Have you been wondering, like many, what is Grid Energy Storage and why is there so much talk about large-scale energy storage? Well, grid energy storage systems (ESS) are large-scale facilities used to store energy in some form or the other (electrical, chemical, potential, gravitational, etc) within an electric power grid. Energy is stored during times when production exceeds consumption and the stored energy is used at times when consumption exceeds production. In this way, electricity production need not be drastically ramped up and down to meet momentary consumption – instead, production is maintained at a more constant level. This has the advantage that fuel-based power plants (i.e. coal, oil, gas) can be more efficiently and easily operated at constant production levels.
In particular, the use of grid-connected intermittent energy sources such as solar (photovoltaic) and wind can benefit from grid energy storage. These energy sources are by nature unpredictable – mean that the amount of electrical energy they produce varies over time and depends heavily on random factors such as the weather. In an electric power grid without energy storage, energy sources that rely on energy stored within fuels (coal, oil, gas) must be ramped up and down to match the rise and fall of energy production from intermittent energy sources. Thus, grid energy storage is one method that the operator of an electric power grid can use to optimize on energy production from intermittent renewable energy resources.
There are several methods that are currently being pursued as a possible means of grid energy storage. Currently, the list includes:
- Pumped Hydroelectric Energy Storage
- Compressed Air Energy Storage
- Super Capacitor