Demand response and vehicle-to-grid: Impact and additionality

Soaking up India's wasted midday solar without new mining

For India the case is direct: flexibility can absorb midday solar that is now being curtailed and ease the evening peak that keeps coal running, with no new mining. Its emissions benefit depends on which hours load moves into, and its benefits can skew towards better-off households.

Grid decarbonisation versus fossil displacement

A shift of two to four hours targets the evening peak, which is the job gas peakers do in the US and coal largely does in India. India curtailed about 2.3 TWh of solar between late May and December 2025, partly because coal units, which cannot go below a 55% minimum load, had to stay online for the evening peak (Ember estimate from Grid-India data). Moving load into solar hours tackles both problems. IEA's net zero pathway (tracking page, data to 2023) needs 500 GW of demand response by 2030, about ten times the 2020 level, and says growth is far behind. Benefits depend on the local grid mix: moving load overnight on a coal-heavy grid can raise emissions.¹²³⁷

Just transition and local community impact

Flexibility can lower bills and replace polluting peak plants, but payments flow to people who own thermostats, EVs and batteries. In the US, more than 20 million households were behind on electricity bills in early 2023, and two-thirds of fossil peakers sit near communities with above-average low-income shares. In India, ToD tariffs apply to a consumer only once a smart meter is installed, and agricultural consumers are excluded from the 2025 deadline. Tata Power's demand response programme, launched in February 2023, targeted 55,000 homes and 6,000 businesses for a 75 MW peak cut, scaling to 200 MW.¹³⁵

Circular economy and end of life

Flexibility gets more out of appliances and vehicles that already exist rather than building new storage, so it creates almost no end-of-life waste of its own. The open question is whether V2G shortens vehicle battery life or reduces its second-life value. Current evidence suggests the effect is small if V2G is well managed, but it comes from lab and model studies, not fleet data.⁸⁹¹⁰

Sources

1. Pathways to Commercial Liftoff: Virtual Power Plants US Department of Energy, 2023
2. Liftoff: Virtual Power Plants (2024 update fact sheet) US Department of Energy, 2024
3. Demand Response (tracking page; undated, latest data early 2023) International Energy Agency, 2023
4. Lok Sabha Unstarred Question No. 41: Power Tariff System (answer by Ministry of Power, 20 July 2023) Parliament of India, Lok Sabha, 2023
5. Beyond capacity: why India's power system must get flexible (chapter: 2025 saw significant solar curtailment to preserve system stability) Ember, 2026
6. Global EV Outlook 2026: Vehicle-to-grid technology International Energy Agency, 2026
7. On the possibility of extending the lifetime of lithium-ion batteries through optimal V2G facilitated by an integrated vehicle and smart-grid system (Uddin et al.), Energy 133 University of Warwick (WRAP repository), 2017
8. German study shows V2G has minor impact on battery degradation (trade press on a study co-authored by RWTH Aachen and the aggregator The Mobility House; not peer reviewed as far as found) New Mobility News, 2025