India Can Integrate 175 GW RE Into Grid

• Indian grid with its existing fast-ramping infrastructure is capable of maintaining grid balance and accommodate targeted 175 GW RE capacities by 2022, according to a new study by NREL, LBNL and Indian partners
• There will be large benefits of fuel savings and reduced emissions with such large amounts of RE capacities added to the grid
• In the post 175 GW clean energy scenario, coal plants operating at part capacity would need suitable incentives for flexibility, according to the report
• Second volume of the study is scheduled to be released in July 2017 which will study system operations in the Western and Southern regions

Amid concerns about India's ability to achieve its renewable goals, a new grid integration study stated it has confirmed the technical and economic viability of integrating 175 GW of renewable energy into India's electricity grid by 2022.

This is the key findings of a study titled 'Pathways to Integrate 175 GW of Renewable Energy into India's Electricity Grid', which was published by a multi-institutional team of India's Power System Operation Corporation (POSOCO) and the US Department of Energy's National Renewable Energy Laboratory (NREL) and Lawrence Berkeley National Laboratory (LBNL).

Using weather and power system modeling, the study explored operational impacts of meeting India's 2022 targets and identified actions that are favorable for integration. "The results demonstrate that power system balancing with 100 GW solar and 60 GW wind is achievable at 15-minute operational timescales with minimal RE curtailment," the authors say. " India's current coal-dominated power system has the inherent flexibility to accommodate the variability associated with the targeted RE capacities, and coal flexibility in low-RE, coal-dominant states can play an  role in facilitating RE integration nationwide."

The study results reveal operational impacts, including:

• 160 GW of solar and wind capacity can serve 22% of India's power demand, providing benefits of fuel savings and reduced emissions.
• The power system as planned for 2022 is able to manage the added variability of wind and solar; new, fast-ramping infrastructure (such as natural gas turbines) is not necessary to maintain balance.
• In a system with 160 GW of wind and solar, coal plants, on average, would operate at only half their capacity, suggesting the potential role for a new tariff structure that moves away from focusing on energy delivery and instead compensates plants for performance that achieves flexibility goals.

According to the report, changing minimum generation levels of all coal plants, from 70% today to 55% of rated capacity (consistent with the Central Electricity Regulatory Commission regulations) reduces RE curtailment from 3.5% to 1.4% and annual operating cost by 0.9%, or 2000 crore INR. Reducing minimum generation levels further, to 40%, reduces RE curtailment to 0.76%, with negligible decreases to annual operating costs, the study says.  If only centrally owned plants achieve 55% minimum generation levels but state-controlled plants maintain minimum generation levels of 70%, RE curtailment is 2.4%. The latter scenario assumes that all coal plants will comply with the Central Electricity Regulatory Commission's regulation that these plants will operate at 55% of rated capacity.

However, that would require new power purchase contracts with coal plants. "Create a model tariff contract that can be used for contracts that are new and up for renewal based on economics of coal plants with lower plant load factors. For existing contracts, explore options used in other countries to renegotiate contracts," local business daily The Economic Times (ET) quoted from the report.

The first part of the study was released recently by the Indian Minister heading Ministry of New and Renewable Energy, Piyush Goyal. At the report release, he said that India's solar power generating capacity will increase to around 22 GW by the end of FY 2017-18. At the end of last fiscal year, the country's total installed solar power capacity was over 12 GW.  

The second volume of the report is expected to be published in July 2017. It will focus on system operations in the Western and Southern regions.

The study is supported by the Ministry of Power in India and the US Agency for International Development (USAID) with co-sponsorship from the World Bank Energy Sector Management Assistance Program (ESMAP) and the 21st Century Power Partnership.

The report can be downloaded on NREL's website.