> factor in the cost of storing solar for 24 hours and it stops looking cheaper. Engineering research on grid-scale storage has barely begun. It's really no mo

> factor in the cost of storing solar for 24 hours and it stops looking cheaper. Engineering research on grid-scale storage has barely begun. It's really no more than ten years old, except for pumped hydro. Before that it was just ideas and concept studies. Already storage is cheaper than gas peaker plants for some short-run uses according to Lazard. And there are some promising, cheap technologies for other uses (longer duration): iron-air batteries, aluminium-air batteries, latent heat and sensible heat storage (air liquefaction; hot rocks), various flow batteries. Look at the trends, not what the costs were two years ago. Once someone starts to look into this stuff properly, the costs go down quickly. Edit: and if the perovskite R&D comes up with the goods, we'll have dual-layer (2x output) PV panels for the same cost (or less) as single-layer Si panels.