As Germany piles on more sporadic energy from wind and solar into its power grid, stability concerns are growing.
Increasingly volatile energies like wind and sun are turning out to be more of an expensive nuisance rather than a benefit.
Researchers at the Germany-based Fraunhofer-Instituts für Optronik, Systemtechnik und Bildauswertung, Institutsteil Angewandte Systemtechnik (IOSB-AST) have studied the risk of grid overloads caused by renewable energies at the community level, the online Ostthüringer Zeitung (OTZ) writes here.
The result, reports the OTZ:
Already in just a few years power will have to be stored locally as well. […] And the answers in their study are, depending on the perspective, thoroughly alarming or spurring for policymaking and economy.”
According to the OTZ, a team of researchers led by Peter Bretschneider at the Fraunhofer’s IOSB-AST conducted a 3-year study, where they literally built a statistical mock-up city of 30,000 that included a downtown, residential areas, commercial district, solar installations and wind parks. “A total of 1847 residential and business buildings that included everything from grandma’s little house to office complex for public officials.”
And so that the mock-up city simulates what is typical today in Germany, it also had everything a town would expect to have with the current German feed-in act:
4456 ‘grid elements’, i.e. power lines, transformers, large points of consumption and feed-in systems, foremost photovoltaics on the roofs.”
Even the homes were provided with the thermal insulation that they are expected to have later on.
The OTZ continues:
Next the Fraunhofer scientists electrified their simulated city. Then using meteorological data they allowed the sun to rise and set, the wind to blow, the temperatures to change – just like in real life.”
Next they extrapolated outwards to the expected conditions of the year 2018 and 2023, leaving the local power grid unchanged and allowing more wind and solar energy to come online as expected from the provisions of the feed-in act. How did the city’s power grid fare? The OTZ tells us the shocking results, and they aren’t pretty:
Already today in the simulated city one of the 14 network nodes gets sporadically overloaded. In 2018 the impacted transformer comes under serious stress 22 days a year, and so does another transformer. Five years later three nodes are impacted by long-term frequent back-feeding of surplus solar energy in the medium-voltage grid. At least one cable in the area exceeds ‘the limits of thermal loading’. […] ‘Yes, a transformer would be glowing – and the cable would go up in smoke,’ system engineer Sebastian Flemming explains the results in layman’s terms.”
The OTZ asks what this all means for the citizens? Flemming responds: “Blackout, for the entire city.”
In the wintertime this would be most inconvenient, and for some possibly even fatal.
Flemming adds that even if a blackout were averted, the wild frequency fluctuations in the grid would have “grave consequences” for many electrical appliances and systems. The OTZ writes:
None of today’s productions systems in the economy could function under such fluctuations, especially everything that is computer-controlled.”
In other words, it would not even take a blackout to cripple a city.
The OTZ then asks what can be done with the surplus electrical energy that will surely result from the wind and sun. Here once again the financially and technically unfeasible storage systems get brought up. Another solution mentioned is the conversion of the electricity into heat for supplying warmth to homes.
But the online OTZ daily writes that solutions appear to be a ways off, and so it warns:
Time is running out: According to the study, beginning in 2018, the first transformers are threatened with prolonged overloading.”
Do these findings of the Fraunhofer Institute surprise us? Not at all. It’s been known for a long time that the feed-in of solar and wind power leads to crazy, uncontrolled power surges in the grid. Supply stability remains the glaring problem that too many among us continue to deny.
Prepare for blackouts!