Can you use regular solar panels INSTEAD of your roof?

[energy_dude]

Usually solar panels are installed on top of the roof. There are also solar tiles that are meant to look like a regular roof but cost more per sqft than regular solar panels. What I never seen is regular solar panels used as the roof. What I'm talking about is placing solar panels directly on top of roof joists. I think it would look pretty cool and modern, much better than slapping panels on top of the roof. Why nobody does it?

[bcroe]

I doubt any building inspector will approve it. But if you can work out all the issues,
you might start a new business. Bruce Roe

[energy_dude]

Is there a reason it's not something normally done? Is there a reason building codes don't allow it? I'm sure someone thought about it before.

[Raul]

It’s been done, and still popular in Europe. There are few system to integrate the panels as covering: GSE, easy roof, and viridian roof integrated. These ones I have used in the past, and still popular in UK on new builds, with slates, or grey flat tiles (stonewall).

[peakbagger]

The problem is sealing the seams between the panels. The panels expand and contract so the gap changes over the course of the day.. Its very difficult to find resilient seals that will hold up to the heat and UV over the long term. Various architects have tried using panels for roofing over the years and generally the sealing system does not hold up. If you do find a good long term system, installing bi-facials would be pretty wild.

[J.P.M.]

Google : "BIPV".

[Mike90250]

Insulation would be hard. you want airflow underneath to keep panels cool in summer. That would be complex in a house roof.

And if a panel breaks (wind blown debris) getting the same size replacement could be a problem.

[Ampster]

As Mike points out cooling is an important issue. That and periodic maintenance may be why Tesla has not been able to go mainstream with solar roof tiles yet. Others have tried and failed. What little I understand from the Tesla tile application is that there is a waterproof membrane below the actual tiles and there is an air gap between the tiles and the membrane.

[foo1bar]

What I'm talking about is placing solar panels directly on top of roof joists. I think it would look pretty cool and modern, much better than slapping panels on top of the roof. Why nobody does it?

Sealing between the panels is a big issue as others have pointed out.

Also, how do you do the peak of the roof? And what do you do for the North roof face (I'm assuming N. Hemisphere)

I suppose it'd be possible to do a shed style roof and have no peak (high edge would be to the north, sloping down to the south). That really would be an odd looking house IMO.

There's also that the firemen want to be able to vent the house in case of fire - so you have to have some way to do that.
And the roof adds some structural stability to the building. So that may be a concern in earthquake zones.

[emartin00]

I just got back from SPI last week and did see something interesting. I thought it was at the IronRidge booth, but I may be mistaken.
Basically it is a giant flat black panel that would go right on the roof deck, and then the traditional PV module would be attached directly to it.
Each of the panels would interlock with each other to seal for rain.

As others have mentioned, with BIPV you typically get lower efficiencies because of heat.

[PNPmacnab]

A lot of people are creating outdoor patio areas using the panels as the sun shield. A minor leak doesn't matter there. It is also more acceptable visually than panels on a roof. Panels are so cheap now that an almost flat angle is viable. Output though lower can be a little more consistent over the day.

[littleharbor]

Some pitch isn't aesthetically a bad thing and is actually necessary for self cleaning.

[Buck Rogers 2000]

A lot of people are creating outdoor patio areas using the panels as the sun shield. A minor leak doesn't matter there. It is also more acceptable visually than panels on a roof. Panels are so cheap now that an almost flat angle is viable. Output though lower can be a little more consistent over the day.

Thanks for the idea!!

[littleharbor]

Here's some images of solar pergolas for thought.

https://www.bing.com/images/search?view=detailV2&id=366F3CA31E50D37CDF1C7EA5CA A7993E1CC9B226&thid=OIP.A-Ond5mIfTsuNA0BQG885AHaFj&mediaurl=https%3A%2F%2Fi0 .wp.com%2Fhughloftingtimberframe.com%2Fwp-content%2Fuploads%2F2014%2F11%2F4-Solar-Pergola-6.jpg&exph=900&expw=1200&q=solar+pergola+shade+str uctures&selectedindex=33&qpvt=solar+pergola+shade+ structures&ajaxhist=0&vt=0&eim=6

4-Solar-Pergola-6.jpg

[Bark]

Looks awesome. I think its a great idea for my vacation home. By the way, I found interesting article https://websolarguide.com/selling-a-...-solar-panels/