I'm 17 in Ghana. I built a solar-sizing tool on my phone — here's the code and every bug I hit.

Collins7-code — Thu, 13 Aug 2026 11:10:08 +0000

Ghana sits under some of the strongest sunshine on earth. Solar supplies
about 1–3% of our grid electricity. The gap isn't desire — it's guesswork.
Families want solar, but nobody can tell them plainly: what size? what cost?
will it pay for itself?

So I built the answer. On a phone. Between classes.

What it does

A Streamlit app that lets any household:

Enter their real appliances (fridge, TV, fans, pump…)
Get a sized system: panels (kW), battery (kWh), inverter (kW), using load math + region-aware peak sun hours
See an estimated cost in cedis
See the payback computed from their real ECG bill (bill ÷ kWh = true tariff — no invented numbers)
Request a professional quote → the sized lead is emailed to me

🔗 Live app: https://ghana-solar-tool-pli6auappdapghergd2rfz.streamlit.app
📂 Code: https://github.com/collins7-code/ghana-solar-tool

The bugs (an honest post-mortem, because that's the real lesson)

1. The form that crashed on submit.
I pasted my lead-capture form above the sizing code. It rendered fine
(empty boxes need no math) — and threw NameError: daily_kwh is not defined
the moment someone submitted. Lesson: test the submit path, not just the
render path.

2. "Make sure you open this page through a web server."
FormSubmit expects browser calls with Origin/Referer headers. My app
posts server-to-server, so it looked like a local HTML file and got refused.
Fix: attach the live app URL as Origin + Referer headers.

3. The silent activation step.
First submission to a new email only triggers a one-time activation email.
Until you click it, leads are accepted but never delivered. I chased a
"broken" pipeline that was just waiting for one click.

What real users taught me

My first real user (a friend) left the appliance table at its defaults —
so her quote wasn't truly hers. Real hands > my assumptions. That's now an
open UX issue: nudge users to personalise the table.

What's next — and where you come in

This project is built in the open. Open issues include: real ECG tariff
bands, measured irradiance data, Twi localization, and mobile UX.

I'm also opening an open-data track with real Ghana infrastructure data.
To show you why it matters: in 2010 Ghana spent US$171M on road
maintenance — yet 58% of the 68,053 km network was still rated fair or
poor. Where should the next cedi go? That's the kind of question this
track will explore, roads first, then energy.

Grab a good first issue. Read CONTRIBUTING.md. Come build with me.

One line for the road