Building with solar in mind

[trevorbayliss]

I am planning on doing a new garage and rear extension next year.

I am aware solar energy and electrical storage is rapidly becoming the next big thing.

Is there anything i can instal in my new build which may be needed in the next few years.

e.g., provide an area for tesla's solar wall storage, or provide certain cabling into the garage from the consumer unit.

 

[JohnW2]

I am aware solar energy and electrical storage is rapidly becoming the next big thing.

In sunny parts of the world, perhaps yes!

Kind Regards, John

 

[Iggifer]

The original Powerwall had some pretty specific requirements, I didn't go on the course but one of my bosses did (no idea why!) but there's a lot of things you need to have that they don't advertise, I can't remember them all but it's all to do with space and distance from your consumer unit I think.

Plus the thing weighs around 100kg, so you'd better build the wall you want it on out of granite!

You can install them outside, but you cannot install them anywhere other than a ground floor (100kg). They also hum and buzz so you wouldn't want it in a room you spend any time in.

In terms of allowing for PV, you'd want a cable from where your consumer unit is (to a meter/isolator then to your consumer unit) to the roof space where you'd want PV. This is typically a 2.5mm² cable for a typical array or 4mm² if you've want to cram loads of panels on. Would need to be calculated to work out the exact size, but doesn't hurt to go bigger.

You will also need somewhere in the loft space to mount the inverter, they're nowhere near 100kg but they can be quite large. A wall is best but they can be fitted to timber fixed to the purlins

The payback time on a Powerwall in this country is estimated to be >10 years, and with a warranty period of 10 years, you might end up never actually making your money back. Return on investment on solar has also changed drastically since the feed in tariff took a nose dive at the start of the year.

We're only really fitting solar on new builds now that require it for planning/to meet SAP calculations

 

[trevorbayliss]

Thanks for info. Reading the financial stuff on the future of solar it is supposed to be acting a bit like the computer. You get 100 x performance for 10x less cost (or whatever the actual calc is). So solar is supposed to be getting much cheaper in the future and much more effective. This is a 10-20 yr timeframe i think. anyway i thought if i do a newish build i may try and think about these future considerations.

The power wall sounds interesting stuff.

Our attic is converted and so solar is a possibility. I was reading last night about tesla's new solar roof tile. IT sounds pretty good.

https://techcrunch.com/2016/10/31/w...f-tiles-and-home-battery-are-such-a-big-deal/

 

[JohnW2]

Thanks for info. Reading the financial stuff on the future of solar it is supposed to be acting a bit like the computer. You get 100 x performance for 10x less cost (or whatever the actual calc is). So solar is supposed to be getting much cheaper in the future and much more effective.

That would be great, but I certainly won't be holding my breath. Apart from anything else, there are some basic laws of physics that one has to live with.

Kind Regards, John

 

[trevorbayliss]

Skyscrapers are being built now with solar glass. The windows generate lecy. This is happening in china and the usa. Chile this year ran for 160 odd days on solar only ! Yes we arnt a sunny place in the UK, but the technology will get better. The big issue with solar is storage of the electric generated. We really need to be able to use it at night when home from work. Hence battery technology is the key.

If you think back to 1996 we were pretty advance really as a society, but when you think what the smart phone has done for us since then you can see so much has changed in this time. I am expecting free solar energy in 2036 and all electric cars/trucks (mostly operated by computers).

 

[motorbiking]

If your garage roof is lower than your house - it might be well suited to a gravity based solar hot water pre-heater, as the mechanism are simpler where the hot water tank is located above the panel. My own solar install is fairly straight forward.. There is a fat 500v DC cable running from the solar grid in to my garage where the inverter is. It then goes AC via a fiarly chunky cable to the consumer unit. You could lay some trunking ducting in advance for this.

You do want to avoid shadows, so photovolatic panels on a low roof are less than ideal.

 

[JohnW2]

If you think back to 1996 we were pretty advance really as a society, but when you think what the smart phone has done for us since then you can see so much has changed in this time. I am expecting free solar energy in 2036 and all electric cars/trucks (mostly operated by computers).

Yes, technological advances often astound us. In terms of the very long term, what you suggest may possibly happen one day (even in UK), but I think that your suggested time-scales are probably far too optimistic. Even if all the required technology (including substantial advances in battery technology) were available today (at sensible prices), I think it would probably take more than 20 days for it to be widely deployed.

Kind Regards, John

 

[Iggifer]

PV/Renewables produced more electricity last quarter than coal power stations - presumably because we had an unusually sunny summer for the U.K. - and PV is being put in on a daily basis

 

[JohnW2]

PV/Renewables produced more electricity last quarter than coal power stations - presumably because we had an unusually sunny summer for the U.K. - and PV is being put in on a daily basis

That's true, but you are talking about all 'Renewable' sources.

The most recent figures I've seen indicate 17% from coal and 24.3% from 'Renewables' (including PV). However, I would have thought that the great majority of 'Renewables' would have been wind and hydroelectric, leaving PV as a pretty small component (which is what one might expect of the UK), almost certainly far lower than coal. Have you any idea what the figure is for PV alone?

Kind Regards, John

 

[Iggifer]

All I can find is that 48% of that 24.6% is wind. Leaving the other 52% shared between PV and Hydroelectric. I can't find any further breakdown of the figures. I'm sure it's out there somewhere

 

[JohnD]

PV/Renewables produced more electricity last quarter than coal power stations - presumably because we had an unusually sunny summer for the U.K.

No, it's because the coal stations were mostly shut down for a period.

Observe the "Yearly" graph at the bottom, and look at the line (black) for Coal generation.

http://www.gridwatch.templar.co.uk/

The graphs do also show hydro and biomass, but PV is not shown because it is not metered as generation, it just shows as reduction in demand. You could probably work it out from the FITS payments, it is probably published somewhere.

 

[JohnW2]

All I can find is that 48% of that 24.6% is wind. Leaving the other 52% shared between PV and Hydroelectric.

Even if all of that 52% were PV (which it obviously won't be), that would still be appreciably less than coal. More realistically, if PV were about half, then that would represent about 6%, as compared with 17% for coal (and 32.3% for gas and 23.7% for nuclear).

I would think that, given that the UK has lots of wind and rain, but not so much sun, it would make sense that 'Renewable sources' would major on wind, hydroelectric and wave sources.

I can't find any further breakdown of the figures. I'm sure it's out there somewhere

I'll have a look around - watch this space.

Kind Regards, John

 

[JohnW2]

All I can find is that 48% of that 24.6% is wind. Leaving the other 52% shared between PV and Hydroelectric. I can't find any further breakdown of the figures. I'm sure it's out there somewhere

I'm not sure where the figures come from, but the Wikipeda gives figures for 2014, which indicate that solar contributed 1.2% (and coal 29.1%) in that year:

Gas 30.2%
Coal 29.1%
Nuclear 19.0%
Wind 9.4%
Bio-energy 6.8%
Hydroelectric 1.8%
Solar 1.2%
Oil+Other 2.5%

These figures are very different from the latest ones provided by electricity suppliers (as previously mentioned) - so either something is wrong or else there has been a lot of change in the past 2 years.

Kind Regards, John

 

[Iggifer]

Wikipedia is your problem I suspect!