Who Needs This Checklist?
If you manage a commercial building—retail space, a small office park, a warehouse—and you’ve got the green light to look into solar, this is for you. I’m not an engineer. I’m an office administrator who got handed this project in 2023 for a 50-person company across two locations. Here’s the 6-step checklist I wish someone had handed me.
You’re not trying to save the planet with this project alone. You’re trying to save money, lock in energy costs, and not screw up anything critical.
Step 1: Know Your Load Before You Talk to Anyone
Before you call a single solar company, you need to know what you’re trying to replace. Don’t rely on what your utility says you use. Get a 12-month history of your kWh usage from your utility portal. This is free, and you can usually download a CSV.
Here’s what to look for: your peak demand (kW) and your total annual usage (kWh). Solar is sized based on annual production. If your usage is seasonal—high AC in summer, for instance—your solar system might cover 90% of your total but only 60% of your summer peak. That matters.
What I mean is that you need to separate “what we use total” from “what we use at the moment the sun is shining.” This is especially true if you’re looking at battery storage. In my case, I found we were using 60,000 kWh annually, but our peak demand hit 120 kW in August. That meant the solar array wasn’t going to cover all our peak load without a battery. Don’t skip this step.
Step 2: Evaluate Your Roof—Really Evaluate It
I said “sure, the roof is fine.” I heard the solar installer say “great, we’ll mount it on the southern exposure.” What we both missed was the 25-year-old skylight that made the best part of the roof unusable. We’re talking the same words but meaning different things. Discovered this when the structural engineer showed up, looked at the roof deck, and said “you’ll need to replace this section before we install.”
Here’s a practical check: get a roofing contractor to look at it before the solar sales rep. Your roof needs to have at least 15-20 years of life left. If it doesn’t, you’ll either need to roll the replacement into the solar cost (making it more expensive) or you’ll be paying to remove and reinstall the panels in a few years. That’s a significant hidden cost.
Look, I’m not saying a 20-year-old roof is a dealbreaker. But you need to get a quote for the roof repair or replacement before the solar contract is signed. Roll that into your ROI calculation.
Step 3: Understand Incentives Before You Ask for Pricing
This is where many admins get tripped up. Solar incentives change frequently. In 2025, the commercial Investment Tax Credit (ITC) is likely still 30% for systems placed in service before 2023, with a step-down coming. But here’s the nuance: the ITC is a credit against your tax liability. If your company doesn’t have enough tax liability, you can’t take full advantage of it. You might need to lease the system or use a partnership.
The question isn’t “what incentives are available?” It’s “what incentives does my company qualify for given our tax structure?” I learned this the hard way when our tax firm advised us that our 30% ITC would be worthless because our non-profit entity didn’t pay income taxes. That was a “hit confirm and immediately thought ‘did I make the right call?’” moment.
Ask your accountant this question before you get multiple bids. It will save you from comparing apples to oranges.
Step 4: Get Three Bids—But Make Them Comparable
Don’t just collect quotes. You need a standard request for proposal (RFP) template. The bids need to specify:
- System size in kW DC (direct current)
- Expected annual production in kWh (and how they modeled it)
- Panel brand and model (e.g., SunPower Maxeon 6 vs. a generic Canadian Solar module)
- Inverter type (microinverters vs. string inverters vs. power optimizers)
- Warranty terms (performance vs. product, 25-year vs. 30-year)
- Battery options (if applicable) including usable capacity and chemistry
- Installation timeline and any penalties for delays
- Financing options (cash, loan, lease, PPA)
In my experience managing this process for two facilities, the lowest quote (a $45,000 system) vs. the mid-range bid ($52,000 with SunPower panels) came down to inverter warranties. The cheap bid used a 10-year warranty inverter. The SunPower system used microinverters with a 25-year warranty. The $7,000 difference saved us probably $2,000 in potential repair costs over the system’s life—but that’s a judgment call. At my company, we chose the mid-range option for the longer warranty and higher efficiency.
Step 5: Verify the Installer’s Credentials
Here’s a step most people skip: check the installer’s license and insurance. Not just the sales rep. The actual installation crew. Ask for a certificate of insurance. Call their reference customers—ask for the property manager, not the CEO. Ask the reference: “Did they show up on time? Were there safety issues? Did they clean up after themselves?”
I had a vendor who couldn’t provide proper invoicing—they gave a handwritten receipt after the deposit. That cost me a headache with our finance team. If that had been a $50,000 solar deposit, it would have been a nightmare. Verify invoicing capability before placing the order.
Also, check if they’ve installed commercial systems before. Residential solar is different—different loads, different mounting systems, different inspection requirements. If they only do residential, look elsewhere.
Step 6: Review the Contract for Hidden Costs
The most important step. Solar contracts are dense. Look for:
- Escalation clauses: PPA (Power Purchase Agreement) prices often escalate 2-3% annually. This can add 30%+ over 20 years.
- Maintenance exclusions: Some contracts exclude panel cleaning or replacement of inverters after year 5.
- Performance guarantees: If the system underperforms, what happens? A credit? A fix? A reduction in price? If there’s no performance guarantee, you have no recourse.
- Permitting costs: Are they included or charged separately? Permitting can add $1,000-$5,000 depending on your municipality.
- Termination fees: If you want to buy out a lease early, what’s the penalty?
Why do hidden costs exist? Because the upfront price is the headline, but the total cost of ownership includes these line items. The lowest quoted price often isn’t the lowest total cost.
A Few Final Words of Caution
Don’t assume “net metering” stays the same. Utilities are changing net metering policies. In some states, you’re paid wholesale rate for your excess power, not retail. This kills the economics. Check with your utility’s commercial department before signing anything.
Consider battery storage now. Even if you don’t install it, think about future-ready wiring. Adding a battery later is cheaper if the inverter is already designed for it. SunPower’s SunVault system integrates smoothly, but many other options exist.
Timeframe matters. I’ve seen projects take 6-12 months from contract to interconnection. Your timeline needs to account for permitting, supply chain delays, and utility approvals. If you need energy savings within a fiscal year, plan for a 10-month timeline.
To be fair, solar isn’t the right answer for every building. If your roof faces mostly north, you’re in a shaded lot, or your energy rates are under $0.10/kWh, the math might not work. But for 70% of commercial properties in sunnier regions, it’s a no-brainer—with the right checklist.
Between you and me, the paperwork is the hardest part. The panels are easy. The contract? That’s where the real work lives.
Have a project question?