[gwright]

That math doesn't work -- at least until someone can demonstrate cost effective grid scale energy storage systems. In other words it is not cheaper and perhaps not greener (it isn't clear how green the production and long term maintenance of solar/wind is)

The basic problem is that in order to provide reliable energy 365 days a year you need to account for the daily and \ seasonal variability of solar and wind. You have two options:

    * maintain a duplicate fossil fuel backup system (fully maintained, staffed, and fueled) for those cold windless nights (so no longer cheaper)
    * deploy a storage system that can effectively time shift energy created by solar and wind across entire seasons (also not cheaper nor demonstrated with current battery technology)

Of course if you don't care about reliable electricity you have one more option:

    * suck it up when there is no sun or wind available

[outworlder]

Citation needed.

My power utility in the Bay Area powers residential customers 100% on renewable energy. Commercial and industrial do have fossil fuels still.

> maintain a duplicate fossil fuel backup system (fully maintained, staffed, and fueled) for those cold windless nights (so no longer cheaper)

Guess what, this is needed even in a world that only fossil fuels are used. Energy demand is variable and we need peaker plants on standby.

> deploy a storage system that can effectively time shift energy created by solar and wind across entire seasons (also not cheaper nor demonstrated with current battery technology)

We already need some storage in the current grid until said peaker plants come online. Maybe it's not 'cheaper' but it's been demonstrated. California alone has 2239MW of stored power at the moment I'm writing this (check the California ISO).

I'm not entirely sure you are familiar with how power grids work.