I live in Finland and me like a large number of other Finns have a plan in which the price changes every hour according to the market price. Typical price for electricity is around 4c/kWh in the summer and around 15c/kWh in the winter. However it’s not uncommon at all for the price to spike into 30c/kWh or even 70c/kWh. Last winter there was a day that it spiked to 200c/kWh.
How do we deal with it? By turning down/off the heating if possible and burning wood instead. If not then you just deal with it and have to pay significantly more for a few months. Then again if your plan has a fixed price to like 10c/kWh then that also mean you’re paying that even when the price drops to zero which also is not uncommon at all. Often happens several times a week during the summer time. Sometimes it even goes into negative. It’s still not literally free though since the transfer cost is around 6c/kWh plus energy fee and taxes.