When it comes to integrating intermittent renewable energy sources into the grid, I would expect Germany to be one of the world’s experts. After all, in 2015, renewable energy accounted for 38 percent of net electricity consumption, according to Fraunhofer Institute for Solar Energy Systems (ISE).
Since May 2011, the country has been on a mission to increase its renewable energy sources to 50 percent by 2030—a hefty goal that, among other things, could adversely affect power grid stability and reliability.
In May 2011, shortly after Japan’s Fukushima Daiichi nuclear accident, German Chancellor Angela Merkel declared that Germany’s 17 nuclear power stations would be shut down by 2022. A set of policies, commonly known as the Energiewende, were written and adopted soon after that. Energiewende aims to transform Germany’s electricity supply to what the country considers safer, more sustainable sources.
The country is well on its way to achieving its 50 percent goal and even moving beyond that, thanks a great deal to its favorable feed-in tariffs, which made Germany the largest market for solar photovoltaic in the world in 2011. According to ISE, solar PV accounted for 6.4 percent of the 38 percent of net renewable energy consumption in 2015.
ISE reports that on sunny weekdays, however, PV power can cover 35 percent of the momentary electricity demand. And, on weekends and holidays, the PV coverage rate can reach 50 percent. In fact, at the end of 2015, more than 40 GW of solar PV was installed in over 1.5 million distributed power plants (mostly rooftops), making solar PV larger than any other type of power plant in Germany.
Perhaps one of the most surprising facts about this quick uptake in intermittent renewable energy is that, despite predictions that the country’s electricity grid would become unstable and less reliable, the grid’s reliability improved, although just slightly, after reaching 30 percent renewables. So far, German engineers and operators have found a way to keep the grid balanced and stable.
Underwriters Laboratory (UL), commonly known as the company that evaluates and tests products and equipment, including most electrical equipment used in U.S. homes, to ensure safety, was not the first to my mind when looking for experts on Germany’s risks and successes in integrating distributed renewable energy into the grid. I learned through an interview with Erin Grossi, UL’s chief economist, however, that the company has done extensive research in Germany to determine how the country was handling the renewable energy growth.
“UL has always tested and evaluated traditional grid products,” Grossi said. “Because more renewable energy sources are being added to the U.S. grid, we knew we needed to move beyond these traditional products to products that are used to add and integrated distributed renewable sources. We felt we needed to look at Germany because it is focusing so heavily on renewables.
“Much of the news we heard and read about Germany’s experience with preparing its grid for large amounts of renewables was negative, so we wanted to ask the engineers how it was really working,” she said. “We discovered that the feasibility question is off the table. While five years ago, many of the players (in the German electricity market) did not believe the plan would work. Today, however, there is no question from any of the players that it will work.”
Utilities, once some of the most vocal naysayers of Germany’s Energiewende, are now believers. They see the transition to renewable energy is happening and they are scrambling to be relevant, she said.
German grid operators and engineers didn’t say the task was easy. Aggressive rooftop solar incentives initially created a pace of change that was too fast, Grossi said. But, once that became apparent, the incentive structure and regulations were adjusted.
It’s interesting to note that to this point most of the grid balancing has been done without energy storage, digital technology and data analytics. These are technology areas in which the U.S leads Germany.
Germany has relied heavily on virtual power plants to balance the grid and keep it reliable so far, Grossi said. The country hasn’t been aggressive with electric vehicle (EV) adoption, which she believes is one of the reasons battery storage hasn’t been used much. And, she said, the Germans even agreed that the U.S. is ahead when it comes to digital technology and analytics. But, they are closely following these technologies’ use in the U.S. and are sure to adopt them as they move forward.
Grossi said a takeaway from her research is that Germany’s utilities have realized the importance of taking an active role in this transition so that another player doesn’t come in and take their customers. She said this is an important lesson for U.S. utilities to heed.
“Most large players in this market, like hospitals, big box stores such as Walmart and other large consumers, want utilities to be involved,” Grossi said. “They want the utilities to take the lead, or at least be their partner.”
Grossi believes that by harnessing Germany’s engineering experience in grid stability and combining it with the U.S.’s technological advances, all nations can be better positioned to scale their endeavors to develop distributed power systems, which are typically fed by renewable energy sources.