Wind-generated electricity reaching the market in bulk was behind negative prices in electricity on the Nord Pool market early on Monday, only the second time this has happened.
"Essentially, there was still large amount of wind power behind this; prices were negative in all Nordic countries, and for the first time in history, the system price was negative," Ingrid Arus, Nord Pool's Baltic regional manager, told ERR Monday.
The price of electricity fell negative by €0.04 at 02.00 a.m. in the Estonian price area of the electricity exchange on Monday.
Between 04.00 and 05.00 a.m. Estonian time, the price was as low as -€1.73, before going positive after 05.00 a.m. when the price recovered to its average level of about €40 per MWh in Estonia.
Nord Pool is an electricity marketplace covering the Baltics and Nordic countries.
Low night-time consumption and adequate transmission capacity was also behind the fall, Arus added.
While this in effect means suppliers have to pay customers to take their electricity, this still works out cheaper than plants having down-time instead.
The exchange price fell into the red in July this year for the first time ever, due to low consumption, high hydro-electric output, and again, a glut of wind-generated electricity.
Editor: Andrew Whyte