Advances in Energy Storage Systems for Renewable Source Grid Integration

Power generation using renewable energy sources has reduced  the use of hydrocarbons for power generation and transportation.  Power generated from renewable energy sources can be integrated  into the grid in connected mode or can act as an independent  power island. Renewable energy supplies 14.8 per cent of the total  industrial energy demand, mainly for low-temperature companies. However,  for heavy industries such as iron and steel, cement, and chemicals, renewable  energy accounts for less than one per cent of the combined energy  demand. Today, an energy mix of electricity, solar, wind, and nuclear is used  to supply loads in many countries around the world, with other energy forms  accounting for less than one per cent of total energy demand. 

The intermittent nature of renewable resources challenges the  performance of the grid by introducing issues with system stability, reliability,  and power quality. The variability and uncertainty of power output are the  two primary problems hindering the bulk integration of renewable energy  sources with the existing grid. Introducing energy storage systems (ESSs) to  the grid can tackle the variability issue by decoupling the power generation  from demand. Additionally, the ESSs enhance the power quality of the grid  by providing ancillary services. The energy storage demand will continue to  grow as the penetration of renewable energy into the electric grid increases  every year. 

ESSs facilitate technologies for well-established and new applications  like power peak shaving, electric vehicles, the integration of renewable  energy, and so on. ESSs make the grid more reliable by acting as a power  source or offering various functions such as spinning reserves, power  quality and fluctuation minimisation, and load levelling from renewable  energy sources. 

Large ESSs are routinely used with renewable generation, such as wind,  to stabilise the power output. There is a big opportunity to transition to a  carbon-free energy future by incorporating ESS with renewable power. ESSs  with high ratings and a long duration will play a significant role in reducing  the environmental impact of conventional power sources. 

The worldwide revenue from energy storage for renewables integration  will exceed 23 USD billion shortly, and the requirements for storing energy  will triple their present values by 2023. Solar energy has surpassed grid  parity, and many markets no longer require policy incentives to encourage  deployment. However, energy storage mechanisms encounter several  challenges, and no storage type has the complete characteristics required  by the modern grid. For example, limitations like storage capacity, response  time, efficiency, cost, and implementation need. Some ESSs, like batteries,  also have an environmental impact by releasing toxic gas. 

There are several ESSs available commercially, but the requirements of  DER integration into the grid require more than one energy storage system.  The rapid growth of power generation from renewable energy sources leads  to the deployment of large-scale, cost-effective energy storage systems  as a necessity for the reliability of the power system. As renewable energy  sources are of different types, a wide range of storage systems is necessary  to accommodate the specific needs of each source.