India needs a robust ancillary services framework to ensure grid stability

Saurabh Kumar | Updated on November 12, 2018 Published on November 12, 2018

The services will not only help maintain load-generation balance but also manage renewable integration into the grid

India’s ongoing mission to substantially increase renewables in its energy mix poses some pertinent challenges, such as the daily intermittence and seasonal variability of renewable power on grid stability. India plans to increase the share of non-fossil fuel in its total installed power capacity to 40 per cent by 2030. Despite being path-breaking, this vision comes with its own set of challenges, foremost among which is grid stability vis-à-vis renewable intermittency.

As a result, ancillary services become critical. Ancillary services are the support services that complement the grid’s operational reliability. These services are procured and pressed into service by the system operator, who can use them to maintain grid frequency, network voltages and other grid parameters within specified limits.

For example, ancillary service can help maintain load-generation balance (in turn, grid frequency) in case of sudden failure of generating unit or transmission element, uncertainties or errors in load forecasts and variable renewable energy forecasts, sudden disturbances in the power system, etc.

The Ancillary Services Operations Regulations, 2015, introduced by the Central Electricity Regulatory Commission, is a framework that enables use of un-requisitioned surplus generation capacity of existing generators as ancillary services. However, such un-requisitioned surplus may always not be available. Therefore, India needs a permanent ancillary services mechanism to manage not only the renewable integration into the grid but also the emergency situations for frequency control.

The challenges

Variability of renewable integration, such as inability to generate solar energy in the night-time, poses a risk of grid instability. Therefore, the energy system needs to be flexible enough to adjust the load changes, ramping up or down quickly depending on the situation.

As India’s renewable capacity increases, it creates more need for supporting interventions such as better system operations, and energy storage system, among others. To support India’s ambitious renewable target of 175 GW, we must invest in developing commensurate ancillary services to support the power system when large quantities of renewables are integrated into the grid.

Another supporting intervention would be forecasting renewable generation and estimating the balancing requirement. This can help in managing the system’s overall variability. In case of any error in forecasting and the resultant deviation from schedule, ancillary services can come to the rescue.

Financial implications

The financial implication of deploying ancillary services needs to be studied carefully in the Indian context. If it is passed on to the renewable energy generators, it could derail the growth of the budding sector. The additional cost of provisioning for ancillary services could impact the economic viability and competitiveness of renewable energy generators and might dampen the sector’s investor sentiment.

Secondly, all disturbances in the power system do not originate from renewable energy sources. There is also a requirement of ancillary services to manage the variability of the power system due to conventional generation as well as consumers deviating from schedule. Therefore, we need to explore the option of a market-driven mechanism to meet the requirement of introducing ancillary services in the Indian power system.

A market-based mechanism will ensure that services are procured at the lowest cost, which would, in turn, maximise the benefit to consumers. A transparent market-driven mechanism will also ensure that future demand requirements are clear and quantified, and that procurement is rationalised. This will allow developers to take account of the value of ancillary services when new projects are at the design stage, as well as when securing finance.

This ancillary services market should be designed to facilitate the evolution of the energy system and should be constantly evolving to meet this challenge. There is a huge scope to deploy innovative solutions as well as existing technologies in innovative ways, to further promote such a market. After all, a robust supportive system of ancillary services is a must to keep the grid stable and power supply reliable.

The writer is Managing Director, Energy Efficiency Services Ltd.

Published on November 12, 2018
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