Sodium batteries for electrical grid storage are now going mainstream. Historically renewable electricity generation created a 'duck curve' where prices were low / negative midday and peaked in the evening.
Battery storage is obliterating the curve. By charging midday and releasing during peak, the electricity price is smoothing drastically [https://shellenergy.com.au/energy-insights/how-batteries-are-changing-the-energy-duck-curve/](https://shellenergy.com.au/energy-insights/how-batteries-are-changing-the-energy-duck-curve/)
This means that the negative or low rates trying to balance renewable power are soon going to be a thing of the past, like within 3-4 years.
