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Installer Due Diligence & Solar Insure SI-30

Orphaned systems · 30-year coverage · what certification really means

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Direct answers to the questions and pushback users are most likely to raise. Sunalysis is a planning model, not a utility settlement engine or tax opinion. If a result surprises you, compare the input assumptions line-by-line against your installer proposal, utility tariff, and tax situation.

What kind of model is Sunalysis?

Sunalysis is a 12-month solar ROI and dispatch planning model. It takes your annual production estimate, spreads it across the selected monthly production curve, compares each month with monthly household usage, estimates direct self-use, surplus export, and battery shifting, then rolls the first-year value into a 30-year financial model (electrification switches you schedule for later years join that model in their chosen years, not in year 1). It is stronger than a simple annual-average calculator, but it is not a full hourly or 15-minute utility-grade simulation.

Is this an hourly battery dispatch model?

No. Sunalysis uses monthly buckets. It captures seasonal mismatch and month-level self-consumption, export, and battery-shift value without requiring interval data. It does model weekday-versus-weekend and seasonal TOU rules (each month is priced on its own schedule, with federal holidays billed as weekends), and if you upload Green Button interval data it prices your solar self-use at the rates of the actual hours your solar served the house. Beyond the overnight-vs-daytime charging window you pick for each car (planned, or one you already drive), it does not know the exact hour your EV charges — nor individual cloudy days or hourly export-credit tables. For final design, compare the result with installer software, your utility tariff, or an interval-data simulation.

I'm not switching everything at once. Can the model wait for me?

Yes — that's what the timing selectors are for. Every appliance conversion row has a "starts: now / in 1–10 years" select, and every EV has its own "Each car arrives" year. A future-dated switch joins the savings, the home's electricity load, and (when equipment costs are included in ROI) its upfront cost in its scheduled year, not today — so nothing is claimed early. The year-1 headline counts only what's live in year 1; the 30-year numbers include every scheduled step from its own year; and the recommended system size targets the full plan, so the roof you buy once is ready for where you're headed. The report's roadmap page lays out your actual timeline.

I ticked "I already drive an EV" and my return got WORSE. Is it broken?

No — and the reason catches almost everyone. Ticking this box does not add your EV's benefit, because that benefit was already counted the moment you entered a bill that includes its charging. Owning an EV genuinely improves solar economics — a bigger bill is a bigger target for the panels — and the calculator already shows that. What the tick changes is only when that slice of your usage happens. Say "overnight" and you've told the model that a chunk of your power is drawn after dark, where panels cannot reach it, so less of your solar is used at home and the projection eases back. That is the honest number, not a penalty for owning the car. Two different questions are at work: "EV vs no EV" — better, already in your bill; and "the same EV, charged at 1am vs spread through the day" — slightly worse, and that is the one this box answers. The fix for the overnight slice is storage: a battery charges on your midday surplus and carries the car after dark, which is why the recommended battery grows when you say you charge overnight. Switch the window to during the day and the number rises instead. Planning another car? That goes through the "Number of EVs" buttons, which do model new load and new gasoline savings.

Can I hand this calculator to my client?

Yes — that's the 🏢 Office tab (it appears when you're signed in on your company's site). With a finished analysis on screen it mints a private link and matching file for one client: your quote — cost, size, production, rates, financing — stays locked exactly as proposed, while they explore the knobs you allow (battery, EVs and their timing, appliances, usage and bills, hold years) on their own time. A 📒 journal saves every version they like, and one tap emails it back to you; opening that reply names the client, restates your quote as sent, and spells out every setting behind every scenario with their changes marked. Links live 14 days by default, and Manage active client links inside the 🎁 panel closes one early. Reading this inside a page titled Your Solar Plan? Then you're the client — explore freely, nothing you change alters the quote, and the Send button returns your scenarios to your installer for advice.

Why did changing the monthly production curve change my ROI only a little — or not at all?

The curve does not create more annual solar. It changes when the annual kWh are assumed to occur. ROI changes only when that new timing changes the value of the energy: more direct self-use, less low-value export, more usable battery shifting, or better matching with seasonal household usage. If your load is high enough to absorb solar in most months, your battery is not binding, export credit is close to retail, or the compared curves are similar, the ROI movement may be small. For the strongest estimate, enter both a custom monthly production curve from your proposal and actual monthly kWh usage from your bills. For example: shifting solar production from winter into summer only helps if you actually use more power in summer (say, running AC). If that extra summer solar would just be exported to the grid for a few cents, moving the curve barely changes your ROI.

Does entering monthly kWh usage actually matter?

Yes. Monthly usage entries define the load shape used by the 12-month dispatch layer. Two homes can use the same annual kWh but have different ROI if one uses more power during high-solar months and the other uses more during low-solar months. If you leave monthly usage blank, Sunalysis spreads annual usage evenly across the year. That is acceptable for a quick estimate but weaker than using actual monthly bill data.

How do I get my exact utility rates into the analysis?

Choose "My actual rates" in Section 1 and you get three paths, in order of reliability. (1) Verified plans — for California's big three (SCE, PG&E, SDG&E), tap your utility then your plan: rates come from official tariff sheets, and SCE's TOU-D-PRIME is reconciled against real customer bills — both seasons, four consecutive 2026 statements. Two things to know when you verify: the loaded prices are all-in (they fold in the ~0.649¢/kWh of fixed-recovery + state-surcharge your bill prints on separate lines, so they intentionally read slightly higher than the tariff sheet’s energy line while reproducing your true cost), and the bar’s labels are rounded to the nearest cent for readability — tap a block (or hover on a computer) for the exact figure. (2) The NREL database — for other US utilities, search by the company name printed on your bill (more reliable than ZIP; see the next question). (3) Type them yourself — tap any block on the rate card and enter the price from your bill, drag the white boundaries to set the hours. The third path always works, anywhere in the world, and every imported plan stays fully editable afterwards.

I searched my ZIP code and my utility isn't listed — or the wrong one is. Why?

Because the ZIP search asks NREL's database to guess your utility from service-territory map polygons, and near city borders that guess is often wrong. A real example: ZIP 91011 (La Cañada Flintridge) returns only Los Angeles DWP, even though addresses there are served by SCE. Two fixes: search by the company name printed on your bill instead of the ZIP — that matches the utility directly and sidesteps the map entirely — or, in California, use the verified plans buttons, which don't consult NREL at all. Sunalysis now offers those verified shortcuts automatically whenever a California search comes back without them. Your bill is always the tiebreaker: whatever company name is printed on it is your utility.

What is the "Bill check", and does it change my results?

It changes nothing — it is a proof, not an input. Every savings figure here is your usage multiplied by your utility's prices, so the Bill check tests those prices against bills you have already paid: enter the kWh and the total bill for a couple of months (in Detailed month-by-month usage & bills), and Sunalysis recomputes what each month should have cost on the loaded plan, beside what you were actually charged. A worst gap under about 6% means the rates driving your projection genuinely reproduce your bills. A large gap usually means the wrong plan is loaded, a community-choice or city surcharge applies, or the bill total isn't electricity-only. One limit worth knowing: it proves your import pricing — the power you stop buying — not the export credit you earn for surplus solar, which is a separate assumption you should set from your tariff.

Going solar forces me onto a different rate plan. Is that modeled?

Partly, and the simplification is disclosed. In California the utility moves new solar customers onto a specific plan at interconnection (SCE: TOU-D-PRIME; PG&E: E-ELEC; SDG&E: TOU-DR1 and friends), so the plan picker labels that group "After solar — your new plan" and prices the analysis on it. Your pre-solar bill is priced on the same plan rather than on whatever you're on today, which means the rate-switch effect itself isn't broken out separately. For SCE we measured the size of that shortcut: pricing both sides on TOU-D-PRIME understates annual savings by roughly $40-160 versus the true before-plan (measured before the July 2026 rate refresh; both plans moved together, so the order of magnitude stands) — small, and in the conservative direction. If you want the sharpest possible before-picture, enter your real monthly bills, which capture exactly what you pay today.

Why does Sunalysis assume electricity rates rise 4%/yr? That's too high.

It is an editable default, not a fact — and it is on the field for you to change to match your region and your own view. We default to 4%/yr for reasons that have made electricity inflation hard to bottom-call, and arguably point upward: (1) Surging demand. After ~two decades of flat U.S. load, AI/data centers, electrification of cars and heating, and reshored manufacturing are driving the steepest demand growth in a generation — utilities are already filing for large multi-year rate increases to fund the build-out. (2) Grid investment. Aging transmission/distribution, wildfire hardening, storm resilience, and interconnection upgrades are huge capital programs recovered through your rates for decades. (3) Fuel-price volatility & supply shocks. A large share of generation still rides on natural gas; international conflicts, LNG export demand, and supply shocks feed straight into electricity prices. (4) Recent history. Several major utilities (e.g. in California) have raised residential rates well above 4%/yr in recent years. Historically the long-run U.S. residential average has been closer to 2–3%/yr, so 4% is deliberately toward the higher end — which is also the more defensible place for a planning default to sit. If you expect slower increases, lower the field and the result updates live; the Skeptic's View button re-runs the whole model on the hardest honest assumptions — 2%/yr escalation, the full market return (no lowered rate and no fee/gap haircut), and no resale premium — so you can see whether the thesis survives a conservative case. Why it matters: at 4%/yr a $200/month bill grows to about $430/month in 20 years — so the savings solar locks in keep getting bigger.

A 10% S&P 500 return for 30 years is fantasy.

10% is a conventional long-run nominal benchmark, not a prediction. Sunalysis uses it so the solar project is compared against a recognizable alternative use of capital. The core comparison is apples-to-apples: solar with every year's bill savings reinvested at the same market return versus simply investing the same money in the market — not raw solar net gain versus the market lump — and it is shown after-tax (federal and state capital-gains reduce the market side; solar bill savings are tax-free avoided cost).

The Market section shows this as an itemized, editable ledger rather than a single number, because a naive "10% vs solar" comparison quietly understates solar on four honest axes: (1) real investors net less than the index (fund fees + the average behavioral gap), so the fair market return is a point or so below the sticker 10%; (2) that 10% is a risky return (30–50% drawdowns, sequence risk) while solar's savings are contractually certain — so we also show what a safe alternative (bonds/CDs) would return; (3) your electricity savings are tax-free, shown as a pre-tax-equivalent context figure at your bracket (not folded into the head-to-head, since both sides start from after-tax dollars); and (4) your panels keep producing after the hold period. Every line is editable.

Skeptic's View strips all of that: it uses the full market return (the hardest honest test — not a lowered one), removes the fee/gap haircut and the tax-free context, cuts energy escalation, and zeroes the resale premium. If solar still holds up under Skeptic's View, the case is robust; where it doesn't, you see exactly which assumption carries it. The un-reinvested net is also shown (as "Spend the savings") for reference.

Isn't "reinvest 100% of the savings" unrealistic? Nobody actually does that.

Fair challenge — most people don't invest every dollar they save, so we don't rest the case on one number. The market comparison shows three tiers, not one: Spend the savings (invest nothing, just pocket the lower bills — the floor), Reinvest half, and Reinvest all (the ceiling, only if you redirect the bill money you no longer pay into the market). Your real outcome sits between the floor and the ceiling, set entirely by your own discipline. We show the eye-catching upside, but the spend-nothing floor is always right beside it — and even that floor is a real, tax-free return. Treat "reinvest all" as the best case, not the expected case.

Why do capital-gains tax changes affect the Solar-vs-market comparison but not Payback or IRR?

Because those are different calculations. Solar payback, IRR, and solar net gain are based on project cash flows: avoided utility purchases, export value, battery-shift value, electrification savings, maintenance, degradation, and replacement assumptions. Capital-gains tax applies to the market-investment comparison, not to electricity you avoid buying from the utility. So changing federal or state capital-gains tax moves the after-tax market figure in the Solar vs. the market comparison, but it should not change the solar project's own payback or IRR. For example: raise your capital-gains tax and the stock-market side gets taxed more, so the gap in that comparison shrinks — but your panels still cut the exact same amount off your power bill, so payback and IRR don't move at all.

Did you account for the time value of money — a dollar later being worth less than a dollar now?

Yes — that's exactly what IRR does. Plain version: $100 today is worth more than $100 ten years from now, because today's $100 could be invested and grow in the meantime. So when Sunalysis reports a return, it isn't just adding up dollars — IRR already weighs when each dollar of savings shows up, counting early savings more than far-off ones. For example: solar that saves $2,000 a year for 30 years is not simply "worth $60,000" — the early years count for more, and IRR builds that in. Sunalysis also shows the plain, un-adjusted total as "Net gain," so you see both numbers: the simple sum and the time-adjusted return. And the whole reason we compare against the stock market is to answer the real time-value question — "could this money have grown more somewhere else?"

An index fund I can sell tomorrow — a roof I can't. Isn't solar an illiquid "return"?

True, and worth saying plainly. Owned solar isn't a liquid security — it's a fixed, inflation-hedged cash-flow asset, closer in character to a tax-free bond than to equities: low volatility, no daily price, but you can't partially cash out. Your liquidity at exit is the resale premium, which is market-dependent (see the resale question). If you might need the money back quickly, weigh that against the steadier, bill-cutting nature of the return — it's a feature for a long-term owner and a drawback for someone who may need liquidity. This is also why the fairest market yardstick for the panels-alone floor is an after-tax bond yield, not the S&P 500; electrification is what lets the whole plan reach for equity-like numbers.

Could a policy change like NEM 3.0 wreck the economics?

It's the one risk no model can remove, so we're explicit about it. Net-metering reform — California's NEM 3.0 is the headline example — cut export credits sharply and lengthened paybacks for export-dependent systems. Two things blunt it here: Sunalysis values the solar you use yourself separately from what you export, and a battery shifts more value to self-use — so the more your savings come from your own roof rather than selling back, the less a future export cut can touch you. Existing systems are also usually grandfathered under the rules in force when they interconnect. Enter your current export rate (not a legacy 1:1 one), and treat policy as a risk to hedge with self-consumption and storage, not a certainty. Conversely, rising retail rates and new programs can also move in your favor.

The headline IRR seems absurdly high. Is this real?

Headline IRR is configuration-specific. A modest solar-only system in a mild climate may show single-to-low-double-digit IRR. A much higher IRR usually means the configuration includes large electrification streams, such as EVs displacing gasoline, heat pumps displacing gas, or pool-heater conversion. Those streams convert fuel spending into electricity demand that can be supplied by solar. The results break down the value drivers so you can see whether the result is coming from solar-only savings, battery shifting, exports, electrification, resale value, or reinvestment assumptions. For example: the panels alone might show about 8% IRR. Add two EVs that replace $4,000/yr of gasoline and the IRR can jump into the teens — not because the panels changed, but because the same sunshine is now replacing expensive gasoline, not just grid power.

What about tax credits?

Sunalysis works from your Net project cost — the price after any incentives you actually receive — so enter that figure, not the gross sticker price. This tool does not assume or promise any specific tax credit. Whether you qualify for a tax credit, and how much, depends on your individual tax situation — for tax credits you may qualify for, consult a qualified tax professional. If you are unsure whether an incentive applies to you, enter the higher gross cost for a conservative result.

"Self-consumed solar value" is much bigger than my old electric bill. Is something double-counted?

Not necessarily. The self-consumed solar value is the retail value of solar electricity used by home loads, including new electrical loads such as EVs, heat pumps, pool equipment, or other electrification. That value can exceed the old electric bill if the home now uses more electricity because former gasoline or gas loads have moved onto the electric side. Sunalysis is designed to offset this by treating electrification savings as fuel avoided minus added electricity required. The Year-1 savings breakdown and the Energy section show whether value is coming from avoided grid purchases, export credits, battery shifting, or non-electric fuel displacement. For example: say your old power bill was $2,000/yr. You add an EV and a heat pump, so the home now uses much more electricity — but you've stopped buying roughly $1,500/yr of gasoline and $800/yr of natural gas. Solar now covers the electricity that replaces all three, so the "solar value" can be around $4,000 — larger than the old $2,000 bill because it's also replacing the gas and gasoline, not double-counting them.

I changed panel efficiency / wattage and ROI didn't move. Broken?

Usually intentional. Your annual production figure should come from a production model or installer proposal, and that production figure should already reflect panel wattage, panel count, roof geometry, shading, inverter limits, and climate assumptions. If Sunalysis also recalculated production from panel efficiency, it could double-count. The panel spec that directly affects long-term ROI is degradation, because it changes production over the 30-year horizon. Use the panel comparison tools for educational side-by-side comparisons, but treat entered annual production as the controlling production input unless you are using a dedicated production designer.

My installer's production estimate looks optimistic.

It might be — installers sometimes quote best-case annual production. Sunalysis trusts the annual production figure you enter, so the result is only as honest as that number. Cross-check it against an independent estimate (for example, NREL's free PVWatts tool) using your address, array size, tilt, azimuth, and shading. If the two disagree, enter the lower figure — or haircut your installer's number by 5–10% — to stress-test the project. Production is one of the two biggest ROI drivers (alongside your electricity rate), so a few percent here matters.

Where do I change the battery replacement year, and which year should I pick?

Where: Full Analysis → §3 Battery storage → 3.1 “Battery efficiency, degradation & replacement”. That panel holds the replacement year, the cost per kWh, an on/off toggle, and an optional second replacement. Quick has no replacement controls — it assumes a refresh at the end of the warranty, so switch to Full to change it.

Which year: the default is the pack’s warranty year, which is the cautious choice. Swept year by year, the money actually peaks about ten years before your hold ends — roughly year 20 on a 30-year hold, year 10 on a 20-year hold — because a replacement needs about a decade of restored capacity to repay its own price. Push it later than that and the gain flattens and then reverses; the pack simply runs out of years to earn back. Pull it earlier and you pay for a fresh pack that has fewer years to work for you, but you get newer equipment and fuller backup. Neither is wrong; they buy different things.

Several packs? With three or more, one failure costs you roughly its share of capacity rather than all your backup, so there is time to compare replacements instead of buying under pressure — an argument for a later year. Two honest cautions: packs bought together age together, so failures tend to cluster, and some manufacturers will not warrant a bank that mixes pack ages or firmware. Ask your installer before planning to replace them one at a time. Sunalysis charges the whole bank in one year either way, so it is the pessimistic case for anyone who would stagger it.

Battery replacement at $500/kWh is too cheap. Why not today's $700–900?

The replacement cost is editable because no one knows the installed residential battery price 10–20 years from now. Today's cost may be higher, but future chemistry, installation practices, competition, and warranty structures may be different. Use $500/kWh as a planning midpoint only if it fits your view. For a conservative case, enter a higher number. For an optimistic technology-cost decline case, enter a lower number. The important point is that Sunalysis shows the assumption instead of hiding it. Two timing facts worth knowing (v8.9.7): the replacement is charged at the warranty year by default — deliberately early, since electronics can fail before cells fade — and in every measured scenario it lands after payback, so this assumption never changes how fast the system pays for itself. Capacity fade follows the maker's warranty-floor slope and flattens at 60% of nameplate — if your pack simply keeps working past warranty, that's upside the model never counted. And if you leave the replacement year and price at the model's values, the report's inputs page now flags them as defaults to confirm — the biggest single default in the model is no longer allowed to hide.

Can too many batteries make ROI worse?

Yes. More batteries can improve backup power, reduce export, and shift more solar into expensive evening hours. But once the battery bank is larger than the home's usable surplus solar and evening demand, additional units may add cost without adding much annual value. If the replacement option is enabled, the future refresh cost also scales with the modeled battery bank. Oversized storage may be reasonable for resilience, medical equipment, outage protection, or whole-home backup, but it should not be assumed to improve financial ROI unless the monthly dispatch results show the extra capacity is actually used.

You only model one battery replacement. What about a second one?

The default is one refresh at the chosen battery replacement year. A second replacement option can be enabled for a more conservative long-horizon case. It is usually off by default because projecting battery chemistry and installed pack prices two decades out is highly uncertain. If you want the worst-case view, turn it on and use conservative replacement pricing.

The default export rate is wrong for me.

It may be. Export compensation varies by utility, tariff, hour, season, retail plan, and country. Sunalysis's default export value is a placeholder when no better value is entered. Replace it with your installer's modeled annual-average export compensation rate, your utility's published estimate, or a conservative value you want to test. In the monthly model, the export rate affects the value of surplus solar that remains after monthly self-use and estimated battery shifting.

What does "curtailed" or "no export value" mean?

It means Sunalysis gives no credit to surplus solar that exceeds monthly household load and usable battery shifting. This can represent a tariff that does not compensate exports, a system that is export-limited, or a conservative stress test. If your utility does pay for exported energy, use an export-credit setting instead. The choice can materially affect ROI for oversized systems.

What about fixed charges, minimum bills, or solar grid fees?

Use the monthly residual / minimum bill field. Most utilities charge a fixed connection or customer charge you pay regardless of solar, and some impose minimum bills or solar-specific grid-access fees. Entering that amount reduces the savings Sunalysis credits to solar each month, so the model does not assume your bill drops to zero. If your utility is proposing new solar fees, model a higher residual to see whether the project still holds up.

The home resale premium feels speculative.

That is fair. Resale value is uncertain and market-specific. Sunalysis treats it as optional and conservative: it contributes only if a sale year or resale assumption is enabled. Skeptic's View removes it. Treat the resale table as a directional estimate, not an appraisal.

Every solar calculator inflates the numbers to sell. Why would yours be different?

Because you can audit the deflation. The result you see is after a repair reserve every five years, a full battery replacement charged at the warranty year, insurance adjustments, panel output taken from the manufacturer's warranty floor (panels typically do better), battery fade at the warranty-floor slope, your old gas appliances credited as if they were efficient models, and zero tax credits. The printed report itemizes every one of these in “Ownership set-asides & rate rules” and its cost table ends by telling you what the bottom line would read without them — and the inputs page tags every figure you didn't personally enter as a default to confirm. If you still doubt a number, ask the built-in assistant to stress the assumption you trust least and watch the result recompute on your own inputs.

The rate card's prices don't exactly match the rate line on my bill. Why?

Two deliberate reasons. First, the bar's labels are rounded to the nearest cent so the picture stays readable — tap any block (or hover on a computer) to see and edit the exact price, and the analysis always uses the exact figure. Second, verified California plans are all-in: they fold in the ~0.649¢/kWh of fixed-recovery and state-surcharge your utility bills on separate lines, because solar avoids those charges too. So a block can honestly read 25¢ where the bill's rate line says 24.152¢ — both are right, and the card says so in its footnote. What should match to the penny is the Bill check: give it a few months of kWh and bill totals and it re-computes what the utility actually charged.

Wouldn't it be smarter to wait a year for cheaper equipment?

Run the arithmetic on your own numbers rather than a slogan. Waiting one year costs you that year’s savings (your year-1 figure is on the results dashboard and the report) and moves every future year one rung up the rate-escalation ladder — while hardware price declines have flattened compared with the 2010s. For waiting to win, next year’s installed price would have to fall by more than a full year of savings plus the compounding you gave up. Sometimes it genuinely does — a roof that needs work first, a new-build coming, a much better utility program announced with a date. The Ask Sunalysis assistant can stress this directly: ask it to recompute your analysis at a 5–10% lower cost and compare that against acting now.

Is this a sales funnel for a specific installer or warranty product?

No. Installer quality, warranty structure, and company stability matter because solar is a long-lived asset, but those sections are meant to teach users what to verify, not to force a vendor choice. The financial model should not depend on a particular installer name unless the user enters costs, warranties, or service assumptions from that installer.

What if the solar company goes out of business?

It happens — even big installers fail (SunPower, one of the largest, went bankrupt in 2024). Your panels keep making power, but the warranty that was supposed to cover repairs can become worthless, and there may be no one left to call for service. That's an "orphan system." For example: a few years in, your inverter dies — if the installer is gone, the free replacement they promised is now your bill, often $1,500–$2,500. Two protections: (1) make sure the workmanship warranty is backed by a separate company, not just the installer; and (2) register the panel and inverter manufacturer warranties in your own name, so they survive even if the installer doesn't. And if you financed, you still owe the loan even if the installer vanishes — so keep the loan independent of the installer where you can.

Single HTML file — is this safe? Where's the source?

It is a single self-contained file so the model can be inspected. Right-click and choose View Source to see the calculations, labels, and assumptions. There is no required backend for the calculator logic. If a future hosted version adds analytics, saving, accounts, or external services, that should be disclosed separately.

What about replacing the roof? Pulling panels off and back on isn't free.

Valid — and commonly omitted by solar calculators. What actually matters is your roof's remaining life versus the panels' 25–30 years, which depends on roof type (asphalt shingle ~20–25 yr; metal or tile 40+). Two plain rules of thumb: (1) if your roof is more than ~10 years old, have it inspected before installing and fix any weak or worn areas first — repairs are far cheaper before the panels go on than after; (2) if it's more than ~20 years old, either re-roof first (cheapest, so the roof and system age out together) or set aside a panel removal-and-reinstall budget — typically about $1,500–$6,000 depending on system size and roof complexity. Sunalysis does not add this automatically because it varies so much by home; if it applies to you, fold it into your Net project cost or the repair reserve. A newer or longer-life roof makes a mid-life removal unlikely.

You didn't account for [inverter / O&M / insurance / SRECs]…

Many of these are already modeled or editable: panel degradation, battery degradation and refresh, repair reserve, insurance increase, inverter replacement treatment, EV maintenance differential, and EV insurance taper. SREC / incentive income is never assumed by default — if your state pays SRECs, the SREC field appears automatically in Full Analysis (next to the export rate) when your selected state has an SREC/incentive market — enter your annual income and its eligibility window and it flows into the cash flow, the panels-alone comparison, and the report. It's generally taxable; the tool doesn't net that out. The Trust section below your results should be used to check what is active in the current scenario. If a factor is important for your project and not explicitly modeled, treat the result as incomplete until you add it manually or adjust the assumptions.

Can I get a printable report to keep or share?

Yes — and it's worth doing. Click the 🖨 Print button at the top of the calculator and choose “Save as PDF” in your browser's print dialog. Sunalysis builds a clean, dated, publication-style report, and every page opens with a plain-English line explaining what it shows — no solar expertise needed. The Detailed report is the complete version: an executive summary and the four ways owning your power protects you (rate hikes, outages, fuel spikes, car upkeep); a “life with solar & electrification” before/after; how you use power day vs. evening; your car and your home compared gas-vs-electric (the 10-year ownership and appliance math); the 30-year money and a “what if you sell early?” resale page; solar vs. the market and cash-vs-finance at your own loan terms; resilience & seasonality with a battery right-sizing check and your electrification roadmap (the year each scheduled switch and car joins the plan); a “how solid are these numbers?” input-confidence read (with an honest “what this does not model” note); a year-by-year cash flow and a full assumptions audit; and a fill-in installer-quote comparison worksheet with a climate-based panel-temperature tip. Want a short version to forward? Choose Brief · 3-pg inside the Print panel for a 3-page Executive Brief. Both documents print identically from Quick Estimate and Full Analysis. Lease or PPA plans get a dedicated “should you own instead?” review.

Have a question that is not here? The best next step is to take Sunalysis's output to your installer, utility tariff, CPA, or qualified financial advisor and ask them to defend any number that surprises you. The purpose of the tool is to help you ask better questions, not to replace project-specific professional review.