Buying Solar + Storage for Your Facility? Run This 5-Step Checklist First

When I took over energy and facility purchasing in 2022, I thought it was simple. Compare specs. Check prices. Pick the lowest quote. Classic rookie approach.

Then we installed a solar + battery setup with a budget inverter I'd never heard of. Six months later, it was offline. The "3-year warranty" meant shipping the unit back to another country at our cost, and "technical support" was a WhatsApp number nobody answered. Replacement costs wiped out every dollar we'd saved. Actually, we went negative.

That experience turned me into a checklist person. Not a sales pitch checklist—a buyer's validation checklist. Here's what I run on every solar and storage purchase now, in the order I use it.

When to use this checklist

If you're a facility administrator, office manager, or operations lead about to approve a solar quote your company hasn't bought before, this is for you. It's five steps, it'll take about an hour the first time, and it exists because I'd rather you learn from my ledger than your own.

Step 1. Verify the inverter brand's real market track record

The inverter is the brain of the system. If it fails, everything stops—your panels become an expensive roof ornament. So before I look at a price, I look at the manufacturer's history.

Our second installation uses SMA. SMA Solar Technology AG—the company that essentially defined the string inverter—has been building them since 1981 (a fact that gave me an odd sense of comfort). More importantly, their 2023 annual report showed roughly 18.5 GW of inverter shipments in that single year, and their cumulative installed base sits above 100 GW worldwide. Numbers like that tell me two things: they'll still be in business next year, and they have a financial reason to keep supporting units in the field. A no-name brand has neither.

Scale isn't everything. It is, however, a strong signal when you're buying the one component you can't easily replace.

Step 2. Check battery weight before you plan the install

This step almost caught me. I assumed a lithium battery would weigh what my old lead-acid battery did. Nope. Did not check.

The spec you need to look up is the 24V 100Ah LiFePO4 battery weight. Quality units from mainstream brands run roughly 45–55 lbs (20–25 kg), depending on the casing and BMS. The equivalent lead-acid battery? Around 130 lbs. That difference changes your entire installation plan:

• Cabinet shelves have to handle the load
• Shipping cost per unit changes
• Ground mount and racking need the right load rating
• Wall-mounting a 55-lb battery is one person's job. 130 lbs is a forklift conversation.

I nearly ordered the lead-acid option to save $300 per unit. It worked on paper. Then freight and rack reinforcement costs showed up, and the "savings" evaporated. Funny how that works.

Step 3. Match the mount to your site, not the other way around

Rooftop wasn't an option for our building, so we went ground-mounted. The Maple Leaf solar ground mount kept coming up in supplier quotes. It's a steel-frame system for fixed-tilt ground arrays, and its spec sheet was one of the cleaner ones we reviewed.

What I verify on any mount now:

• Wind and snow load ratings (actual tables, not "it'll be fine" claims)
• Panel dimension compatibility—width, length, and clamp range
• Steel vs. aluminum construction
• Whether the quote includes rails, clamps, and ground screws or just the frame

The lesson that cost us: I assumed "same specification" meant identical performance across vendors. It didn't. One quote's "complete kit" omitted the end clamps entirely—a detail only visible if you read the full bill of materials.

Step 4. Calculate run time yourself

Every solar generator spec sheet screams something like "2,000W output." That number tells you nothing. Ask "how long will a solar generator run" and the honest answer is math, not marketing.

Run time (hours) = battery capacity (Wh) × usable depth-of-discharge × inverter efficiency ÷ load (W)

Example from our backup unit: a solar generator with a 1,024 Wh LiFePO4 battery, 90% usable capacity (lithium allows deeper discharge than lead-acid), 85% inverter efficiency, and a 150W load:

1,024 × 0.9 × 0.85 ÷ 150 = 5.2 hours

That answer differs from what the marketing sheet implied. Did we believe it? No. We tested it. The generator shut down right around 5 hours at a constant 150W load. Good enough.

Why does this matter? Because when a blackout hits and your staff still wants to work, the person who under-spec'd runtime is the one fielding angry calls. Do the math first.

Step 5. Compare total cost, not unit price

By this point, you've confirmed the equipment itself. Now comes the real comparison:

• Unit price
• Freight and shipping (batteries are heavy—see Step 2)
• Mounting and rail compatibility
• Installation labor for ground mounts vs. rooftops
• Commissioning support and warranty claim process

Here's the story I keep in my head: I saved $80 once by ordering from a vendor with no local support. The inverter failed during commissioning, phone support cost us $120 in wasted service calls, and the site ran on diesel for a week. The budget choice lost money. The project sponsor looked unprofessional to the board. (Surprise, surprise—the strongest proposal wasn't the costliest. It was the most complete one.)

Quality is a brand issue. When your name is on the purchase, a $200 saving that creates two weeks of operational noise is the worst trade on the table.

Mistakes I still see

Three things I keep catching in other people's projects:

Ignoring interconnection rules. In most regions, grid-tied inverters need UL 1741 certification and IEEE 1547 compliance. If the spec sheet doesn't mention them, ask. Fixing it afterward means engineering stamps and fees that can run $800–$1,500.

Not reading the BMS specification. The battery management system never makes it onto the marketing page. Two 24V 100Ah LiFePO4 batteries can look identical; one might have a BMS that drops out at 10A continuous load. Download the datasheet. It's dry. That's fine.

Assuming the mount's load rating includes panels. Some ground mount kits rate the frame only. Panels, rails, clamps, and cabling all add load. That's how a windstorm rearranges what used to be an array.

One last thought. Don't let your first solar purchase be the one you learn on. Buy a small solar generator first, test your assumptions, then scale up. That's how we went from "budget everything" to approving an SMA system that survived its second year—an inverter brand my CFO now defends, and invoices accounting actually processes. Quality, it turns out, is a cost-reduction strategy.