WhatSun — Your Curious Energy Advisor for solar + battery homes
Your Curious Energy Advisor
What can the sun do for you?
Learn more inside.
The Tesla app shows you what happened. WhatSun tells you and your household what to do today — a 2-minute morning plan in plain English. No dashboards to babysit, no automations to fight, no setup. Works in any browser.
Start free forever — no credit card needed · 5-minute setup · Works on any device
What you get every morning
Not another monitoring dashboard. A daily action plan.
Today's plan in plain English
Exact charge targets for every EV, a battery reserve goal, and a grid risk forecast — written for humans, not engineers.
Your #1 priority action
One scrolling ticker tells you the single most important thing to do today. No decision fatigue.
A text for your household
Morning briefing ready to copy and send: 'Sunny day — charge the X to 80%, hold off on the dryer until 4 PM.'
Trends that prove it's working
Solar accuracy, self-sufficiency, and grid reliance tracked over time. See seasonal patterns build automatically.
Where WhatSun fits
WhatSun is advisory, not control. It never changes your Powerwall settings — so it never fights Tesla's algorithm, never breaks when Tesla updates their API, and never gets you a "please disconnect" email. If you want hands-off automation, tools like NetZero do that. If you want a homelab, Home Assistant does that. WhatSun is for people who'd rather have a clear daily plan than a second system to manage.
Built in California, for NEM 3.0 and time-of-use homes, by an owner running two solar arrays, three Powerwalls, and two EVs.
Ready for tomorrow morning?
Set up your system in 5 minutes. Get your first plan tomorrow at sunrise.