Siemens team of experts at Corporate Technology is developing technologies for storing electricity generated by renewables by transforming it into other forms of energy.
Photovoltaic systems and wind turbines often produce more power than it is needed. Nevertheless, a transition to a new energy mix – in other words, ensuring a comprehensive supply of heat and electricity with virtually no recourse to fossil fuels – is still far from being realized, Siemens said.
“Our job is to develop new technologies capable of converting and storing huge volumes of electricity economically,” said Professor Armin Schnettler , who heads Siemens Corporate Technology’s Research in Energy & Electronics department.
What’s needed are solutions capable of converting electricity into types of energy that lend themselves well to storage, such as heat, cold, hydrogen or other chemicals, the company explained.
“Although we have made great advances with the development of battery solutions, these are suitable only for short-term storage, in other words minutes or hours at the most,” said Schnettler . “As part of a future energy infrastructure it will be necessary to use different options and energy forms in parallel.”
“Because of their high power density, chemical storage media are an ideal way to make the best use of excess electricity,” explains Maximilian Fleischer , in charge of chemical storage systems development at the Corporate Technology’s Research in Energy & Electronics department.
Therefore, the department’s researchers are working on electrolysis procedures, for example, that can be used to turn renewables-generated electricity into chemicals that are in demand, such as carbon monoxide, ethylene or alcohols.
Electrolytic cells provide good results even with a fluctuating power supply. Compared to batteries or pumped-storage systems, electrolysis offers the benefit that it gains in efficiency when it’s operated at a lower current density, since less energy is lost as heat that way.
Siemens added that electrolysis also offers new business opportunities for the company, facilitates the expansion of renewables, and can be fed with carbon dioxide from exhaust gases, thus reducing the use of oil that would otherwise be used to manufacture fuels or chemicals.
Ultimately, the best energy storage options in any given situation will depend mainly on what the energy will be used for in a given geographical area, Siemens concluded.