We can rely on electricity to brighten a dark room or power our computers whenever we need it to. This dependability is owed to the electric grid, a sophisticated infrastructure that forever manages the production and consumption of energy.
The grid works by connecting us, the consumer, with the source of our electricity. By distributing energy produced in fossil fuel power plants, nuclear plants, solar panels, or wind farms, the electric grid ensures we can access electricity when necessary. But that’s where the grid falters; it distributes energy, it doesn’t store energy for later. This is problematic for renewable power, as demand for electricity is often highest when its dark and there is no wind.
This imbalance between supply and demand necessitates effective, low-carbon storage technologies capable of releasing energy to consumers even when the sun isn’t shining, and the wind isn’t blowing.
One promising technology is Gravitricity. Emerging from Scotland, the nascent Gravitricity concept uses excess energy to winch and hold a large weight at the top of an already-existing disused mineshaft. When the sun or wind is not producing energy, the weight is lowered as necessary, turning the winches into electricity-supplying generators. Raising the weight charges the system, dropping the weight discharges the stored energy. A typical Gravitricity system can store and release enough electricity to power 13,000 homes for two hours.
Lithium-ion batteries, compressed air energy storage (CAES), the flywheel, hydrogen storage, and pumped storage power plants are other technologies capable of storing renewable energy. Unfortunately, many of these technologies come with high carbon and financial costs to create, install, maintain and replace the systems.
The Gravitricity concept provides a solution to these issues. By using already-dug mineshafts, the system is relatively cheap to install, and the lowering and raising of the weight happen with minimal friction, meaning the system can be charged and discharged over and over again for up to fifty years with zero degradation. These factors render Gravitricity an ideal green-energy storage system, and potentially the cheapest form of storage on the global fast-response energy market.
As you read this, the Gravitricity team is building its concept-demonstrator in Scotland. This will be followed by a fully operational commercial prototype in Northern England, with a view to rolling out the technology throughout South Africa, Australia and Europe.
The Gravitricity concept helps us move closer to a renewable energy power grid. Instead of using the electric grid to tap into electricity that is readily available due to the constant burning coal, a single Gravitricity system could enable 13,000 homes to access energy generated by the wind and sun even on a still night.
This article was written by Daniel Grainger. Visit his LinkedIn profile to discuss any renewable energy writing needs you may have.