Plug in solar

lohr500

https://forums.moneysavingexpert.com/discussion/comment/81970886#Comment_81970886

I'm using three of these ballast boxes :

https://www.cityplumbing.co.uk/p/fastensol-black-plastic-solar-panel-base-requires-4x-end-clamps-and-4x-screws/p/649293

lohr500

https://forums.moneysavingexpert.com/discussion/comment/81968532#Comment_81968532

I've taken your comments on board regarding the max voltage and I reached out to Hoymiles Tech Support for their opinion. They replied as follows :

You mentioned that the maximum voltage of your two series-connected PV panels reaches 99.6V. Although this is still below 100V, once the voltage exceeds 96V, the efficiency of the inverter will decrease. If the voltage exceeds 100V, it may cause damage to the inverter. Therefore, we still strongly recommend that you choose PV panels with a maximum voltage within the range of 22V to 96V.

On this basis, I'm now looking at other plug-in inverters. I am also awaiting a reply from Hoymiles regarding their 2 MPPT input 800w inverters, where the spec sheets suggest you can connect up to 14 amps/60V per string which would give plenty of headroom with the panels I have aquired.

The good news is that I can cancel the order for the Hoymiles inverter I was planning to use.

Thanks for your comments. It's great that there is such a wealth of knowledge sharing on the MSE Forum.

QrizB

Here's a thread from when we were talking about plugin solar back in 2023, before it was cool 😎

Interestingly, the French company Sunology that gets mentioned in the opening post is still going. Their nicely-designed PLAY plugin panel is still available, and they're now asking €599 (about £520 at urrent exchange rates) for a 480W bifacial panel, inverter and stand.

Not the cheapest opton, but it certainly looks very straightforward to install and relatively good-looking.

QrizB

Over in Germany, plug-in solar enthusiasts run half-day workshops where for 25 Euros you are taught about plug-in solar and are given two pre-loved watt solar panels to take away. You buy your inverter separately.

Here's an example of one that's happening tomorrow:

https://balkon.solar/news/2026/03/03/steckersolar-basteln-in-teningen/

HillStreetBlues

Sorry if it's been answered before but how long is the expected cable length expected to be?

TroubledTarts

Quick update

So at the moment with 6kwh of ecoflow batteries We are filling two of them each day with two 450w bi facial panels. Or as we call it two tumble dryer loads and 1 hour on the treadmill as these all sit in the garage.

Just waiting for my ecoflow microinverter to battery plug lead and then we can decide how much to send back into the house (probably 100wh) so for the eagle eyed of you that's 2.4kwh flowing back into the house so we will more than likely need a top-up as we already use most of our solar output but with Agile we will top the ecoflow attached battery up to cover the hours needed but basically add another panel when we see one at a decent price.

Also filled out my G98 to send in

MouldyOldDough

How are my assumptions and calculations ?

How long would it take to charge a 100 kWh EV battery from a bank of 8 solar panels in 1/2 sunlight ?

Assumptions:

1. Solar Panel Wattage: Let's assume each solar panel is 350 watts.
2. Solar Efficiency in Half Sunlight: In half sunlight, each panel produces 50% of its rated output.
3. Sunlight Hours: Assume 4 hours of effective sunlight per day.
4. Battery Size: 100 kWh is the battery size you want to charge.

Calculation:

1. Solar Panel Output in Half Sunlight:
   • In half sunlight, each panel produces 175 watts (50% of 350W).
   • With 8 panels, the total output would be:
     • 175W × 8 = 1,400W (1.4 kW).
2. Charging Time:
   • To charge a 100 kWh battery with 1.4 kW of solar power:
     • 100 kWh ÷ 1.4 kW = 71.43 hours.
3. Daily Charging Time:
   • If you're getting 4 hours of sunlight per day:
     • 71.43 hours ÷ 4 hours/day ≈ 17.86 days.

Summary:

Under these assumptions, it would take approximately 17.9 days to fully charge a 100 kWh EV battery using 8 solar panels in half sunlight (with 4 hours of sunlight per day).

QrizB

The calculation seems correct.

As for the assumptions:

• While you can but 350 watt solar panels, most panels used for permanent residential installations these days are around 500 watts.
• Half sunlight would imply half the standard insolation, which might result in half the standard output from a panel.
• Four hours of full sunlight per day is a reasonable assumption from April to September. If you're looking at a year-round average, 2.5 hours might be more reasonable. In December you might get less than one hour per day, on average. However as you're assuming half sunlight, you should double these numbers.
• 100kWh is on the larger side for EVs. Smaller cars start at about 30kWh, most family cars are in the 50-60kWh range. 100kWh implies a large performance model or maybe a Sprinter-size van.

None of this seems particularly relevant to this thread, though; you're unlikely to be allowed a 2.8kWp plugin solar PV system, and no-one would expect to use one to charge an EV.

Reed_Richards

How long would it take to charge a 100 kWh EV battery from a bank of 8 solar panels in 1/2 sunlight ?

if you can generate 1.4 kW for 4 hours that's 5.6 kWh. But you may only get about 90% conversion efficiency from input to battery storage so that might add 5 kWh to the battery.

What you would actually want to do is replenish the charge that you used the previous day. So if your EV does 3 miles to the kWh, 5 kWh gives you 15 miles. So if you average 15 miles a day then you will be able to keep your EV battery topped-up, subject to your other assumptions.

Qyburn

https://forums.moneysavingexpert.com/discussion/comment/81977535#Comment_81977535

Don't underestimate the seasonal variation. For example we've been getting between 1,000 and 1,300 kWh per Summer month, May to August. December and January only 70 or 80 kWh.