Fraunhofer calculates that Energiewende is affordable
Fraunhofer ISE looked into what Germany's energy transition will look like not just for electricity, but also heat. The researchers hoped to find out which combination of technologies would be the most affordable.
This week, Renewables International reported on German industry association BDI's Energiewende Navigator. Overall, the website seems professional and somewhat objective, but a closer look reveals that some of the arguments are skewed to produce a certain result. For instance, in a survey of the public, Germans were asked whether they would be willing to pay 20 to 30% more for the energy transition than would be charged without it (only 23.9% said they would). Where did the BDI get that estimate from? All estimates are that the differential cost of the energy transition will be beneficial over the long term.
Now, Germany's Fraunhofer Institute for Solar Energy Systems has looked into which technology (PDF in German) combinations will provide the least expensive outcome, and they not only looked at the power sector, but also at the heat sectors (process heat for industry was not included, however); the transport sector was not dealt with. The main finding is that a complete switch to renewables would not be more expensive than Germany's current energy supply even assuming that the cost of fossil fuel remains stable. And the assumptions for the cost of new technologies are based on the IEA's assessments – not an organization known to be friendly to renewables.
The researchers do not beat around the bush: “If we do not reduce demand for heat by around 50% below the current level, the technical potential of wind and solar power will not suffice to ensure a reliable supply.” On the other hand, the heat sector can be used as a way of storing excess renewable electricity.
For a 100% supply of renewable electricity and heat, the researchers estimate that 170 GW of wind power would need to be installed on shore along with 85 GW offshore (compared to the current roughly 30 GW, almost all of which is onshore). For solar, 200 GW of photovoltaics (currently at around 31 GW) would need to be installed to provide power along with 130 GW of solar thermal for heat applications. Biomass consumption would not have to be used significantly for either heat or power in this scenario.
Without consideration of imports and exports, Germany would then need 70 GW of power-to-gas capacity to store excess renewable electricity as synthetic gas. The country would also have 95 GW of gas turbines, some of which would be a part of cogeneration units, to ensure reliable power supply. As Renewables International has often reported, Germany will continue to need at least 80 GW of dispatchable generation capacity to prevent power outages for the foreseeable future.
The researchers admit that their scenario is “extreme.” Unlike Denmark, Germany has no plans to go 100% renewable; the target for 2050 is 85%, and that's just for the power sector. But as project director Hans-Martin Henning explains, “We wanted to show scientifically what can be done at what cost with technologies already available. It is up to society and politicians to decide what the actual design should be.” Perhaps the BDI can have a look at the study for its future surveys of public opinion. (Craig Morris)