science

It’s generally not the fuel for the plant that drives up your power bill. It’s things like paying to build, operate and maintain plants, transmission infrastructure, etc.

There are also other things inflation, like demand driven rate setting hikes that encourages people not to run appliances in the evening.

All in all, the primary goal of this plant is reducing carbon emissions.

Electricity storage through batteries is not cheap though

Capitalism babeeeeee

The storage capacity is sized for daily consumption, not the yearly figure you quoted. And of course, this is one small project out of the hundreds of plants that will be needed to meet climate goals.

The biggest issue with solar right now is that the output varies over the course of the day, leaving other power plants to take up the load at night or during cloudy weather. The attached battery storage averages out the solar plant's output, letting it be a useful contributor to the grid around the clock. There's other benefits like grid stabilization and peak shaving, where the battery stores and releases oversupply from the rest of the grid, not just the attached solar panels.

I don't have other numbers handy, but that 3GWh number is storage capacity, which isn't comparable to annual usage.