Offgrid (kindof) solution sought

MicktheMan

We have a holiday mobile home (1 of 12) in a park which is open most of the year. There is one official electricity meter for the whole park and each unit then has a sub meter to measure individual usage.

The base load of the mobile home is ~3 kWhr per 24 hrs when unoccupied (ranges from 30 to 800W) and it is this load I would like to more or less cover with a small solar solution for say 8 months of the year. The extra power we use when there is to be supplied from the grid as normal.

The main constraints are 1) there to be no interruption in power to the van & 2) that we are not allowed to backfeed any excess power generated back into the rest of the park.

Am looking ideally for a diy solution and am open to any / all suggestions on how best to solve this cost effectively.

DC999

300 quid for 4 port micro inverter in Kelllighers. Which is larger than you need.

I got 4 old panels plus rails for 200 quid on donedeal.

100 quid (or less) for mc4 extender cables, screws, silicone....

If you put the microinverter on a smartplug, you can see the output. Shows as consuming and is doesn't understand it's generating.

Will they let you install panels on your roof?

Option B is turn off all power when not in use and save the 3kWh a day.

unkel

https://www.boards.ie/discussion/comment/122533622#Comment_122533622

No can do on the micro inverter. It will feed back into the rest of the park when the PV production is higher than the load

unkel

The easiest is to find out why the mobile home is using so much electricity when not in use. Do you leave the fridge plugged in? Anything else? If you just unplug all drain causing appliances, you will have no bill for the days you're not there as @DC999 suggested. I would go with that too.

MicktheMan

Thanks for your replies @DC999 & @unkel.

Option B of turning off power when not in use is not really an option though and I know where the consumption is. 2 fridge freezers and a combined mvhr and HP unit (Nilan CompactP) are the culprits which are best left switched on standby. I could switch off one of the fridge/freezers for the cooler months for sure but I still have the other base loads to cover.

I was thinking something like; solar panel(s) / charge controller / battery / inverter connected to an automatic changeover switch with the other side of the changeover switch connected to grid.

Would something like this work or is there a simpler solution?

Big Lar

Someone in Galway is selling a Solis 1.5 kw grid tied inverter for sale on Adverts for €230, this with 4 panels on the roof, set export to zero should do the trick ?

https://www.adverts.ie/other-electronics/solar-inverter/34726080

unkel

https://www.boards.ie/discussion/comment/122534787#Comment_122534787

I sold a 2.5kW grid tie inverter for €100 yesterday. An SMA Sunny Boy too!

And yes that suggestion you made should work. You do need the optional proprietary CT kit for the Solis for that though and not all Solis inverters have that option / slot so be careful buying.

MicktheMan

https://www.boards.ie/discussion/comment/122534787#Comment_122534787

Sounds simpler than what I had envisaged.

I didn't realise you could set the inverter up to export nothing without any other extra hardware such as an isolating switch. Good to know. Thanks

MicktheMan

https://www.boards.ie/discussion/comment/122534823#Comment_122534823

Thanks for the heads up on the extra CT kit needed.

Buffman

Is it the park owners who won't allow you to export any excess to them? Do they not want the hassle of the paperwork etc? What sort of meters are installed?

I'd have thought they'd be delighted to get some 'free' electricity from you which they can then charge your 'neighbors' full whack for without having to pay the energy provider for it.

graememk

https://www.boards.ie/discussion/comment/122551170#Comment_122551170

Technically. As it's on the grid, it needs an nc6/nc7 etc...

Export limiting will stop drawing attention to it though.

MicktheMan

https://www.boards.ie/discussion/comment/122551170#Comment_122551170

Inertia, don't want to do the paperwork, don't want the boat rocked … take your pick, I don't know.