Energy Storage

Energy storage is an important component in the renewable grid due to the intermittent nature of many forms of renewable energy. Energy storage is used during peaks in energy demand and topped up during troughs, going some way towards levelling out the demand profile.

Storage Technologies

There are a number of renewable energy storage technologies available.

Compressed air is pumped into underground caverns during off-peak periods and then released during the peak to run a generator.

Pumped hydro, in which water is pumped to a holding reservoir above an existing dam during troughs in energy demand and then released during the peaks to run a hydro-electric turbine.

Hydrogen and more efficient electro-chemical reactions (similar to batteries) are in development, but are quite expensive on a grid-wide scale at this stage.

Flywheels provide system ‘inertia’ and handle short-term fluctuations in demand. This technology is used to smooth out the variation in wind power in Denham, Western Australia, where there is a very high proportion of wind power.

Energy Security

It is also worth noting that if renewable technologies are distributed strategically their reliability increases. The probability of energy supply from a well distributed and diverse renewable grid falling dramatically is much smaller than that of a grid relying on large coal and gas power stations, which can go offline due to unplanned outages or fuel shortages. The issue of energy security was highlighted recently in WA when the Varanus Island gas explosion seriously impacted on WA's energy supply. See our reports page for more information.