The energy storage industry (i.e. batteries for storing generated electricity, like the Tesla Powerwall) in the U.S. is growing at a tremendous pace, with deployment increasing 6-fold in just a three-month period this year.
Why is this a big deal?
- It makes solar and wind energy more practical because you smooth out the ups and downs of uneven generation (i.e. the sun’s not always shining, so you’re not always producing the same amount of solar power; a battery lets you store extra electricity and use it when your panels aren’t producing as much electricity)
- It makes deploying solar arrays less expensive (because you need fewer solar panels to get the electricity you need)
Let’s use my house as a simplified example. Here’s an approximation of the amount of electricity my rental house (with its inefficient HVAC and non-Energy Star appliances…sigh) uses in the hot and humid Southeast U.S.:
|August 2015||1575 kwh|
|July 2015||1500 kwh|
|June 2015||1400 kwh|
|May 2015||1100 kwh|
|April 2015||950 kwh|
|March 2015||1525 kwh|
|February 2015||1425 kwh|
|January 2015||1325 kwh|
|December 2014||1125 kwh|
|November 2014||975 kwh|
|October 2014||1250 kwh|
|September 2014||2325 kwh|
If you have a solar panel array with NO energy storage, you need to have an array that can produce 2,325 kwh of electricity per month (assuming you want all of your electricity to come from your solar array). Using a solar calculator from Wunderground (and assuming use of a higher-end GE solar panel), this would require 68 solar panels at my house, taking up 1,050 square-feet and costing $110,000! It would also produce nearly double the amount of electricity that I need over the course of the year (so I’m paying for more capacity than I need), but I would have to keep all of that generating capacity just to meet the needs of my peak consumption month.
By contrast, if you have the ability to store excess electricity produced by your solar panels and save it for a time when your panels are less productive or you’re using more electricity (e.g. a hot summer day), you theoretically only need the ability to produce 16,475 kwh per year, rather than a specific amount each month (I know this is over-simplified, but I think it demonstrates the value of energy storage quite well.) SO, with energy storage capabilities and the same solar panels, I would need only 42 solar panels taking up 650 square-feet and costing $68,000. That’s 38% less space and less money!
I’m not a solar engineer so I can’t claim any real expertise here, but it does seem obvious that energy storage has the potential to make solar less expensive (because you need fewer solar panels to meet your needs) and therefore makes solar more accessible to the general population (because the capital costs are lower).
Lack of consistent/on-demand production has long been a complaint of renewable energy sources like solar and wind energy, but this boom in energy storage could be just what’s needed to tip the scales and make renewable energy a household phenomenon.