If you need predictable price buy futures.
If they increase in price then firm production is stimulated to build to meet the gap.
https://www.next-kraftwerke.com/knowledge/futures-market
If the grid balance is dominated by bursty renewables then you can potentially price the stable / on-demand generation out of the market (or lead to a massive contango to incentivise said producers)
If the grid balance is dominated by bursty renewables then you can potentially price the stable / on-demand generation out of the market (or lead to a massive contango to incentivise said producers)