Finding business models in different segments or technologies is not that easy. Using storage capacities in the electricity market seems to be a very attractive business, because the electricity production will be much more volatile in the future due to unplannable renewable production such as wind and solar energy. This fluctuating electricity feed will make a natural symbiosis with storage systems.
To solve one of the most common antagonisms: electricity is not storable, that is a fact and it is physics. So electricity must be consumed in the moment where it is produced But there are electricity storage systems! So how do they work? To store electricity or better electric energy, electric energy must be converted into another form of energy. Usually different forms of energy can be stored. To get electric energy again, that form of energy must be converted into electric energy again. That’s how electric storage systems are working – all of them.
Let us take an example: Pump storage systems are usually two or more big water reservoirs with an altitude difference between the two reservoirs. The upper reservoir is filled with some water, the lower reservoir is full with water. Both systems are connected with water tubes. One tube is used for pumping up water from the lower reservoir to the higher reservoir with an electric pump. When this pump is running it converts electric energy into gravitational energy. That gravitational energy is stored as the water is stored on a higher altitude. Often it is called hydro energy, but water itself is not the energy source it is just the medium. The energy source it the gravitation. So converting electric energy into gravitational energy leads to losses due to inefficiencies of the pumps.
Once the water is in the upper reservoir it waits to be converted into electric energy again. During that time we will see some storage losses due condensation of the water, so in this case less gravitational energy is available.
When the decision comes to produce electricity again, water is released thru a different pipe to the lower water reservoir again, hits at the end of the tube a water turbine and again gravitational energy will be converted into electric energy – also with losses on that side.
This common principle is typical for all electric storage systems. For batteries for example, electric energy will be converted into chemical energy by a chemical reaction, which varies depending on the type of batteries. This reaction has also with some losses. During the storage itself, there might me some chemical reactions going on, where we do see also energy losses and the reconversion of chemical energy into electric energy by a chemical reaction has losses. Self-discharge, deep discharge and overcharge are just some technology specific problems, which lead to more losses or a loss of technological lifetime.
Beside their specific problems, electric storage systems will become a significant part of the future electrcity system.
