16/08/2026
☀️🔋 SOLAR + EV CHARGING — THE COMPLETE GUIDE (Please Read & Save 📌) by 10NERGY
PDF Link: https://drive.google.com/file/d/1f-IvubP8spsc41LLrm5OMwZUFtSmpGuM/view?usp=sharing
This is the single most misunderstood topic among us. I'm asked some version of it almost every week. Let me try to tackle it comprehensively for EVERY setup, so I can just point people here.
━━━━━━━━━━━━━━━ 📚 FIRST, THREE THINGS YOU MUST UNDERSTAND ━━━━━━━━━━━━━━━
🔌 1) THE CAR ONLY CHARGES ON ONE PHASE. BYD gives you two AC charging options, and BOTH are single-phase:
The 7kW wall charger (needs an RFID card swipe)
The ~2kW portable charger (plugs into a normal socket) So a three-phase inverter is NEVER required for the car — it will only ever pull one phase. Forget "single vs three phase inverter." That was never the real question.
📟 2) A THREE-PHASE METER READS NET POWER. This is the key to everything. At any instant, the meter adds up all three phases together. So if one phase is pulling 8kW from the grid while the other two phases are each exporting 4kW, the meter reads ZERO — no import, no export, nothing billed. Remember this; we exploit it below.
🏦 3) NET METERING vs NO NET METERING — THIS IS THE BIG FORK.
Net metering is allowed ONLY on three-phase connections. It banks your solar units and nets them against your consumption. The grid becomes your battery.
No net metering means every unit you EXPORT is billed to you EXACTLY like a unit you IMPORT. Read that again: without net metering, pushing power out to the grid earns you nothing — it COSTS you, just like consuming does. So export must be avoided at all costs, and you must charge from your own excess solar (or battery). Everything below flows from which side you're on.
━━━━━━━━━━━━━━━ ✅ CASE A: THREE-PHASE CONNECTION WITH NET METERING (the easy life) ━━━━━━━━━━━━━━━
If you have net metering, relax — almost nothing matters:
Single-phase OR three-phase inverter? Doesn't matter.
Inverter size? Doesn't matter. Even a 5kW inverter with 7kW of panels is fine, as long as your system generates surplus units over the month (a credit bill).
Sun or no sun at charging time? Doesn't matter. You can charge at NIGHT and still benefit from solar.
Why night charging still benefits you: with net metering (NOT net billing), your off-peak units are netted off FIRST, before any excess import is billed or excess export is compensated. So your daytime solar credit quietly pays for your night-time charging.
How is this possible with a small inverter? Net metering settles on TOTAL units over the billing cycle, not on the instant. Your system exports and banks units during the day; you import to charge the car at 7kW whenever you like; the two net off. The inverter never has to supply 7kW at the same moment.
⚠️ The ONE precaution: do NOT charge during PEAK hours (currently ~7:00–11:00 PM) unless it's an emergency. There's no solar in the evening to offset it, so peak charging gets billed at the expensive peak rate. Off-peak is ~20 hours a day — plenty of window.
━━━━━━━━━━━━━━━ ✅ CASE B: THREE-PHASE CONNECTION WITHOUT NET METERING ━━━━━━━━━━━━━━━
No banking with the grid, and — crucially — any power you export is billed to you exactly like power you import (point 3). Exporting is a pure loss, so it must be prevented. An export-control device (a CT sensor or smart meter that feeds readings to the inverter) handles this.
Here's the big advantage of THREE phases (remember point 2): the export-control only has to hold export to zero in the NET sense. If one phase is importing 8kW — say your 7kW charger plus some home load — while the other two phases are each exporting 4kW of surplus solar, the meter reads ZERO. It assumes no energy was taken, and nothing is billed. So your surplus solar on the other phases quietly feeds the car ACROSS phases, penalty-free.
Rule of thumb: charge only from EXCESS solar — power your panels are making ABOVE your household's own use — for the whole time the car is charging. As long as surplus stays above the charger's draw (7kW, or 2kW on the small charger), you pull nothing net from the grid.
Inverter can be single OR three phase, sized to run car + house together.
A battery helps a lot: it stores daytime solar, rides you through passing clouds, and — if it's big enough — powers your loads during peak hours (more on that below).
━━━━━━━━━━━━━━━ 🔧 CASE C: SINGLE-PHASE CONNECTION (net metering NOT possible) ━━━━━━━━━━━━━━━
One phase only — so there is NO cross-phase netting escape, and no grid to bank into. On a single-phase connection, any surplus you push out is billed straight back to you as if you'd consumed it, so you must genuinely avoid export and self-consume. You have to generate and store the energy yourself. The math is straightforward:
To run the 7kW charger you need a 10kW+ single-phase HYBRID inverter (to supply the 7kW car PLUS your house load at once) with an adequate battery — 16kWh preferred.
A 12kW single-phase inverter is perfectly fine — it clears the bar.
On-grid single-phase with no battery? You can only charge while the sun is directly making more than you need.
When solar is limited, drop to the 2kW charger (below).
━━━━━━━━━━━━━━━ 🐢 THE 2kW CHARGER — DON'T IGNORE IT ━━━━━━━━━━━━━━━
The little portable charger is more useful than people think:
Use it on days you're not driving anywhere and the sun isn't strong enough to feed the 7kW charger. Slow and steady still fills the battery.
With an adequate battery (16kWh+) arranged so the battery serves your load during peak hours, you can even run the 2kW charger DURING peak — because it's running off your battery, not expensive grid units.
It's also better during grid instability: the 2kW charger RESTARTS charging automatically when the grid comes back. The 7kW wall charger does NOT — if the grid trips mid-charge, it needs an RFID card swipe to resume. In load-shedding-prone areas, that auto-resume is a real convenience.
━━━━━━━━━━━━━━━ 🧪 A REAL EXAMPLE (my own setup) ━━━━━━━━━━━━━━━
19kW of panels, split across a 5kW single-phase on-grid inverter and a 12kW single-phase hybrid inverter with a 16kWh battery. I have a three-phase connection WITH net metering. My area gets three-phase faults, so I deliberately run single-phase inverters — and thanks to net metering, that costs me nothing in solar benefit (Case A: inverter phase doesn't matter). I charge the 7kW off-peak, lean on the 2kW charger when the sun's weak or when I'm parked at home, and my battery lets me trickle on the 2kW even during peak. Best of all worlds.
━━━━━━━━━━━━━━━ 📌 QUICK REFERENCE ━━━━━━━━━━━━━━━
Car = single-phase 7kW + 2kW portable. A three-phase inverter is NOT needed.
3-phase + net metering → charge anytime OFF-PEAK, day or night. Inverter type/size/battery/sun all irrelevant. Just avoid peak.
3-phase, NO net metering → charge only on excess solar; the zero-export device + phase-netting does the rest.
Single-phase connection → 10kW+ hybrid inverter + ~16kWh battery for the 7kW charger; otherwise use the 2kW charger.
Big battery = you can even charge (on 2kW) during peak, off your own stored power.
Grid keeps tripping? The 2kW charger auto-resumes; the 7kW needs an RFID re-swipe.
━━━━━━━━━━━━━━━ ⚠️ ONE IMPORTANT DISCLAIMER ━━━━━━━━━━━━━━━
Energy meters TYPICALLY measure and bill on this net-power basis — import on one phase cancelled by export on the others. But meter models and utility settings can vary. Before you rely on cross-phase netting to charge, please confirm how the meter in YOUR area actually behaves — test it, or ask someone locally who has. Don't exploit what you haven't verified.
PDF Version in the making for reference. Will share once it is ready. Pictures show my 12kW Hybrid SP (with net metering) and 16kWh battery setup plus another client's system showing a bigger storage system just for reference.
