Many power grids around the world are already transitioning to high shares of renewables. The cases of Germany, California, and Denmark are among the leading examples. Germany has already reached a 30% share and targets 35% by 2020. California will meet its target of 33% by 2020. Denmark is already at 33% wind power.
How are these regions managing to integrate and balance such large shares of renewable energy? This question must be considered in the context of the “prevailing wisdom” of 15-20 years ago among virtually all electric power companies and power engineers. This “prevailing wisdom” was that going above 5-10% shares of “variable” renewables like wind and solar would spell doom for the reliability of the power grid, and the lights would go out. (And perhaps we might manage 15%, according to the thinking of the day.) That "prevailing wisdom" of the past is being soundly refuted as outdated and incorrect, given what is already happening today among the world's renewable energy leaders.
Based on my work during 2014, I am pleased to provide three 5-page educational articles I've written on the cases of Germany, California, and Denmark. The articles are written for a non-technical audience, so that anyone can understand the main ideas:
How is Germany Integrating and Balancing Renewable Energy Today?
How is California Integrating and Balancing Renewable Energy Today?
How is Denmark Integrating and Balancing Renewable Energy Today?
The Danish case represents the most advanced forward-looking thinking, but all three cases reflect the leading-edge of the integration and balancing question globally. There are common elements to all three, and some specific differences too. Some of the important messages are the high value and impact of day-ahead weather forecasting, the flexible operation of conventional plants (gas and coal) selling into ordinary wholesale and balancing electricity markets, and the huge but untapped potential for demand-side flexibility. Also significant is that energy storage is not yet a necessary part of the balancing equation, even as high shares of renewable energy are achieved over the next several years. (Although Denmark is using some heat storage, and California and Germany have some pumped hydro storage.)
Translations: Japanese translations of these articles are forthcoming by the Japan Renewable Energy Foundation. Links to the JREF postings will be provided here when available. Chinese translations are also forthcoming in March 2015.
Acknowledgements: The work on which these articles are based is supported by several organizations, including the Japan Renewable Energy Foundation, the China National Renewable Energy Center, the Institute for Advanced Sustainability Studies (Potsdam, Germany), and the Institute for Sustainable Energy Policies (Tokyo).