Case Study Solar Calculator
A guided solar sizing tool that turns curious visitors into qualified leads.
Emolith needed a way for homeowners and businesses to size a solar + battery system themselves — and for the sales team to receive a ready-to-quote lead at the other end.
Overview
An appliance-by-appliance energy audit that ends in a real system recommendation.
The calculator walks a visitor through their actual energy use — over 40 appliances with realistic running and surge wattages — across two segments: residential households and business / industrial sites.
From that, it recommends a matched inverter, a battery bank assembled from 48V batteries, and a panel count and kWp, then runs a roof-fit check and estimates annual savings and payback. The lead — and an itemised auto-offer — lands in a small admin backend for the sales team.
What we did
We built the visitor-facing wizard as a fast, self-contained module that drops into the existing site, with solar-specific questions — single vs. three-phase, roof area, orientation, tilt, shading, day-vs-night split, and a backup-hours target — feeding the sizing math.
On the other side, an admin panel manages the full lead list and pipeline (new → contacted → quoted → won / lost) and auto-generates an itemised offer against the Emolith catalogue in USD landed-cost prices.
Pricing lives in one place: a single config holds the EUR→USD rate and landed-cost markup, so a rate change updates every price — wizard and admin offer — instantly.
How we built it
The frontend is deliberately lightweight — vanilla HTML, CSS, and JavaScript — so it loads fast and is trivial to embed and theme with Emolith's branding.
The backend is a small Node / Express service with a SQLite database (better-sqlite3), storing leads and serving the admin panel. No heavy framework, nothing to babysit — exactly the right size for the job.
Outcome
- Turns anonymous website visitors into qualified, itemised solar leads.
- Gives customers an instant, credible system recommendation with savings and payback.
- Auto-generates a rough offer with catalogue SKUs and USD pricing for the sales team.
- Prices update everywhere from a single config — exchange rate and landed-cost markup in one place.
A tool that does real work on both sides: visitors get a credible answer in minutes, and the sales team gets a warm, itemised lead instead of a name in an inbox.