A new study has been published that challenges power company claims that Germany needs to slow down its renewable power development to wait for new high voltage transmission.
Germany’s electricity “experts” often claim that the rapid pace of renewable power development needs to be slowed until new high voltage transmission lines can be built. Unlike the US, where most of the US population lies in coastal areas, many major population centers in Germany lie far from coastal offshore power generation. Advocates of giantism and centralized power claim that is and other issues mean that Germany has to focus on building new transmission lines if it hopes to meet its targets in the energiewende (energy transformation).
The new study, done by Ecofys, found that:
Regarding geographical distribution, “If grid expansion is delayed, about €800 million [in total power system costs] can be saved per year if we spread wind and photovoltaic installations more evenly across the country,” said Christian Nabe, electricity market specialist at Ecofys.
In addition, the study found that increased amounts of PV and onshore wind, with a decreased but still consistent share (15 GW) of offshore wind, would create a system that was more robust against grid expansion delays. If more offshore wind (25 GW) is added, then grid expansion becomes more urgent as offshore wind power generated in the northern part of the country needs to be transported to southern consumption centres. According to the study, replacing 10 GW of offshore wind with PV and onshore wind would not disadvantage the total system cost, create more emissions or require increased curtailment, where a wind farm must be shut down. (The study predicted that restricted grid development would create a need for 1 to 4 percent, or around 15 TWh, in wind curtailment in 2030.)
System flexibility will be key to Germany’s energy future. If grid expansion as a source of flexibility is limited, the study found, other options such as compressed air energy storage, gas back-up plants and load shifting will be the most cost-effective means. Battery storage was not assumed to be a cost-optimal technology before 2030.
So the Ecofys study showed clearly that decentralizing power in Germany even further pushes the need for four planned HVDC lines back even further into the future, and that there is no need to wait for them to be built.
Ecofys also demonstrates that the benefits of decentralization outweigh using solar and wind resources in sub-optimal areas.
The new study does not show that new HV transmission lines can be eliminated, just that Germany does not have to wait for them to push ahead toward their 2020 renewable power targets. In advanced countries, the transmission grid does need to be reconfigured to meet energy transfer needs of a new renewable-centered grid. The obsolete grid was based on fuel and water needs of old coal and nuke plants. When Germany meets its 2020 targets of meeting 80% of its electricity and heating needs from renewable power, it will no longer need that grid.