2018-08-28
Energy storage key to brighter renewable future

It is heartening that India is committed to increase the share of renewable energy in its overall electricity generation mix. The country has set in motion a programme to install 100 GW of solar photovoltaic (PV) plants and 60 GW of wind turbine plants by 2022. This is a commendable step towards a 100 per cent renewables future, which necessitates flexible generation in the overall power generation system.

While the generation costs of the large-scale wind and solar projects are becoming competitive, the challenge of grid integration and balancing remain. Efforts on achieving a certain degree of capacity adequacy at an aggregate level are being undertaken. However, energy storage can play a significant role in grid integration and balancing of variable generation sources besides addressing the congestion in the transmission system. By increasing the systems’ overall flexibility it can improve the power quality, reduce peak demand, enhance the capacity of distribution networks, and reduce deviation penalties. As such, energy storage can serve multiple applications in the electricity grid.

Use of energy storage system by commercial or industrial consumers, in conjunction with renewable energy, has the potential to improve power quality and reliability for such consumers. Renewable energy, especially solar, has huge fluctuations which can be managed by linking it to storage batteries. This could also allow various thermal generating plants to operate at their best efficiency point, which will result in savings in fuel consumption.

Unlike any other asset on the grid, energy storage can play multiple roles, acting as both load and capacity depending on whether it is absorbing excess generation or feeding back into the grid, respectively. Large renewables generators are facilitated to use the energy storage for a variety of applications, which add value to the system. This includes scheduling accuracy and reducing deviation penalties, reactive power management, fault ride through load firming, peak load management, transmission capacity optimization, reducing the transmission congestion, ancillary service support to the grid such as frequency regulation, ramp control, spinning and operating reserves, among others. Depending on the application, there would be an economic value added to the generation project or to the overall system.

While early deployments of energy storage within India is under pilot mode, we are currently witnessing significant growth in the marketplace to hybridize storage with solar (or wind) and thermal generation, unlocking a multitude of potential revenue streams. The energy storage system can charge and discharge in response to an increase or decrease, respectively, to the grid frequency. Similarly, during the load levelling, the power can be stored during the periods of light loading on the system and delivering it during the high demands, reducing the load on less economically peak-generation facilities. Also, the variable intermittent power output from a renewable power output from a renewable energy plant, such as wind or solar, can be maintained at a committed (firm) level for a period of time.

Energy storage technology can be applied as a solution to various grid challenges and needs as it not only increases reliability, resilience and “future-proofs” the grid and microgrid applications but, it also enables more dispatch of renewables into the system.

Advanced technology and innovations for using the energy storage solutions as spinning reserves have the potential to be environmentally-sound solutions if seen as a probable solution with the generation assets. Software controls and data analytics can be used to maximize the performance and longevity of energy storage, further bringing down its cost and making it more available for use.

With the combination of various assets, an optimal path towards a 100 percent renewables future can be created. Already renewable and thermal energy integrated with storage is driving a paradigm change in power markets around the world. Next, with the capabilities of energy storage, renewables will begin to replace the existing inflexible thermal capacity, which when combined with reduced storage costs, will enable renewable energy to become the new baseload.

Source- ET Energyworld