Charge your car on sunshine.
SundialEV watches your solar in real time and steers the surplus into your EV, so it charges your car instead of going to the grid for pennies. Built for net billing.
Keep up to $45/mo (and more) of solar in your car — and your Powerwall full.
SundialEV routes surplus solar to your Tesla instead of exporting it for 3¢, and never raids your battery. You set the floor; it coordinates the rest.
Typical net-billing rates, per kWh
Works with Tesla · Enphase · SolarEdge · +10 moreFree, no card required
Charging on solar
100% self-poweredLive in the app — solar-only charging, in real time
100+ homes charging on solar across 7 countries
7 countries · See the fleet map
Works to utilize my solar to charge my car! I have it set up so I don't draw from the grid to charge my car (free fuel!)
ChronoVII · App Store
Provides an amazing amount of control for how and when you charge your vehicle. Support is also very responsive.
Mark A. Hartman · App Store
This app makes charging for the most part easier especially if you only want to charge on excess solar
ecyka2000 · App Store
- ✓ Surplus solar goes to your car instead of being exported for pennies
- ✓ The car won't drain your Powerwall — stored energy stays reserved for your home, for the evening peak and outages
- ✓ You set how full the Powerwall charges before the car starts
- ✓ It coordinates automatically — set it once
Selling solar back to the grid is now the worst trade in your house.
SundialEV closes the gap by burning your sunlight at home — into the car — instead of selling it for pennies.
Three connections. One automation. Zero new hardware.
Add the gear you already own. That's it.
SundialEV connects through manufacturer APIs — Tesla Fleet, SolarEdge Monitoring, Enphase Enlighten. Nothing to wire, nothing to drill, nothing to call an electrician for. Drive something other than a Tesla? SundialEV speaks OCPP — the open standard your smart wall charger already uses — so it manages charging at the charger instead of the car.
- ✓ Tesla EVs, Wall Connectors, and Powerwalls
- ✓ SolarEdge & Enphase inverters
- ✓ OCPP wall chargers — Wallbox, Emporia, and more — for any EV brand
- ✓ More integrations shipping monthly
The car connects in three taps.
Tesla? Sign in with your Tesla account, pick the car, flip the toggle — SundialEV sees the EV, solar, grid, and battery through one connection. Anything else? Point your OCPP wall charger at SundialEV from its settings app and it's managed the same way — no car account needed.
If you have it, we probably talk to it.
SundialEV works through manufacturer APIs over the cloud. No new metering hardware, no new wall connector, no firmware fights with your installer.
Solar-first, never solar-stranded.
One glance, whole home. Solar, battery, home, grid, and car — live kilowatts on one card, with idle devices dimmed so the numbers that matter stand out.
Hour by hour, watt by watt. The energy flow chart splits every hour of production between your EV, your home, and your battery — plus a forecast curve for the rest of today.
Drive a Rivian, Ioniq, Bolt, or anything else? SundialEV controls OCPP wall chargers like Wallbox and Emporia directly — no car account needed. Tesla drivers keep full vehicle-level control.
Cheap-hours insurance. Set weekly grid top-up windows (say, 12–4 AM at 32A) so the car is never short on a cloudy week — SundialEV shows exactly how many kWh each window adds.
Two windows, your rules. Avoid-hours pauses grid charging when rates spike (4–9 PM), and Sell-at-peak pauses solar charging so your surplus exports to the grid during your best sell-rate hours. SundialEV charges around both.
Add every car in the driveway. SundialEV follows whichever one is plugged in at home — and if both are, it stays with the current car until you switch, counting the other as house load.
Road trip in an hour? One tap overrides everything and fills the battery at full speed — pick a target, or run until you unplug. Flip back to Auto when you're done and SundialEV takes it from there.
Connect your car's account and SundialEV reads its real battery level — so charge targets, top-ups, and the dashboard work off the actual number instead of a timer. It's a read-only add-on: your wall charger still does the charging.
You connect it once, under Device setup → EV / Charger → Optional: connect your EV.
- Ford Mustang Mach-E, F-150 Lightning, E-Transit. How it works →
- Rivian Beta R1, with an OCPP wall charger. How it works →
Inverter we don't integrate yet? Push it to us. A small script on your network POSTs your production — and optionally grid and battery — to SundialEV's push API, and it charges from those numbers like a natively connected system. Home Assistant, an Envoy on your LAN, Node-RED, a Raspberry Pi.
Read the push API docs →POST /api/public/push-solar-data
{ "apiKey": "sk_sundial_…",
"siteMeters": { "production_kW": 4.2 } }Things people ask before signing up.
Do I need to install anything?
No. SundialEV connects through APIs to your existing Tesla, SolarEdge, or Enphase setup. There's no extra meter, no extra wall connector, and no electrician call. If your gear can talk to its native app, it can talk to SundialEV. If you're connecting an OCPP wall charger instead of a Tesla, you'll point the charger at SundialEV from its settings app — a few minutes, no hardware changes.
How much will I actually save?
Some users save up to $45 a month (and more). Your number scales with how much you drive, your TOU rate, and how much daytime solar you currently export — an EV owner in PG&E or SCE territory exporting 60%+ of their daytime solar lands around there. Savings are computed against your actual utility tariff — NEM 3.0 export rates, not hand-waving — and projected on your dashboard once we have a few days of data.
Does this work without a Powerwall?
Yes. Powerwall makes the math richer — but you can use SundialEV with just solar + EV. The app simply skips the battery-priority logic and routes everything to the car when there's surplus.
Do I need a Tesla?
No. Tesla vehicles get direct control, and every other EV works through an OCPP-compliant wall charger (Wallbox Pulsar Plus, Emporia, and others). SundialEV manages the charger itself — no car account needed.
I drive a Ford — what works?
Ford EVs — Mustang Mach-E, F-150 Lightning, and E-Transit — connect natively, so SundialEV knows your car's battery level and can charge to a target instead of guessing. Charging itself runs through your wall charger (a Wallbox Pulsar Plus or Emporia), so you'll need one of those too: Ford's connected-vehicle API is read-only by design. Setup and limits. Free, like the rest of SundialEV.
I drive a Rivian — what works?
Your Rivian charges on surplus solar through an OCPP wall charger, like the Wallbox Pulsar Plus. In Beta, Rivian R1 owners can also connect their Rivian account, so SundialEV knows your car's battery level and can charge to a target instead of guessing. It's read-only: SundialEV never sends a command to the car, and the wall charger does the charging. You sign in with your Rivian email, password, and the one-time code Rivian sends — the password is used once and never stored, and Rivian asks you to reconnect from time to time. Tested so far on the R1S. SundialEV is an independent app, not affiliated with Rivian. Setup and limits.
Which chargers are supported?
Any OCPP-compliant smart wall charger. The Wallbox Pulsar Plus is our most-tested model, with Emporia chargers also supported — SundialEV starts, stops, and adjusts charging power to track your surplus solar. See the full list under Compatibility.
My inverter isn't on your list — am I stuck?
Probably not. If you can read your system on your own network — Home Assistant, an Enphase Envoy in local mode, a Modbus meter, Node-RED — you can POST those readings to SundialEV's push API, and it charges from them exactly like a natively connected system. It's part of the free tier; the full format is on the push API page.
What happened to ChargeHQ?
ChargeHQ shuts down on September 7, 2026. SundialEV is a US-built alternative — solar-surplus charging for Tesla and OCPP wall chargers, with NEM 3.0 savings tracking. See our migration guide.
What if I'm grandfathered into NEM 2.0?
Honest answer: the savings are smaller, because your export rate is closer to retail. You'll still come out ahead — SundialEV avoids round-trip losses and lets you control charging during peak windows — but the killer math is for NEM 3.0 customers.
Is SundialEV free?
Yes — SundialEV is free to use. Connect your car or charger, set your charging policy once, and start keeping more of your own solar. No credit card, and no charges of any kind.
Is my Tesla data safe?
We use Tesla's official Fleet API with OAuth — same security model as the Tesla app. We never store your Tesla password (we never see it). You can revoke access anytime from your Tesla account.
Keep every kilowatt you make.
Connect your car — Tesla directly, or any EV through your wall charger. We'll link your gear, project your savings, and start the automation.
Get SundialEV free Get SundialEV free