Custom solar: set your own rules for solar charging

Pure, smart and fast solar cover most homes. Each one makes a fixed choice about when charging starts and how much grid power is allowed. Pure solar takes none, smart solar adds a constant 920 W, fast solar takes whatever it needs for full speed. Custom solar removes that fixed choice and hands it to you.

With three settings in the Peblar web interface, you decide at what point the charger starts, what it aims for while it runs, and whether it should wait for the sun at all. This article explains each setting, and walks through five common situations with the values that fit them.

If you are new to solar charging, start with our explainer on how solar charging works with Peblar. This article assumes you know the basics: the charger measures your grid connection, and an EV needs at least 6 A per phase to charge.

Why a fourth mode

Every home produces and uses power differently. A house with a heat pump has a high, steady base load all day. A house with a home battery wants to fill the battery before the car. A house with a small set of panels on a north-facing roof rarely reaches the surplus that pure solar waits for.

The three standard modes work well for the average home. For the rest, custom solar lets you match the charger to your own situation instead of the other way round.

The three settings

You find custom solar in the Peblar web interface under solar charging. It has three settings. The values you see when you open it are the ones pure solar uses, so you always have a known reference to start from. All power values are in watts, and they follow the same sign as your energy meter: exporting to the grid is negative, importing from the grid is positive.

Start/stop power threshold

The grid power at which the charger starts charging, and below which it stops again.

A threshold of -1300 W means: start once the house is exporting 1300 W or more. This is a sensible default, because 1300 W is roughly what a single-phase charge at 6 A draws. Set the value closer to zero, for example -600 W, and the charger starts earlier in the morning and keeps going later in the afternoon, using some grid power to bridge the gap to 6 A. Set it further from zero, for example -2000 W, and the charger waits for a bigger surplus before it starts.

The threshold may also be positive. A positive value means the charger starts while the house is still importing from the grid, as long as the import is below your value. This is for homes where a solar surplus never appears at the meter, but you still want to charge during the hours the panels are working hardest.

The threshold only controls starting and stopping. It is measured at the meter before the charger starts, so the charger's own charging power does not count towards it. Once charging runs, the grid power target takes over.

Grid power target

Once charging is active, the charger continuously adjusts its current to hold this value at your grid connection.

A target of 0 W means the charger uses exactly your surplus, no more and no less. Your meter sits at zero for as long as the sun allows. A negative target, for example -500 W, keeps 500 W flowing to the grid at all times. A positive target, for example +1500 W, allows the charger to pull that much from the grid on top of the surplus, which shortens the charging time.

The charger always supplies at least 6 A once it is active, whatever the target says. If the surplus falls below that, the difference comes from the grid until the threshold tells the charger to stop.

Always charge

Tick this box and the charger skips the threshold. It starts charging the moment you plug in and follows your grid power target from the first second, at a minimum of 6 A. With a target of 0 W that means a quick start at 6 A. With a positive target, the charger starts at the current that target allows. Either way you keep solar charging for the rest of the session.

Five situations, five settings

The examples below use a single-phase charger. On three phases, the minimum current is 6 A per phase, so multiply the surplus figures by three.

1. Small solar installation

Eight panels on an east-facing roof, peaking at about 1800 W. Pure solar rarely starts, because the surplus after household use barely reaches 1300 W.

Threshold -600 W, grid power target 0 W, always charge off. The charger starts once the house exports 600 W, tops up to 6 A from the grid, and from there uses everything the panels produce. The car charges most of the day, and the grid share stays small.

2. Heat pump running all day

Panels produce 2000 W on a good day, but the heat pump keeps household usage at around 3000 W. The meter shows 1000 W of import all afternoon, so no standard solar mode ever starts.

Threshold +1000 W, grid power target 0 W, always charge off. The charger starts as soon as the import drops to 1000 W or less, which is when the panels are at full output. It then aims for zero at the meter, so it charges on whatever the heat pump leaves over, and adds grid power only for the 6 A minimum.

3. Home battery first

You want the home battery to fill before the car takes any surplus.

Threshold -1300 W, grid power target -400 W, always charge off. The charger waits for a clear surplus, and while charging it leaves 400 W flowing towards the grid. Since the battery sits before the meter, that 400 W goes into the battery first. Adjust the target to match your battery's charging power.

4. Car needs to be ready by lunch

You plug in at 09:00 and want a decent charge by 13:00, but still prefer solar where possible.

Threshold -1300 W, grid power target +2000 W, always charge on. Charging starts the moment you plug in, at about 8.6 A, because the charger may take 2000 W from the grid straight away. The threshold is ignored. Once the sun comes through, the charger adds the surplus on top of those 2000 W. You get speed, and every kWh from the roof is still used.

5. Pure solar, your way

You like pure solar, but you want it to start a little earlier.

Threshold -900 W, grid power target 0 W, always charge off. Charging starts at a smaller surplus than pure solar would wait for. During the first and last hour of the session a little grid power bridges the gap to 6 A. In between, the charger runs on solar alone.

How to set it up

Open the Peblar web interface on your home network and go to solar charging. Select custom solar. Enter your threshold and grid power target in watts, tick always charge if you want a quick start, and apply. The settings take effect on the next session. Reset brings the three values back to the pure solar defaults.

Custom solar needs the same power measurement as the other solar modes: a compatible energy meter, a HomeWizard P1 meter, or a supported inverter. If your charger already runs pure, smart or fast solar, nothing extra is needed.

Frequently asked questions

Can I use custom solar together with load balancing?

Yes. Load balancing sets the upper limit on the charging current so your main fuse is protected. Custom solar works within that limit.

What happens at night?

With always charge off, the charger waits until the threshold is met, so it does not charge at night. With always charge on, it follows the grid power target, which at night means grid power only.

Why does my meter never reach exactly my grid power target?

The charger adjusts its current in steps and household usage changes constantly, so the meter moves around the target rather than sitting on it. Small swings are normal.

Can I change the settings during a session?

Yes. Apply the new values and the charger follows them from that moment on.

Do I need to update anything?

Make sure your charger runs the latest firmware. Updates are installed remotely, so there is nothing to do on the charger itself.

Your roof, your rules

Custom solar is available on Peblar Home and Peblar Business. Set the three values once, and the charger does the rest. Plug in, charge, drive.