A response to US critics of Germany's Energiewende: Mark Jacobsen.

REW.com: “In 2009, Jacobson caught people’s attention with his co-authored article A Plan To Power 100 Percent of the Planet With Renewables, which was the cover story of November’s Scientific American.” “In 2012, he partnered with The Avengers’ Hulk Mark Ruffalo to co-author The Tesseract Is Here!, a Huffington Post opinion piece likening the film’s Tesseract, a source of unlimited energy, to renewables. To cleantech and comic lovers worldwide, this was the epitome of cool! Additionally, his 2010 TED Talk debate with Stewart Brand Does the world need nuclear energy? is a must-watch for any renewables fan.
….Q: The New York Time’s article “Germany’s Effort at Clean Energy Proves Complex” states that “one of the first obstacles encountered involves the vagaries of electrical power generation that is dependent on sources as inconsistent and unpredictable as the wind and the sun. And no one has invented a means of storing that energy for very long, which means overwhelming gluts on some days and crippling shortages on others that require firing up old oil- and coal-burning power plants. That, in turn, undercuts the goal of reducing fossil-fuel emissions that have been linked to climate change.” However, others claim that more coal power plants have been shut down than started up (at least 20) and your work has shown that this would indeed be the case. What is your take on what is likely happening in terms of reserve fuels and emissions in this scenario?
A: “Ensuring the reliability of the grid is merely an optimization problem. If fossil generators are used to fill in gaps, it is only because the current grid is inefficient and the health and climate impacts of fossils are not reflected in the costs of these fuels. It has nothing to do with whether it is possible to have a reliable grid with wind, water, and solar power. Several groups have shown that it is possible to combine wind and solar and use geothermal as a base load and fill in gaps between demand and renewable supply with hydroelectric and/or stored concentrated solar power to provide a grid reliable to 99.8 percent and higher. In addition, using demand response can help reduce demand at peak times. Further, oversizing the grid with wind and solar to make it easier to match normal electric power demand, and using excess wind and solar to produce hydrogen for transportation and district heat (as done in Denmark) can allow for a reliable grid and provide energy for other sectors of the energy economy.
Q: The article also states the plan has created a strain on Germany’s power grid. A spokesperson for the grid operator Tennet is quoted saying: “Where energy was previously brought into the state and distributed to small communities, these communities are now producing the power, and we need to find a way to transmit it to the larger urban areas. Everything has been stood on its head.” Is this a valid concern or a normal step of transitioning energy systems?
“Most people would argue that having local sources of energy increases local jobs and energy reliability, particularly when a disaster occurs. The fact that the local communities are producing too much can easily be rectified by converting other sectors of the local energy economy (e.g., transportation, heating/cooling, industry) to electricity.”