How to Compare Solar Quotes Apples to Apples

To compare solar quotes apples to apples, first make every bidder price the same job. Give each company the same 12 months of usage, future-load plan, roof information, utility account, ownership choice, and requested scope. Then compare DC and AC size, exact equipment, year-one production assumptions, gross cash price, complete financing terms, program assumptions, adders, timeline, warranties, exclusions, and service responsibility. A cheap monthly payment or a low cost per watt cannot settle the decision by itself.

Teamsun’s residential solar service is one possible proposal route. Use the same comparison method on Teamsun and every other bidder. This guide does not represent Teamsun’s prices, financing terms, equipment, project timelines, warranties, or ability to perform a specific scope; those require a written, property-specific proposal.

The 60-second method: Put each proposal through a comparability gate before scoring it. Reject the comparison—not necessarily the bidder—when the quotes use different consumption, future loads, roof areas, ownership models, or incentive assumptions. Request a corrected version. Once the inputs match, use the 100-point scorecard below to compare value, uncertainty, and execution responsibility.

Why are solar quotes often impossible to compare at first?

Solar proposals can describe different projects for the same house. One may use twelve actual bills; another may use one bill multiplied by twelve. One may add a future electric vehicle and heat pump; another may size only for past consumption. One may include roof or electrical work; another may call it a post-survey adder. One may show the gross cash contract price; another may lead with a financed monthly payment after subtracting an assumed tax benefit.

That means the first task is not picking the lowest number. It is deciding whether the numbers answer the same question.

The Federal Trade Commission tells homeowners to compare detailed bids that identify system size, expected production, the full installation cost including permits, any production guarantee, and equipment and workmanship warranties. For a lease or power purchase agreement, the FTC adds payment changes, ownership of incentives and renewable energy certificates, repairs, roof work, transfer, early termination, and end-of-term options (FTC solar buying guidance).

Homeowners describe the same comparison problem less formally in forums: “Why are the sizes different?” “Is this low rate hiding a higher financed price?” “Why did one company blend the battery into the solar price?” “Which annual-production number should I trust?” Those questions are useful language signals, not evidence that a particular quote is good or bad. The answer is to reconstruct each offer into one common data set.

Start with this comparability gate:

Gate	Quote A	Quote B	Quote C	Pass condition
Same 12-month consumption period and total kWh				All use the identical dated bill set
Same future loads				EV, heat pump, water heating, addition, pool, or none stated separately
Same site and roof facts				Same roof planes, shade basis, roof condition, service, and known constraints
Same requested project scope				Solar-only, battery, roofing, panel work, EV charger, tree work, and trenching separated
Same ownership category				Cash purchase, financed purchase, lease, and PPA are not blended
Same utility/account premise				Correct utility, rate class, meter/account arrangement, and current program path
Same comparison date				Rates, incentive rules, product availability, and quote validity checked on one date

If a row fails, send the same correction request to every bidder. For example: “Please revise this proposal using the attached bills totaling ___ kWh from ___ through ___, show the EV as a separate ___ kWh assumption, use only the south and west roof planes, provide solar-only and battery pricing separately, and state the gross cash price before any incentive.” Do not award points until the bidder answers or labels the uncertainty.

What buyer-supplied baseline should every installer use?

Create a one-page comparison brief before asking for revised quotes. The brief is not a system design. It is a controlled input sheet that prevents each salesperson from inventing a different starting point.

Record actual energy use and the bill structure

Use the same consecutive 12 months of electric bills for every quote. Record monthly kWh, not only dollars. Dollars change when supply, delivery, riders, and fixed charges change. The FTC notes that homeowners may continue paying utility fixed charges after solar and recommends reviewing both metered kWh and fixed costs (FTC solar buying guidance).

Your baseline should name:

• the utility and exact rate class shown on the bill;
• each month’s grid consumption in kWh and the 12-month total;
• whether the home has competitive supply, municipal aggregation, time-of-use billing, net metering, an existing renewable system, or multiple meters;
• known seasonal anomalies, vacancy, construction, or a broken HVAC system;
• whether the goal is bill reduction, resilience, electrification, carbon reduction, or a defined mix.

Do not ask installers to make current bills disappear in their projections. Ask them to show which bill components solar is modeled to reduce, which remain, and what export-credit rule they used. Massachusetts DPU warns that credit inputs and schedules vary by utility and change over time; its July 2026 guide explicitly says not to rely on a historical example rate for future estimates (Massachusetts net-metering guide). That caution applies broadly: a proposal’s utility escalation rate is an assumption, not a promise.

Separate future loads from historical loads

List every future load with an expected start date and an estimate source:

Future change	What to give bidders	How to display it in each quote
Electric vehicle	model or efficiency assumption, annual miles, home-charging share	added annual kWh as a separate line
Heat pump	equipment/load estimate, fuel being displaced, expected heating and cooling use	added monthly or annual kWh; do not equate fuel dollars to kWh
Heat-pump water heater	model or modeled annual use	separate annual kWh
Addition, accessory dwelling, pool, hot tub, workshop	design load and expected operating pattern	separate annual kWh and timing
Efficiency work	insulation, air sealing, appliance, HVAC, or schedule change	reduction shown separately, with source

If the estimate is uncertain, request a base design and a future-load alternative. That makes the cost of adding capacity visible and avoids treating a speculative load as historical fact.

Give every bidder the same property facts

Include roof age, roofing material, known leaks or repairs, plans to reroof, attic or structural documents, main-service rating, main-panel photos, meter arrangement, major loads, generator or battery, property survey if ground equipment is contemplated, and any historic, condominium, HOA, flood, or zoning constraints you know about.

Do not climb the roof or open electrical equipment to collect this information. Photographs from safe locations and existing records are enough for the bidding baseline. Each installer remains responsible for its own site survey, engineering, code, permit, and utility review.

The U.S. Department of Energy says solar suitability depends on roof age and condition, orientation, shade, and location, and points homeowners to NREL’s PVWatts for an independent starting estimate—not a substitute for a custom installer model (DOE Homeowner’s Guide to Solar). Use that independent estimate as a reasonableness check only after matching its inputs to each proposal.

How do you normalize solar system design and equipment?

Compare both DC nameplate capacity and AC conversion capacity, then compare exact equipment and layout. “Twenty panels” is not a size. A panel count can hide different wattages, inverter architectures, roof coverage, and production constraints.

Create these columns for each proposal:

Design field	Quote A	Quote B	Quote C	Comparison rule
Module quantity and exact model				Record manufacturer and full model suffix
Module DC watts each				Verify quantity × watts
Total DC capacity (kWdc)				Compare stated total with your calculation
Inverter/microinverter exact model and quantity				Record full model; “premium inverter” is insufficient
Total or limiting AC capacity (kWac)				Ask how the proposal defines and calculates it
DC-to-AC ratio				Use as a design input, not a standalone quality grade
Battery model, usable capacity, continuous/peak power				Keep battery separate from solar-only comparison
Roof planes and module layout				Compare orientation, tilt, shade, setbacks, and access
Attachment/racking system				Record exact family and roof integration approach
Monitoring and communications				State homeowner access, fees, connectivity, and ownership
Required service or panel work				State included scope, design basis, and allowance

Use two checks on capacity:

1. DC capacity: module quantity × module nameplate watts ÷ 1,000.
2. AC capacity: the inverter or microinverter system’s applicable aggregate output or other program-defined AC value. Ask the designer to state the method because utility and incentive programs can define capacity differently.

That distinction matters in Massachusetts. The DPU’s net-metering guide notes that a solar facility’s AC capacity used for certain cap-allocation purposes may be calculated as 80% of its DC rating, which can differ from “as-built” AC capacity (Massachusetts net-metering guide). Do not apply that program rule to every engineering comparison. Instead, require the proposal to label physical equipment capacity, utility application capacity, and program eligibility capacity separately when they differ.

Exact models matter because warranty documents, operating limits, monitoring features, replacement paths, and compatibility attach to model numbers—not marketing tiers. Do not rank a proposal only because one module has a higher nameplate wattage. A higher-watt module may simply result in fewer modules or a different layout. Compare the complete design against the same roof, energy goal, production method, and service plan.

For a battery, create two totals: solar-only and battery-only incremental scope. Record usable energy, power, backed-up loads, operating mode, transfer equipment, load-management hardware, warranty metric, permit/interconnection impact, and whether the design can operate during an outage. A blended “solar + storage” monthly payment prevents a clean comparison.

How do you compare production estimates without treating them as guarantees?

Normalize every quote to year-one AC energy in kWh, then inspect the model inputs. Divide year-one kWh by kWdc to calculate a simple specific yield in kWh per kWdc. Different yields are not automatically wrong, but a large spread forces each bidder to explain shade, orientation, losses, weather data, clipping, curtailment, and snow assumptions.

Use this table:

Production field	Quote A	Quote B	Quote C	Evidence requested
Year-one AC production (kWh)				signed proposal/model report
DC system size (kWdc)				equipment schedule
Specific yield (kWh/kWdc)				year-one kWh ÷ kWdc
Weather-data source and period				model report
Shade method and survey date				shade report or documented remote assumption
Orientation and tilt by roof plane				plan/layout
Loss factors				loss diagram or line list
Inverter clipping or export limit				model and utility design basis
Annual degradation assumption				proposal and product warranty basis
Consumption offset definition				production ÷ which consumption total?
Guarantee, if any				separate written terms, remedy, exclusions

The Department of Energy says PVWatts estimates production for a specified address and recommends a custom installer estimate (DOE Homeowner’s Guide to Solar). Run one consistent independent model if you can reproduce the roof planes and shade limitations fairly. Do not compare an unshaded PVWatts default against a proposal that includes measured shade and call the proposal wrong.

Distinguish four terms that proposals often blur:

• Nameplate capacity is rated power under defined test conditions.
• Estimated production is modeled energy under stated assumptions.
• Consumption offset is modeled production divided by a stated consumption baseline; it is not necessarily bill offset.
• Production guarantee is a contract promise only if written terms define measurement, period, exclusions, notification, and remedy.

Weather, household use, tree growth, outages, equipment behavior, utility rules, and rate changes can affect actual economics. CFPB says a solar borrower’s financial obligation may not depend on system performance and warns that production and savings can be overstated (CFPB solar-financing issue spotlight). Score transparency and reproducibility, not merely the highest kWh forecast.

How should cash, solar loans, leases, and PPAs be compared?

Separate the project from the payment method. First request the gross cash contract price for the exact scope before incentives. Then place financing or third-party ownership terms in separate columns. Monthly payment is an output, not the price.

Purchased with cash or a loan

For each purchase proposal, record:

Purchase field	Quote A	Quote B	Quote C
Gross cash contract price before incentives
Solar-only cash price
Battery, roof, electrical, EV, tree, trench, or other separate price
Cash price per DC watt for comparable solar scope
Financed principal
Difference between principal and cash price
Stated interest rate
APR
Term
Payment schedule, including any later change
Finance charge and total of payments, if disclosed
Prepayment, re-amortization, recast, lien/security, transfer, and payoff terms

Cost per watt is gross cash price for the comparable solar-only scope ÷ DC watts. DOE recommends the formula as a quote-comparison tool (DOE installer-selection guidance). It is a screening ratio, not a verdict. It becomes misleading when one numerator includes a battery, reroof, service upgrade, trench, financing markup, or other scope and another does not.

CFPB documented that some solar-specific loans bake program, platform, lending, or “dealer” fees into the principal while emphasizing a low rate. Its report uses an illustration in which a $30,000 cash project becomes a $39,000 principal before interest; that is the regulator’s example, not a Teamsun price or a market benchmark. CFPB also describes loans whose payment changes if an expected large prepayment is not made (CFPB solar-financing issue spotlight).

Do not accuse a bidder of hiding a fee from the price difference alone. Ask for the cash price, amount financed, APR, payment schedule, total of payments, lender documents, and an explanation of every difference. Compare the same project using realistic payoff horizons. A low-rate, higher-principal loan may behave differently from a higher-rate, lower-principal loan if you sell, refinance, or prepay.

Teamsun has a separate solar financing service page, but no financing option should be accepted on sales-slide math alone. The lender agreement controls the loan.

Lease or power purchase agreement

A lease and a PPA are not purchase prices. In a lease, the homeowner generally pays for use of a third-party-owned system. In a PPA, the homeowner generally pays a contract rate per kWh produced. The FTC says third-party ownership can determine who receives tax benefits, incentives, and renewable energy certificates and that long-term agreements must be compared on escalators, repairs, roof work, transfer, termination, buyout, and removal (FTC solar buying guidance).

For each lease or PPA, record:

• legal owner, seller, installer, service provider, contract administrator, and financier;
• starting payment or PPA rate and when billing starts;
• escalation percentage, frequency, and first increase date;
• term, renewal, purchase option, valuation method, and end-of-term removal;
• minimum-production promise and exact remedy, if any;
• maintenance, monitoring, insurance, roof access, removal/reinstallation, and outage responsibilities;
• sale, transfer, buyer-credit, notice, assumption, payoff, and early-termination rules;
• owner of state payments, utility credits, tax attributes, and renewable energy certificates.

Do not put a 25-year PPA total beside a cash contract price and call the lower number the winner unless both totals use disclosed, defensible assumptions and reflect different ownership rights. First decide whether you want to own equipment or purchase a service. Then compare offers within that ownership category.

What changed for federal solar tax assumptions in 2026?

For homeowner property placed in service after December 31, 2025, the federal Residential Clean Energy Credit is not available under current IRS guidance. A 2026 residential quote should not subtract an assumed 30% homeowner credit from the contract price, present it as assured savings, or build a payment plan around receiving it.

The IRS page reviewed July 4, 2026 says the credit applied to eligible new property installed from 2022 through December 31, 2025 and “is not available” for property placed in service after that date. It also says the credit was nonrefundable, excluded interest and loan origination fees, and was claimed for the year installed rather than merely purchased (IRS Residential Clean Energy Credit).

Use this tax-and-incentive normalization table as of August 10, 2026:

Proposal claim	Normalized treatment
“30% federal homeowner credit” on a system first placed in service in 2026	Enter $0 in the homeowner-credit comparison unless a qualified tax adviser identifies a different current law and eligibility basis
State incentive, tariff payment, rebate, or property-tax treatment	Record program name, administrator, eligibility, application owner, current source, effective date, payment recipient, tax assumption, and whether reserved
Lease/PPA provider says incentives reduce the rate	Record the homeowner’s contract rate and rights; do not enter a homeowner tax credit the homeowner does not own
Quote shows “net price” after incentives	Restore gross contract price and show each incentive as a separate conditional line
Financing assumes an incentive-funded prepayment	Score the actual payment schedule without that prepayment, then separately model it only with adviser-confirmed funds

This is not tax advice. State and program documents can lag federal changes. For example, a state consumer guide that still describes the former homeowner credit should not override the current IRS page. Require the bidder to date every tax statement and label who must verify it.

Third-party owners or businesses may discuss different federal tax provisions, but those are not automatically a homeowner credit. Do not translate an owner’s possible business tax treatment into a homeowner promise without qualified tax advice and the controlling contract.

How do New England utility and program rules change a quote comparison?

A solar quote must use the actual utility, account, meter configuration, rate class, and current program—not merely the state. Utility approval, municipal permits, and incentive enrollment are separate workstreams. Score a bidder on whether it identifies the path and owner of each task, not on whether it promises an authority-controlled date.

Connecticut: identify Eversource or United Illuminating and the RRES path

Connecticut’s Residential Renewable Energy Solutions program is administered by Eversource and United Illuminating. PURA says 2026 brought updated Buy-All and Netting tariff rates and application fees, and it has directed work on standardizing financial and production disclosures (Connecticut PURA RRES page).

Require a Connecticut proposal to state:

• the correct electric distribution company and account/rate premise;
• whether the design assumes Buy-All or Netting and who chose it;
• the tariff vintage, any claimed adder, application fee, disclosure, and eligibility source;
• who submits the combined or related program/interconnection package;
• whether utility-required equipment, meter work, or upgrades are included or conditional;
• the milestone called “permission to operate,” “authorization to energize,” or its exact utility equivalent.

Eversource says the RRES program and interconnection review are handled together for its Connecticut process and may require additional technical, metering, or application information (Eversource Connecticut renewable interconnections). A proposal should not call a town permit the final utility approval.

Massachusetts: identify utility territory, interconnection, net metering, and SMART 3.0

Massachusetts regulated electric companies include Eversource, National Grid, and Unitil; some communities have municipal utilities with different program paths. DPU says a distributed-generation owner needs the local utility’s written Interconnection Service Agreement and later Authorization to Connect before connecting (Massachusetts utility interconnection).

SMART 3.0 is current in 2026. Massachusetts says DPU approved company-specific SMART 3.0 tariffs on July 8, 2026 and that small systems at or below 25 kW AC receive a defined per-kWh solar incentive payment, subject to program rules (SMART 3.0 program details). A quote should state its assumed eligibility, tariff, payment owner, application status, and interaction with net metering or alternative on-bill credits. DPU explains that a system cannot generate SMART alternative on-bill credits and net-metering credits at the same time (Massachusetts net-metering guide).

Do not compare two Massachusetts savings projections until both identify the same utility, rate class, credit mechanism, SMART path, and current rate source.

Rhode Island: distinguish net metering from Renewable Energy Growth

Rhode Island’s 2026 Residential Guide to Going Solar treats net metering and Renewable Energy Growth as distinct options and gives homeowners a state process checklist (Rhode Island OER residential solar guide). Rhode Island Energy publishes program rules and tariffs, including 2026 Renewable Energy Growth materials (RI Energy RE Growth resources). The PUC’s 2026 docket is the official record for that program year (RIPUC 2026–2027 RE Growth docket).

Require a Rhode Island proposal to name the elected pathway, payment and renewable-energy-right owner, current tariff or credit source, enrollment availability if relevant, interconnection responsibility, fees, and contingencies. Do not score a projected annual payment until the proposal identifies the program source and the party entitled to receive it.

Rhode Island’s Attorney General also warns that the residential transaction may involve separate sales, installation, and finance companies and recommends multiple quotes plus close review of price components and financing (Rhode Island AG solar consumer page). Put each legal entity into the worksheet; do not treat one salesperson’s logo as proof that one company owns every obligation.

How should roof, electrical work, permits, adders, and change orders be compared?

Normalize the known scope, the allowance, and the trigger for additional work. A proposal that identifies a plausible service upgrade or roof repair may look more expensive while carrying less post-contract uncertainty. A lower quote with “as needed” exclusions may move cost into change orders.

Use this risk register:

Potential scope	Included work	Allowance or price	Trigger for change	Who approves	Schedule effect	Warranty owner
Roof repair or replacement
Structural reinforcement
Main panel/service upgrade
Meter socket, disconnect, transformer, or utility work
Trenching or ground equipment
Tree work
Hazardous material or concealed condition
Permit, inspection, engineering, program, and interconnection fee
Panel removal/reinstallation for future roof work

For each item, demand a written distinction among included, excluded, allowance, unit price, and unknown until survey/authority review. “Standard installation included” is not an adequate scope definition.

State contract rules reinforce this documentation. Connecticut DCP says home-improvement agreements and changes must be written and should identify the entire work and price, material brand or quality, permit responsibility, dates, and payment schedule (Connecticut home-improvement contract guidance). Massachusetts recommends interviewing at least three contractors and obtaining a detailed written estimate and contract covering cost breakdown, project description, schedule, payments, and permit responsibility (Massachusetts HIC homeowner resources). Rhode Island CRLB recommends multiple detailed bids with labor, materials, fees, contingencies, timeline, and payment terms; it says jobs over $1,000 require a written contract (Rhode Island contractor guidance).

Those rules do not make every proposal a final engineering package. They do give you a fair comparison principle: uncertainty must have an owner and a written process. Ask who can authorize a substitution, what evidence triggers an adder, how the price is calculated, whether you can reject a material change, and what happens to deposits or financing if the revised project is unacceptable.

If your roof and solar scopes are intertwined, use Teamsun’s solar-and-roofing company guide to compare coordination models. The quote worksheet here only normalizes cost and responsibility; it does not decide which trade should perform each task.

How do you compare timelines, permission to operate, and closeout?

Compare milestone ownership and prerequisites—not one promised completion date. A bidder controls staffing and submittal quality. It does not control municipal review, utility study, inspection availability, program approval, equipment supply, lender processing, weather, or a required grid upgrade.

Ask every bidder to complete this same timeline:

Milestone	Responsible party	Prerequisite	Estimated range and basis	Customer action	Evidence of completion
Contract and cancellation period					signed documents
Site survey and roof/electrical findings					survey/design report
Final design and customer approval					approved plan/equipment schedule
Financing approval or funding condition					lender document
Local permit application and approval					issued permit
Utility interconnection/program application					application/reference number
Installation					installation record
Electrical/building inspection					signed inspection/closeout
Utility meter work and authorization/PTO					utility written authorization
Monitoring handoff and training					owner login and baseline report
Warranty, lien release, as-built, manuals, closeout					complete closeout package

Massachusetts’ official interconnection page makes the distinction concrete: the owner must receive both an Interconnection Service Agreement and subsequent Authorization to Connect from the utility (Massachusetts utility interconnection). Connecticut and Rhode Island have their own utility/program documents. A contract should identify the controlling milestone instead of using “PTO” as an undefined sales term.

Payment milestones should follow verifiable progress. Do not assume “installation complete” means the system may operate or that every closeout document has been delivered. Compare when loan payments, lease payments, or PPA billing begin; what happens during an approval delay; and whether final payment precedes inspection, utility authorization, monitoring access, or correction of a punch list.

How do warranties and post-sale service affect the comparison?

Record who promises what, what event triggers coverage, and who pays labor, shipping, access, diagnostics, removal, reinstallation, and roof restoration. Warranty years alone do not reveal service value.

Split each proposal into these layers:

Layer	Provider	Term/start date	Covered failure	Exclusions	Labor/shipping/access	Claim route	Transfer
Module product warranty
Module performance warranty
Inverter/microinverter warranty
Battery warranty, if applicable
Racking/attachment/flashing product warranty
Installer workmanship warranty
Roof penetration or roofing warranty
Production guarantee, if any
Monitoring/service plan

Read the actual warranty documents before awarding points. The FTC says written warranties should be available for review before purchase and may cover a lot or a little (FTC warranty guidance). Teamsun’s solar warranty comparison guide explains the layers in more depth; this page uses them only as comparison inputs.

Ask who takes the first service call, who can access the monitoring portal, whether the installer is authorized for the proposed equipment, what response target is contractual, and what happens if the original installer, financier, owner, or manufacturer changes or closes. Do not accept “25-year warranty” as a substitute for the legal provider, written remedy, and cost allocation.

Also compare the closeout package. It should identify the installed models and serials, final plan or as-built information, permits and inspection evidence, utility authorization, program documents, monitoring ownership, warranties, installer/service contacts, payment record, and any lien releases required for the project. A complete handoff makes future service, roof work, insurance, and home sale easier.

What is the 100-point solar quote scorecard?

Score only after the comparability gate passes. Use zero when a material answer is missing, partial points for a documented uncertainty with a fair resolution process, and full points only for clear, consistent, verifiable evidence. This is a buyer worksheet, not a claim that one company or product is universally best.

Category	Points	Full-credit standard
Same usage, future loads, goals, site, roof, and utility baseline	15	Uses the buyer brief; separates future loads; documents site assumptions and survey limits
Design and exact equipment	15	Reconciled kWdc/kWac, exact models, layout, architecture, battery separation, monitoring, and electrical basis
Production and bill model	15	Year-one kWh, reproducible assumptions, losses, yield, offset definition, rate/credit source, and guarantee clearly separated
Price, financing, and ownership economics	20	Gross cash price, comparable scope, financing principal/APR/payments/total, or complete lease/PPA/escalator/transfer terms
Utility, program, tax, permits, and closeout	10	Correct utility/program and current sources; no 2026 homeowner federal credit; task owners and evidence named
Roof, electrical, adders, and change-order risk	10	Known scope, exclusions, allowances, triggers, approval, pricing method, schedule effect, and trade responsibility documented
Timeline and execution responsibility	5	Milestones, dependencies, authority-controlled steps, payment/billing start, and completion evidence stated
Warranties and serviceability	10	Actual documents identify providers, coverage, remedy, exclusions, labor/shipping/access, claims, monitoring, transfer, and installer failure path
Total	100	Compare value and uncertainty after hard-stop review

Scoring worksheet

Category	Quote A	Quote B	Quote C	Notes/evidence link
Baseline /15
Design /15
Production /15
Price and ownership /20
Utility, program, tax, permits /10
Roof, electrical, adders /10
Timeline /5
Warranties and service /10
Total /100

Do not let the total override a hard stop. Pause if the legal entity is unclear; the contract does not match the proposal; a 2026 homeowner federal credit is subtracted; the bidder will not provide a gross cash price for a purchase; equipment can change without meaningful consent; production cannot be traced to assumptions; required trade credentials cannot be verified; or payment obligations begin before a clearly defined delivery milestone you accept.

This page intentionally does not provide an exhaustive contract-content checklist, a list of 25 signing questions, a red-flag catalog, a cost-per-watt benchmark, a warranty-exclusion encyclopedia, a line-item price template, or a sizing diagnosis. Those are separate decision jobs. The scorecard’s purpose is to weight comparable evidence.

If two proposals finish close, choose based on the unresolved risk most likely to affect your project. A five-point lead created by an optimistic production number is weaker than a small lead supported by a complete roof scope, lower financed principal, current program evidence, and accountable service route.

Request a solar quote you can put into the same worksheet. Send Teamsun the baseline you used with other bidders and ask for any missing assumption to be labeled. Teamsun must still confirm service area, scope, equipment, financing availability, schedule, and project fit in writing.

What questions should you send every bidder after scoring?

Send one written clarification round to every bidder. Copy the questions exactly so one company does not receive a more favorable chance to improve its score.

1. Confirm the dated 12-month usage total and list every future-load assumption separately.
2. Confirm the exact roof planes, shade method, roof condition assumption, and survey limitations.
3. Reconcile module quantity and wattage to total kWdc; state physical and program-relevant AC capacity.
4. Provide exact model numbers and identify any permitted substitution plus customer approval rights.
5. Provide year-one kWh, specific yield, weather source, shade, losses, clipping/export, snow, and degradation assumptions.
6. State the gross cash contract price before incentives and separate solar, storage, roofing, electrical, EV, tree, trenching, and other scope.
7. For financing, provide principal, APR, term, payment changes, finance charge/total of payments where disclosed, and payoff/prepayment/re-amortization terms.
8. For lease/PPA, provide owner, rate/payment, escalator, term, incentives/REC owner, performance remedy, service, roof, transfer, buyout, termination, and removal terms.
9. Remove any homeowner federal Residential Clean Energy Credit for property first placed in service after December 31, 2025, or provide the current primary authority supporting a different treatment.
10. Name the exact utility, rate class, interconnection path, state program, tariff/credit source, application owner, fees, and payment recipient.
11. Identify permit, engineering, inspection, utility, program, and closeout responsibilities and evidence.
12. List every included, excluded, allowance, contingency, and change-order trigger, including who approves it and how it is priced.
13. Provide the actual warranties and service plan; name providers, labor/shipping/access responsibility, claims path, transfer, and orphaned-system plan.
14. State every payment or billing milestone and what happens during authority, inspection, equipment, financing, or change-order delay.
15. Identify the legal seller, installer, electrician/contractor entity as applicable, lender, system owner, program applicant, and service provider.

Score the revised documents, not the salesperson’s verbal answer. If a response changes price, design, ownership, production, scope, or timing, require a revised proposal and contract version with a date.

Frequently asked questions about comparing solar quotes

How many solar quotes should I compare?

Three detailed proposals usually provide a useful comparison, and Connecticut, Massachusetts, Rhode Island, FTC, and DOE consumer materials consistently recommend multiple bids or contractors. More quotes do not help if they use different inputs. Normalize the first credible set before collecting endless offers.

Should I choose the lowest solar quote?

Not automatically. The least expensive offer may be strong, or it may exclude roof work, electrical work, permits, service, or utility contingencies. It may also use a different system or production assumption. Compare identical scope and risk allocation first.

Is the lowest cost per watt the best deal?

No. Cost per watt is a useful gross-cash, solar-only screening ratio. It does not grade production quality, inverter sizing, roof complexity, battery scope, financing, service, warranties, or change-order risk.

Why do solar companies quote different system sizes?

They may use different consumption periods, future loads, roof planes, shade assumptions, module wattages, offset goals, utility/program constraints, or design rules. Ask each to use the same baseline and explain the remaining difference.

Should I compare panel count or system kW?

Compare total DC kW, AC capacity, exact models, layout, and estimated kWh. Panel count alone is not comparable because module wattage varies.

Can I trust the highest production estimate?

Trust a reproducible estimate more than a high estimate. Compare weather source, shade, roof geometry, loss factors, clipping/export constraints, snow, degradation, and specific yield. Keep a written production guarantee separate from an estimate.

How do I compare a cash quote with a financed quote?

Request the gross cash price for the same scope, then add financed principal, APR, term, payment schedule, total payments, and payoff or re-amortization terms. Compare realistic ownership duration and prepayment plans.

What is a solar dealer fee?

It is an industry term sometimes used for a lender/program/platform cost embedded in the financed principal. CFPB says labels vary and disclosures may not show the price difference clearly. Do not assume the amount; compare cash price and principal and ask the lender and installer to explain the difference in writing.

Can a 2026 quote subtract the 30% federal solar tax credit?

Not for homeowner property first placed in service after December 31, 2025 under the IRS page current on August 10, 2026. Enter zero unless a qualified tax professional identifies current authority and your eligibility. Never reduce the signed contract price to a conditional “net cost.”

How do I compare a solar lease with a PPA?

Compare ownership, starting lease payment or PPA rate, escalation, term, production obligation, maintenance, roof work, incentives/RECs, home-sale transfer, buyout, termination, and removal. Then compare projected total household energy cost under transparent assumptions.

Does a permit mean I can turn the solar system on?

No. A local permit or inspection does not replace the utility’s written interconnection authorization. Require the proposal to name each milestone and the document that proves completion.

What if exact equipment is unavailable after I sign?

The contract should state substitution rights, performance/specification limits, price effects, warranty effects, and your approval or cancellation rights. Do not rely on “equal or better” without defined criteria.

Should roof replacement be inside the solar quote?

It can be inside or separately contracted, but the worksheet should isolate the roof price, contractor, material, permits, warranty, solar attachment coordination, future removal/reinstallation, and change responsibility.

How much weight should installer reviews receive?

Reviews can reveal patterns but do not replace licenses, registrations, written scope, financial documents, warranty documents, and current utility/program evidence. Use Teamsun’s solar installer license guide to verify the legal entity and scope.

What if a company refuses to give a cash price?

You cannot normalize a purchase proposal against another cash or loan offer without the gross cash price. Ask again in writing. If the seller offers only a lease or PPA, compare it as third-party ownership rather than pretending it is a financed purchase.

Sources and methodology

This guide was researched and updated on August 10, 2026. It combines current federal consumer and tax guidance, current Connecticut, Massachusetts, and Rhode Island program and contractor guidance, utility/interconnection sources, representative first-page comparison content, and recurring homeowner questions. Forum discussions informed phrasing and objections only; they were not used as authority for prices, savings, law, tax, or system performance.

The core primary sources are the FTC solar guide, CFPB solar-financing issue spotlight, IRS Residential Clean Energy Credit page, DOE Homeowner’s Guide to Solar, Connecticut PURA RRES page, Massachusetts utility interconnection guide, SMART 3.0 program page, Rhode Island OER solar guide, and Rhode Island AG solar consumer page.

No market price, savings promise, Teamsun proposal term, finance offer, equipment set, project result, installation count, credential, or service guarantee was assumed. Search volume and keyword difficulty remain Validate with Semrush/Ahrefs/GSC.

Turn comparable information into a purchase decision

The best solar quote is not the one with the largest savings graphic, lowest monthly payment, highest production number, or longest warranty headline. It is the proposal that survives one common baseline, makes its assumptions reproducible, states the gross and financed economics, identifies current program rules, assigns project risk, and gives you enforceable documents for delivery and service.

Complete the comparability gate first. Score only the corrected proposals. Preserve every revision, attachment, lender disclosure, warranty, and program source. Then choose the offer whose price, design, ownership, risk, and service obligations fit your actual home and decision.

Get a solar quote you can compare apples to apples. Send the same 12-month usage, future-load plan, roof and electrical information, utility account, ownership preference, and requested scope you used with every bidder. Teamsun will need to confirm the actual project, service area, scope, equipment, pricing, financing availability, program treatment, and schedule in writing.