In Germany a test has been successfully conducted of a 100% renewable energy power plant using wind, solar and biogas to provide round the clock electric power. The Kombikraftwerk 2 is a “Combined Renewable Energy Power Plant” that links together geographically dispersed assets into a virtual power plant. Unlike plans for 100% renewable energy written by activists such as Mark Jacobson that are designed to influence the political debate but could never actually function, this plan is designed by engineers to actually work in the real world. Many climate activists reject all carbon based fuels but the Germans recognize the crucial role played by methane as a renewable that can both fill in for the intermittency of wind and solar as well as providing much needed energy storage. This novel new renewable energy model demonstrates the need for natural gas backup, energy storage in the gas pipeline network, carbon capture and utilization and renewable natural gas.
The Kombikraftwerk 2 is a pilot study funded by the German government and conducted by a consortium of leading companies including Siemens and SMA along with academics and the weather service. The main focus of the study was to demonstrate on live facilities that grid stability could be maintained as the power outputs from wind and solar fluctuated. Through a combination of slight curtailment and biogas power, precise voltages and frequencies were successfully maintained on the power grid. The test system linked together 37 wind turbines, four biogas CHP plants, twelve PV systems and one pumped hydro reservoir into a virtual 80 MW plant intended to meet the power demand of one small town or equivalently 1/10,000th of Germany’s overall power demand. All of the plants were active commercial facilities. Most of the documentation for the project is in German, but here are links to English videos and papers. The videos provide an excellent overview of the operations and a vision for how the system is meant to work in the future including the advanced power to gas systems.