Plans for solar and battries

[myozone]

I think this post fits in here.

With all the energy price rises I’m looking at changes, so here goes with the new to me forum.
I have ideas for our future power, heating and transportation and would appreciate comments.
We use about 600-700 L of oil and 2100 kWh of electricity PA. I already use Node-red, EmonCMS and InfluxDB, Grafana for logging.
The plan would be to have a FIT tariff with Octopus Agile Output or someone else to feedback unused energy.

Power
LG Neon panels 4kW with enphase micro inverters due to neighbour’s chimney shadow
BYD LVS 20KW battery bank
Victron Multiplus inverter/charger 5 kW

Heating
Replace a 10 year old 25 kW oil boiler with an air to air heat pump with 5 wall boxes Mitsubishi?
Hot water for kitchen and bath room sinks under sink 2kW 10L water heater.

Transport
Replace 15 year old diesel VW Polo with a Citroen eDispatch 75 kW LWB van and convert to a camper.
1.6kW 12 volt Victron Inverter to power 2 ring portable hob, fridge/freezer and possibly V2H powered by the vans DC-DC converter – I need to find out its power, most are >2kW.

Dave.

[nowty]

You mean a SEG (Smart Export Guarantee) not FIT (Feed In Tariff), no FITs anymore for newbies.

Can you only fit 4kW of panels ?

The 5kW battery inverter is going to make it a full G99 application.

How are you going to heat water for bath or shower ?

[AE-NMidlands]

I don't understand how a traditional system boiler (I assume) and a whole system can be replaced by an air-to-air heat pump. Does "5 mitsubishi wall boxes" mean new pipework and just 5 rooms with a unit like a hotel a/c unit in them? If they are £250 each then I would rather find a way to re-use my existing small-bore system and the radiators...
A

[billi]

Can you only fit 4kW of panels ?

Exactly , beside the costs of this batterybank and the Victron , the PV idea of only 4 kw seems tiny

[nowty]

Can you only fit 4kW of panels ?

Exactly , beside the costs of this batterybank and the Victron , the PV idea of only 4 kw seems tiny

Especially as myozone seems to want to go full electric.

[Ken]

Why do you need to replace the oil boiler. I would be keeping this and then try to use as little as possible oil by fitting the HP you suggest. However i hope that you do not think that the PV will power your HP in Dec,Jan when for all intents and purposes there is zero spare leccy for running a HP. So in money terms how much will you save by running a HP from grid leccy versus the oil boiler. Of course on enviromental grounds it is a no brainer.

The max amount PV makes sense just by itself.

EV camper van is good unless you are thinking of going off the beaten track as charging/range anxiety is going to be a nightmare.

You would of course charge your EV and heat the hot water (HW) of a cheap night time rate so that makes sense.

[marshman]

__

[myozone]

Thanks for the great input. The 'multi' would be an external compressor with 5 inputs/outputs to the wall boxes. Heat pump

You can have the either 10 pipes from the evaporator or a loft mounted manifold with the normal suction and pressure lines to the evaporator.

I was told the existing radiators and pipes would be too small and the cost of replacing them and the piping would be around £3000

The roof for solar is about ~28m² so I would guess good for 5.5 kW of panels I wrongly assumed 4kW was the maximum.

The shower is electric 8.5kW which is fine. Good idea keeping the oil boiler in place, we still have 2 storage heating in place - unconnected. Thinking about 'extra' energy could go into the storage heaters, notmuch sun in winter though...

I think the vans range anxiety would be an issue at first until I get used to it, I do like the idea of 'multi use' van though, camper, V2G higher up etc.
This guy got on ok with it

Obviously I need to look again into Smart Export Guarantee being a total newbie I was still thinking FITs

[marshman]

As far as I know it is the size/power of the inverter that the DNO is concerned with, i.e. how much power you can potentially feed in to the grid, and not the size/power of the PV array. You can have as much PV as you want or the inverter will take. The application form asks for the power of the PGM, i.e. the inverter. It is not interested in where it gets the power from.

When choosing the inverter check it's inputs can take the amount of PV you are thinking of. Look at both the actual power but also maximum voltage and current and number of separate strings.

[John_S]

Some inverters have the ability to limit the export to the Grid to 3.68kW or 16 amps even if the output is greater because of self consumption.
DNO approval of the inverter is required. This is an option if the DNO won't approve a bigger inverter. Others who have gone this route should be able to advise more.

Will you battery bank etc be able to supply the 8.5kW shower?