Tesla's own support page says Charge on Solar only works with a Powerwall and only charges a Tesla. If you have solar and no Powerwall, SundialEV fills that gap: it charges your Tesla from surplus using your inverter's data — Tesla Solar, Enphase, SolarEdge and more. If your solar was interconnected after April 15, 2023 (NEM 3.0), exports earn a fraction of retail — 4.5¢ per kWh against about 35¢ to import on PG&E (rates as of July 2026), so every kWh your car absorbs instead is worth far more.
It's built into the Tesla app — no extra account or setup.
Tight car-to-Powerwall integration: the car adjusts about every 10 seconds, with the Powerwall covering swings in Self-Powered mode.
A sun slider charges from any source up to a daily-range floor, then solar-only up to your limit; several Teslas at one site are supported.
If Charge on Solar isn't showing up or isn't charging, check the requirements Tesla lists on its support page:
Source: Tesla Charge on Solar's own page, checked September 26, 2026.
| Feature | Tesla Charge on Solar | SundialEV |
|---|---|---|
| Solar-surplus charging | Yes | Yes — follows your live surplus |
| Works without a Powerwall | No — “Charge on Solar only works with a Powerwall” | Yes — Tesla Solar, Enphase, SolarEdge, Solis, Growatt, Emporia Vue, Sense, or the push API |
| Savings tracked against your tariff | Not stated | Yes — your utility's import and export rates, looked up by zip |
| Powerwall first, then the car | Yes — tied to the Powerwall's Backup Reserve | Yes — solar goes to the car once the Powerwall reaches your priority level |
| Sell-at-peak window | Not stated | Yes — a daily window where solar exports instead of charging |
| Non-Tesla EVs | No — “will only charge a Tesla vehicle” | Any EV on a Wallbox Pulsar Plus (OCPP) or Emporia charger; Ford battery level (beta) |
| Cloud or self-hosted | Cloud (Tesla app) | Cloud — iOS, Android and web apps |
| US utility rates | Not stated for Charge on Solar | Yes — US utility rates, NEM 3.0 and net billing |
Every Tesla Charge on Solar cell links to the page it came from, checked September 26, 2026. “Not stated” means their pages don't say either way. Spotted something out of date? Email support@sundialev.com and we'll fix it.
Enter your zip and the calculator uses your utility's real rates.
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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
SundialEV charges from your solar surplus automatically.