WhatSun — Your Curious Energy Advisor for solar + battery homes
Your Curious Energy Advisor
Make your solar home think.
Every morning, WhatSun turns your Tesla solar, Powerwalls, and EVs into a plain-English energy plan — advice first, autopilot where you allow it. Then it proves what it saved, down to the kilowatt-hour.
Nothing to install, no homelab, no dashboards to babysit: it reads your Tesla account, starts planning the same day, and lands on your phone.
Free forever plan · No credit card · 5-minute setup · Designed mobile-first
FROM THE FOUNDER'S ROOF — 30 DAYS WITH WHATSUN
Observed at the founder's own home — your roof, battery size, driving and rates will shape your own numbers.
Try it without signing in
Move the sun, change the weather, plug in the car — watch the plan rewrite itself.
Emergency buttons for bad days
When the grid wobbles or a storm rolls in, lift a safety cover and press. Go off grid runs the house on sun and Powerwall alone. Bunker 100% turns on Tesla Storm Watch and fills the battery. One lever puts everything back.
Live weather alerts show on the console, and grid outages are detected, timed and logged automatically.
Demo only — in the app these change your real Powerwall settings.
Everything your solar home has been missing
Real math from your own Tesla readings — not guesses, not generic averages.
Cars that charge themselves on sunshine
- ✓Automatic charging follows spare solar every 2 minutes
- ✓Backs off the moment the house pulls from the grid
- ✓Never-below floor keeps every commute covered
- ✓Start/stop and charge-limit sliders, like the Tesla app
Powerwall control & outage readiness
- ✓Backup reserve and battery mode from one popup
- ✓Off-grid and Bunker 100% emergency console
- ✓Tesla Storm Watch with live weather alerts
- ✓Grid outages detected, timed and logged
A daily plan in plain English
- ✓Morning briefing from Watson, your curious advisor
- ✓Peak Defense shield for the 4–9 PM window
- ✓Evening wrap: what happened vs. the plan
- ✓Household text everyone can actually follow
Honest costs, real savings
- ✓Every car kWh split into sun, Powerwall and grid
- ✓Priced hour by hour at your real time-of-use rate
- ✓Supercharger costs synced; away charging auto-logged
- ✓Monthly charging budget per car
Bill audit that checks PG&E's math
- ✓Upload a bill — delivery and generation split out
- ✓Peak, partial-peak and off-peak reconciliation
- ✓Rate trends: see which charge keeps rising
- ✓Next-bill prediction locked in, not shifting daily
Upgrade advice with real payback
- ✓Battery, more panels, carport, second charger, ADU
- ✓Gas-to-EV swap: fuel plus maintenance savings
- ✓Spots sun you send to the grid and suggests an EV
- ✓Enter real installer quotes and compare bids
Tips Watson proves with your real numbers
- ✓Free tactics: 2-car sun shuttle, pre-cooling, appliance timing
- ✓Tap "I'm trying this" and Watson measures it
- ✓Before vs. after from your own meter, after 7 days
- ✓Predictions get sharper as real results come in
Plus family sharing — everyone in the house sees the app, only you change the settings.
Start free. Upgrade when it clicks.
One plan, one price. 7-day free trial.
- •Tesla + Powerwall sync
- •Today's hourly solar curve
- •Tomorrow's headline & 7-day outlook
- •7 days of history
- •Weekly Watson household text
- ✓Everything in Free
- ✓Automatic solar car charging
- ✓Powerwall & emergency controls
- ✓Live power-flow view
- ✓Daily briefing, Peak Defense & evening wrap
- ✓Real charging costs & budgets
- ✓Bill audit, rate trends & bill prediction
- ✓Upgrade advisor with installer quotes
- ✓Savings tips measured against your real bill
- ✓Unlimited history & family sharing
Where WhatSun fits
Tesla runs your hardware. WhatSun decides what it should do today. Every morning you get a plain-English plan for your solar, your batteries, and your cars — what to charge, what to hold back, what the peak hours will cost you. Where you allow it, WhatSun takes the wheel: cars soaking up spare sunshine on their own, Powerwall reserves set before the expensive hours hit. You choose how much control to hand over. The advice is always yours to ignore. No homelab, no rules to write, no second system to babysit.
And Watson stays curious. He keeps hunting for free ways to save — like swapping two cars so one charges on sun while the other commutes — then checks your real numbers a week later to prove what actually worked.
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.