We have all been there: The lights exit and the ability firm sends you a textual content message. A tree fell on a transmission line or the climate turned extreme, and you will be out of electrical energy till individuals in onerous hats can get issues operating once more.

In 2021, the common American family skilled somewhat greater than 7 hours of energy outages, with the everyday outage lasting 2 hours, in keeping with the US Vitality Data Administration.

When that occurs, you in all probability end up wishing you had a backup supply of energy. For years, that is sometimes meant a generator fueled by gasoline, propane, pure fuel or another fossil gasoline. Extra just lately, it’d imply a set of photo voltaic panels in your roof and a battery within the basement or the yard, a system that may set you again tens of hundreds of {dollars}.

However what about simply the large residence battery by itself? 

“For any individual who’s motivated to get a generator, they’re additionally motivated to get a battery,” Jigar Shah, director of the Division of Vitality’s Mortgage Applications Workplace, informed CNET.

On the renewable vitality business’s annual RE+ commerce present in Las Vegas in September, we spoke to business of us to determine if a standalone residence battery actually can serve the perform of a generator. This is what we discovered.

Are you able to get a battery with out photo voltaic panels?

A house battery that gives one thing like 12 kilowatt-hours of backup electrical energy may cost you $10,000 or extra, however that also pales compared to the price of the battery and photo voltaic panels collectively, which could run you nearer to $30,000. (Getting precise estimates may be tough as a result of these methods are designed in your particular residence and desires, and since the photo voltaic business is not tremendous clear about pricing.)

Some batteries can solely be put in alongside photo voltaic panels, and it is undoubtedly a worthwhile consideration when you’re out there to turn into vitality unbiased out of your utility. Photo voltaic and battery firms are pivoting from the thought of promoting “photo voltaic panels” to the thought of promoting a whole “photo voltaic vitality system,” and even merging photo voltaic panels, batteries and sensible residence know-how to create one cohesive sensible vitality system. 

However the fundamental reply to the query is, sure, you will get a house battery with no photo voltaic panels connected. And the battery market is getting aggressive, with a variety of firms — each these with acquainted names and those who have solely been round a couple of years — exhibiting off merchandise on the RE+ present flooring. 

That evolving market means costs are getting extra inexpensive. “Battery costs just lately, over the previous few months, are undoubtedly coming down,” mentioned Zoe Gaston, principal analyst for US distributed photo voltaic on the consulting and analysis agency Wooden Mackenzie.

The draw back to batteries with out photo voltaic panels is that your battery must be charged by one thing. On this case, it is being charged by vitality from the grid that you simply pay your energy firm for. That vitality is perhaps costly, and it is perhaps generated at a polluting coal- or gas-fired energy plant. Maintain that in thoughts.

Tax credit change the mathematics on batteries

It was that you simply could not get a federal tax credit score for a battery except it got here connected to photo voltaic panels. The Inflation Discount Act, handed by Congress in 2022, modified that. Now a battery is eligible for the 30% residential clear vitality credit score, similar to photo voltaic panels, so long as it is not less than 3 kilowatt-hours in capability.

That change goes a good distance towards making batteries extra inexpensive.

“Resiliency, to a typical house owner, may be achieved in a few methods. The traditional method individuals have achieved it for years is simply to put in a backup generator,” mentioned Chris Rogge, options architect in clear transportation and vitality at Black & Veatch, a building and engineering agency. “That has its personal challenges so far as emissions and noise and upkeep go, but in addition financial inequality. Not everybody can afford to throw a $10,000 backup generator on their home.”

State-level insurance policies are additionally encouraging development within the battery market and nudging individuals towards putting in them. In California, adjustments to photo voltaic internet metering insurance policies (the best way you receives a commission for surplus vitality offered again to the grid) are encouraging householders to retailer and use their very own vitality reasonably than promote it.

What batteries can try this turbines cannot

Mills run if you want them, when the ability goes out. Batteries do not simply need to be there as backups. 

“Standalone vitality storage can be utilized extra economically than a backup generator, as a result of it is not a stranded asset during times when there is not an influence outage,” Rogge mentioned. 

Some states and utilities have what are known as time-of-use charges, through which electrical energy prices extra throughout occasions of peak demand (assume the late afternoon and early night) and fewer throughout occasions of decrease demand (such because the nighttime). “You need to use vitality storage to retailer vitality when it is cheaper and run off of your vitality storage throughout peak hours,” Rogge mentioned.

That perform, often called vitality arbitrage, helps in additional methods than one. It will possibly prevent cash — additional rising the worth proposition of getting a battery. As a substitute of being one thing you purchase for a number of thousand {dollars} and use solely when the ability goes out, it could possibly prevent cash each single day.

However the truth that it is getting used each single day would possibly itself be a bonus, mentioned J. Stephen Pollock, chief income officer of Lunar Vitality, which makes batteries. If a battery is functioning often, you will probably discover points throughout a time you do not really want it. With a generator, you will not use it — or notice there’s an issue with it — till you want it.

A battery can be cleaner, that means you will not have to fret about fireplace dangers, smells, noise or fumes as you’ll with a generator. And you do not have to fret about sustaining a gasoline connection, which typically requires individuals to check and certify them yearly. “Shopping for a battery is cheaper than that,” Shah mentioned.

Batteries additionally are inclined to have longer warranties than turbines — sometimes 10 years or extra, in comparison with three to 5 years for turbines.

What turbines can try this batteries cannot

The issue with batteries is that, if there’s nothing to cost them (like photo voltaic panels), you are caught with nevertheless a lot vitality is in them when the lights exit. That may not be an entire lot. The common American residence makes use of roughly 900 kilowatt-hours of electrical energy per thirty days, or about 30kWh per day. A Tesla Powerwall, probably the most in style residence batteries on the market, holds as much as 13.5kWh — lower than half a day of regular vitality use. 

A generator, in the meantime, will maintain producing electrical energy so long as it has gasoline, and that may very well be lots longer than a battery will final. So for prolonged outages, a battery with out photo voltaic panels shall be no use as soon as it is drained, however a generator will maintain chugging.

The standard energy outage is not a multi-day blackout: The common energy outage within the US is about 2 hours, greater than sufficient time for a battery. And a battery can last more if it is solely used to energy important electrical masses as a substitute of every part.