Solar Calculator (Panel, Inverter, Battery & kWh)
Plan commercial and industrial photovoltaic (PV) projects with free solar calculators for solar panel array sizing, solar inverter kW, solar battery autonomy, annual kWh production, and MPPT screening—before transformer and cable checks.
Not a residential bill-savings quote: EnergySage-style “how much will I save?” tools estimate home incentives and utility rates. This hub sizes array / inverter / battery equipment for C&I planning. Partner electrical checks live on the Power calculator and Electrical calculator hubs.
What is a Solar Calculator?
A solar calculator on CalcPanel is a planning workflow for commercial and industrial PV: define energy need, convert it to array kW, estimate production, then screen charge-controller current before transformer, cable, and interconnection reviews. It complements—not replaces—OEM design software and site irradiance studies.
Common Solar Calculations
- How to calculate solar panel array size from daily kWh and peak sun hours.
- What peak sun hours mean versus daylight clock hours.
- How to estimate solar kWh production from a known array.
- Difference between panel sizing and energy production tools.
- How to size an MPPT charge controller from Isc and parallel strings.
- When to move from PV screens to transformer and cable sizing.
Solar applications & deployment scenarios
No separate scenario landing pages yet—use these planning cards (guides + tools) for off-grid, commercial roof, and BOS wiring intents. Cards summarize; deep sizing lives on tools and guides.
Off-grid cabin & remote load
Description: Remote sites need a disciplined load roll-up before array and storage quotes. Start with appliance watts × hours in the off-grid load calculator, apply contingency, then convert daily kWh into array size using worst-month peak sun hours—not summer averages. Battery autonomy days then sets usable bank kWh at your DoD and round-trip efficiency. Keep surge watts separate for inverter peak ratings so continuous energy and motor starts are not mixed. This path is planning-only: shopping kits and portable power stations are out of scope.
Cabin / RV absorb: Use the tool’s Remote cabin and RV / van presets—no separate Tier S scenario URL. Cabin kits and “solar for cabin” shopping intents stay out of scope; energy → panel → battery → MPPT is the workflow.
Typical load: 3–15 kWh/day cabins, telecom huts, RV/van day loads, and small workshops.
Recommended runtime / autonomy: Often 2–5 days of critical load at winter PSH; confirm chemistry DoD.
Start: Off Grid Solar Calculator →
Battery bank guide
Commercial roof & warehouse array
Description: Industrial and commercial roofs usually start from known daily or monthly energy offset targets, not camping-kit wattages. Size DC array kW from daily kWh ÷ (PSH × derate), estimate annual production with an explicit loss %, then screen inverter AC rating via DC/AC ratio. Interconnection, transformer, and cable checks follow after the energy screen. Use the commercial array guide for method depth; tools stay linear planning screens—not OEM weather-year bids.
Typical load: 30–120+ kWh/day process, lighting, and HVAC offset on mid-size roofs.
Recommended runtime / autonomy: Grid-tied often minimal storage; hybrid BESS sized separately on critical circuits.
Commercial array guide →
Panel sizing tool
String layout, MPPT & DC cable (BOS)
Description: After array kW is known, configure series-parallel Voc/Isc, verify cold open-circuit voltage against MPPT max input, then screen controller amps with Isc × parallel × safety factor. DC feeder ampacity is absorbed on the cable-size calculator (#solar-dc-cable)—enter design amps from the string layout, not a separate solar-cable URL. This BOS lane prevents underrated charge controllers and undersized DC conductors before procurement.
Typical load: 2S2P–3S4P commercial strings; 20–60 A class MPPT currents common on small hybrids.
Recommended runtime / autonomy: N/A for BOS ampacity—pair with battery autonomy only when DC-coupled storage is in scope.
Wiring / series-parallel →
Solar DC cable screen
Solar Calculator FAQ
How do I estimate solar payback or ROI?
We do not ship a consumer solar payback calculator. Screen annual kWh with the PV energy production calculator, then map avoided cost with the industrial energy estimator (kWh × tariff). Capex, incentives, and TOU demand charges need a project financial model—not this hub.
What is a solar calculator?
A solar calculator helps size solar panel array kW, estimate annual kWh, size a solar inverter, and screen solar battery autonomy / MPPT current for commercial and industrial PV planning—not astronomy pages, camping kits, or portable power stations.
Where do I start for solar panel, inverter, or battery sizing?
Start with the solar panel sizing calculator, then the solar inverter sizing calculator. For storage bank kWh / autonomy days use the solar battery bank calculator—not lithium shopping keywords.
How many solar panels do I need?
Use the solar panel calculator: Array kW ≈ daily kWh ÷ (peak sun hours × system efficiency), then panels ≈ (array kW × 1000) ÷ module watts. Example: 40 kWh/day at 5.0 PSH and η 0.80 → 10 kW ≈ 25 × 400 W panels.
How do I size a commercial solar array?
Start with the solar panel calculator: Array kW ≈ daily kWh ÷ (peak sun hours × system efficiency). Then estimate yield and size MPPT controllers for string current.
What is the difference between panel sizing and kWh production?
Panel sizing finds required array kW from daily energy use. The kWh production calculator estimates annual/monthly energy from a known array size, peak sun hours, and system loss.
How is MPPT sizing different from UPS battery tools?
MPPT sizing screens PV charge-controller amps from module Isc and parallel strings. UPS runtime and battery calculators serve backup power—do not merge those intents.
Where do I size solar for a cabin or RV?
Start on the Off Grid Solar Calculator with Remote cabin or RV / van presets, then panel sizing and battery autonomy. We do not publish a separate cabin/RV scenario landing page—see Applications.
