You will have seen occasional moans from me about how my system doesn't perform so lekker on overcast days. I thought about an upgrade, and also a changeover switch so that I could - on nice bright days - move the non-backed up circuits to the backed up side, at my own risk of causing an overload.

My initial thought was to get my 6 north facing panels replaced with something more powerful. They are 325w. If I could put 550s in their place then I could get a bit more PV, especially in the afternoons. I understood that when the weather was really bad they wouldn't make much difference, but they'd give me more in the afternoon and the system might have a better chance of getting fully charged.

I got a quote from the guys I bought the system from. It surprised me because I thought that my existing cabling, connectors, panel mounting hardware and so on would be retained. But not... everything brand new.

The quote was for more panels than I asked for, but it did represent a situation that been mentioned in conversation, so I'm not upset about that. 

But, with all the new hardware etc it doesn't look like a good ROI in terms of money spent for extra PV power gained.

I can see an argument for having to replace everything, but still, it's not small change, far more than just the cost of the panels and some labour.

Any thoughts on this? Would those of you who do installations have wanted to replace everything? Is mounting hardware panel specific so that what works for one brand may not work for another? Have I completely underestimated what is required?

Maybe I should have a chat and see if they can find a way clear to just change panels and leave everything else in place.

Edited August 10, 20232 yr by Bobster.
clarity

This also goes to a favourite bee in my bonnet: Who maintains/alters systems in the long run? Say I sell this house and the buyer wants more panels or a bigger battery? Are there guys who take on that work?

46 minutes ago, Bobster. said:

You will have seen occasional moans from me about how my system doesn't perform so lekker on overcast days. I thought about an upgrade, and also a changeover switch so that I could - on nice bright days - move the non-backed up circuits to the backed up side, at my own risk of causing an overload.

My initial thought was to get my 6 north facing panels replaced with something more powerful. They are 325w. If I could put 550s in their place then I could get a bit more PV, especially in the afternoons. I understood that when the weather was really bad they wouldn't make much difference, but they'd give me more in the afternoon and the system might have a better chance of getting fully charged.

I got a quote from the guys I bought the system from. It surprised me because I thought that my existing cabling, connectors, panel mounting hardware and so on would be retained. But not... everything brand new.

The quote was for more panels than I asked for, but it did represent a situation that been mentioned in conversation, so I'm not upset about that. 

But, with all the new hardware etc it doesn't look like a good ROI in terms of money spent for extra PV power gained.

I can see an argument for having to replace everything, but still, it's not small change, far more than just the cost of the panels and some labour.

Any thoughts on this? Would those of you who do installations have wanted to replace everything? Is mounting hardware panel specific so that what works for one brand may not work for another? Have I completely underestimated what is required?

Maybe I should have a chat and see if they can find a way clear to just change panels and leave everything else in place.

This is not the 1st time we head of someone who want to throw out a whole system when there can be some equipment added. Yes I'm not a installer but I know most people would not want to fit or operate 2 systems. That is what I would rather do. It also lowers the risk of having no PV system if there is 2 systems that can work independently from each other. 

Without k ow your detail I think a 2nd inverter that can work with 3-8 panels per string and can take 2 strings like the Kodak Max and Luxpower SNA 5kW might be something to consider.

This is like having a few cars even if you can just drive 1 at a time

Would like to see what others say about this. 

Hi Bobster, with reference to mounting hardware only. (also not an installer, so there could be good reasoning im not thinking of)

I would suppose it depends on the type of bracket used (i.e. anti theft brackets, that may be damaged on removals?)

 

But if it is the mid-clamp and end-clamp type with a capscrew. Surely these could be re-used, provided the panels are a similar thickness.

I don't see the justification to replace all, if the above is true.

 

When you say, everything, does this include the mounting brackets from the rails to the roof? Additional's may be needed to account for the weight difference between 325w panels vs 550w panels

Perhaps the reasoning to adjust rails spacing is for the larger panel footprint, but even so, that hardware should be acceptable to some degree. 

P.s. after reading Scorps reply, if it is the whole system being upgraded, maybe there are other factors. I was reading your question applying to just the panels and their hardware.

5 minutes ago, Garthox said:

Hi Bobster, with reference to mounting hardware only. (also not an installer, so there could be good reasoning im not thinking of)

I would suppose it depends on the type of bracket used (i.e. anti theft brackets, that may be damaged on removals?)

 

But if it is the mid-clamp and end-clamp type with a capscrew. Surely these could be re-used, provided the panels are a similar thickness.

I don't see the justification to replace all, if the above is true.

 

When you say, everything, does this include the mounting brackets from the rails to the roof? Additional's may be needed to account for the weight difference between 325w panels vs 550w panels

Perhaps the reasoning to adjust rails spacing is for the larger panel footprint, but even so, that hardware should be acceptable to some degree. 

P.s. after reading Scorps reply, if it is the whole system being upgraded, maybe there are other factors. I was reading your question applying to just the panels and their hardware.

The last paragraph mentions to have a chat and see if the installer might see their way to only change the panels and not everything. That made me reply like I did. 

What I'm discussing is a quote for replacing the existing panels. Currently I have 6 panels facing N and 6 facing E. My initial idea was to get a bit more woema on the N facing string. The discussion then went to having a W facing string as well. The quote (and this is just a report, not a complaint) is for 15 panels in 3 strings (I presume, because there's not enough N facing roof to do it any other way). There are 12 panels in place already, and the quote has 15 of everything.

To be clear: The proposal is not to add panels alongside what's already on the roof, but to replace those panels.

The quote was given afer a site visit that included an aerial inspection done with a drone.

I'm not angry about this, just surprised. There may be some good reasons for this that I have missed, and @Garthox suggests one.
 

Edited August 10, 20232 yr by Bobster.

Also not an installer, but I'd be concerned about placing new panels on top of existing equipment. Issues of size and weight have already been raised, and I'd guess the electrical specification of cables and components would come into consideration. I'd also wonder about the age of the equipment, and be not keen to offer a warranty if the lifespan of the structure is not certain to last the lifespan of the panels.

Is this maybe a scenario where a dedicated hot water solution makes sense? Just assuming you don't have this since it's not in the footer.

Maybe a solar EV tube to take over the production of hot water from the solar PV, considering the lower space/footprint it takes up? If space on the North side is limited, maybe consider shifting one panel to the East-string to make space for it.

Otherwise, maybe a Geyserwise with a couple of PV panels on the West-side doing DC water-heating? That might end up cheaper than replacing a set of still good panels including hardware before their time has come.

 

 

In regards of reusing the old mounting hardware, most likely you can re-use it but it will depend on the current panels mounting method and size, compared to the new panels. Take a look below at the different mounting methods for JA Solar, if you are using clamps, the allowed deviation is +/-50mm from 1/4 of the Length or Height of the panel. With different panel sizes the rails will have to be re-positioned.

 

Edited August 10, 20232 yr by PowerUser

55 minutes ago, GreenFields said:

Also not an installer, but I'd be concerned about placing new panels on top of existing equipment.

I'm expressing myself badly. The request was to take the old panels off the roof and put new ones up.

55 minutes ago, GreenFields said:

Issues of size and weight have already been raised, and I'd guess the electrical specification of cables and components would come into consideration. I'd also wonder about the age of the equipment, and be not keen to offer a warranty if the lifespan of the structure is not certain to last the lifespan of the panels.

Is this maybe a scenario where a dedicated hot water solution makes sense? Just assuming you don't have this since it's not in the footer.

I have a heat pump, run on the backed up side of the DB.

The problem I'm trying to solve is when we have overcast days, or even overcast mornings and then the battery doesn't charge from PV.

55 minutes ago, GreenFields said:

Maybe a solar EV tube to take over the production of hot water from the solar PV, considering the lower space/footprint it takes up? If space on the North side is limited, maybe consider shifting one panel to the East-string to make space for it.

Otherwise, maybe a Geyserwise with a couple of PV panels on the West-side doing DC water-heating? That might end up cheaper than replacing a set of still good panels including hardware before their time has come.

 

29 minutes ago, PowerUser said:

In regards of reusing the old mounting hardware, most likely you can re-use it but it will depend on the current panels mounting method and size, compared to the new panels. Take a look below at the different mounting methods for JA Solar, if you are using clamps, the allowed deviation is +/-50mm from 1/4 of the Length or Height of the panel. With different panel sizes the rails will have to be re-positioned.

 

Thanks. There's clearly more to this panel mounting business than I'd thought.