Solar Roof Tiles

Nice...I wonder how much that lot cost.

(They didn't seem to work that fast and how much did it cost to have the band playing while they worked?)

I've asked them those very questions. So watch this space...

From their meter reading on the video it appeared as though they were only getting around 250W. No idea how much insolation m² there was nor what m² they had just stuck on the roof - looked to me more than 5m².

Such a nice idea though - I have been pushing for ages for companies to start producing attractive and easy-to-install PV roof tiles. Should be on all new builds once they prove cost-effective.

JB

I thought that was a Voltage reading...dunno how much current they push out.

Maybe I'll look again...but the Sunday Roast is calling _{<eat me eat me>.}

Del

Organic and free range, of course!

They work a lot faster when they play punk but breakage is higher.

How do those cells stack up against "Sliver Cells"

Here is a linky to an Australian TV program called Catalyst, there is also a video linky on there too.

How do they fair with ICE impact, we sometimes get Tennis Ball sized hail stones, or bigger/smaller, that damage most things in their way.

Also how do they handle heat, when its 45 Deg C in the shade, and being Black, so much hotter?

I have had no response to my email yet but have left an a/p message asking the following:

1. Impact resistance (fist-sized hailstones):

2. Max temperature tolerance:

3. Fault finding:

4. Replacement with array in situ:

I'll let you know when I know. (If they get back...)

The C21e solar tiles have integrated "thru-flow" ventilation which will cool them a bit. Main problem is usually with inverter and controllers (my Outback units function up to 65°C, my Isofoton PV panels will still work comfortably at and above that temp.

Let's see if their customer service is as impressive as their website presentation!

JB

Oops, forgot to put the link to the sliver cells in the previous post :P

http://www.abc.net.au/catalyst/stories/s1865651.htm

Hey Snaketails: Really exciting stuff. So sliver (not sILver) solar cells are literally slivers of ordinary thickness silicon - as many as 7-800 "veneers" of a normal thickness silicon cell. Amazing levels of cleanliness are needed to slice these slivers from the silicon - 100 million times cleaner than an ordinary lab (whatever an ordinary lab is, of course).

They will use 90% less silicon, hence end up being around a quarter of the price.

Interesting that the thinner slivers each produce the same power as the standard thicker one - not sure about the physics of this, but I'm sure someone will elaborate.

Thanks for this info, keep us posted on trials and and videos you come across.

Good stuff!

JB

BTW Try this. Pretty poor definition and missing its audio track, but still gives a little more info on sliver cells.

I am just a little curious of how complicated it would be to service an array like this. I have troubleshoot arrays of as much as 16 PV cells. Usually some of the wires or connectors go bad due to weather heat conditions here in California. I can not picture how some one will be able to pointed out a specific cell from the whole array and replace the bad unit.

I've often wondered why there weren't solar cells like this available. Guess the technology wasn't there yet?

What about the odd size of a roof as per solar shingle size?

I saw there were some different panels in the video along the edges of the roof. But didn't see anything on these particular parts of the roof. Are these other panels able to be cut to fit the odd size areas of a roof?

How do you handle the roofs with gables and such? Regular roofing shingles?

What about all the vent stacks that come through the roof? How are these handled?

Looks like they put these on new builds or re-roofs - I imagine they could be made to fit in with other roof coverings like slate - although some bodging would be needed!

Curved solar tiles might be difficult to manufacture! Also, most curved tiles are red or grey. Black, of course, is the preferred colour for the background of a pv cell.

Not sure about the odd sizes and shapes and fiddly stuff like collars for vent stacks and pipe outlets etc.

They look to me as though they will slot in reasonably well, as long as properly sealed. Vent stacks? Good point.

I suppose they have no intention of the whole roof being coved by pv cells - although I suppose it is only manufacturing costs that would prevent it in principle.

Maybe a good look at their online documentation will help - then you can let us have some answers to your interesting questions...

JB

BTW

Another larger photo of how they join to flat shingles:

So there is no need for all ridges and edges to be covered. I suppose they are aiming to maximise the flat sun-facing area as much as poss.

JB

Wow! That looks very neat.

Nano Solar

This is certainly worth a look, as well.

Basic idea is to use a combo of semi-conductor elements (copper, indium, gallium, sulpho-selenide) produced so thin that it is used like an ink spread on a substrata. These "building-integrated" solar cells are so thin and flexible that they can be built on building surfaces (roofs, glass and even paint).

Similar links: here for those who sprechen Deutsch and here for nano technology using red/blue light-absorbing polymers (music's a bit irritating but nice general vid).

BTW "rooves" if what Aussies say for "roofs"?

JB

A 365 day average of 500W per home would do nicely, thanks. Any indications on the sort of investment needed to achieve this figure, please?

PWSlack: Investment needed for 365 day, 500W total average daily power harvested.

Per W = £3.73 (source exchange rate of 1 GBP = 1.25701 EUR)

500 x £3.73 = £1865.00 say with realistic life-time of 10 years.

That's 10x365 = 3650 days x 500W per day = 1.825mW total

So each W will have eventually cost you £0.001 per W (based on the £1865 initial investment and assuming no additional outlay during the assumed decade life-span).

Okay?

<...Okay?...>

Not yet. The above calculation is inconsistent in its units, though there is still some hope.

Domestic electricity here is around £0.10GBP per kWh on domestic tarriffs. The 500W figure represents a typical quarterly domestic electricity consumption in kWh for a home that cooks electric, read from the bill, divided by 91 days and 24h. So the power capture rate from the sun needs to exceed this figure by a factor of at least 2 to allow for both day and night. So the installation needs to be sized for a maximum capture rate of say 1200W.

The kWh monetary value of the solar system above, representing the value of the energy captured over the lifetime of the installation, is missing from the above figures. Without it one cannot do a rigorous comparison that would justify the investment!

Getting down to specifics for a particular installation scheme:

• What is the value of an installation that will produce, oh let's say, 12kWh per day on average at 53degN, with a nominal maximum capture rate of 1200W?
• How compatible is the colour and thickness of the solar tiles with recovered clay roof tiles (a reddish-brown) on a nineteenth-century building?
• What size would it be were it to be installed on a roof that points due south and is inclined at 57deg to the horizon, and is partially shaded by trees in the summer?
• What is the prospect of getting Planning Consent for an installation in a designated Conservation Area, where those trees are protected?

Your 4 questions:

1. What is the value of an installation that will produce, oh let's say, 12kWh per day on average at 53degN, with a nominal maximum capture rate of 1200W?

I cannot work this out without longitude, but I will assume Long. = -2. If you want to know all the parameters I have used then let me know.

At Lat. 53 Long -2 and on a tilted surface of 53º (I cannot get exact figures for 57º) you will get an average of 2.7kWh/m²/day of insolation (working on an annual average). In order to produce 12kWh per day you would need 2136.8 monocrystalline 125mm² solar tiles (that's 267.1m² overall) assuming each 52w tile runs at 20% efficiency (i.e. 10.4w see datasheet) and 8 tiles per m².

The value would be HUGE!

FYI in sunny southern Spain at Lat. 37 Long. -5 with 4x175w traditional panels and a tilted surface of 52º we get an annual average of 6.1kWh/m²/day of insolation . That's a lot more insolation than at Lat. 57º! With my kit (which cost around £10,000 and should keep ongoing for 10 years - details if you wish) I achieve an average of 3kWh/day (min of 0 and max of 4.5) on an annual basis. Not much, but it's all we need most of the time. At a stab, workng at 2.26 times the price (as that is the factor of our insolation relative to that at 57º, I would think that you were looking at around 9.04 times that figure for a daily 12kWh return if you wanted to use the kit I have and forget the solar tiles. This is multiplying our 3kWh/day system cost of £10,000 by 3 to get 12kWh/day by the insolation difference of 2.26 - hence 9.04.

Of course this is very rough, as there are components you would not ned to magnify by a factor of 4 (like inverters and controllers, etc) but batteries and panels will be increased proportionately and the inverters and controllers etc will have to be upgraded.

2. How compatible is the colour and thickness of the solar tiles with recovered clay roof tiles (a reddish-brown) on a nineteenth-century building?

They would stand out and appear black in comparison with your reddish-brown tiles. No idea what thicknes or shape your clay roof tiles are.

3.What size would it be were it to be installed on a roof that points due south and is inclined at 57deg to the horizon, and is partially shaded by trees in the summer?

As I said above, roughly something around 267.1 m² of roof. HUGE!

4. What is the prospect of getting Planning Consent for an installation in a designated Conservation Area, where those trees are protected?

Unless you have a massive south-facing roof of in excess of 267.1m² you will have to use your neighbours' roofs. They might have more objections than the Planning Authorites!

Hope this helps. If it doesn't, I will have to stop trying to help people who are cleverer than I am!

JB

I suspect your factor of 2 to account for day/night consumption may not be appropriate. Typically, consumption peaks in late afternoon/early evening, and most consumers significantly reduce their consumption at night (my experience suggests that 60% of consumption generally occurs between the hours of 9 AM and 5 PM, but this is probably a local effect. Peak insolation is generally realized between 9 AM and 3 PM, again a local effect). Furthermore, the time of maximum insolation, especially in high northern/southern latitudes is going to vary significantly over the year. Here in the tropics, year round we get about 12 hours of sunlight per day, but only about six hours of peak insolation. The main issue for sizing the units is that the peak consumption generally does not coincide with peak insolation;while this can be compensated for somewhat with a more westerly orientation of the collectors, one looses some efficiency because late afternoon sun angle decreases the actual insolation (a tracking system, significantly adding to the cost while only marginally increasing capture, in this region, may be more appropriate further north). I do not see how to add tracking to the roof tiles, though...

http://www.warmyourfloor.com solar tiles are actually lighter than the clay tiles, saving cost and impact during shipping, and the cost-savings for the homeowner are also pretty dramatic