This webpage displays some rough forecasts of hourly electricty prices for the next week, based on expected demand, wind and solar generation. I have also included the day ahead half-hourly prices (averaged to hourly) once these are known and have been imported.
The prices are essentially estimates of the day ahead hourly auction results in p/kwh, converted into retail prices for region C by multiplying by 2, and adding 12 from 4-7pm. Prices include 5% VAT.
If you want to know how historic forecasts performed, you can see the latest forecast before a past datetime, eg http://energy.guylipman.com/forecasts?region=C&before=2020-12-31T12:00
It should be noted that future wind generation and resulting prices are likely to be significantly different than those forecast.
I have described the methodology used in a bit more detail in this blog post. You can also see the code for this model on github