Heavy Duty Set-Up or 4 Smaller Set-Ups ?

[Landlord]

I've added my enquiry here as my original in Battery Storage was not including Solar Panels, now it is............

OK - my roof is

West facing = 21M x 3M
East Facing = 21M x 3M

Pic Attached (the car in pic gives an idea of roof size better)

The TOTAL electric use across all 4 tenanted flats is 10,000 kWh per Year. Non have gas.

What would people suggest please?

My budget is £30,000 but it needs to pay me back before I die (hopefully 20-40 years left yet ) - The idea is to sell electric to my Tenants at 10p below market rates and also to make some money to pay for the system and upkeep. Ofgem have confirmed the resale from solar or storage is permitted.

Should I treat it as one big scheme with powerwall type battery storage OR 4 individual set-ups?

I would have to incorporate an inverter(s) big enough to run an 8kw shower and 2kw heater at same time IN EACH FLAT (I think I've seen large 10kw inverters?)

I am located on the coast in the South West (nr Weston-super-Mare)

The roof (shown under the large arrow) is higher than mine so I'm "probably" in 100% shade by 4pm spring/autumn and 8pm summer

The white boxed area to the left of my roof is my locked storage area so LOTS of room for "stuff". It's also where the 4 incoming meters are located.

Please assume I know nothing (because I don't lol)

[Countrypaul]

Is the house on 3 phase electricity supply or just single phase? 4 x 8kW = 32kW which is over 100A supply. If on single phase what is the main incoming fuse?

Given that showers are normally quite short (<10 mins?) it might not be worthwhile having 4 large inverters just to cope with the rare event of multiple users having showers at the same time with a large overlap.

[Landlord]

Single Phase - 4 incoming metered supplies (each flat has its own incoming supply)





Unfortunately, 3 of my 4 current Tenants all work at the same location at the same times so showers may well be taken at same time (probably not but never know lol) - guess as they do everything else together they could even share a shower

[Joeboy]

Imagine that you may wish to part out your investment down the road, it would be simpler with four independent systems. It's an interesting idea especially if you can help your tenants out by selling them power at sub par rate. Would be nice to be able to meter their consumption per unit and export for example on an outgoing contract so the excess while at work thru day isn't wasted.

I would suggest that the PV would be best as an option when time and circumstance allows. Covering an 8kW shower, never mind 4 of them is a big ask. Would be able to pull 4kW from the solar array assuming enough incoming at your cheaper rate while pulling the remainder from grid.

If I was doing this I would cover as much roof as possible with PV, get an outgoing contract along with four independent setups from said arrays and leave the batteries out of it.

There are folk out there who have relatives working for power companies, these folk can get discounts on their power. Does this mean you may have an A1 applicant for a unit yet they want to do their own thing with power?

With that being a possible and outwith your control other than to pass on an A1 tenant i'd make sure I had the outgoing contract on the four set ups in your name and before I put out penny 1 i'd make sure it was all possible including the wiring in of use meters for each property as your charges for PV used have to be unimpeachable and traceable for your own protection as well as your tenants. That roof is a big asset un-used but i don't see it being worth batteries.

Looking forward to seeing how this progresses. Also at that size and investment well worth having it priced at least 3 contractors and forward plan for the legit breakdowns that will come over the years. Is there such a thing as a multi prop solar cover annual maintenance contract payment?

[rogeriko]

Unfortunately PV only works around noon +2h -2h probably when no one is home. your best bet is to install 4 hot water tanks and heat the water in the tanks for free from the PV during the day and then for cheap using night rate electric. Tanks would have to be big enough for 2 showers becaus for 6 months in the winter PV produces virtually nothing so you would have to rely on night electric.
How is the building heated??

[Joeboy]

Unfortunately PV only works around noon +2h -2h probably when no one is home. your best bet is to install 4 hot water tanks and heat the water in the tanks for free from the PV during the day and then for cheap using night rate electric. Tanks would have to be big enough for 2 showers becaus for 6 months in the winter PV produces virtually nothing so you would have to rely on night electric.
How is the building heated??

Roger, that's not entirely true. I see meaningful volumes of power from 0930 until 1600 and my set ups are compromised with location, orientation and shading.

I agree on.peak production times as you have said being around these hours but that's not the whole story especially with simple timers for the folks?

It would be interesting to hear the OP's thoughts on altruism or profit with a soupcon of benefit to tenants. No moral judgement, just wondering where he/she stands?

Personally, if I drop 30k on an investment I expect as a minimum a 4% return, aim for 5.5% and I am happy at 7%. Only saying this last as RE investment has a different ROI and worth talking about?

[Landlord]

Thank You guys

Being honest, i can get 5% with Ripple I believe so I want a return close to that if possible. Both have risks.

My money is sat in premium bonds doing nothing.

Im happy for tenants to save money, but not at the expense of my investment : it has to work or I might just leave where it is or go stock market.

[Gareth J]

Sounds like it'd only really work with battery storage. Without it, incentivising use when it's sunny will be hard. Especially if tennents are out most of day.

In which case, the economics should be a bit easier to predict. Ask a couple installers what they can get you for your £30k and go from there. Their output figures can be checked on pvgis and once you have some numbers, working out costs/roi should be relatively straightforward.

[Joeboy]

Thank You guys

Being honest, i can get 5% with Ripple I believe so I want a return close to that if possible. Both have risks.

My money is sat in premium bonds doing nothing.

Im happy for tenants to save money, but not at the expense of my investment : it has to work or I might just leave where it is or go stock market.

I would work backwards on this, how much can I get paid per kwh on an exporting contract, can I legitimately set up 4 of outgoing cotracts on the units, what is the max I can export per contract (likely 3.6kW per unit). How much PV can.i squeeze on at what cost. That's your basic model with metered sales to units at their tou as a variable extra. Its a good idea if the figures work and you would be doing the world a favor? Does anyone have rough estimates for their outgoing figures? Help him along?

If you limit it to 4 of 4kW pv systems and a 7.5p per kW from Octopus you should be able to work out a rough anticipated output of the systems and go from their pursuing a installer discount for 4 of installs on 1 site. While at it check what the max PV install per unit you can do before hitting your DNO limit and run that through your calculator too. Just cos you have 30k to spend doesn't mean you should spend it all. I still consider batteries to be a red herring in this instance as you won't see that money back.
3MWh per unit pa generates £900 pa on a fixed 7.5p per kW contract. I don't know how much solar you can generate down there but if you could negotiate to less than £15k for the 4 units you would have a 6% roi. More sun, harder negotiations to contractors and you might see 7%. Sounds OK to me! I'd maybe go for that myself.

[billi]

Unfortunately PV only works around noon +2h -2h probably when no one is home. your best bet is to install 4 hot water tanks and heat the water in the tanks for free from the PV during the day and then for cheap using night rate electric. Tanks would have to be big enough for 2 showers becaus for 6 months in the winter PV produces virtually nothing so you would have to rely on night electric.
How is the building heated??

Well Roger , that idea will probably cost an arm and a leg to redo the plumbing of those apartments to wet hot water incl 4 tanks .... i suppose a battery will be much smaller in size per the same kWh storage and cheaper
And i hope you meant more or less 6 weeks not 6 month of deep dark winter

Billi