Solar frickin' wall of block of flats

[tszaboo]

I don't think this was mentioned before.
I was visiting Strassbourg (France)some years ago, and saw this.
The panels are mounted on the side of a flock of flats.
Some notes: There isn't a building close by, to shade these panels.
They are facing south. ( hint for Australians, that's good)
There seems to be some panels on the top of the building (according to satellite image) but there is plenty of space there to put extra panels.
This will create bigger output in winter, than an optimal fixed angle installation.

https://www.google.be/maps/@48.5756815,7.771481,3a,75y,320.97h,97.44t/data=!3m6!1e1!3m4!1sOgYapgZWMuqW3L2Tfs3kvw!2e0!7i16384!8i8192



What do I think? I think vertical installation makes sense. It is better than having a billboard or an ugly gray wall. The two building has 65-65 panels, which would operate at around 70% efficiency (does anyone have a calculator for this?).

[German_EE]

Amateurs!

These guys have covered three sides of a skyscraper https://wonderfulengineering.com/worlds-first-skyscraper-that-is-covered-with-solar-panels/

[coppice]

There are some flats in China with solar panels on the wall above/below each row of windows in the tower. This kind of thing might well make sense in northern climates where the sun is low in the sky during the season of maximum demand. There are other flats with solar thermal tube assemblies in a similar location.

[m98]

Those are probably solarthermal-panels, as mounting them in such a way is quite common.

[coppice]

Amateurs!

These guys have covered three sides of a skyscraper https://wonderfulengineering.com/worlds-first-skyscraper-that-is-covered-with-solar-panels/

It seems like that was a remedial move after the tower's original construction was screwed up, and the original facing started falling off within months of occupation. I sense some greenwashing, to try to tone down the ridicule about the original facing.

[Twoflower]

Those are probably solarthermal-panels, as mounting them in such a way is quite common.

No, if you look closer on Streetview you can see they are photoelectric cells facing south. The roofs are not covered with cells. 

I wonder why thy are mounted flat. A slight tilt upward would probably gain much without too much hurting the installation.

[Gyro]

Those are probably solarthermal-panels, as mounting them in such a way is quite common.

Solarthermal collectors seem to be getting badly ignored these days in the race to put up Photovoltaic ones. They have very high thermal efficiency and having a decent supply of hot water in the house is a lot more useful. Electrically heating water takes a surprising amount of electricity especially when that electricity is coming from low efficiency photovoltaic panels.


EDIT: You also don't need space consuming inverters, just a couple of temperature sensors, and an water pump.

[SiliconWizard]

Those are probably solarthermal-panels, as mounting them in such a way is quite common.

Solarthermal collectors seem to be getting badly ignored these days in the race to put up Photovoltaic ones.

True, but they are not ignored by all.

Funnily enough, countries that live off oil like Qatar and Saudi Arabia have whole farms of solarthermal collectors. Meanwhile, countries that use a lot of oil but don't produce any seem to favor PV panels.
Go figure.

[raptor1956]

If you live at a higher latitude it may be more efficient to mount the panels vertically versus horizontally.  Of course, if you have the option for a fixed mounting you'd want to angle the panels a bit shallower than (90 - average elevation angle of the Sun) over the year.  But, on an office building or tower like structure, mounting the panels on the south facing wall (northern hemisphere) or north facing wall (southern hemisphere) -- the problem is that if another building is built next to the Sun side of the building and it blocks the Sun then you're power generation is significantly reduced.

Imagine a building in the northern hemisphere at, say, a 50N latitude on the north shore of a body of water such that no other building can be built that might obscure the Sun.  If that building were, say, 100m wide on the sun facing side and 300m tall it might generate as much as 3MW and over an average day perhaps 16-20MWh per day -- that amount of power/energy might well be more than the building needs.  Of course, window area would likely reduce the power/energy generated by a third or more.  But, there are solar windows that generate some power while providing visibility through them so the net could be 75% of a full coverage system or, in this example, about 12-15MWh/day which could be enough to fully power the building.


Brian

[tszaboo]

Those are probably solarthermal-panels, as mounting them in such a way is quite common.

Solarthermal collectors seem to be getting badly ignored these days in the race to put up Photovoltaic ones. They have very high thermal efficiency and having a decent supply of hot water in the house is a lot more useful. Electrically heating water takes a surprising amount of electricity especially when that electricity is coming from low efficiency photovoltaic panels.


EDIT: You also don't need space consuming inverters, just a couple of temperature sensors, and an water pump.

These are PV.

In most climates, collectors dont make sense anymore. It is cheaper to add a few panels to a pv installation, and have an electric boiler. It costs about 3500 EUR here, to make hot water of a family of 4, 4 sqm system. The same buys you a 10 panel system.

Also, you need a heat exchanger,  regular maintenance, complicated control for hot water for heating and shower, etc... PV is just a lot easier to do.

If you live at a higher latitude it may be more efficient to mount the panels vertically versus horizontally.

It is at 48°, about where the USA Canada border is.

[raptor1956]

Those are probably solarthermal-panels, as mounting them in such a way is quite common.

Solarthermal collectors seem to be getting badly ignored these days in the race to put up Photovoltaic ones. They have very high thermal efficiency and having a decent supply of hot water in the house is a lot more useful. Electrically heating water takes a surprising amount of electricity especially when that electricity is coming from low efficiency photovoltaic panels.


EDIT: You also don't need space consuming inverters, just a couple of temperature sensors, and an water pump.

Inverters are not a big space eater -- how are you going to store the heated water?  Does the inverter consume more space than the water storage tank?  Yes, homes have water heaters now and most have a storage tank, but to store the amount of water needed the tank would almost certainly need to be larger -- conventional water heaters do not store a days worth of heated water and in fact tend to only have about 1-2 showers worth of storage.  Additionally, many new homes use on-demand or tankless water heaters.


Brian

[raptor1956]

Those are probably solarthermal-panels, as mounting them in such a way is quite common.

Solarthermal collectors seem to be getting badly ignored these days in the race to put up Photovoltaic ones. They have very high thermal efficiency and having a decent supply of hot water in the house is a lot more useful. Electrically heating water takes a surprising amount of electricity especially when that electricity is coming from low efficiency photovoltaic panels.


EDIT: You also don't need space consuming inverters, just a couple of temperature sensors, and an water pump.

These are PV.

In most climates, collectors dont make sense anymore. It is cheaper to add a few panels to a pv installation, and have an electric boiler. It costs about 3500 EUR here, to make hot water of a family of 4, 4 sqm system. The same buys you a 10 panel system.

Also, you need a heat exchanger,  regular maintenance, complicated control for hot water for heating and shower, etc... PV is just a lot easier to do.

If you live at a higher latitude it may be more efficient to mount the panels vertically versus horizontally.

It is at 48°, about where the USA Canada border is.

Yes, the US Canada border is right around the 48-50 degree north line so most of Canada is above 50N while most of the US is below 50N.  A good bit of Europe is right around 50N with the UK and Scandinavia being above or well above that.

https://www.energy.gov/eere/articles/five-fun-facts-about-nrel-s-new-solar-windows-innovation

https://pv-magazine-usa.com/2018/11/21/a-15-efficient-solar-window-that-delivers-120-of-us-electricity/

It appears that the efficiency of some of these solar windows is greater than I though -- above 11%.


Brian

[Marco]

Solar collectors have important limits on how cheap they can get, PV will get to the point where it has a negative cost as a facing material relative to any alternative. Glass isn't the cheapest facing material, but it's functional and with the electricity it's going to be a non brainer.

[boffin]

Yes, the US Canada border is right around the 48-50 degree north line so most of Canada is above 50N while most of the US is below 50N.  A good bit of Europe is right around 50N with the UK and Scandinavia being above or well above that.

Only two significant Canadian cities (Edmonton, Calgary) are north of of the 50th.  Probably 80+% of the Canadian population lives south of 50N

[raptor1956]

Yes, the US Canada border is right around the 48-50 degree north line so most of Canada is above 50N while most of the US is below 50N.  A good bit of Europe is right around 50N with the UK and Scandinavia being above or well above that.

Only two significant Canadian cities (Edmonton, Calgary) are north of of the 50th.  Probably 80+% of the Canadian population lives south of 50N

Yes, in the east the main cities are more like 45N even as the large landmass of Canada is mostly above 50N.  Still, 45N is in the ballpark of 50N and would be right at the point were vertical surpasses horizontal mounting of solar panels/windows.  The main problem with exterior wall/window solar is that you have to be unobscured by other buildings so in an urban setting only those buildings at the southern edge (northern hemisphere) will get full Sun while other buildings further north will get less Sun.  But, if you do have such a location you might be able to generate all the energy needs of the building.


Brian

[tszaboo]

Yes, the US Canada border is right around the 48-50 degree north line so most of Canada is above 50N while most of the US is below 50N.  A good bit of Europe is right around 50N with the UK and Scandinavia being above or well above that.

Only two significant Canadian cities (Edmonton, Calgary) are north of of the 50th.  Probably 80+% of the Canadian population lives south of 50N

Yes, in the east the main cities are more like 45N even as the large landmass of Canada is mostly above 50N.  Still, 45N is in the ballpark of 50N and would be right at the point were vertical surpasses horizontal mounting of solar panels/windows.  The main problem with exterior wall/window solar is that you have to be unobscured by other buildings so in an urban setting only those buildings at the southern edge (northern hemisphere) will get full Sun while other buildings further north will get less Sun.  But, if you do have such a location you might be able to generate all the energy needs of the building.


Brian

If you look at the picture, there is about 3x8x3=72 apartments and 65 solar panels in one building. That is not going to be even close to "all the need". In fact I dont think any apartment building could provide enough solar to break even. Most standalone houses barely have enough capacity for their electricity need, excluding heating, which needs more power.

And to return for solar collectors for one more second: I was talking about home systems. Large scale systems have totally different economics.

[NiHaoMike]

Solarthermal collectors seem to be getting badly ignored these days in the race to put up Photovoltaic ones. They have very high thermal efficiency and having a decent supply of hot water in the house is a lot more useful. Electrically heating water takes a surprising amount of electricity especially when that electricity is coming from low efficiency photovoltaic panels.

A heat pump water heater (for hot water, not space heating) uses on the order of 300-500W. Pretty easy to power even on a 12V system.

[Brumby]

At least you are less likely to have a bus driving over them.   

[SparkyFX]

Ahhh thats the problem, got hit by the bus!

[BrianHG]

I don't think this was mentioned before.
I was visiting Strassbourg (France)some years ago, and saw this.
The panels are mounted on the side of a flock of flats.
Some notes: There isn't a building close by, to shade these panels.
They are facing south. ( hint for Australians, that's good)
There seems to be some panels on the top of the building (according to satellite image) but there is plenty of space there to put extra panels.
This will create bigger output in winter, than an optimal fixed angle installation.

https://www.google.be/maps/@48.5756815,7.771481,3a,75y,320.97h,97.44t/data=!3m6!1e1!3m4!1sOgYapgZWMuqW3L2Tfs3kvw!2e0!7i16384!8i8192

(Attachment Link)

What do I think? I think vertical installation makes sense. It is better than having a billboard or an ugly gray wall. The two building has 65-65 panels, which would operate at around 70% efficiency (does anyone have a calculator for this?).

If a single apartment is using all the panels, with a large enough battery pack, they will get away with free power.
I think just the panels are for the building itself only saving some money for the landlords.

[Circlotron]

Amateurs!

These guys have covered three sides of a skyscraper https://wonderfulengineering.com/worlds-first-skyscraper-that-is-covered-with-solar-panels/

Technical journalism is as bad as ever though, especially when the writer goes with the name Uber Geek.

"The solar panels generate enough power on an annual basis to power 55 homes with power for one year."

Translation: 'The solar panels provide enough power to supply 55 homes'.

[Miyuki]

I am at 50 north and vertical solar panels according to calculation makes sense as it flattens power production during year (makes more in winter and lower in summer, in year total it is similar amount of energy, but is better for real utilization)
But not have connected installation yet to measure real results

[Nauris]

Pvgis says if it is 19.5 kW (65x300W) peak power it makes aprox. 14 MWh per year if vertical and 20 MWh if optimal angle (in Strasbourg).  That is still far from covering all energy use, should have at least covered the whole wall with panels.

[ebastler]

If you live at a higher latitude it may be more efficient to mount the panels vertically versus horizontally.

It is at 48°, about where the USA Canada border is.

Why wouldn't the pivot point be at 45° latitude? What am I overlooking -- the increasing athmospheric scatter/absorption at low angles?

[SiliconWizard]

Solar collectors have important limits on how cheap they can get,

True, and likely the main reason why they are not deployed more.

PV will get to the point where it has a negative cost as a facing material relative to any alternative. Glass isn't the cheapest facing material, but it's functional and with the electricity it's going to be a non brainer.

Well, I'm not sure about that though.
And if that becomes true cost-wise, I'm not sure either about the respective qualities of PV as a facing material. For instance as to their resistance to fire, and other criterions... Cost is a thing, but if we are going to make all buildings a fire hazard, this can't be that good.

One question I also have is whether PV panels don't tend to heat up facades/roofs more than many other materials, which in countries where heat is a problem, and A/C has enormous costs, would probably not be worth it. I'd be interested in having the POV and experience of people having panels on their house's roof. Is the house temperature rising because of them or does it have no measurable impact?