[lrasinen]

I took the electricity spot prices for the first three months of this year (so that it covers the cold period), and ran a simple simulation on it.

The simulation model assumes we're charging during the 12 cheapest hours, and discharging during the most expensive 12 h, and then calculated the average price differential per day. This is of course suboptimal, since the day-ahead prices are available.

The mean differential in the data is 56.5 €/MWh, and on 64% of the days the differential is over 22.8 €/MWh. 10%, 50% and 90% percentiles are 3, 54 and 119.

So at least during the winter time (when consumption is greatest) you'd expect to hit the price goal more often than not.

Adding the rest of the year up to now drops the mean to 52 €/MWh and the median down to 38 €/MWh. Still pretty good.

(As for cherry-picking the data: this year was easily available and didn't dig too hard for older data, but it was one of the mildest winters in recent years.)