Victron or Lux

[sharpener]

IME the big question is whether or not you use an electric cooker.

We have 2x 16A ovens and an “11kW” induction hob. However if you put a chicken in the oven it pulls full power for 5-10mins while it heats up then only pulls a little to keep it hot. The hob similar, when you crank a ring to bring the veg to the boil it pulls 2kW, but keeping it simmering uses hardly any. You rarely have all rings pulling full power simultaneously.

Yes of course. And we cook the veg in the same pan as the potatoes are already in. But you do not have a lot of control over whether the thermostat in the oven and the simmerstat on the ring will both call for heat at the same time, never mind boiling the kettle as well.

Sure it is possible to overwhelm a 16A inverter if you have an extreme number of super-powerful electric cooking appliances. But it is pretty easy not to as well…

I’d only be convinced that you need more than 16A of inverter capacity if you had a heat-pump that draws power 24/7.

The rainwater system has a pump that draws 650W while the hot tap is turned on (and a lot more when starting), and the MVHR unit about 165W (245 when we are cooking fish!). So it soon mounts up, I have put a diode in the supply to the heated towel rail so it only takes 69W on the summer setting and a timer so it is only on 3hrs/day but there are limits...

[ahas]

Thanks all for the comments, lots of food for thought.

90% of time the 3.6kwh solaredge + 3.6kwh lux will be sufficient with a bit of time shifting.
I think it's the future possibilities with Victron that seem appealing, weighing that up with the octopus compatible Lux.

I would go squirrel-pod and Pylontech. Cheap, effective, reliable.

Victron is far more flexible and you can integrate an archipelago of devices into a single system that communicates and reports as one. However you pay for that.

A thread from Apr 2022 priced a lux squirrel at 975+vat. Speaking to the big *vert* beard priced me a smidge under £1,300+ vat..! That can't be right? That's victron money! And a Lux can only be supplied with a battery, so couple a Lux and Pylontech 3000C. That's £2600+vat!?!

[Oldgreybeard]

We use between 1kWh and 2kWh of peak rate electricity each month, all of it as a consequence of the 3kW inverter not being able to meet spikes in demand. Looking at those spikes in demand they are always when the oven or hob, sometimes both, are turned on. The spikes never last more than about 4 or 5 minutes, less in the case of the spikes from the hob. We can pull up to about 7kW when cooking, so the 3kW inverter can't keep up, but the duration of these spikes in demand is so short that it would make no sense to size the inverter to try and meet them.

Larger inverters tend to have larger losses, so the net result of over-sizing the inverter is most probably to push total consumption up, rather than down. A few watts of losses 24/7 soon adds up to being greater than three or four kW from the grid for a minute or two.

[ahas]

Thanks Oldgreybeard that makes good sense.

Following on from finding the Lux squirrel being priced higher than expected, I started looking into 3kwh inverters last night and appears to be a reasonable proposition. A few have opted for a Sofar3000 this seems like quite a cost effective bit of kit.
As you said that will cover 90% of the spikes and on the odd occasion you need to use peak electricity will equate to a few pence, but keeps the inverter running more efficiently.

Which 3kw ac inverter is it you have and would you recommend it?

Thanks
ahas,

[Oldgreybeard]

I have the Sofar ME3000SP, works OK but is a bit quirky in terms of the way the menus and modes are put together. Some of the settings aren't very intuitive as to what they do, but not really an issue once you've worked out what some of the Chinglish really means.

Looking at our usage over the past few months, since the tariff change on 1st April we have used a total of 11kWh at the peak rate and 472kWh at the off-peak rate (most of that charging the car when it's not been sunny enough). That works out to about 97.7% of our electricity usage being at the off-peak rate and the total we've paid for the peak rate usage (all using the ovens and hob, I think) has been about £3.66, so under £12 per year. It would take a very long time for the additional cost of a higher power inverter to be recovered from that sort of incremental saving.

[ahas]

Great stuff - thanks Oldgreybeard, a bit of knowledge is power.

Out of interest and technical question looking at the specs the ME3000SP it charges discharges at 60A
The victron 48/3000 does 32A that's quite low or am I missing something?

So in a slight change of direction, I'm a bit put off by the high price of the Lux, feels a bit of profit taking /scalping! So looking now at alternative AC chargers.
The SofarME3000SP looks good (thanks Oldgreybeard for the feedback), the Solis 3.0kW 5G RAI also look pretty interesting, solid charging and rate can be 'clocked' to charge/discharge at 110% so 3.3kwh.

Any others worth considering?

Thanks in advance!

ahas,

[Stinsy]

Have a look at Solax. Another cheap/cheerful but also established/reliable brand interchangeable with Solis and SoFar.

[Oldgreybeard]

The ability to charge the battery pack at a fairly high rate is very useful. The ME3000SP seems to be able to hit about 65A at times, and I've often wished it would be a bit higher, so the pack could be charged faster. I'd not want a lower charge rate, as there are plenty of times where we get short bursts of solar generation on cloudy days where being able to stuff as much as possible into the battery is useful.

[ahas]

The ability to charge the battery pack at a fairly high rate is very useful. The ME3000SP seems to be able to hit about 65A at times, and I've often wished it would be a bit higher, so the pack could be charged faster. I'd not want a lower charge rate, as there are plenty of times where we get short bursts of solar generation on cloudy days where being able to stuff as much as possible into the battery is useful.

Have a look at Solax. Another cheap/cheerful but also established/reliable brand interchangeable with Solis and SoFar.

Thanks both for the info above. Will do some digging!

[newtoallthis]

Thanks for the responses boys and girls.

Another related question, I have a 3.68 KW grid tied PV system and plan to use excess capacity to charge batteries via a Vectron.
If I want an addtional PV array, could I avoid the installation of another Inverter and use an MPPT charger to the batteries direct and hence use the Vectron inverter to convert back to mains voltage. This would mean that both the existing and the new system could charge the batteries and this would mean importing less electricity particularly during the winter.

If this is possible, then when I make my G99 application then I only need to quote the existing 3.68 KW inverter and the Vectron inverter 5KW (3.68 + 5 = 8.68KW ) if I can't do it this way then an extra PV system will need its own inverter and hence I will have to apply for (3.68 + 5 + new system 4 kw= 12.68KW)

I suspect that Northern Power Grid are more likely to approve 8.68 KW than 12.68 KW

Anybody know what is possible ?