Technology

Simple and Brilliant idea for Train Electricity Storage

The Californian start-up Ares has an amazingly simple idea for an energy storage: you send heavy train cars, driven by excess wind or solar energy, a mountain up. Is the current acute needs, the cars go down the mountain and generate energy through regenerative braking. A test facility will be installed in California now.

The Californian start-up Ares on an amazingly simple-looking idea has come in finding efficient storage possibilities for renewable energy: heavy laden train cars are sent up a mountain and down, where they generate electricity. New technologies developed for the storage system use this “advanced observation”, however the space required is high. The first test facility is now produced on a mountainside in Nevada.

Track has a gap of almost eight percent

The U.S. State of California intends to cover half (50%) of its energy needs from renewable sources by 2030. In the production of wind and solar energy is itself the problem, but their reliable power supply in the power not so much. To make sure that the energy generated too much some days must be stored efficiently. In addition to the previously developed, such as pumped storage power station or the huge battery of Elon Musk – now the début of a new idea the advanced rail energy storage (Ares).

So to speak, the resource of gravity uses the expensive around $ 55 million plant, which should be done in 2019 and to store energy and release. It is being built nearby from Pahrump, a small town in Nevada on the California border on about 43 hectares of land on a 600 m-high Hill. On a 8 km long track with a gap of almost eight percent, the car formations with the help of electric locomotives are sent when uphill, when the local solar and wind plants produce excess energy. The wagons are weighted with cast concrete forms, so a wagon weighs about 300 tonnes.

Braking, electric motors convert kinetic into electrical energy

If the energy is acutely needed, the railway rolls back down the mountain. By so-called regenerative braking the kinetic energy will be converted back by the electric motors in electric energy, which is then fed into the grid. A first short distance for demonstration purposes, is on the a 5.7 t prototype on the road, has already built Ares. The new plant, for which the company already has a permit can have a capacity of 50 MW and producing around 12.5 MW / h of electricity.

Tehachapi train
An Ares test facility in Tehachapi, California: heavy of train cars are used as power storage for renewable energy. Photo: Ares

However, it admitted Ares-Chef James Kelly in an interview with utility dive, the new system was still not large enough to work economically. “50 megawatts are not enough for this. We are as we get larger. always more efficient” As a plus Ares however claim that no energy is lost during the storage time and unlike such as batteries the system has a high life expectancy in several decades.