of main meter installed at the receiving station on the basis of readings of ABT meters installed on LT or HT side of the wind and solar PV project as the case may be.
- In case of DC integration, assessment of solar and wind power injected from the hybrid project in to the grid will be worked out by apportioning the reading of main meter installed at the receiving station on the basis of readings of DC meters installed at the DC output of the wind and solar project.
- Battery storage can be added to the hybrid project to reduce the variability of output power from wind solar hybrid plant; provide higher energy output for a given capacity at delivery point, by installing additional capacity of wind and solar power in a wind solar hybrid project; and ensure availability of firm power for a particular period.
The government will encourage the development wind-solar hybrid systems through various programs. All fiscal and financial incentives available to wind and solar power projects will also be made available to hybrid projects.
When contacted, an MNRE official told Mercom, “In India if we see, small wind-solar hybrid projects are under initial stages of implementation. But, we realized there’s a need for a policy framework to bolster growth in this segment of renewables. Going hybrid also puts a sort of check on the intermittency of solar or wind, if considered separately.”
In January 2018, Solar Energy Corporation of India (SECI) had invited expressions of interest (EoIs) from engineering, procurement, and construction (EPC) contractors to develop a 160 MW of large-scale solar wind hybrid project with an energy storage system in the Ramagiri district of Andhra Pradesh.
The National Thermal Power Corporation (NTPC) too had issued a notice inviting tender (NIT) to set up a 3.5 MW solar plus wind hybrid power project at NTPC Kudgi in Karnataka.
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