A new CSTEP study shows that co-locating solar plants with battery storage improves power reliability. Researchers used a Karnataka case study to find optimal configurations for a 100-MW power block. They said, "simply adding batteries to solar projects will not guarantee economical, reliable power," as costs depend on delivery times.
Co-locating solar power plants with battery energy storage systems (BESS) can improve the economics and reliability of firm renewable power, but the project design must balance cost, supply reliability and renewable energy curtailment, according to a new study by the Center for Study of Science, Technology and Policy (CSTEP).
The study, titled 'Co-locating solar and battery storage for reliable power supply', examines how solar and battery capacities should be sized to meet defined power delivery obligations, using a Karnataka case study of a continuous 100-MW power block over durations ranging from two hours to 24 hours.
It finds that the optimal combination depends not just on the duration but also the time of power delivery.
Obligations extending into non-solar hours require more storage and can raise costs. Across the modelled optimal configurations, the levelised cost of energy ranged from ₹5.73 to ₹6.79 per kWh.
For a round-the-clock supply obligation, the model's preferred configuration comprised 515 MW of solar capacity and 1,300 MWh of battery storage.
It covered 76.4 per cent of annual demand at ₹5.73 per kWh. Raising demand coverage to 85.8 per cent would require 768 MW of solar and 3,120 MWh of storage, increasing the cost to ₹8.32 per kWh.
CSTEP recommends that renewable-plus-storage tenders explicitly consider curtailment alongside cost and demand fulfilment.
It also calls for geographic information system-based site selection and delivery schedules designed around actual power system requirements, rather than standardised supply windows.
The study cautions that grid import and export constraints, dependence on imported battery cells and uncertainty over long-term revenue streams remain barriers.
It also notes that its analysis did not account for battery degradation over the project lifetime.
The central message is that simply adding batteries to solar projects will not guarantee economical, reliable power. Procurement must be designed around factors such as the time of electricity supply and how efficiently the combined system can deliver it.
Minister Pralhad Joshi leaves RoW resolution to states
New and Renewable Energy Minister Pralhad Joshi has left the 'right of way' issues plaguing the wind industry to the State governments, saying the ball is in the states' courts, because "land is a State subject".
Answering a question at a press conference in Chennai, on the sidelines of the Windergy 2026 event recently, Joshi called upon State governments to solve the RoW issues -- after all, it is in their interest to get cheap clean energy, something that will help industries to export.
In this context, Joshi referred to the Green Energy Corridor-III scheme, announced recently with an outlay of ₹1.86 lakh crore, including a central government assistance of ₹55,000 crore, for which the State governments would have to compete ("challenge mode"). He said land availability would be an important factor in such a competition.
Wind installations in India are growing. After a poor record in the first quarter of the current year (1.35 GW), projects picked up to reach 3.1 GW in the first six months, raising hopes for annual installations of around 7 GW.
Yet, the big factor hampering smooth implementation of wind projects is the RoW issue, with most projects suffering delays from filibustering protests in the name of extracting fair compensation for the landowners from the developers.
Recently, the Ministry of Power came out with tweaked guidelines for paying compensation, but industry fears that protests may continue regardless.