According to wikipedia it’s 110 billion m³ in the US.

Some estimates & predictions for the security of supply for fossil fuels are a lot less optimistic than IEA outlooks. If we will continue to allow the socialization of the external effects of the current energy paradigm is also questionable.

The solution establishing itself as the #1 choice for seasonal storage in Germany is currently the Power-to-Gas conversion to link the power & gas grid (enabling surpluss wind & solar to make use of the existing infrastructure).

For a 100% renewable energy system it would take 40-60 GW of P2G capacity (in a unrealistic scenario that looks at Germany as an isolated island).

Since P2G is highly scaleable it can be mass produced (lowering cost) and could be applied in a distributed way. (As a “upgrade” for existing biogas facilities, … )

According to the Fraunhofer Institute the installation cost of 1 GW of P2G capacity should end up below 1 billion Euro.

So we are looking at up to 60 billion € for the power to gas capacity… multi-TWh storage capacity already exists in the gas grid.

Since Wind & solar compliment each other quite well on a monthly timeframe, alot of storage capacity wouldn’t even be neccessary.

To quote from your link:

“To move beyond 40% to 80% renewable power (the target for around 2050),
Germany could need as much as 14 GW of short-term and 18 GW of seasonal
power storage to meet its peak power demand of around 80 GW in the
moderate scenario. At that point, power prices would be roughly 10%
greater than in 2011, but reaching 100% renewable power will be quite
expensive indeed. The German engineers estimate that the final 20% will
triple the need for power storage, raising prices once again by around
19%.”
Read more at http://cleantechnica.com/2012/10/09/german-study-not-much-power-storage-or-coal-power-needed-for-40-renewable-power-supply/#pSTSrKwK1kvQ1Yrz.99

One thing that comes to mind is the LA Solar Atlas: http://cleantechnica.com/2011/03/21/los-angeles-could-be-solar-powered-sort-of-ucla-study-finds/

Not even any of our states to the country as a whole: http://cleantechnica.com/2013/01/29/top-solar-states-vs-top-solar-countries-cleantechnica-exclusive/

But yes, these matters have been studied a little bit in the US already.

I’d recommend: http://cleantechnica.com/2012/02/20/clean-energy-could-supply-u-s-with-70-of-electricity-by-2030-noaa-director-says/

And maybe: http://cleantechnica.com/2012/12/11/wind-solar-storage-could-power-full-electric-grid-cost-effectively-99-9-of-the-time-by-2030-report/

More such stories here: http://cleantechnica.com/70-80-99-9-100-renewables-study-central/

http://cleantechnica.com/2012/10/09/german-study-not-much-power-storage-or-coal-power-needed-for-40-renewable-power-supply/