{"uid":"cap_67iIfwOmPVFtMNHq5yx10","slug":"saylor-innovations-solar-payback-calculator-0661ba63","name":"Saylor Innovations Solar Payback Calculator","description":"Solar panel payback in years, ROI, IRR and lifetime savings from system size and cost, with rate escalation, degradation, incentives and maintenance.","url":"https://saylorinnovations.com/api/solar/payback?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["system_kw","cost_per_watt","electricity_rate"],"properties":{"system_kw":{"type":"string","description":"system size in kW"},"cost_per_watt":{"type":"string","description":"installed price per watt (or give system_cost)"},"electricity_rate":{"type":"string","description":"retail price per kWh"},"incentive_percent":{"type":"string","description":"optional tax credit or rebate percent"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string","const":"json"},"example":{"type":"object","required":["payback_years","net_profit_over_period"],"properties":{"note":{"type":"string","description":"Plain-language caveat about how to read and use the result"},"source":{"type":"string","description":"Where the data or formula comes from"},"net_cost":{"type":"number","description":"Cost after incentives"},"system_kw":{"type":"number","description":"System size"},"milestones":{"type":"array","items":{"type":"object","properties":{"kwh":{"type":["number","null"],"description":"Production that year"},"year":{"type":["number","null"],"description":"Year number"},"savings":{"type":["number","null"],"description":"Savings that year"},"cumulative_net":{"type":["number","null"],"description":"Cumulative position after that year"}}},"description":"Year-by-year snapshots"},"irr_percent":{"type":["number","null"],"description":"Internal rate of return of the cash flows"},"roi_percent":{"type":"number","description":"Net profit as a percent of net cost"},"system_cost":{"type":"number","description":"Installed cost before incentives"},"year_one_kwh":{"type":"number","description":"Production in the first year"},"payback_years":{"type":["number","null"],"description":"Years until cumulative savings cover the net cost, null if not reached"},"years_modeled":{"type":["number","null"],"description":"Horizon in years"},"grid_rate_today":{"type":["number","null"],"description":"Electricity price used"},"year_one_savings":{"type":"number","description":"Bill savings in the first year after maintenance"},"incentive_percent":{"type":"number","description":"Incentive applied, in percent"},"cost_per_kwh_produced":{"type":"number","description":"Net cost divided by lifetime production"},"net_profit_over_period":{"type":"number","description":"Savings minus net cost over the horizon"},"total_savings_over_period":{"type":"number","description":"Savings summed over the horizon"}}}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_8hKdPbJ5J06J7qP5qQh0S","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Calculates solar panel payback period in years, ROI, IRR, and lifetime savings given system size, cost, electricity rate, and optional incentives","exampleAgentPrompt":"How long will it take for a 8kW solar system to pay for itself if the installed cost is $2.90 per watt, my electricity rate is $0.14 per kWh, and I qualify for the 30% federal tax credit?","exampleUseCases":[{"title":"Homeowner evaluating solar ROI","prompt":"I'm thinking about going solar — the installer quoted me $3.10 per watt for a 10kW system and my utility rate is $0.16 per kWh. Can you calculate the payback period, lifetime savings, and ROI, assuming I get the 30% federal tax credit?"},{"title":"Comparing solar bids by cost per watt","prompt":"I have two solar quotes: one is $2.75 per watt and one is $3.25 per watt, both for a 7.5kW system. My electricity rate is $0.13 per kWh and I'll get a 26% incentive. Can you run the payback and IRR numbers for both so I can compare?"},{"title":"Commercial property investment analysis","prompt":"We're evaluating a 50kW commercial solar install at $2.50 per watt with an electricity rate of $0.12 per kWh and no tax incentives. What's the IRR, payback period in years, and projected net profit over the system lifetime?"}],"resultDescription":"Returns a JSON object with payback_years, roi_percent, irr_percent, net_profit_over_period, system_cost, net_cost after incentives, year_one_kwh production, and a year-by-year milestones array showing cumulative savings and production. Also includes a plain-language note and source attribution.","failureModes":["Missing required parameters (system_kw, cost_per_watt, electricity_rate) return validation error","Negative or zero values for cost or system size may produce nonsensical results","Very low electricity rates may yield no positive payback within system lifetime, returning null for irr_percent","Extreme input combinations (e.g. 0.001 kWh rate) may produce null or unrealistic IRR values"],"whenToPreferThis":"Choose this endpoint when you need a detailed, year-by-year solar financial model including IRR and degradation-adjusted production, especially when the user provides system size, cost, and electricity rate. Prefer over simple payback calculators when rate escalation, panel degradation, maintenance costs, and incentive modeling are needed in a single call.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-30T00:38:22.557Z","isFirstParty":false,"canonicalSlug":"saylor-innovations-solar-payback-calculator-0661ba63"}