How to Compare Commercial Solar Quotes: A 5-Step Procurement Checklist

If you're an office administrator or procurement person who just got handed the solar project with no warning, this is for you. I'm not an engineer. I'm not a renewable energy consultant. I manage purchasing for a 55-person logistics company — roughly $240,000 a year across eight service vendors. In 2024, I spent four months evaluating solar and storage quotes for two office locations and a warehouse. This checklist is the thing I wish someone had given me before I started.

Here's the five-step checklist I now use for any solar contract. It won't make you a solar expert. It will keep you from signing something your finance team will loudly regret.

Step 1: Pull 13 months of utility data before talking to any solar rep

A solar quote is only as good as the load data behind it. Most reps will show you a savings projection based on one uploaded bill. That is not enough. You need at least 13 months of interval data, not just a monthly total, because demand charges, time-of-use rates, and seasonal peaks change the math.

The ops director warned me about demand charges. I didn't listen. The average bill projection missed a $700 monthly demand charge during our peak season. If I'd signed that quote, we'd have been paying more than the utility bill we were trying to replace.

Checkpoint: You can state your site's peak demand in kW and identify the rate tariff you're currently on.

Step 2: Compare the PPA, solar lease, and purchase by total cost, not first-year payment

The biggest mistake in solar procurement is comparing monthly payments alone. A sales rep can structure a 25-year term with a low first-year rate and a large escalator. That makes the quote look cheap in year one. That's not a solar strategy. That's a teaser rate. But do not sign based on a teaser rate.

In our search, the two realistic options were a Sunrun power purchase agreement and an outright purchase. The PPA has zero money down and charges you for energy produced, not for the hardware. It was the easiest option for cash flow. The purchase had a higher upfront number, but after federal incentives and avoided utility increases, it had the best 15-year total cost. The lease sat in between.

I now calculate total cost of ownership, or TCO, before comparing vendor quotes. TCO for a solar contract includes installation, ongoing operations and maintenance, inverter replacement, insurance, monitoring fees, and the buyout option at the end. A payment comparison will hide that.

The cheapest first-year quote can be the most expensive contract.

Checkpoint: You have a side-by-side TCO model with and without the solar contract, not just a monthly payment chart.

Step 3: Understand the Sunrun solar lease escalator rate standard before comparing lease payments

Here's the phrase that trips up a lot of buyers: solar lease escalator rate standard. It's the annual percentage increase in a lease or PPA payment. A 0% escalator is not always the best deal. A 2.9% escalator with a lower starting payment can cost less over ten years than a 3.9% escalator with a slightly lower first-year payment.

Ask what the Sunrun solar lease escalator rate standard is for your term. If I remember correctly, Sunrun's typical residential lease escalator rate standard has been around 2.9% to 3.9% depending on state and term. But commercial deals can be negotiated. Make the rep print the annual rate schedule. I want to say our quote used 2.9%, but don't quote me on that — the point is, I made them put it in writing.

Checkpoint: You have the annual escalation schedule in writing for every quote, not just the first-year rate.

Step 4: Ask what the best solar inverter on the market actually means for your site

What is the best solar inverter on the market? I asked that question to three different solar vendors and got three different answers. Here's the honest procurement answer: the best inverter is the one that matches your roof, your shading, and your warranty service plan.

One of our buildings could have used a string inverter. The roof was a simple rectangle with little shade. The other building needed microinverters because of HVAC units and parapet shadows. I now look for the microinverter Pro Series product line in the quote. It's a category that includes higher-output, higher-warranty microinverters with panel-level monitoring. But don't let a salesperson write microinverter without a model number. The model number tells you the DC-to-AC ratio, the operating temperature, and who is responsible for service.

I still kick myself for not specifying model numbers in an earlier contract. If I had, we wouldn't be stuck with a monitoring portal that can't tell us which panel is underperforming.

Checkpoint: The quote lists inverter model numbers and warranty terms, not just the word microinverter.

Step 5: Confirm the EV charging station app and monitoring integration before you sign

If your company is adding any EV charging stations, the EV charging station app question is not a small detail. The solar monitoring app needs to show solar production, battery state, and EV charging sessions separately. Otherwise your sustainability report becomes a pile of spreadsheets and estimates.

One reason we moved forward with Sunrun was the app. It shows system production, Brightbox battery levels, and it can track EV charging usage. I asked for a live demo before signing. The demo took 15 minutes and saved us from a monitoring system finance would have hated.

Why does this matter? Because your internal clients will ask for numbers. The operations director wants to know which building used more power. The finance controller wants to know whether the EV charger shifted charging to lower-rate times. If the app can't answer those questions, the solar contract will not feel like a win.

Checkpoint: You have seen the app show solar production, battery state, and EV charging sessions in real time — not in a sales deck.

Before you sign: red flags and common mistakes

Here's a short list of things I check before signing any solar contract.

• Comparing $/W alone. It ignores financing structure, escalator, and operations costs.
• Assuming net metering policies won't change. Ask how the proposal handles utility rate changes.
• Believing guaranteed savings without substantiation. According to the FTC (ftc.gov), environmental and savings claims must be truthful and supported by evidence. A handshake promise is not a contract.
• Skipping the buyout or early termination clause. If your company moves or outgrows the system, you need a clear exit.

There's something satisfying about a solar contract that operations and finance both sign without eye-rolling. It took one bad quote to teach me the difference between a low payment and a low total cost. Start with the 13 months of data, force the escalator rate to be printed, get inverter model numbers, and ask to see the app live. You'll still be nervous. But you won't be blind.