The primary source at https://grid.iamkate.com/ states Britain today is generating 90%+ of electricity from renewables. The site provides real-time grid monitoring with this figure listed under the current energy mix.

Discussion of the data appears at https://news.ycombinator.com/item?id=47553484 which references the grid.iamkate.com dashboard and shows 294 points along with 192 comments. The primary source contains no additional historical context or forecasts.

All figures are taken directly from https://grid.iamkate.com/ with no external data incorporated. The site tracks instantaneous generation shares across fuel types including renewables.