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If $9 Billion of Renewable Energy Is Curtailed in 2030, What Opportunities Will Emerge? Part 1

Sep 01, 2016

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The intermittent nature of renewables is well established, though hard data on its impact is just now starting to become available. Germany, a world leader in wind and solar, is showing growing levels of curtailment (defined here as the reduction of otherwise scheduled electricity output). As the wind plus solar share of electricity grew from 10% to 26%, the share of curtailed (or wasted) wind plus solar energy grew from about 0.2% to around 1.8%. As seen on the chart below, since 2009, a consistent pattern has emerged relating curtailment to renewable penetration.

Growth of Renewables and Curtailment


 (Sources: AG Energiebilanzen, German Federal Network Agency, Electricity Reliability Council of Texas, UK National Grid, Lantau Group)

Consider if the rest of the world followed this trend line through 2030. The 2016 Renewable Energy Roadmap (REmap) from the International Renewable Energy Agency (IRENA) outlines a feasible path to doubling the share of renewables by 2030. The 40 countries covered represent 80% of global energy consumption. Under the REmap scenario, 60% of global solar plus wind energy would come from countries generating between 20% and 30% of their electricity from such sources, comparable to Germany’s 26% in 2015.

If each country followed the curtailment trend established above, annual curtailment would amount to 128 TWh, or 0.4% of total global generation. This energy is worth $9 billion, assuming a value of $70/MWh, the estimated variable cost of a combined-cycle generator in the United States in 2030. Given the low cost of renewables and compared to the $1 trillion or more in annual savings projected by IRENA, the curtailment may be easily justified.

Caveats and Variations

Even if renewables grow that quickly, there are many caveats to this assessment. Curtailment occurs locally, a nuance that country-level analysis does not capture. Furthermore, there are vast variations among countries in geography, transmission infrastructure, generation mix, market structures, and other variables. Germany’s trailblazing growth has led to some specific growing pains that are being addressed, with major transmission upgrades being built to address the issue. Still, given the poor track record of curtailments in other places with less renewables, curtailment could even be higher. See approximate trends on chart.

China has curtailed 15% of its wind since 2011, worth over $6 billion at the rates above. The Electricity Reliability Council of Texas (ERCOT) cut curtailment from 17% (2009) to 0.5% (2014) with transmission upgrades and market reform, but with just 11% of generation from wind still did “worse” than Germany by not falling below the trend line. With curtailment data just starting to be collected in some regions and the feverish projected growth of renewables, this high-level approximation can outline the potential magnitude of curtailment.

So if $9 billion of energy is curtailed, what opportunities will emerge? The second part in this blog series will cover some of these potential options. Transmission upgrades and storage technologies have been getting a lot of coverage lately, but flexible generation technologies may be even more important to our clean energy future.