Electricity is a unique commodity, since it must be produced at the same time as it is consumed. This is an especially difficult problem, because electric loads can change rapidly within a few minutes. The solution is to develop energy storage technologies. This is easier said than done, due to the complexity and expense of large-scale energy storage systems.
Renewable energy sources increase the need for energy storage. Wind and solar production can change quickly and unpredictably, due to local weather conditions. Since electric loads and renewable energy production are both fluctuating, sufficient energy storage is essential for reliability.
Electricity prices increase during high demand and decrease during low demand. Significant cost savings can be achieved by purchasing and storing energy during low demand and releasing energy during high demand. Energy storage systems are often cost effective since they can “buy low” and “sell high”.
Utility-scale energy storage was uncommon in the twentieth century but is widespread in the twenty-first century. Dramatic improvements in battery technology have made massive battery banks feasible and cost-effective.
Pumped storage, compressed air, flywheels and gravity batteries are some examples of unconventional alternatives to batteries. There are also unusual batteries which are alternatives to conventional batteries.
Thermal storage is another option which can shift energy across time. Thermal energy can be stored and then used directly to generate power during high demand. Another option is to use thermal energy from storage during high demand, instead of using power during high demand.
Energy storage systems can save money by satisfying peak loads with inexpensive off-peak power. They enable greater use of renewable energy sources, so we will have less pollution. They reduce the need for costly grid upgrades and reduce stress on aging infrastructure. In addition, they can increase reliability of the power grid by providing extra capacity when power is needed the most.
