SolarCalc vs Voltbox

SolarCalc is the ultimate professional solar energy calculator and rooftop PV feasibility tool for homeowners, solar contractors, engineers, and renewable energy enthusiasts. Determine exact solar panel requirements, battery bank storage, financial payback (ROI), and 20-year energy savings based on your local solar irradiance and monthly electricity consumption. CORE CAPABILITIES: 1. INTELLIGENT PV & BATTERY CALCULATOR - Calculate optimal solar array size (kW), panel count, and required roof space. - Accurate annual kWh generation forecasts using regional irradiation and peak sun-hour data. - Complete financial feasibility: Net installation cost, annual savings, payback timeline (years), Net Present Value (NPV), and Levelized Cost of Energy (LCOE). 2. 20-YEAR COST COMPARISON & ROI - Interactive financial comparison between staying on the grid versus going solar. - Lifetime cash-flow projections and cumulative net savings metrics. 3. SMART SYSTEM DIAGNOSTICS & UPGRADE PLANNER - Input your existing solar modules, inverter capacity, and battery storage. - Add household appliances and electric vehicle (EV) charging profiles to detect power bottlenecks and receive engineering upgrade recommendations. 4. EXPANDED SOLAR ACADEMY - Master clean energy engineering: Bifacial modules, TOPCon N-Type technology, LiFePO4 vs. Gel batteries, Hybrid inverters with EPS backup, Micro-inverters, and Surge Protection (SPD). 5. LIVE PRIVACY MODE - Keep your investment and billing figures confidential during presentations and screen sharing with a single tap. 6. PROFESSIONAL PDF PROPOSALS - Generate client-ready B2B solar feasibility reports with custom company branding and detailed technical specs. 7. EV & SOLAR INTEGRATION - Calculate solar energy needed to charge your electric vehicle and maximize fuel savings. Make confident, profitable solar investments today with SolarCalc!

Voltbox: PV Installer Toolkit is a professional calculator toolkit for solar/PV installers, built around NEC Articles 690 and 705. Fast, accurate, and yours to own — pay once, keep it forever. 12 CALCULATORS Array & String Design (free) • String Sizing — max modules per string, temperature-corrected (NEC 690.7) • PV Circuit Sizing — conductor & OCPD sizing for source circuits (NEC 690.8/690.9) Interconnection & Safety • 120% Rule — backfeed breaker vs. busbar interconnection check (NEC 705.12) • Rapid Shutdown — array boundary & voltage/time limits reference (NEC 690.12) • DC Arc-Fault Protection — whether 690.11 AFCI protection applies to your install Circuit Installation • Voltage Drop — DC array-to-inverter run (NEC Ch. 9 Table 8) • Conduit Fill — DC source/output conductors in conduit (NEC Ch. 9 Table 1) • Grounding & Bonding — GEC (690.47) and EGC (690.43/250.122) sizing • AC Output Sizing — inverter output circuit conductor & OCPD (NEC 690.8) • Rooftop Temp Adder — ambient temperature correction for rooftop conduit (NEC 310.15(B)(3)(c)) Storage & Estimates • Battery Sizing — ESS backup capacity from critical load & duration • Production Estimate — quick annual output ballpark from peak sun hours WHY VOLTBOX • One-time purchase for Pro — never a subscription, never a recurring fee • Save and organize calculations by project • Built for the job site: fast, no clutter, no login screens, works with no signal • No account required — open the app and start calculating String Sizing and PV Circuit Sizing are free. Unlock Pro once to get every other calculator. Voltbox is a reference tool based on the NEC. Always verify results against the current code edition adopted in your area and confirm compliance with a licensed electrician or installer before performing any installation.