The difficulty with renewables

General Studies Paper 3

• Context: The target of having 500 GW of non-fossil generating capacity by 2030 may look impressive. But, it may prove to be elusive unless we can enhance our storage capacity.

Why is storage not a prominent challenge for the energy sector in current times?

• India has more than 200 GW of coal-based capacity. The Central Electricity Regulatory Commission recognises 55% as the technical minimum. It means that a 1,000 MW plant can run at 550 MW.
• The additional operating cost for running the plant at 55% capacity is allowed by the CERC as legitimate expenditure.

Why is there a need for a focus on storage capacity in the future?

• When India’s renewable capacity goes up further, some of the coal-based units would generate at the technical minimum and the extra renewable energy would be used to charge the batteries.
• This stored energy could be used to supply electricity during the non-solar hours, especially when the coal-based generating units would be phased out gradually.
• Some minimum coal-based generation would be required for meeting a part of the base load.

What are storage options for India and hurdles faced by storage options?

• These options are hydrogen-based storage, lithium-ion batteries and pump storage plants.
• Hydrogen storage is feasible for long-term storage. One can use this stored energy, for example, in situations when coal mining goes down or when hydro generation depletes due to low reservoir levels.
• For day-to-day storage, batteries are still the ideal source. Though the cost of batteries has declined by about 80% over the last decade, it is still quite expensive. Moreover, the pace of decline in the cost of batteries has reached a plateau.
• Pump storage plants, India has a total capacity of about 4.7 GW but only 3.3 GW is functional. A survey of the CEA estimated a pump storage potential of about 100 GW.
• Pump storage plants have not really grown in India due to several factors, including high investment costs, long gestation periods, non-remunerative pricing models and lack of adequate sites having the topography that is required for operating a pump storage plant.

What will be other challenges for the renewable energy sector in India?

• The financial condition of our distribution companies will be another hindrance. The additional solar and wind capacity has to come from the private sector.
• No developer will invest unless there is some credible payment security mechanism.
• Problems with land acquisition, and securing the right of way for laying down transmission lines will also continue to hinder progress.