Kerala is among India’s leading states when it comes to household adoption of rooftop solar panels under the PM Suryaghar Yojana.The flagship central scheme offers every beneficiary free electricity up to 300 units every month and cash subsidy for equipment. While the scheme’s success has been uneven across the country, Kerala has been an enthusiastic adopter. In fact, it ranks fourth in rooftop solar installed capacity — ahead of several big states such as Tamil Nadu, Karnataka and Madhya Pradesh.Yet, it is this very success that is at the heart of the state’s challenge in meeting its power demand. This sounds counterintuitive — after all, shouldn’t more rooftop solar panels ease electricity supply?The answer is not so straightforward. Here’s a look at how the electricity consumption patterns in Kerala are undermining the successes from the state’s record solar energy generation.Kerala’s solar success storyAccording to the latest available state government data, Kerala’s solar production touched 2,508 megawatts (MW) by the end of May 2026. The vast majority of this installed capacity — 2,036 MW — is from rooftop panels.Status of key solar schemes. The data in these tables is as of May 31. The numbers, particularly Kerala’s, have now increased.Under the PM Surya Ghar scheme, Kerala has 2.96 lakh installations covering 3,03,531 households. Its installed capacity from PM Surya Ghar alone is 1,150 MW.Neighbouring Karnataka, for comparison, has only 22,383 installations covering 33,843 households, with an installed capacity of 91 MW.Story continues below this adThe share of solar power as a whole is more than 50% per cent of the state’s total installed capacity from all sources. This proportion is even better than the all-India share of solar power in the overall power generation mix — 150 GW of the total installed capacity of 532 GW.So what is the issue with this?In many industrially developed states, the demand for power peaks during the day. In Kerala, however, the peak demand is from 6 to 11 pm as 75% of the consumers are domestic. Industrial and commercial connections account for only around 20% of the total consumers.This has created a mismatch between an abundance of solar energy during the day and the shortage of power supply at night.To be sure, this mismatch is not a Kerala problem alone. The country’s power grid has indeed been facing its greatest strain at night time. This, however, is more a function of supply failing to even meet the relatively reduced night-time demand, rather than demand rising during those hours. In Kerala, the latter is the key problem — demand rises at night.Story continues below this adAlso Read | Power subsidies are slowing household solar adoption. A solution: More subsidiesIn the state, solar energy, which is generated during the day time, is not consumed during those hours.According to estimates by the KSEB, the decentralised ‘producers-cum-consumers’ of rooftop solar energy — or ‘prosumers’ — use only 36% of the solar power produced during the day. The remaining 64% is exported to the state power grid. At night, these prosumers take back (consume) around 45% of the banked power.A prosumer is a household or business that generates its own electricity via solar panels for personal use and feeds the excess power back into the utility grid.So how does this affect the grid?Story continues below this adThe power produced from solar plants during the day is exported to the low-tension power distribution grid. But excessive feeding of solar power to the grid during the day, when consumption is low, increases the voltage in the system. This, in turn, increases the chances of electrical appliances and transforms getting damaged.Normally, a 3 KW household solar power unit generates 12 units of power. The consumption is usually around six units. To maximise the gains from the on-grid rooftop solar plants, prosumers use more electrical appliances especially during the night hours, which again increases the demand for power supply in the peak hours.Also Read | Temperature drops at night. So why is India’s power grid facing the most strain in those hours?An illustrative example of this is the increased sale of induction cookers in Kerala after the proliferation of rooftop solar plants.Story continues below this adSo, when power supply declines in the national market at night, Kerala’s electricity utility is forced to buy it at higher prices to meet its rising demand.Kerala’s power generation mixKerala has traditionally been dependent on hydroelectricity. But according to the latest data, 83% of its daily power demand is now met by purchases from power exchanges. According to data presented in the Assembly last month, the daily average consumption is 88.45 million units.Of this, the total domestic generation in Kerala from hydel, wind and solar is only 15 million units. The remaining 73.41 million unit demand is met by purchases from the national market at competitive rates — which often run up to Rs 10 per unit during peak hours.In the last ten years, Kerala was able to add only 150 MW to its hydel power production, whereas the solar capacity during the period increased by 2400 MW.The road aheadStory continues below this adThe challenge facing Kerala, at its core, is the same challenge facing the country. As the share of renewable power sources increases, so does the mismatch between when electricity is generated and when it is needed. The answer, as The Indian Express has reported earlier, is storage.Also Read | India is rapidly scaling up renewable energy. Now it needs to store itThe KSEB has lined up a battery energy storage system (BESS) to “store” the solar power produced during the day — rather than pumping it back into the grid. This will ensure that the power can be used during the peak nighttime hours.KSEB has been one of the early movers from among state-run entities in this regard. The first such storage unit with a capacity of 125 MW is expected to be commissioned at Mylatti in Kasaragod in October this year.Story continues below this adSimilar BESS facilities with varying capacity will come up in Kochi, Thiruvananthapuram and Areekode (Malappuram) at later stages. The KSEB has been demanding that the battery system be made mandatory for all solar plants above 3 KW. The suggestion, however, has not so far been cleared by the regulatory authority.