Do we really require the balancing reserve to integrate wind power to grid?
While India reaches to a installed capacity of over 20GW of wind power, handling the variability of wind power is a significant challenge the grid operators face today. The states such as Tamilnadu has about 45% of its installed capacity as wind power and the sudden ingress or withdrawal of wind causes considerable difficulties in grid operation. During periods of sudden wind generation ingress, if the load is not there the grid frequency falls and the utility has to adopt for load curtailment of wind power. Further, if wind generation suddenly decreases the utility either has to shed load.
While various studies have advocated the need of a balancing reserve to handle the large capacity of wind power penetration, it needs significant investments in creating the balancing reserves. at the same time the studies have also highlighted the need of smart grid technologies such as demand response, energy storage and improved forecasting technologies to handle the variability of the wind power.
A recent study conduced by NREL highlights that the active power control of wind turbines can assist in balancing the generation and load, thereby improving power system reliability. There are three forms of APCs that can be adopted which include the synthetic inertial control, primary frequency control (PFC), and automatic generation control (AGC) regulation. Many of the control capabilities proposed by NREL study have been generally proven technically feasible, and a few areas throughout the world have already started to request or require wind plants to provide them. Currently the wind turbines are rarely recognized as having these active power control capabilities. However incorporation of these capabilities can lead to the fact that the wind turbines itself will control its generation in line to the grid load conditions and adopt itself as a balancing reserve.
Providing the active power control in wind turbines shall have differences in the perspective among various stakeholders For example, a manufacturer may know the capabilities are technically feasible but may not see a market for it because there is no demand from a utility off-taker to provide the capability. On the other hand, the system operators may desire the capability but be unsure of exactly how it performs or whether or not it will actually improve system reliability.
It is important that large scale penetration of wind power in India needs some of the innovative strategies and active power control can be an economical option for which the government needs to assess the feasibility in Indian context so that wind power developers providing APC, do not adversely impact the costs borne by consumers.
Image source: NREL