
OffGrid Power Planner
energycalculator.blog
ElectroPlan
elec calc
Size My Solar
Build your perfect 12V electrical system without the guesswork. VoltPlan makes electrical planning for vans, boats, and off-grid setups simple and fun.

HelioScope
CampPowerCalc
ElectroPlan
energycalculator.blog
EnergyPro
PV-DesignPro
Deterministic, open energy planning calculators for solar panel output, battery runtime, wire voltage drop, EV charging speeds, and home electricity usage.
Which is more popular?
Website, pricing, platforms and company facts side by side.
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| Website | voltplan.app | powelab.org |
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| Platforms | ||
| Company | Startup from Germany · 1 - 9 employees · 2025 | Startup from the United States · 2026 |
| Listed in |
In their own words, as submitted to SaaSHub.


VoltPlan is an intuitive web app that helps DIYers, vanlifers, boaters, and off-grid enthusiasts design safe and reliable 12V/24V electrical systems—without needing an engineering degree. Plan your entire setup with visual wiring diagrams, automatically calculated wire gauges and fuse sizes, and...
PowerLab is an open-source, client-side computational engineering workbench for distributed clean energy systems. It provides transparent mathematical engines for: Solar PV Sizing: Optimal seasonal tilt angles, temperature derating, string sizing, and NREL SAM benchmark validation. Battery...
What each product offers, as listed by its team.


An editorial look at what each product does well and who it suits.


Overall verdict
Why this product is good
Recommended for
No analysis of PowerLab yet.
How often each product is chosen within a category, 0–100% relative to the other.


As answered by people managing VoltPlan.app and PowerLab.
VoltPlan.app's answer
VoltPlan is built with Next.js for speed and scalability, DaisyUI for a clean and accessible UI, and PocketBase as a lightweight backend for syncing and persistence. The app is designed to feel fully local and responsive while enabling optional features like cloud saves and sharing.
PowerLab's answer:
PowerLab is engineered using modern web and computational technologies: - Pure deterministic TypeScript calculation engines - Next.js App Router and React for responsive user interfaces - Vanilla CSS and design tokens for high-performance mobile accessibility - Client-side browser storage for local scenario preservation - NREL PVWatts V8 API integration for authoritative solar insolation baselines
VoltPlan.app's answer
VoltPlan combines visual wiring design with smart calculations for wire gauge, fuse size, and battery runtime—all in one easy-to-use browser-based tool. It’s built for real-world 12V/24V setups, not just abstract circuits.
PowerLab's answer:
PowerLab replaces closed, proprietary black-box estimation tools with fully transparent, deterministic mathematical engines. Every calculation factors in real physical anomalies, such as Peukert electrochemical capacity loss in battery storage, cold-temperature open-circuit voltage expansion in photovoltaic strings, and locked rotor amperage surges during motor starts. The entire system runs client-side with zero subscriptions, paywalls, tracking, or required accounts.
VoltPlan.app's answer
VoltPlan is free for personal use, requires no signup, and gives you accurate results tailored to vans, boats, and off-grid systems. While others focus on industrial schematics, VoltPlan puts DIY users first—with a library of real-world components and one-click PDF export.
PowerLab's answer:
Traditional renewable energy modeling tools like PVsyst, HelioScope, and Aurora Solar lock critical sizing calculations behind expensive subscriptions and obscure their underlying equations. PowerLab provides fully auditable formulations aligned directly with NFPA 70 / NEC 2023, IEEE 1547-2018, and NREL SAM methodologies. Users get instant, reproducible calculations with complete transparency into every formula, derating coefficient, and assumption used.
VoltPlan.app's answer
DIY van builders, boat owners, and off-grid enthusiasts who want to safely plan and share their electrical systems—without spending hours learning electrical engineering.
PowerLab's answer:
PowerLab is built for solar photovoltaic designers, electrical engineers, clean energy researchers, vocational renewable energy apprentices, and independent off-grid system builders who require reliable, standards-compliant sizing calculations without commercial friction.
VoltPlan.app's answer
VoltPlan started as a tool for designing a boat’s electrical system. Frustrated by spreadsheets and inconsistent advice in forums, we built something better: a clear, shareable, and accurate way to plan real-world 12V/24V installations. Today, it helps thousands build with confidence.
PowerLab's answer:
PowerLab was founded to solve a fundamental problem in clean energy engineering: the lack of open, transparent, and reproducible modeling tools for distributed systems. Sizing errors like ignoring Peukert capacity loss or inverter motor surge regularly cause real-world system failures. PowerLab was engineered to provide an accessible, open-access laboratory where anyone can verify clean energy calculations against established physical and electrical standards.
PowerLab's answer:
Share your experience with using VoltPlan.app and PowerLab. For example, how are they different and which one is better?
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