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May 3, 2013

Grid power backup via Solar power and flywheels at affordable prices

1000 to 3000 watts of solar power that operate stand alone as well as on the grid can be used to provide power during a power outage and provide lower electrical costs at other times.


200 watt standalone solar is $400 or less.

400 watts is $700 or less.

2200 watts can be had for about $2000.

Solar power is improving as a way to provide low cost robustness in the event of emergencies.

Batteries are too expensive and don't last long enough. Pumped hydro is cheap but not feasible for most locations. Thermal storage is promising but still too expensive or hard to scale. Compressed air is cheap and scalable but not yet efficient enough.

Flywheels may be getting a second life, however. Silicon Valley inventor Bill Gray has a new flywheel design that would deliver distributed and highly scalable storage for around $1,333 a kilowatt [?hour? if it is $1333 per kilowatt, does that mean $50-75 per kwh ? That is pumped hydro prices.], making it price competitive with pumped hydro and compressed air. With an efficiency of more than 80 percent, it would rival the best storage alternatives, and come with a 10-year guarantee.

Alveo Energy (Stanford spinoff) claimed that they could get costs down to $100 per kwh with a water and blue dye battery system.




A new flywheel design offers some hope of affordable energy storage for home systems, such as rooftop photovoltaic panels.

The Kickstarter project was successful and has raised over $56,000.

Read more via NBF