As compressed air or compressed nitrogen in underground tanks. Ur ac unit could also do side duty as generator. .

They waste an extreme amount of energy and have almost no range.
Compressed air energy storage for grid applications on the other hand, does work.

99% of all electrical storage used in the US is such pumped storage systems.

http://water.usgs.gov/edu/hyhowworks.html

http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity

You have to understand when it comes to ways to generate electricity, the quickest to turn on or off is Hydroelectric generators. IF the water is released the turbine turn, if the water is turned off, the turbines stop to spin.

You can NOT do that with Nuclear, oil, natural gas or coal generation. Wind only provides electrical power when the wind is blowing, Solar when the sun is out. Thus Hydroelectric generation is the most efficient way to produce power and is the quickest to turn on or off. Thus the most efficient way to store electrical power for later use.

The basic concept is simple. During those time periods when you have more electrical production from sources other then Hydro, you use that excess electrical power to pump water behind dams. During peak periods the water is releases to run water generators.

As stated above, this is how 99% of electrical power is stored today in US.

You need a particular alignment of geologic features to do hydro power (or grid-scale pumped storage). Essentially, you need a good sized lake and then a fairly steep descent from that lake. If you're doing pumped storage, you need another lake below to catch and hold the water. The lakes could be made by dams, but you need the steep river, as well as space for the lake around that river.

That set of geologic features doesn't appear all that often. We've already built hydro power plants on pretty much all the suitable places in the country.

Pumped storage opens a few more options, since you don't have to have a naturally-flowing river. But not nearly enough to handle everything.

Batteries have the advantage of "just working" anywhere, regardless of geology. It should be noted grid-scale battery storage also has large disadvantages that weren't covered in the article.

The article in the OP says:

Includes links to the report
http://www.democraticunderground.com/112765172

I just hope I live long enough to see it materialize.

My wife's not going to do that. The no refrigerator / no washing machine / no clothes dryer lifestyle does not appeal to her and she's paying the electric bill.

But I've lived it, as a child and adult.

My great grandma didn't even have indoor plumbing. We lived with her some summers on the family homestead. Providers of your beef. My mom's cousin still owns the ranch. (One of his kids is a techno-geek like myself.)

Carry the water to the wood stove, wait until it's hot, wash! Multiple naked people in the kitchen! An 1800's Scandinavian immigrant thing, I suppose. My great grandma's breasts reached nearly to her naval. I saw 'em.

If my electricity is disconnected tomorrow I can still post here on DU thanks to solar power, but I do confess washing my clothes by hand and hanging them up to dry on the porch is such a nuisance I might be a bit stinky in such circumstances.

I love my parents dearly. Living as indigent Americans in a public park in France was still a grand adventure, no horrors! Even though the bathroom facilities were among the worst imaginable, including random masturbating or vomiting drunks, mostly guys... France got rid of us by giving us ferry tickets to England.

Dropping off the grid is easy. Walk to your main circuit breaker, turn it off. Or don't pay your electric bill.

Only then do things become interesting and worthwhile.

Where we live now we depend on city water and sewage. Everything else, including transportation, is optional. This region's export is food.

There are important things in life: food, water, safe shelter, appropriate medicine, and education. All the other shit is optional and far too often just shit.

Perhaps in exchange for free electric service the electric utility would install a 500 milliamp limiter in your breaker box. It could be built into a "smart meter."

Bring your own household load management, (modular battery systems or ??? ), add supplemental solar, or just utilize the micro electric service as-is to charge your smart devices and power your LED lights.

Micro levels of electric power service might even be entirely subsidized by government as a means of encouraging people to "drop out" of high energy, high environmental cost consumer society.

Successful, comfortable, low energy lifestyles might evolve. Would you like air-conditioning? Buy the solar panels to support it, or think up other ways to stay cool. And so on...

Eventually you might end up with lifestyles where residential construction is greatly simplified and much less resource-intensive. Remodeling? Recycle all the copper wiring and coper water pipes inside the walls, replace with a single, very simple 16 gauge copper circuit and PEX water pipe.

Send the recovered copper to "developing" nations where new residential electrical and water service would be installed in a similar fashion.

Etc.