If you asked me whether your commercial property should add battery storage, I'd say: it depends. I know that sounds like a cop-out, but it's actually the right one. I've spent the last 12 years handling energy emergencies for commercial facilities. Most of my job is triaging problems—outages, demand spikes, failed inverters, charge controllers that stop talking to the battery. The pattern I've learned through hard experience is that the right solar-plus-storage setup depends entirely on the problem you're trying to solve.
So let's classify you into one of three scenarios. Each one ends with a different recommendation.
Three scenarios, three priorities
Scenario A: You need backup. If losing power means losing money—grocery stores, data closets, clinics, warehouses with security gates—battery storage is a backup asset. The size is determined by critical loads and outage duration.
Scenario B: You want to cut operating costs. If your utility bill includes demand charges or expensive afternoon rates, storage is an economic asset. The size is determined by your load shape and utility tariff.
Scenario C: You're adding EV charging. If you're installing chargers for tenants, employees, or a fleet, storage and software have to work together. The size is determined by charging demand and your site's available capacity.
These are not the same problem. As I learned the hard way, a battery sized for one scenario can be completely wrong for another.
Scenario A – Backup first because outages are expensive
Let's start with the classic case. A few years ago, a client called me at 4:30 PM with a failing refrigeration unit and a storm predicted for midnight. Normal lead time for ordering a replacement battery was three to four weeks. We found one in stock, paid a rush fee, and had it installed the next morning. We didn't lose a single pallet. That's the emergency mindset: protect the load that costs you the most.
For commercial backup, don't buy a battery big enough for the whole building unless you enjoy paying for unused capacity. Start with the loads that actually hurt when they go dark. For one facility, that might be 40 kW of freezers. For another, it might be a single 5 kW IT rack. The difference between those two systems is enormous.
A lot of customers ask me about the Vivint Solar website when they're shopping for solar-plus-storage. It's fine to look at product specs there, but don't get caught up in the brand. The old Vivint Solar headquarters was in Lehi, Utah, but after Sunrun acquired the company, the name and website mostly point to Sunrun. What matters more than headquarters location is your local installer's service response time and whether the system can be maintained five years from now.
If backup is your goal, the practical checklist is:
- List critical loads and their runtime needs during an outage.
- Get the utility's average outage duration for your area—not the salesperson's guess.
- Size the battery to cover those loads, not the building's total connected load.
- Decide whether you need a generator as the long-duration backup and battery as the bridge. I know generators aren't clean, but when lives or inventory are at risk, they're hard to beat.
Scenario B – Cost first because demand charges are eating you alive
This is where battery storage gets interesting for property owners who already have solar. Solar covers daytime energy, but a battery can also avoid demand spikes and capture value when rates move around.
The ERCOT battery storage news in 2024 was a useful example. ERCOT—the grid operator for most of Texas—added a lot of grid-scale storage not because Texans wanted backup, but because batteries could be dispatched when wholesale electricity prices spiked. The same logic appears at a smaller level on commercial bills: if your utility charges you for your 15-minute peak demand, a battery can shave that peak and pay for itself over time.
I only believed this after getting burned. A client of mine—a small manufacturer—kept seeing high bills, but no one could explain why. I assumed it was the machine loads. When I pulled the utility data, the problem was one bad afternoon in July: a condenser unit, a few welding machines, and a compressor all ran at once, setting a new peak demand. That single 15-minute interval added about $4,700 to the next twelve months of bills. A properly sized battery would probably have paid for itself in about three years, depending on how the tariff changed.
So before you buy anything, get these three numbers:
- Your demand charge rate, in dollars per kW per month.
- Your facility's top five peak demand days in the last year.
- Your time-of-use energy rates, especially the window between 3 PM and 7 PM.
If your demand charge is more than about $10 per kW per month, a battery is worth modeling before you dismiss it. If it's low, skip the battery and keep solar alone. This is a math decision, not a vibes decision. Take this with a grain of salt: utility tariffs change, so run the numbers on your current rate before assuming anything.
Also, if you're going to market your renovated building as green, be careful about marketing claims. Per FTC Green Guides (ftc.gov), environmental claims must be truthful and not misleading. A solar-plus-storage system can absolutely support those claims, but the wording has to match what the system actually does.
Scenario C – EV charging because tenants and fleets are asking for it
Adding EV chargers is a different animal. Your solar array may produce enough annual energy, but a row of Level 2 or DC fast chargers can create a sudden, simultaneous load. If you're not careful, the first day you activate those chargers becomes your new peak demand day.
A facilities manager in Kirkcaldy described this exact setup to me last year. He was planning six EV chargers for a corporate car park and asked about battery storage not because he wanted outage backup, but because he didn't want the chargers to push his building into a higher demand window. That's the right instinct—battery storage Kirkcaldy is a real topic for buildings with EV charging, not just for outage protection.
For EV charging, the battery is a buffer. It smooths the load at the building's utility meter while still allowing the chargers to work at full speed. If you already have solar, the battery also stores midday solar energy and feeds it to the chargers in the evening when people actually plug in.
How to develop an EV charging station app (and why you probably shouldn't)
A lot of property owners ask me about how to develop an EV charging station app. The honest answer: for one building or even a small portfolio, don't build your own app. There's too much work in payments, maps, billing, and charger communication. Use an existing charging network app or white-label software. Building your own makes sense only if running chargers is your core business, not if you're a landlord adding parking amenities.
That doesn't mean the software question is off the hook. Even if you use a white-label solution, the charger hardware has to speak a common protocol. That's usually OCPP, which stands for Open Charge Point Protocol. If a charger doesn't support OCPP, think carefully before buying it—you'll be locked into one vendor's cloud.
If you do decide to build, the minimum user flow looks like this:
- Find a charger: map, location, and status.
- Start a session with a QR code or app tap.
- Authenticate payment.
- Monitor the session.
- Get a receipt.
That's the product. Everything else—revenue sharing, load management, tenant billing—comes after these five steps are stable. I'd also budget for someone who knows backend integration, because an EV charging app is less like a website and more like a payments terminal with maps.
How to know which scenario you're in
At this point, you might be thinking that you're a little bit of all three. Most commercial properties are. Here's how I think about it:
If your worst fear is the lights going out, start with Scenario A. Get the backup math right, then see if extra battery capacity can also cut costs.
If your worst fear is the utility bill at the end of the month, start with Scenario B. Storage might be an investment rather than an emergency expense.
If you're about to install EV chargers, start with Scenario C. The battery decision needs to be tied to charging capacity and software, not just the solar array.
Don't assume your site is too small for this kind of analysis. Some of the best projects I've worked on were one-building operations where a modest battery and a sensible software setup fixed a specific pain. A small site doesn't need a worse answer—it needs a focused one.
And if you're not sure, get the data first. For me, that means pulling a year of utility bills, looking at peak demand days, and asking your electrician what the site actually needs. I've done this enough times to know that the answer almost always comes from the numbers—not from a shopping trip across installer websites.
The headline is simple: there's no universal design for solar-plus-storage. There's only the design that fits the problem after the emergency was triggered, the bill data has been analyzed, or the EV chargers were announced. That's the scenario you're in. Everything else is just hardware.