New builds and solar panels

[phope]

It's been a hectic week, so haven't had much time to read up on this topic, so perhaps those with more knowledge and experience than me on solar panels can chip in.

Location: North East Scotland. We're going to view a new-build development tomorrow with a view to maybe putting down a deposit on an unconstructed plot - plan being that we could tailor the final spec to our own choices, room layouts, etc and have completion in late 2020 which suits us just fine. (also a big plus that the homes all have full fibre broadband direct to the home...150-300 megabits )

A quick look around the development shows that the properties built to date all have 3-6 solar panels integrated as standard into the roofs depending on size of home and depending on spec/size, some have gas combi boilers and some with condensing boilers. None have under-floor heating and isn't an option at all from the developers (mid size Scottish firm)

The aesthetics of panels don't bother me at all and I understand a little of the energy efficiency requirements of the 2015 Scottish building regulations for emissions, balancing the mix of insulation and renewable energy sources like solar, heat pumps, etc

Would I be right in thinking that:

As a typical modern panel has a peak generation of around 300 watts, a 3-6 panel system would generate max of 1kW to 2kW peak per day - this could be say max 10-20% reduction in metered usage compared to a home without panels?

Without any battery storage solution evident in the house specs so far or feeding back into grid, the electric generated is simply used to relieve grid usage during the daytime and to pre-heat water, cutting down on boiler usage?

Battery storage systems like Tesla Powerwall and the like seem really expensive for the amount of charge they can store (around £6500 for a single 13 kWh pack) and really aren't suited to small scale panel installations like these 3-6 panels, or am I wrong?

Edited by phope on Saturday 18th January 23:07

[Evanivitch]

Battery systems just don't make financial sense.

But it is worth pointing out that you can also instruct them to charge using off-peak energy rates and hen you can use that power during peak time. That's not to say it's economic to do so.

[Jambo85]

A mate of mine bought a very similar sounding house also in the NE, and he also mentioned the panels don’t feed into the grid. I’m wondering if this is due to the number of houses and the local grid simply can’t take what the peak output would be on a sunny day. It’s immaterial at the moment financially because there’s no FIT but I think an export tariff is likely to be coming so if you genuinely can’t feed in that’s annoying. Also if you have a combi boiler pre heating water is out too.

I also wouldn’t buy a house on the strength of fibre internet - it’ll be everywhere soon enough!

Sorry for being so negative but hope it’s somewhat helpful!

[Aluminati]

It's a developer ticking a box. The actual benefit of 3-6 panels is zero.

[gangzoom]

We have a 4KW solar PV system so 12 or so panels installed by previous owners. The facing isn't great been split between SE and SW, so with current low sun generation actually drops off at noon when its suppose to peak.

In December the panels generated sub 50kWh, which is about 2 days worth of electricity usage for us.



We also have a Tesla Powerwall, the main use of the Powerwall at present has been to shift virtually all of our grid electricity usage from the evenings to off peak rates - Essentially the Powerwall charges it self on cheap electricity, meaning we can run the house 95% of cheap off peak rates. The savings aren't massive about £20-30/month.



In the summer the Powerwall will hopefully charge most of the time off solar, which should ensure a big drop in grid electricity usage.

[Evanivitch]

Jambo85 said:

A mate of mine bought a very similar sounding house also in the NE, and he also mentioned the panels don’t feed into the grid. I’m wondering if this is due to the number of houses and the local grid simply can’t take what the peak output would be on a sunny day.

Then the panels must not be connected full stop, which is quite bad for them (but not so bad this time of year).

Jambo said:

It’s immaterial at the moment financially because there’s no FIT but I think an export tariff is likely to be coming so if you genuinely can’t feed in that’s annoying. Also if you have a combi boiler pre heating water is out too.
!

Export tariffs already exist. However, unlikely to be as lucrative as the FIT which assumed you exported 50 percent of production.

https://octopus.energy/outgoing/

[ARHarh]

Aluminati said:

It's a developer ticking a box. The actual benefit of 3-6 panels is zero.

How can the benefit be zero? If it generates electricity it is a benefit surely

[bsc8180]

I wonder if the panels are for solar thermal as opposed to solar pv?

[anonymous-user]

Are the ones with panels Social Housing?
On developments around my way, only those have them fitted (as standard, plus a shed !)

[phope]

No - all the properties have them, including neighbouring social housing

[phope]

bsc8180 said:

I wonder if the panels are for solar thermal as opposed to solar pv?

Some of the properties are definitely gas combi boilers but still have panels, so I can only guess at this stage that the panels (limited as they are in number) must still generate some electric for daytime usage

Edited by phope on Sunday 19th January 09:42

[phope]

Aluminati said:

It's a developer ticking a box. The actual benefit of 3-6 panels is zero.

I agree to an extent - they’ll be doing the bare minimum needed to keep the house style within a efficiency calculation/threshold for building regs.

[phope]

Jambo85 said:

I also wouldn’t buy a house on the strength of fibre internet - it’ll be everywhere soon enough!

Sorry for being so negative but hope it’s somewhat helpful!

Small village like this will always be near the tailend of any big future rollout of universal fibre so to have it 10 years or so ahead of others would be attractive. I hadn’t even realised the newest properties were getting it, as the very earliest ones in the development are still listed on Openreach as copper.

Floor plans for available house styles that I quickly snapped whilst having a initial conversation with salesman the previous week do clearly show optical termination units though and he did state that full fibre was now specced for the latest builds

No harm in healthy scepticism/ negativity!

[jason61c]

what I don't get is why underfloor isn't an option!? Its cheap to do, especially while building a house.

Underfloor is the best way to heat.

[phope]

Don’t know why. We had it in our last house - it was great

Salesman simply said it wasn’t even an option on any house style, even the largest 5 bed homes they are offering.

[megaphone]

jason61c said:

what I don't get is why underfloor isn't an option!? Its cheap to do, especially while building a house.

Underfloor is the best way to heat.

It's much cheaper and easier to instal rads. Putting in UFH is a pain with new builds, running in pipes and ensuring they don't get trashed by a load of unforgiving builders, having to lay two lots of floor fill, getting pipes tested in between, all costs time and money.

[Jambo85]

phope said:

Jambo85 said:

I also wouldn’t buy a house on the strength of fibre internet - it’ll be everywhere soon enough!

Sorry for being so negative but hope it’s somewhat helpful!

Small village like this will always be near the tailend of any big future rollout of universal fibre so to have it 10 years or so ahead of others would be attractive. I hadn’t even realised the newest properties were getting it, as the very earliest ones in the development are still listed on Openreach as copper.

I’m in an old house a mile from any kind of settlement and the trunking is all in for FTTP with the fibre itself being imminent. Nothing like ten years to wait...

I’m not knocking it but there are so many higher priorities when looking for a house!

[wombleh]

Maybe worth having a thermal store? Or do they need bigger radiators fitted...

[Evanivitch]

Jambo85 said:

I’m in an old house a mile from any kind of settlement and the trunking is all in for FTTP with the fibre itself being imminent. Nothing like ten years to wait...

I’m not knocking it but there are so many higher priorities when looking for a house!

Depends how and what you do for work. I couldn't work from home without a good internet connection.