• Tech Tech

A 63-amp limit knocked out Tesla solar charging, so a homeowner built a new workaround

Power is free from 11 a.m. to 2 p.m., and the poster said automation already works.

Solar panels on a rooftop.

Photo Credit: iStock

A Tesla owner on the subreddit r/TeslaSolar said an import limit on their 63-amp single-phase switchboard disabled Tesla's "Charge on Solar" feature. They wanted to use NetZero, morning solar production, and a three-hour free electricity window as a workaround.

Here's what to know

In the post, the homeowner explained that they wanted to set up a solution to send surplus solar to the car from sunrise until 11 a.m.

After that, the home moves into a separate charging period. Power is free from 11 a.m. to 2 p.m., and the poster said automation already works for both the Tesla and Powerwall during that period.

By shifting EV charging to morning solar production and then using the free-power block for larger loads, the household can reduce paid grid imports and its use of a "paltry" 3-cent grid tariff.

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Going solar is one of the best ways to save money on home energy, especially for households juggling an electric vehicle, a battery, and fixed utility windows. For a similar setup, homeowners can use EnergySage to get free solar installation estimates and compare quotes.

More background

The switchboard limit and tariff were the main obstacles. The owner had a Powerwall, a free-power window, and peak and off-peak pricing, so the missing piece was software logic.

That puts the focus on consumption. If morning solar can cover part of the car's charging and free grid power can top off both the car and battery, the homeowner would preserve stored energy for the rest of the day.

For households with both rooftop solar and an EV, those timing decisions can meaningfully affect monthly bills. An EV and home battery are two of a home's biggest flexible loads, so matching them to solar output and a free period is a practical way to get more value from equipment.

For homeowners considering a similar setup, EnergySage's solar map shows the average cost of a home solar panel system by state along with solar panel incentives in each state. Together, those resources can help homeowners get the best price for rooftop solar panels and access available incentives. With EnergySage's help, the average person can save up to $10,000 on a solar purchase and installation.

Adding battery storage to a solar setup is one of the best ways to protect your home during outages, save on energy costs, and go off-grid. Battery capacity can also make automations more valuable. Homeowners can explore EnergySage for information about home battery storage options, including competitive installation estimates.

Where can I learn more?

These stories cover Tesla's Charge on Solar rollout, Powerwall charging features, and broader smart-charging efforts.

• In 2023, Tesla introduced Charge on Solar to let drivers refill EVs with rooftop surplus.

• Tesla unveiled an incredible Supercharger concept backed by its own solar farm in 2024.

• At Tesla, app version 4.38 added a game-changing feature for Powerwall energy management.

• Researchers built a revolutionary EV smart-charging system to ease grid strain.

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