low-carbon power

2 Articles

Germany’s Solar Expansion And The Negative Effects Of Electricity Overproduction

May 25, 2024 by 184 Comments

Amidst the push for more low-carbon energy, we see the demolishing of one of the pillars of electric grids: that of a careful balancing between supply and demand. This is not just a short-term affair. It also affects the construction of new power plants, investments in transmission capacity, and so on. The problem with having too much capacity is that it effectively destroys the electricity market, as suppliers need to make a profit to sustain and build generators and invest in transmission capacity. This is now the problem that Germany finds itself struggling with due to an overcapacity of variable renewable power sources (VRE) like solar and wind.

With a glut of overcapacity during windy and sunny days, this leads to prices going to zero or even negative. While this may sound positive (pun intended), it means that producers are not being paid. Worse, it means that when, for example, France buys German wind power for negative Euros via the European Electricity Exchange (EEX), it means that Germany actually pays France, instead of vice versa. The highly variable output of wind and solar also means a big increase in curtailment and redispatch measures to keep the grid stable, all of which costs money and drives up operating costs.

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Using The Electricity Grid In Cities As A Source Of Heat

September 15, 2019 by 32 Comments

In the process of finding new, low-carbon ways to provide our homes with heat and electricity, it is that one might consider sources that never before came to mind. In London such a source that has been examined by researchers and an electricity network operator are the 2.5 meter wide tunnels that run for many kilometers underneath the city. In each of them are many more kilometers worth of electricity distribution cables, each of which produces so much heat from electric resistance that active cooling is required.

Currently, every 1.8 kilometers there are shafts that lead to the surface, through which cold surface air is brought in and the warm tunnel air is exhausted into the air. The study by London South Bank University researchers and UK Power Networks looked at using this heat directly for heating local houses, replacing the use of gas boilers. This is in effect similar to heating with waste heat from industrial processes, but with noticeable differences.

The thermal power available from each 1.8 kilometer section of tunnel differs between 100 – 460 kW by installing equipment at the top of the shafts. With London looking at using heat from the London Underground for heating in a similar fashion, it would be fascinating to see whether the combined heat from both underground sources could provide the city with a sizeable source of low-carbon heat, while increasing creature comfort.