Hybrid energy offers grid fluctuation fix

Posted Mar 12, 2018 by Tim Sandle
Electrical grids require modification due to the increase in renewable energy sources. Industry leaders aim to expand both electricity storage capacity and flexible energy management. To achieve this, a new hybrid energy storage system has been developed.
Located on Quebec s North Shore  the Micoua electric substation converts 315kV power from five hydro...
Located on Quebec's North Shore, the Micoua electric substation converts 315kV power from five hydroelectric dams for transmission at 735 kV. Hydro-Quebec's non-descrimination policy allows the selling of power to states below the border, such as New York.
Claude Boucher
Increasingly, electrical grids are switching over from fossil fuel-derived sources of energy to renewable energy sources, like solar and wind power. This switch-over requires the electricity storage capacities to be expanded and new solutions for flexible energy management.
To aid this, technologists from the Fraunhofer Institute for Solar Energy Systems ISE, located in Germany, have devised a hybrid energy storage system. The new platform consists of a lithium-ion battery together with a super capacitor, to assist with short-term performance requirements.
The new hybrid storage system is designed to be fitted to a medium-voltage grid via a new form of modular inverter. The platform has been tested out in a field test located on the North Sea island of Borkum. Here the system was operated from one year, where the system was compared with conventional technology.
Looking out to the North Sea: a seagull s view?
Looking out to the North Sea: a seagull's view?
The new system was developed for the European Union NETfficient project. Since most renewable energy sources see strong fluctuations as the result of environmental conditions, this presents a challenge to the energy sector. Moreover, as the proportion of renewable sources in the energy mix constantly increases alternative methods are required to compensate and ensure grid stability and energy availability. This means alternate electric storage technologies and energy management systems.
With the trial, the distributed storage facility and generators were integrated into a smart grid. The energy management was controlled by an intelligent energy and network management system. To this some forty home storage units plus five commercial storage units were connected. Also tested out was a thermal storage unit and a hybrid energy storage unit.
In a statement, Olivier Stalter, who is in charge of the Power Electronics, Networks and Intelligent Systems division at Fraunhofer ISE, said: “In addition to the 500 kWh lithium-ion battery, one of the most important components in the system is the battery inverter developed at Fraunhofer ISE.”
He adds: “It has a total output of one megawatt and consists of highly compact and particularly dynamic subunits with an output of 125 kW each. This allows us to realize all system sizes down to the multi-megawatt range.”
The outcome was that the system proved to be suitable for use as an efficient primary reserve, capable of reducing peak loads and addressing self-consumption solutions on an industrial scale.