FindSolar.caSolar batteries have become the most-pitched add-on in Canadian solar, and the pitch usually blurs two different purchases into one price: a battery as backup power, and a battery as a money-maker. They are not the same purchase. One is insurance, one is arithmetic, and a battery that fails as arithmetic can still succeed as insurance, as long as you knew which one you were buying.
The backup case
A battery with backup-capable hardware keeps your essentials running through an outage, something grid-tied solar alone cannot do. The value is personal: how often your power fails, for how long, and what an outage costs your household in spoiled food, frozen pipes, a flooded sump or a home office offline. Price it the way you would a generator, and the backup case stands or falls on your own outage history rather than on anyone's savings slide.
The money case
A battery earns money by moving power in time: storing midday solar that would have exported at a low rate, then discharging it in the evening so you avoid buying at retail. The margin is the gap between your retail rate and your export credit. Where net metering pays full retail for exports, that gap is near zero and the battery has no daily job. Where exports pay much less than retail, every stored kWh earns the difference, and provinces moving that direction make the arithmetic more interesting each year. Ontario's rebate structure adds a wrinkle worth knowing: the non-export path pays up to $5,000 for storage precisely because the battery is what makes a non-exporting system work hard.
What batteries cost, in planning terms
On planning ranges, an essentials-class battery around 10 kWh installs for roughly $10,500 to $14,000 including hardware and labour, with larger comfort- and whole-home-class systems scaling up from there. Our cost calculator carries these ranges by size so you can see the premium next to the solar itself. Batteries are bought for capability first; treat any payback claim on the storage portion with the same verification you would apply to a production estimate.
Buying once versus buying twice
Installing battery and solar together usually costs less than retrofitting later: one crew, one permit round, one inverter decision. But battery-later is a legitimate strategy, especially while your province's export rules are stable. The key is to make the choice deliberately at design time: a hybrid-ready inverter or a documented AC-coupling plan keeps the later door open cheaply. What stings is neither choice, but discovering in year three that nobody planned for either.
Questions homeowners ask
Will a solar battery actually save me money?
It depends on the gap between your retail rate and your export credit. Where exports earn near-retail, a battery has little daily work and its value is mostly backup. Where exports pay well below retail, each stored kWh earns the difference. Run your province's rules before believing any savings claim.
How big a battery do I need for my house?
Size from the loads you want protected and for how long, not from the house. An essentials circuit of fridge, lights, internet and furnace fan runs on a 10 kWh class battery for many hours; add a well pump, more rooms or longer outages and you step up in capacity and surge rating. List loads first, shop second.
Can a battery let me avoid selling cheap solar power back to the grid?
Yes, that is its day job where export credits are low: store the midday surplus, discharge it through the evening, and keep your solar at retail value instead of export value. The lower your export rate relative to retail, the more each cycle is worth.
Can I run my furnace, well pump or air conditioner from a battery?
Furnace fans and most well pumps, yes, with an inverter rated for the motor's starting surge. Central air and electric heat are heavyweight loads that drain storage quickly and often stay off the protected panel by choice. It is the surge and continuous ratings that decide, so put every motor on the design list.
How long do home batteries last and what happens when capacity fades?
Quality lithium batteries are typically warranted around 10 years to a stated remaining capacity, often about 70%, with cycle or throughput limits in the fine print. Fading is gradual, not a cliff: year-eleven storage still works, just smaller. Read the warranty's capacity, cycle and claim terms before comparing prices.
Is it cheaper to install a battery at the same time as solar?
Usually, since you pay once for the crew, permits and inverter architecture. But later is fine if the system is designed for it: a hybrid-ready inverter or a documented AC-coupling path keeps retrofit costs sane. Decide at design time which door you are keeping open, and get it in writing.