Solar, Inverters, batteries, etc

[snoopy]

Novel concept

Challenge ,I suppose, is how well will it withstand salt water erosion, maintenance cost against that - and you will have to lay long cables to a point on shore along the seabed. Blade damage to whales, turtles and dolphins?

Can it work for small coastal communities - possibly, provided those communities can maintain it and have access via the ocean to do so.

Price tag compared to a small SMNR with the same output? Bonus of course is that the tide is free -from nature - till someone taxes that also via NERSA.

[Ugly Duckling]

Red tape
https://www.georgeherald.com/News/Artic ... 2408241049

[snoopy]

Its highly unlikely for a roof to collapse given the light weight materials used in PV panels these days, and the fittings. One high wattage PV panel weighs about the weight of 6 tiles. Far less than the guy who walked around on your roof batons and trusses and fitted the tiles. If the wood structure cannot support the weight of a couple of workmen on your roof, the materials used were inferior from the onset and a OHS hazard from the start. So that would point to inferior materials being used in construction these days. And regulation failing there.

The PV panels are not the heavy weight panels of yesteryear. The rails also offer further lateral strength to your roof structure. So here you have jam stealers riding on a new income stream realized, all that was needed for that is local authority to change regulation for the income stream, costing the residents substantially more per installation, and only to benefit a couple of people in society, and not society at large - like in CT as well.

Acts and regulations including by-laws in legal terms are deemed the will of the people - its amendable - but its far easier to prevent this kind of regulation being established and passed in the first place than trying to get it scrapped later collectively as residents of a town - even though its not impossible especially when it does not serve the interest of society at large but only financially benefits a few.

If the people affected therefore, don't want it - or it actually serves no useful purpose to them, but just costs them more expense (its not their will) - make sure the city or town cans the regulation on local level before its passed.

CoC makes sense as does the sign off by a qualified professional. But if your roof collapses because of solar panels - your roof trusses were most likely not sound from the onset. For which the builder, building draughtsman or architect is responsible and should have been regulated when the house was constructed (root cause).

If you into high tech and building a new home - Marley makes PV solar tiles, so no need to add anything extra. The tile itself is a solar PV panel. But watch the local authority trying to charge you this extra cost as well, just because they passed it into a by-law or regulation for the benefit of a couple of people.

[richard C]

"....your roof trusses were most likely not sound from the onset. For which the builder, building draughtsman or architect is responsible and should have been regulated when the house was constructed (root cause)."

<<moderated - language>>, it is exclusively the engineer who designs all structures (including timber roofing) and is responsible for their performance - not one of the people you mention !!!!

[Ugly Duckling]

Do all the add-on solar geyser installations jump through the same hoops. The concentrated mass of the geyser on the trusses is more of an issue than the distributed mass of the panels.

[snoopy]

"....your roof trusses were most likely not sound from the onset. For which the builder, building draughtsman or architect is responsible and should have been regulated when the house was constructed (root cause)."

<<moderated - language>>, it is exclusively the engineer who designs all structures (including timber roofing) and is responsible for their performance - not one of the people you mention !!!!

Over the years the actual density of wood used in trusses and batons has deteriorated, younger - less dense wood is used in newer homes, the same often applies in window frames , doors and door frames - What I'm saying it that adding solar panels to a roof should not require anyone to spend more money for more inspections, other than a CoC . or for anyone to write additional regulations which simply push up the cost of installations, which benefit only a couple of people financially and not society at large. The SANS regulation should be adequate.

If an engineer says use 14 Mpa bricks and the builder cuts corners using 7mpa bricks in a house, its not the engineer at fault. But the builder trying to cut corners in the construction. The construction industry - despite regulations being in place, RED Book, SANS etc, simply hasn't been policed properly in SA for ages. Many builders in SA will never be allowed to even enter the building trade in other countries, because they "bakkie builders".

In recent years we've seen more building collapses than in the past, and roofs simply flying off or collapsing even in shopping malls with no solar panels on the roof. Why? The industry is cutting corners.

New solar panels are not going to make your roof trusses collapse - if anything, it will strengthen the lateral strength of the roof structure to which its fixed.

[richard C]

"....your roof trusses were most likely not sound from the onset. For which the builder, building draughtsman or architect is responsible and should have been regulated when the house was constructed (root cause)."

<<moderated - language>>, it is exclusively the engineer who designs all structures (including timber roofing) and is responsible for their performance - not one of the people you mention !!!!

Over the years the actual density of wood used in trusses and batons has deteriorated, younger - less dense wood is used, the same often applies in window frames , doors and door frames - What I'm saying it that adding solar panels to a roof should not require anyone to spend more money for more inspections, other than a CoC . or for anyone to write additional regulations which simply push up the cost of installations, and benefit only a couple of people financially. The SANS regulation should be adequate.

If an engineer says use 14 Mpa bricks and the builder cuts corners using 7mpa bricks in a house, its not the engineer at fault. But the builder trying to cut corners in the construction. The construction industry - despite regulations being in place, RED Book, SANS etc, simply hasn't been policed properly in SA for ages. Many builders in SA will never be allowed to even enter the building trade in other countries, because they "bakkie builders".

In recent years we've seen more building collapses than in the past, and roofs simply flying off or collapsing even in shopping malls with no solar panels on the roof. Why? The industry is cutting corners.

New solar panels are not going to make your roof trusses collapse - if anything, it will strengthen the lateral strength of the roof structure to which its fixed.

While I agree with your comments regarding the installation of solar on a roof. The building regulations are rigorously enforced, from submission to execution. Collapses are rare, and illegal work remains as it always has been - a small part of the industry and pursued by the authorities. It is not rife, and it does not go unpunished.

[snoopy]

Ive just recently challenged an architect who wanted to take a chance with a construction plan - he never gave his client the all the facts or all of the law, the proposed design he submitted was based on old law, already amended but not applied - it took me and a civil engineer to put him back in his lane. These things happen often. Its not the holy grail of industries, like any other industry there are chancers especially in this economic climate where money is tight.

Acts and municipal by laws are being written to create jobs and additional income streams- where its not necessary for society to go to more of this kind of expense. Its an abuse of the legal system and the consumer.

[snoopy]

And no solar tube type roof top geyser installations don't jump through the same hoops, despite their concentrated load/mass on top of the roof.

And that's exactly why all this extra by law regulation (to make PV installation MORE costly, merely to benefit a couple of people who work in the specific by law region) is BS.

Furthermore you will find that in most of these type of by-laws the muni writes out its own liability for writing the by-law and imposing it - it wont take any liability if it caused you harm or unnecessary additional expense. Which means once they pass it into law you have little legal recourse against them for any loss incurred by yourself, and resultant of their by law if you own a house within their boundaries.

A residents/rate payers association will have to institute a class action suit against a muni - to have these kind of by-laws reversed, once they are approved by the council...as the assumed "will of the people".

[snoopy]

Interesting. Did not notice this bit before:

(f) the erection of any solar water heater not exceeding 6m2 in area on any roof or 12m2 when erected other
than on any roof; and

There are very limited 'minor building works' exemptions to the National Building Regulations, and this is one.

So PV systems are actually regulated building alterations. And they technically do need to be approved on building plans. I have heard (but do not have access to the docs to verify), that there are exemptions to engineering load analysis requirements that cover most PV installations (exempting them from engineering requirements).

So, as usual, the law is an ass. Complaining about it won't help. To get change, get your political party involved, or get a lobby group together. I assume this is how solar water heaters got their exemption.

[snoopy]

There is too little involvement of communities in aspects like this, and the muni's are becoming like little mafias in a sense in their attempt to find new income streams - but the lack of consumer/rate payer involvement is typical of SA, and its very frustrating at grass roots level. This passive attitude of the SA ratepayer is taken advantage of.

The only people who will welcome any kind of ratepayer resistance against by-laws and regulation (local government) that don't really benefit society. Are those who stand to lose financially (for no logical reason) from it being passed into law. Those who financially benefit from the law being passed , will be very grumpy against resistance opposing it, obviously. And even more grumpy if a judge recalls a by-law that did not benefit society at large but ensured a income stream for a few who had the power to write it into local regulation without public participation.

Every string of PV on a roof top usually adds at least 2 or 3 lateral "battens" (rails) of aluminium alloy steel to a roof top , over and above the existing wooden or light steel roof support structure of the roof covering. The PV panel frames add additional strength vertically also supporting the trusses, as these are bolted to the lateral rails. The whole frame of the PV string therefore acts as a reinforcing structure to the roof even though it is light weight.

You are never going to be able to snap a PV rail by hand, despite its light weight, but you can snap a normal wooden roof batten by hand. And the alloy steel rail will last as long as any roof batten will, probably much longer.

This winter our area had a level 6 storm, with extreme winds gusting at up to 135km/h. Our PV panels didn't move or budge and neither did the roof its mounted on.

I wonder what special bylaw (and additional inspection and expense) is required for buildings in Sutherland or Ceres to carry the load of snow across the top of a standard roof in winter? And how much snow on a roof top is too much for SA building regulations?

Re solar tube type roof top geysers.

Installers must ensure , not the home owner.... that the roof structure can support the solar geyser system. As they often have roof top tanks with 100-200l of water in them (SANS 10106:2014 5.3.1)

The installer cannot therefore install one, or even sell a solar geyser to a home owner -if the INSTALLER did not ensure that the roof structure can support the device. Any bylaw pertaining to this will then need to regulate the installer compliance - and not shift this SANS liability to the home owner.

[Trevorn]

I suspect this article is being interpreted incorrectly by the writer and others.

It starts off saying the INSATLATION needs to be signed off by a PR engineer.

I interpret that as the engineer is not signing off the design of the roof, but the condition of the roof. (although design may be a small part of the sign off) and the quality of the actual PV panel installation. Although if you wish to install on a thatched roof, then design will most certainly be an issue

Any roof structure in good condition based on SANS specs or even rational design ( be it wood or LFS) will easily handle the weight of solar panels, as well as a heavy load of snow. In that configuration the loads on the purlins are in compression. Take a solar installation, with wind loading and wind coming under the panels and the loads will oscillate between compression and tension.

Remember your solar installation is not attached to the roof trusses directly but via the purlins. The fact the article is focusing on the trusses tells me the writer has not researched this well. The purlins being smaller will decay before the trusses do.

I would say the following should be checked.

Condition of purlins and trusses.

Is the junction attaching the alu extrusion to the purlin waterproof? If not you wont have an issue in the first few years, but in time you will as the purlin decays and fasteners corrode.

Are the fasteners sufficiently corrosion resistant? You would have different requirements for Gauteng and the West Coast.

Are there enough brackets attaching the structure to your roof and are they correctly spaced?

Is the general quality of the installation up to standard?

Remember this is something that probably wont be regularly maintained and is expected to last for 20 or even 30 plus years, making the quality of the initial installation very important. The average person wont know what to look out for. Rotting timber and corroding fasteners will be your long term problem, not the design of your roof.

[ddevos]

Remember your solar installation is not attached to the roof trusses directly but via the purlins. The fact the article is focusing on the trusses tells me the writer has not researched this well. The purlins being smaller will decay before the trusses do.

Sorry Trevor, but I have to disagree! Most certainly, in the case of tile roofs, the rail brackets are definitely attached to the trusses directly. There isn't a way to attach them to the purlins, their design just does not make provision for that and the supplied screws are longer than the height of purlins anyway, and that applies to ALL bracket designs that I have seen so far. That is apart from the fact that purlins simply cannot be regarded as strong enough for attaching roof rails to them, no matter whether they are new or old.

[Trevorn]

[quote=ddevos post_id=2335659 time=1724693049 user_id=10853]
[quote=Trevorn post_id=2335654 time=1724692275 user_id=29352]
Remember your solar installation is not attached to the roof trusses directly but via the purlins. The fact the article is focusing on the trusses tells me the writer has not researched this well. The purlins being smaller will decay before the trusses do.
[/quote]

Sorry Trevor, but I have to disagree! Most certainly, in the case of tile roofs, the rail brackets are definitely attached to the trusses directly. There isn't a way to attach them to the purlins, their design just does not make provision for that and the supplied screws are longer than the height of purlins anyway, and that applies to ALL bracket designs that I have seen so far. That is apart from the fact that purlins simply cannot be regarded as strong enough for attaching roof rails to them, no matter whether they are new or old.
[/quote]

You probably right Dirk.

When I had my installation done, I made up a steel grid structure from 200 mm lip channel bolting onto the parapet, so the tiles are not lifted at all.

My reasoning was I don't have conventional trusses, but a vaulted roof. If there ever was a leak I would have issues trying to seal it. (So would most people) Using a surface mount grid means I can visually inspect it and maintain it, and it will not cause a leak.

Yes it is unconventional, but it worked out well for me as the size of the roof and panels meant there was only a 300 mm space between the last panel and the parapet, so the steel structure is hardly visible from the ground.

Anyway my point is the article is referring to the installation not roof design. I suspect the PR engineer will be more interested in the installation and condition of the roof rather than the design of the roof.

[snoopy]

From the article..

A structural engineer registered with the Engineering Council of South Africa (Ecsa) has to sign off on all installations. According to local structural engineer Marius van Coller, there is a reason for an engineer's inspection.

He says there is a risk of structural collapse if the roof truss design is not adequate for the number of solar panels being installed.

Its my argument that if your roof structure was built to SANS standard as it should be -there is no risk of structural failure as result of adding solar PV panels. If your roof structure was built under spec, then yes, but then even workmen will make your roof collapse if they put load on it. And then it would be an inferior and illegal roof structure from the onset when the house was built. If anything the PV panel rails etc will reinforce the roof, which is tied to the walls and the walls to the foundation of your house.

In terms of roof top solar geysers this is what the Installer must be compliant with.

Installers must ensure that the roof structure is able to support the solar system. (SANS 10106:2014 5.3.1)

• Where it is not possible to comply, a professional engineer or registered technologist must design the installation in such a way that the safety and performance principles of the standard are incorporated. (SANS 10254 2017 4.1.1.2 and SANS10106 2014 4.1.7)

• Water heaters or storage tanks with a capacity of 200 litres or more may not be attached to a wall. (SANS 120252-1 2012 8.4.6.5)

I've seen many installations where the 200l tank is fitted to a wall, often in garages or an outside wall.

• The solar system must be installed in such a way that it does not accelerate the deterioration of the roof. (SANS 10400-L, SANS 10243, and SANS 10252-1)

There is no SANS regulation for solar PV panels per se, , except for the wiring code SANS10142-1-2.

But the panels and the fittings are manufactured to international standards, which require them to comply with many regulations globally if they are to be sold in those markets, especially the 1st world markets (EU, AUS etc).

SANS 10142 is for electrical setups and SANS 10106 for solar water heaters

SANS10142-1-2 only applies to the wiring code of a solar PV system linked to an inverter. Which needs to be installed by a master electrician (competent person).And for which a CoC is required, and thats completely acceptable - because you dont want an installer installing inferior wiring to your house for the system.It would also be a requirement of your building insurance that your house wiring is correct and to SANS code, with the system installed.

SANS 10142-1: 2024 Edition 3.2 was released on 12 August 2024. A couple of days ago.