A public secret The fluctuating wind and solar PV shall be the main source for electricity in Denmark, but the ordinary electricity demand does not match these fluctuations. This creates problems for the grid company and wild price fluctuations for all consumers. But something happened. Let’s have a look at the electricity supply from the power grid to a typical Danish town. The annual average load is 20 MWe, and the peak load (the cooking peak 6 p.m., December 24) is close to 100 MWe, which is the maximal capacity of the power cable to the city. Re- cently the annual average demand has in- creased to 40 MWe without changing the maximal load. What has happened?
A closer look at the fluctuations of the demand shows 4 inter- esting features:
the maximal demand increases to 100 MWe when the elec- tricity price is close to zero, which it often is in a windy peri- od during night hours the demand falls back to the original 20e MW or even to zero MWe when the price is high, which it often is in weeks with no wind.
the town exports up to 20 MWe capacity to the grid in case of very large prices
the town offers competitive up and down regulation ser- vices to the grid, typically from 40e MW up regulation to 80 MWe down regulation.
Made with FlippingBook - Online magazine maker