Greening the Grid

India can integrate the entire targeted 175 GW of renewable energy into the national electricity grid based on projected power system plans and regulations according to a study conducted under the U.S. – India bilateral program. The report confirms the technical and economic viability of integrating 175 GW of renewable energy into India’s power grid by 2022, and identifies future course of actions that are favorable for such integration.

The study “GREENING THE GRID: Pathways to Integrate 175 GW of Renewable Energy into India’s Electricity Grid” was launched by Mr. Piyush Goyal, Minister for Power, according to a government release.

During study, it was found that power system balancing with 100 GW of solar and 60 GW of wind is achievable at 15-minute operational timescales with minimal reduction in renewable energy output. India’s current coal-dominated power system has the inherent flexibility to accommodate the variability associated with the targeted renewable energy capacities.

Initially there were questions raised regarding the viability of adding 175 GW of intermittent renewable energy to the grid. Many thought it would destabilize the grid as renewable energy production fluctuates according to weather.

The report was prepared by Power System Operation Corporation (POSOCO) and the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) and Lawrence Berkeley National Laboratory (LBNL) using advanced weather and power system modeling, under the leadership of Ministry of Power and the U.S. Agency for International Development (USAID) with co-sponsorship from the World Bank Energy Sector Management Assistance Program (ESMAP) and the 21st Century Power Partnership.

“This study will prove to be helpful in scaling up renewable energy in India effectively and sustainably,” stated Michael Satin, Director of Clean Energy and Environment at USAID/India.

It is time for the people of India to get ready and embrace the change with a ‘New Mindset’ of a ‘New Grid’ for a ‘New India’, which is ready to integrate large amounts of renewable energy, stated Mr. Piyush Goyal.

Key Findings of the Study:

  • Power system balancing with 100 GW of solar and 60 GW of wind is achievable at 15-minute operational timescales with minimal RE curtailment. This RE capacity generates 370 terawatt hours (TWh) annually, a 22% share of total electricity consumption in India, reaching a nationwide instantaneous peak of 54%. Annual RE curtailment (assuming sufficient in-state transmission) is 1.4%, consistent with experiences in other countries with this level of RE penetration.
  • Fuel requirements for coal and gas fall 20% and 32%, respectively, and CO2 emissions fall 21% (280 million tons) in 100S-60W compared to a No New RE scenario. As a result, plant load factors for coal drop from 63% to 50% with nearly 20 GW that is never economical to start.
  • Changes to operational practice can reduce the cost of operating the power system and reduce RE curtailment, but are not essential for 160 GW RE integration. Scheduling and dispatch that is optimized at the regional, rather than state level can support more efficient operations of thermal plants and reduce annual operating costs by 2.8%, or ₹6,300 crore (~$980 million). National coordination provides even further cost savings (3.5% savings) and reduced RE curtailment (to 0.9%).
  • Reducing minimum generation levels of large thermal plants is the biggest driver to reducing RE curtailment. Changing minimum generation levels of all coal plants, from 70% today to 55% of rated capacity (consistent with the CERC regulations) reduces RE curtailment from 3.5% to 1.4% and annual operating cost by 0.9%, or ₹2,000 crore (~$311 million). Reducing minimum generation levels further, to 40%, reduces RE curtailment to 0.76%, with negligible decreases to annual operating costs.3 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 peak systemwide 1-hour up-ramp increases 27% compared to a system with no new renewables, to almost 32 GW up from 25 GW. This ramp rate can be met if all generating stations exploit their inherent ramping capability. The peak systemwide 1-hour up-ramp increases 27% compared to a system with no new renewables, to almost 32 GW up from 25 GW. This ramp rate can be met if all generating stations exploit their inherent ramping capability. We found no significant change in either production cost or RE curtailment when coal generation ramp rates were made less flexible in the simulations, although this study assumes a similar load shape for 2022 as prevailing today.
  • A copper plate sensitivity delivers 4.7% savings and 0.13% RE curtailment. The “copper plate” represents a transmission system with no constraints and operations with no barriers to scheduling.
  • Batteries insignificantly impact emissions and total cost of generation. Batteries do reduce curtailment (from 1.4% to 1.1%); however, the value of this curtailment is offset by the batteries’ efficiency losses during operation. In the 100S-60W scenario, 2.5 GW of batteries (75% efficient) reduce RE curtailment by 1.2 TWh annually but lose 2.0 TWh annually due to inefficiencies. Also, there is insignificant impact on the total cost of generation because the overall generation mix changes little.
  • Retiring 46 GW of coal (20% of installed coal capacity) does not adversely affect system flexibility, assuming adequate instate transmission. Retiring coal plants that operate less than 15% of their capacity annually (205 generation units, totaling 46 GW in capacity) has almost no effect on system operations.

“The study lays out a detailed roadmap of integrating 100 GW of solar and 60 GW of wind by 2022. The challenge of course is in the timely execution and political considerations, which has always been a challenge in the Indian power sector. However, this administration has so far shown the will to transform the Indian energy sector,” said Raj Prabhu, CEO of Mercom Capital Group.