The typical situation now, as Philip Alexander Hiersemenzel of Younicos points out, is that coal or natural gas must fill in, and it must continuously be running in order to do so when needed, so Germany must essentially “import grid stability” and export excess coal power.
That’s where Younicos steps in.
One Younicos battery system with 100 MW** of capacity can replace 1 coal-fired power plant used for spinning reserve. 2 GW of Younicos batteries, providing ~1 hour of backup capacity, could replace all thermal power plants in Germany that are used for frequency regulation, resulting in 60% renewables and taking out about 25 conventional power plants.
The Younicos system uses Samsung lithium-ion batteries, sodium-sulfur batteries, and vanadium redox flow batteries. But the special sauce that Younicos brings to this hybrid battery system is the software. Developed over the course of 8 years, this is no simple software. Philip noted that Younicos has tested dozens of different lithium-ion batteries to choose the best for its needs (we saw a case full of maybe two dozen different lithium-ion batteries they had tested) but that each of them is complicated and getting them to function very well and last long as frequency regulators is a very challenging matter. Philip noted that as different as the various lithium-ion batteries looked, they were that different on the inside. They looked very different.
Younicos has ~50 software engineers on staff as well as numerous chemical engineers and mechanical engineers. In total, it currently employs ~120 people full time.
http://cleantechnica.com/2014/10/01/younicos/