Three solar companies evaluate a property and present three very different costs for a system. Each one is quoting a different system with different equipment, with different assumptions about what your roof will actually produce. Two proposals can sit ten thousand dollars apart and describe nearly identical work.
Here is how to read a solar quote line by line: what belongs in one, which number matters most, and what should make you slow down before you sign. This approach works for home or commercial solar quotes.
The Nine Things Every Solar Quote Should Show
A strong proposal is specific. Before comparing prices, check that each quote tells you:
- System size in both kW DC and kW AC. Your solar panels generate direct current (DC), and the inverter converts it into the alternating current (AC) that your home actually runs on. The DC figure is the sum of your panel ratings and is almost always the larger of the two, because inverters lose a little energy in the conversion and most systems are designed with more panel capacity than inverter capacity. Price per watt is conventionally calculated from the DC number, while New Hampshire’s net metering rules measure system capacity in AC, so ask for both.
- The exact panel model and count.
- The exact inverter or microinverter model. This one gets left out more than any other item on the list.
- Estimated annual production in kilowatt-hours. More on this below, because it is the number that decides everything else.
- Total price and price per watt. If price per watt is missing, you can work it out yourself in about ten seconds. (We’ll discuss the equation for calculating price per watt later in this post)
- Panel, inverter, and workmanship warranties, stated separately. Every quote should have three different warranties. A quote that says “25 year warranty” without saying which one is hiding something.
- Who handles permitting and the utility interconnection application. A permit must be filed with your city or town, and an interconnection application much be filed out for your utility. The cost of the permit and application will vary depending on who submits them.
- A project timeline from signed contract to power on. Permitting timelines vary from town to town in New Hampshire, so you might see a date range.
- The payment schedule. How much of the payment is due at signing, install, and at commissioning.
If a quote is missing three or more of these, it is a sales sheet, not a proposal. Ask for the missing items before you spend any time comparing it to any other proposals. Our guide on how to compare solar proposals walks through this side by side.
Anyone Can Quote a System Size. Ask What It Will Make.
System size tells you how much equipment is going on your roof. It does not tell you how much electricity your system will produce.
Electricity production is measured in kilowatt-hours per year. In New Hampshire, a well-sited array produces roughly 1,200 kWh per year for every kW installed, according to Eversource. Based on this number, a 10 kW system should be quoted around 12,000 kWh a year. Given New Hampshire’s climate, a tenable range is about 1,100 to 1,300 kWh per kW, depending on roof pitch, direction, and shading.
If a proposal claims more than 1,300 kWh per kW, the energy estimate is inflated.
Here’s what to ask the solar company:
- What shading analysis is this based on, and what angle and pitch were used?
- Ask for the shade report itself, not just the summary number.
Any installer who has actually been on your property will have the report for you. Anyone working from a satellite image and a phone call will not.
Estimating Annual Production in Kilowatts Hour
To estimate the annual production, take the total price you’ve been quoted, and divide it by the size of the system. For example, a kilowatt (kW) is 1,000 watts, meaning a 10 kW system produces 10,000 watts of power. For example, a $30,000 quote for a 10 kW system equates to $3.00 per watt (price divided by watts = price per watt).
In New Hampshire, residential solar generally costs $2.60 to $3.50 per watt, with roughly $3.00 as the midpoint. Using this formula,you can compare quotes, even when the system sizes differ.
Keep in mind, the lowest number per watt is not automatically the best deal. A cheaper quote paired with a shorter workmanship warranty and a subcontracted install crew is a different product, not a discount. You must compare price per watt and the system installed together.
Five Things That Should Not Be on Your Quote
A 30% federal tax credit in the savings math.
The federal residential clean energy credit expired for systems installed after December 31, 2025. A New Hampshire homeowner buying with cash or a loan in 2026 receives nothing from it. If a current quote still shows a 30% line reducing your cost, the savings figure is wrong, and the payback estimate is years off. Businesses are the exception, since commercial solar still qualifies under a separate section of the tax code.
Any claim of one-to-one retail net metering.
In New Hampshire, utilities give you credit for extra solar energy you send to the grid, but not at full price.
“Up to” savings with no assumptions shown.
Every long-term savings number rests on a guess about how fast electricity prices rise. Ask what escalation rate they used. A reasonable installer will tell you without hesitating.
Pressure to sign today.
A discount that expires when the salesperson leaves your kitchen is a sales tactic. A solar system is an investment that requires time to finalize
No clear answer about who does the physical install.
Subcontracting is common in the solar industry. It is not automatically bad, but it complicates the warranty conversation considerably when something needs fixing in year seven, and the sub is no longer working in New Hampshire.
Eight Questions to Ask Before You Sign
Ask these to the quoter, and notice how quickly each gets a straight answer.
- What is your workmanship warranty, and what exactly does it cover?
- Are your installers employees or subcontractors?
- What production number did you use, and what shade analysis is behind it?
- Does this price include the interconnection fee and town permitting?
- What happens if my roof needs replacing in year 12?
- What is your process if a panel underperforms in year 6?
- How long have you been installing in New Hampshire specifically?
- What incentives are included in this quote, and are they still available in 2026?
Question 8 is what separates current proposals from recycled templates. We go deeper on this list in 8 questions to ask solar energy companies, and on the reasoning behind them in 4 things to consider when deciding who to get a quote from.
Get a Quote You Can Actually Compare
At Granite State Solar, we provide everything you need to confidently compare our quote with other solar proposals and understand the differences between them. We offer free, zero-pressure site evaluations where we review your solar access and energy usage to create the most accurate quote possible for your home.
Getting multiple quotes is a smart way to make sure you’re choosing the solar company that offers the best overall value. Reach out today to schedule your free site visit and receive a detailed quote from Granite State Solar, then use this guide to easily compare it with other proposals.
