Hey Product Hunt! 👋 I built **PowerLab** because I was tired of online solar and battery calculators that are actually just lead-generation forms. Most of them assume 100% ideal physics, hide the math, and force you to hand over your phone number just to see exaggerated savings claims. PowerLab was built on three simple principles: 1. **Transparent Physics**: Every formula and loss factor is visible and editable on-screen — including inverter idle tare draw (15W–50W), battery chemistry DoD limits (AGM vs. LiFePO4), solar seasonal tilt geometry, and EV fast-charge tapering. 2. **100% Privacy by Design**: Zero accounts, zero tracking, and zero server databases. Everything calculates in pure TypeScript right inside your browser. 3. **Built for the Field**: Full offline PWA support and one-click printable PDF specification sheets for job sites, van builders, and solar permitting. **Tech Stack**: Next.js 15 App Router, React, TypeScript, and lightweight Vanilla CSS. I’d love to get your feedback, hear your thoughts on the physical loss models, and know which energy calculators you’d like to see added next! ⚡

PowerLab — Energy Planning Tools

energy & solar calculators with visible physical loss models

energy & solar calculators with visible physical loss models