If you’re into energy policy, there’s a must-read article in Der Spiegel, about how wind-power is destabilizing Germany’s energy grid:
It was 3 a.m. on a Wednesday when the machines suddenly ground to a halt at Hydro Aluminium in Hamburg. The rolling mill’s highly sensitive monitor stopped production so abruptly that the aluminum belts snagged. They hit the machines and destroyed a piece of the mill. The reason: The voltage off the electricity grid weakened for just a millisecond.
Workers had to free half-finished aluminum rolls from the machines, and several hours passed before they could be restarted. The damage to the machines cost some €10,000 ($12,300).
In the following three weeks, the voltage weakened at the Hamburg factory two more times, each time for a fraction of second. Since the machines were on a production break both times, there was no damage. Still, the company invested €150,000 to set up its own emergency power supply, using batteries, to protect itself from future damages.
What was the problem?
Behind this worry stands the transition to renewable energy laid out by Chancellor Angela Merkel last year in the wake of the Fukushima nuclear disaster. Though the transition has been sluggish so far, Merkel set the ambitious goals of boosting renewable energy to 35 percent of total power consumption by 2020 and 80 percent by 2050 while phasing out all of Germany’s nuclear power reactors by 2022.
The problem is that wind and solar farms just don’t deliver the same amount of continuous electricity compared with nuclear and gas-fired power plants. To match traditional energy sources, grid operators must be able to exactly predict how strong the wind will blow or the sun will shine.
But such an exact prediction is difficult. Even when grid operators are off by just a few percentage points, voltage in the grid slackens. That has no affect on normal household appliances, such as vacuum cleaners and coffee machines. But for high-performance computers, for example, outages lasting even just a millisecond can quickly trigger system failures.
This graphic shows just how large the wind and solar fluctuations can be:
Catalina Schröder, the author of the Der Spiegel article, tries making lemons into lemonade by pointing out that backup-power providers are doing a lot more business, but of course, this is “broken windows” thinking: ultimately the cost of power redundancy comes out of the consumer’s pocket.