How to Compare Solar Quotes

Most homeowners collect solar proposals and discover they can’t actually compare them. One quotes “108% offset”, one leads with a monthly payment, one shows an arbitrary discount. The panel counts differ, the warranties are buried on page 14, and every single one claims to be the best value.

That isn’t an accident. A proposal that can’t be compared can’t be beaten.

This guide is the checklist we’d want a family member to use, including us. Where we make a claim about Energy Select, we’ve included the license number, certification number, or registration so you can verify it yourself in about ten minutes. If a company won’t hand you the same list, that tells you something.

Part 1: The Company

A beautiful production estimate from a company that won’t exist in five years is worth nothing. Below are some important things to look for when comparing different solar companies:

Maryland Home Improvement Commission (MHIC) License

In Maryland, installing residential solar is home improvement work. The MHIC says so directly: “Solar panel systems must be mounted by a licensed home improvement contractor, regardless of whether the system is attached to the roof or other part of the house, or attached to the land adjacent to the house.”

Look it up here. Energy Select’s MHIC number: 133726

Master Electrician License

Many solar companies do not employ an electrician. They subcontract that work, which means the person who designed your system is not the person who has to make it function, and the master electrician whose license goes on the permit may be splitting that week across a dozen other solar companies. When the license sits inside the company, the person who sized your conductors is reachable, is accountable, and has their own license on the line.

Look it up here. Energy Select’s Master Electrician License: 447

NABCEP Certification

The North American Board of Certified Energy Practitioners (NABCEP) is the solar industry’s professional standard. Look for NABCEP’s PV Installation Professional (PVIP) certification, their flagship credential. Most Maryland incentives list this certification as a requirement.

Look it up here. Energy Select’s NABCEP PVIP Certification: PV-042519-018371

Business Longevity and Good Standing

History doesn’t predict the future, but a company that has survived two recessions, a tariff cycle, and the 2025 tax credit expiration has demonstrated something. A company incorporated eight months ago offering a 25-year workmanship warranty has demonstrated the opposite.

Look it up here.

You’ll see date of formation, entity status, good standing, resident agent, and filing history. “Not in Good Standing” means the business is out of compliance with Maryland requirements. “Forfeited” means the entity has lost the right to do business in Maryland under that name.

Energy Select Standing: Good Standing Energy Select’s Date of Formation: 04/02/2003

Business Structure

This is the hardest thing to see from a proposal and one of the most important. A large share of the solar market operates on a sales-only model: the company that knocks on your door, runs the design, and signs the contract is a sales organization. The installation is handed to a subcontracted crew the sales company doesn’t employ, train, or control. When something goes wrong (a leak, a failed inspection, an underperforming array), you’re calling a salesperson who has no authority over the people who did the work, and who may have already been paid.

The licensing framework gives you a clean way to test this. The installing entity has to hold the MHIC license and have the master electrician. So: is the company in front of you the same company that holds those licenses? If the proposal is from “SolarCo Marketing LLC” and the permit will be pulled by “Regional Install Partners Inc.,” you’re dealing with two companies and one of them has no operational control over your roof.

Questions to ask:

• Who will physically install this system? Are they your W-2 employees?
• Whose MHIC license number goes on the permit application?
• Who is the master electrician of record, and do they work for you?
• If there’s a problem in year three, who do I call, and who pays?
• Are you the entity on the contract, or is there an assignment clause?

Energy Select does the whole job in-house. Sales, design, permitting, and installation are all handled by people on our payroll.

Part 2: Compare the Numbers

Year 1 Production

The year 1 production is arguably the single most important number in the whole comparison. This is the metric to build your comparison around. Year 1 production is the company’s estimate, in kilowatt-hours, of what the system will actually generate in its first year.

Note: We deliberately do not compare on “offset” (the percentage of your usage the system covers), because offset is a fraction, and companies control the denominator. Offset equals estimated production divided by estimated consumption, and we regularly see consumption estimates that are simply wrong: pulled from a single summer bill, extrapolated from square footage, or quietly inflated so a bigger system looks necessary, or quietly deflated so a small system looks like it covers everything.

Production is production. It doesn’t move when someone guesses at your usage.

Ask for it in kWh, for year one, from every company. If a proposal only gives you a percentage, ask for the number behind it, and ask for the consumption figure they used, then check it against twelve months of your own bills.

Panel Wattage & Panel Count

These two numbers together tell you the true size of the system, and they’re the easiest place to spot a proposal that’s been dressed up.

Let’s start with a hypothetical: would you rather have forty 400-watt panels or thirty-two 500-watt panels? Trick question, since the total system size is 16 kW (16,000 watts) either way. “More panels” is not “more solar.” Multiply wattage by count and you have the system size in watts.

Example:

• (40) panels × 400 watt panels = 16,000 watts (16 kW)
• (32) panels × 500 watt panels = 16,000 watts (16 kW)

Panel wattage isn’t everything: efficiency, degradation rate, warranty terms, and the manufacturer’s financial health all matter. But true system size is where you start, because it’s the number that makes two proposals comparable.

Production Ratio

Production ratio is the check that catches inflated production estimates. The formula:

Production Ratio = Year 1 Production (kWh) ÷ System Size (watts)

A 10,000-watt system producing 13,000 kWh has a production ratio of 1.3 (You’ll sometimes see the same idea expressed as “specific yield” in kWh per kW: same number, times a thousand). Compare this number against Maryland benchmarks:

• A well-sited, unshaded, south-facing Maryland system production ratio typically lands around 1.25 to 1.35.
• East- or west-facing planes run meaningfully lower, often 1.05 to 1.20.
• Shading can push a ratio below 1.0. That isn’t automatically a bad design; it’s a fact that should be explained and clear, not hidden.

Anything above 1.35 deserves hard questions, and 1.4 is at the edge of what a perfect Maryland roof can do. Above that, either the production number is inflated or the system size is understated, and both are problems. Those numbers belong in Arizona, not Maryland. On the other end, an unexplained ratio below about 1.05 usually means real shading the proposal didn’t model, or a deliberately conservative number designed to make a production guarantee easy to hit.

The ratio is driven by tilt, orientation, shading, and equipment. A company that can explain why their ratio is what it is has done the engineering. A company that can’t is either being disingenuous or not capable of creating an accurate model.

Shade Report

This is the number one problem we see in competitor proposals.

Trees, dormers, chimneys, vent stacks, and neighboring rooflines all cut production, and shade losses are non-linear: a little morning shade in December costs more than the same shade in June. A design that ignores shading produces a production number that looks great on paper and never materializes. At best that’s carelessness. At worst it’s a savings projection built on output the system cannot generate.

Any reputable company should be willing to hand you a shade report. Here’s what a real one contains:

The three industry-standard metrics (used identically by Aurora Solar, HelioScope, and Scanifly, the leading solar software available):

• Solar Access %: the share of available sunlight left after accounting for shade.
• TOF (Tilt & Orientation Factor): how your roof’s actual tilt and azimuth compare to the optimum for your latitude.
• TSRF (Total Solar Resource Fraction): Solar Access × TOF. The bottom line: how much of an ideal, unshaded, optimally-oriented array’s resource your roof actually gets.

What to ask for:

1. The name of an industry-leading design tool: Aurora, HelioScope, Scanifly, Solmetric SunEye. “Our software” is not an answer.
2. A Shade Report, showing all three numbers: Solar Access, TOF, and TSRF.
   • Per roof plane, not a whole-system average. Averages bury the bad planes.
   • Monthly figures, not just annual. Winter shading is what hurts in Maryland, and it disappears in an annual average.

Setbacks

More often than not, solar in Maryland has to leave firefighters a way to get onto your roof in case of emergencies. That means clear pathways to walk and clear space at the roof’s ridge for vertical ventilation. Because these requirements are AHJ-specific (Authority Having Jurisdiction, typically the city or county where the solar is getting installed) and not required in every state, out-of-state and national companies routinely design systems as if they don’t apply.

The result is a proposal showing more panels than will ever be installed. And since production, savings, and price all flow from panel count, a design that ignores setbacks isn’t just optimistic. It’s describing a system you’re not going to get.

Simply ask “Which jurisdiction did you design this to, and what setbacks did you use?” Most AHJs in Maryland have setbacks, so a design showing no setbacks is often wrong, requiring a re-design. This will often result in a worse, less efficient, and smaller system. On a typical Maryland roof plane, ridge and rake setbacks cost roughly 15% to 25% of that plane’s usable area, often the difference between a 9 kW and an 11 kW system on the same roof. A proposal that skips them isn’t 20% better. It’s 20% wrong.

Part 3: Equipment

Inverter Type

The inverter converts DC from the panels to AC for your house. There are three different types:

String Inverters: Panels are wired in series into strings feeding a single central inverter. Lowest cost, fewest components on the roof. Tesla is now the leading US residential string inverter brand.

String Inverter with Power Optimizers: A string inverter paired with an optimizer mounted behind each panel. Each panel operates at its own maximum power point, so shading and mismatch are isolated, and you get panel-level monitoring. SolarEdge is the dominant brand.

Microinverters: A small inverter behind each panel. The conversion happens on the roof. Each panel is fully independent. Monitoring is panel-level. There’s no single component whose failure takes the whole system offline: if one microinverter dies, you lose that panel, not the array. Design is more flexible on complicated roofs. They cost more. Enphase is the leading brand.

We use Enphase microinverters as our residential standard, because most of the roofs we work on in Maryland have trees, dormers, or multiple planes, and because panel-level monitoring means we can see a failing panel before you do. Under a string inverter, an underperforming panel can stay invisible for years.

Inverter Manufacturer and Model

Get both if you can. “Microinverters” is not a spec; ask for the manufacturer and the model number, because warranty terms, efficiency, output, etc. vary by model.

A 25-year warranty is a 25-year promise from a corporation, and it’s worth exactly what that corporation’s survival is worth. Also be wary of inverter brands with no meaningful US track record. A 25-year warranty from a manufacturer with three years of US market presence is a different product from the same words on a paper from a company that has been shipping here for two decades. A “25-year system” built on a 12-year inverter has a mid-life replacement in it that the savings projection probably doesn’t show.

Part 4: Miscellaneous

SRECs, and who keeps them

Maryland has a Renewable Portfolio Standard with a solar carve-out, which creates a market for Solar Renewable Energy Certificates. You earn one SREC for every 1,000 kWh (1 MWh) your system produces, and you can sell them.

By default, the system owner owns the SRECs: you, if you bought it; the financier, if you leased it. But installers and lenders can and do contractually claim them. Maryland’s own contractor standards for its grant program require clearly stating who owns the SRECs and, if the customer owns them, explaining how to monetize them. Ensure you know who gets them.

If you’re paying cash or financing:

Line item:	What to look for:
Cash cost	The total, out the door, before any incentives.
Price per watt	Cash cost ÷ system size in watts. The single best cross-proposal price comparison.
Incentives	Look for relevant, real incentives and ensure you know who gets them, in writing.
Loan APR and term	Get the actual APR, not the monthly payment. Some companies have great prices, but terrible loan terms. Low-APR solar loans are typically funded by a dealer fee that is built into the price.
Escalating payment structure	Many solar loans assume you’ll apply a lump-sum principal payment in month 18, and the payment jumps if you don’t. Ask whether the payment changes at any point.

If it’s a lease or PPA:

Line item:	What to look for:
Rate per kWh (PPA) or monthly payment (lease)	Compare against your current utility rate and against the price-per-watt math on a cash purchase.
Escalator	The annual increase. Typically 1-3%. A 2.99% escalator over 25 years nearly doubles your payment.
Term length	Usually 20-25 years.
The Lease/PPA provider	Different lease/PPA companies offer different terms and some are better than others.