EPJ Plus Highlight - Scaling up renewable energy

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Published on 19 February 2014

A new study focuses on the feasibility of scaling up renewable energy to cover the needs of a country the size of Germany

Can renewable energy adequately supply the power grid, despite its intermittent nature? This is the key question in a new study published in EPJ Plus. The study is based on an analysis of concrete data from 2012 for the German national grid, which also utilises electricity from both on and offshore wind (8%) and solar sources (4.8%). Friedrich Wagner from the Max-Planck Institute for Plasma Physics in Greifswald, Germany, outlines the key issues associated with the use of renewable energy on a large scale.

Following a political decision to phase out nuclear power and reduce CO₂ emissions from fossil fuels in Germany, the country is now entering a new era in which electricity production is no longer demand-led. Instead, it involves scaling the renewable energy production infrastructure to accommodate such an intermittent supply.

The author scaled the 2012 German data in such a way that renewable energy constitutes a larger than actual share of electricity production, reaching up to 100% and thus covering the country’s electricity needs for one year. He found that the corresponding power infrastructure has to be able to deliver three times the energy load at peak use.

This leads to excess power production, sometimes incurring negative demand-led prices when supply significantly exceeds demand. Excess power can only be partly stored, due to the lack of large storage capabilities, or partly exported, to avoid the risk of disrupting neighbouring electricity markets. This setup still requires backup power from thermal power plants to cover periods of low wind and solar energy production.

The author concludes that it would be difficult for renewable energy sources to match the low CO₂ emissions of European countries that mostly produce electricity using nuclear and hydro power, such as Switzerland, Sweden and France.