Renewable Energy Storage: Developing Solutions

June 4, 2006 – Vol.11 No.11

RENEWABLE ENERGY STORAGE: DEVELOPING SOLUTIONS.

Wind, solar and eventually tidal and ocean energy provide intermittent power sometimes when there’s no demand for it: wind turbines churning in the middle of the night, for example. Unused energy from renewables needs to be saved. Companies are trying to provide technologies to do just that.

VRB Power has developed its VRB Energy Storage System (VRB-ESS), an electrical energy storage system that converts chemical energy into electrical energy.

With VRB-ESS energy is stored in different ionic forms of vanadium in a dilute sulphuric acid electrolyte. When stored energy is needed the electrolyte is pumped from plastic storage tanks into flow cells across a proton exchange membrane (PEM) where one form of electrolyte is electrochemically oxidized and the other is electrochemically reduced. Consumable electric current is created across the poles of the flow cells and the reaction is reversible when electricity is applied to the cells.

The company has been selling the system with some success around the globe.

The latest sale will be a 120-kilowatt hour system to the Riso National Laboratory in Denmark. The country now gets about 20 percent of its electricity from the wind, but it would like to get about 35 percent. Riso is hoping energy storage technologies, such as a VRB-ESS system, can help store wind power that’s generated but not used, thus increasing their net wind energy capacity.

Lithium Technology Corporation (LTC) builds large-scale, high-power rechargeable lithium-ion cells and batteries. The company makes products that are 10 times greater in capacity than a laptop computer battery up to 100,000 times greater.

The company has received a $1 million order from Sunergy Investco of The Netherlands for the joint development of a solar energy storage system using lithium-ion batteries.

Sunergy is looking to sell solar energy systems to world markets especially in developing countries where distributed solar energy can be a low cost alternative to building a power grid. The company is looking for a robust energy storage system that needs little maintenance and can operate in extreme temperature conditions.

For LTC the $1 million payment is for the first phase project that will lead to a total of $5 million invested.

Visit VRB Power at http://www.vrbpower.com/ and LTC at http://www.lithiumtech.com/