Dumb question about physically moving solar panels

[gfmucci]

That's what I thought about my mother 20 years ago when I put in my PV, so didn't recommend it to her.
She's 101 now.
Break-even on GT PV is now about 1 to 3 years before labor (depending on utility rates.)
3 to 9 years including labor.
That's based on my local $0.15 to $0.50/kWh. If you pay $0.05/kWh, PV isn't for you.

$0.12 per k watt hour here. So 12 year +/- break even with labor? That takes me to 87. Hmmm.

 

[Wellbuilt]

Getting them up there is really not to bad .
I had a loader parked in the drive way it was just easer to walk up with them .
They would slide off if they where just laying there, the only problem I had was one of the pos and negative got reversed And Junior could not remember witch bank of panel where on what breaker
I still don’t know

 

[newbostonconst]

Carried mine, 24 panels by myself, up the ladder. Scary for the first couple then was fine. 47 years old....

Sometimes a ladder in the bed of a truck is more secure, if you can place it against something, and you don't have to climb as far.

 

[jtvt]

I would rent a telescopic boom lift or a rough terrain forklift.

 

[Wellbuilt]

I would rent a telescopic boom lift or a rough terrain forklift.

we are all cheep skates we don’t want to spend money on that ?

 

[caki]

Here two ways I did: for the first 16 panels, steel cable between two tall trees. A pain to string cable.

Second method used a J channel steel frame with a platform for the panel that would slide up and down:

and last but not least is the question of maintenance after they are in the roof:

 

[JimStLaurent]

36 panels got a ride to the roof on this DIY panel ladder lift. Screwed a beam onto the top of a ladder. Built a sled with rails that rode along outside the ladder. Attached a pulley and rope. then a big guy on the ground pulled them up. Two us unloaded at top and carried them to the next staging area.

Standing seam metal roof, made harnesses and ropes mandatory. A third guy on the roof helped with rope management while moving things.

 

[Hedges]

Second method used a J channel steel frame with a platform for the panel that would slide up and down:

4 rows of panels on 5 horizontal rails. Do you have close-ups or detail drawings of how the panels attach?

I'm planning something like that but have concerns about strength, that panels bolted by the usual holes on long side of frame could have frames tugged off the glass. I'm thinking I need to add ties to the shorter end pieces of the frames to keep them together.

Conventional mounting has each panel straddle a pair of rails, and either top clamps or bottom clips. Frames secured to rails that way are held, can't bow apart.

 

[Sanwizard]

How do you guys actually get panels on your roof? I moved 2x 310W canadian solar panels onto the short roof above my garage and it was not easy. I backed my truck a little bit into the open garage and hoisted the panels from the ground (leaning against the truck) to the truck bed, then further onto the roof. I ended up scratching the side of my truck a little even though I had towels between the panels and paint. Carrying them up a ladder would not be possible (49lb/22kg). Do you guys build ramps? Pulley system? Crane? What have you used to get panels raised?

I originally manned up and used one hand on the ladder, and the other on a panel. Qcell 330w panels, 67 inches high. That was hard and dangerous, so I went to home depot, bought some rope and a pulley, and a $2 caribiner i could hook onto the panel. I attached the pulley to the top of the ladder. It became much simpler to then push the panel up the ladder, take up slack on the rope, step up one rung, and repeat until even with the mount.
I only did a couple panels a day, as this old guy is very out of shape.
My roof was way to steep for any other way except renting a lift, which can get expensive.

 

[caki]

4 rows of panels on 5 horizontal rails. Do you have close-ups or detail drawings of how the panels attach?

I'm planning something like that but have concerns about strength, that panels bolted by the usual holes on long side of frame could have frames tugged off the glass. I'm thinking I need to add ties to the shorter end pieces of the frames to keep them together.

Conventional mounting has each panel straddle a pair of rails, and either top clamps or bottom clips. Frames secured to rails that way are held, can't bow apart.

The panels are frameless so I've used these clamps: https://www.ebay.com/itm/274278823741
They go on top of a Ironridge XR10 rail. While I have not observed any problem with the rails moving apart as they are on a metal roof, I have observed that the panels have bowed some due to their weight. Being frameless panels they have less support and that worries me. But it has been 3 years, snow and summer in NC and no panel has cracked or experienced any failure.
In retrospect I wish I had figured out a way to have the rails under the panels, but the spacing of ridges on my roof didn't match with the size of the panels. Anyway, I'm hoping for the best. I already got my payback so anything from now on is profit.

 

[vinthewrench]

Always, always have fall protection,.. That means at a minimum a rope and some form of harness that prevents you from falling off the roof. I usually just fashion a prussik cord to allow me to move around the roof while I work close to the edge.. You can make a hasty harness from webbing if you dont need to do this too often..

you can make a prussik with a fishermans knot

use this knot for important connections.

 

[Hedges]

The panels are frameless so I've used these clamps: https://www.ebay.com/itm/274278823741
They go on top of a Ironridge XR10 rail. While I have not observed any problem with the rails moving apart as they are on a metal roof, I have observed that the panels have bowed some due to their weight. Being frameless panels they have less support and that worries me. But it has been 3 years, snow and summer in NC and no panel has cracked or experienced any failure.
In retrospect I wish I had figured out a way to have the rails under the panels, but the spacing of ridges on my roof didn't match with the size of the panels. Anyway, I'm hoping for the best. I already got my payback so anything from now on is profit.

So those form a frame, clamping the glass full length on two edges.
I can't tell from the pictures if you have anything on the other two edges, like normal panel frames.
Seems like with a gap between ends of panels, you could install more of these so panels are framed on four sides. Probably just on the glass, no other support, but serves as a stiffener so glass won't bend.
Sounds like it is secure enough, though.

3 years break-even. That's where I put hardware for DIY grid-tie these days (at my lowest time of use rate.)
Starting 3 years ago, maybe longer or maybe compared to higher rate.
Time to do a backup system for grid-failures, if you haven't already.

 

[caki]

So those form a frame, clamping the glass full length on two edges.
I can't tell from the pictures if you have anything on the other two edges, like normal panel frames.
Seems like with a gap between ends of panels, you could install more of these so panels are framed on four sides. Probably just on the glass, no other support, but serves as a stiffener so glass won't bend.
Sounds like it is secure enough, though.

3 years break-even. That's where I put hardware for DIY grid-tie these days (at my lowest time of use rate.)
Starting 3 years ago, maybe longer or maybe compared to higher rate.
Time to do a backup system for grid-failures, if you haven't already.

Yes, the short side has no support at all. There is a small gap for expansion. I'm going to test using an aluminum T-bar that I would slide on that gap with the "T" upside down. That should give support on the short end of the panel with minimum cost and complexity. But I have not been able to find the strip yet.
I've considered battery but the grid here is very reliable, so I just have a backup generator that I never used. But I recently acquired an RV, so adding solar to the RV is my new project.

 

[Hedges]

What kind of inverter do you have? Does it support optional battery, or does it do frequency-watts so it can interact with a battery inverter?
What does the future hold for your grid, is it coming under strain from climate change, population growth?

Maybe for the RV you could use an inverter which forms an island grid and manages grid-tie inverters. When out using the RV it would operate with its small PV array, but when parked at home it could plug into the house and serve as a battery backup UPS, with some of the house PV on its output.

Some (light weight high frequency) battery inverters probably support PV inverters up to 100% the battery inverter wattage rating. My heavy, low frequency transformer based Sunny Island support up to 200%. A single 6kW SI is 140 lbs and puts out 120V. With a 120/240V transformer at the house it would support 6kW of GT PV passing through to grid connection on the input, or if not fed by grid it would support 12kW of GT PV remaining in "island" mode. My permanent setup has a small battery, and while the sun during a power failure is up GT PV inverters run household loads like A/C and everything else. The battery just provides starting surge and supports small loads at night. Other battery inverters which perform frequency shift management of GT inverter might be a better fit for RV use.

 

[Sanwizard]

Yes, the short side has no support at all. There is a small gap for expansion. I'm going to test using an aluminum T-bar that I would slide on that gap with the "T" upside down. That should give support on the short end of the panel with minimum cost and complexity. But I have not been able to find the strip yet.
I've considered battery but the grid here is very reliable, so I just have a backup generator that I never used. But I recently acquired an RV, so adding solar to the RV is my new project.

Backup generators are interesting, but mine seems to work using Murphy' law of physics. Its a Generac whole house 20KW Natural Gas fed system. It tests itself once a week.

BUT, EVERY time I have actually needed it, it had an issue. One was a bad control board, another time a bad transfer switch, a third time bad gas valve. It got to the point where I bought a little Honda 2100i, which works every time. I bought the propane conversion kit for that also. Works great. That being said, its only for the fridge and some lights via extension cords. That is why I am building some big ass batteries charged via solar and connected to two MPP LV6548's. I want to be able to run my entire house off Solar if needed, long term.

 

[HRTKD]

Backup generators are interesting, but mine seems to work using Murphy' law of physics. Its a Generac whole house 20KW Natural Gas fed system. It tests itself once a week.

BUT, EVERY time I have actually needed it, it had an issue. One was a bad control board, another time a bad transfer switch, a third time bad gas valve. It got to the point where I bought a little Honda 2100i, which works every time. I bought the propane conversion kit for that also. Works great. That being said, its only for the fridge and some lights via extension cords. That is why I am building some big ass batteries charged via solar and connected to two MPP LV6548's. I want to be able to run my entire house off Solar if needed, long term.

I just sold a 10K Generac portable that was 16 years old. There was almost a line on my porch to buy it. I could have demanded asking price but I let the guy talk me down a bit because he brought his own helpers and I didn't have to do anything. It's a really heavy unit and I was really not looking to provide any muscle.

Anyhow, the generator I have in my RV is a 5.5KW Onan, which is 15 years old. The instructions are rather explicit that the generator is to be "exercised" once a month. That involves not just starting the engine, but also putting it under a load. I have to wonder if your Generac's self-test involves a load. The only time I've had a problem with the Onan is when the trailer wasn't level. The generator got pissy about the oil level being low (due to the angle). My ignorance, my fault.

Anyhow, back to moving solar panels. I'm getting older and wiser and am more aware of my limitations. I would rent a unit for moving things onto a roof. The cost of a rental may be slightly more than the cost of a dropped panel.

 

[Sanwizard]

I just sold a 10K Generac portable that was 16 years old. There was almost a line on my porch to buy it. I could have demanded asking price but I let the guy talk me down a bit because he brought his own helpers and I didn't have to do anything. It's a really heavy unit and I was really not looking to provide any muscle.

Anyhow, the generator I have in my RV is a 5.5KW Onan, which is 15 years old. The instructions are rather explicit that the generator is to be "exercised" once a month. That involves not just starting the engine, but also putting it under a load. I have to wonder if your Generac's self-test involves a load. The only time I've had a problem with the Onan is when the trailer wasn't level. The generator got pissy about the oil level being low (due to the angle). My ignorance, my fault.

Anyhow, back to moving solar panels. I'm getting older and wiser and am more aware of my limitations. I would rent a unit for moving things onto a roof. The cost of a rental may be slightly more than the cost of a dropped panel.

Load testing would be VERY beneficial! The Generac test seems is only internal to the unit. It always passed weekly self test even when the control panel was bad.( the aspect that was bad was its comms to the transfer switch) They should expand the test to include transfer switch initialization via control panel to test actual load.
Perhaps Kohler does a better job?

 

[caki]

What kind of inverter do you have? Does it support optional battery, or does it do frequency-watts so it can interact with a battery inverter?
What does the future hold for your grid, is it coming under strain from climate change, population growth?

Maybe for the RV you could use an inverter which forms an island grid and manages grid-tie inverters. When out using the RV it would operate with its small PV array, but when parked at home it could plug into the house and serve as a battery backup UPS, with some of the house PV on its output.

Some (light weight high frequency) battery inverters probably support PV inverters up to 100% the battery inverter wattage rating. My heavy, low frequency transformer based Sunny Island support up to 200%. A single 6kW SI is 140 lbs and puts out 120V. With a 120/240V transformer at the house it would support 6kW of GT PV passing through to grid connection on the input, or if not fed by grid it would support 12kW of GT PV remaining in "island" mode. My permanent setup has a small battery, and while the sun during a power failure is up GT PV inverters run household loads like A/C and everything else. The battery just provides starting surge and supports small loads at night. Other battery inverters which perform frequency shift management of GT inverter might be a better fit for RV use.

I have Enphase M215 inverters. I found them new at $35 each, so I built everything around that. Enphase now has a battery system that can work with the M215 invertes, but they are not cheap. I'm in NC, there is a lot of growth, but we are close to a substation so I think that explains the reliable power that we get. Major events here are hurricanes that will bring down power for some days when we have a direct hit.
Anyway, on the RV, that is my plan. To have a battery and panels on the RV. When parked I switch to the individual Enphase inverters. When on the road they charge the battery. If there is a power outage I move to the RV that I can leave the battery at 40% charged.
While I would love to implement an off grid system, I still need to consider the other needs of the family (College bills, trips, etc) and the ROI of the projects that I work on. I judge that the RV will provide me a project that provides the best ROI at this time.
I appreciate your feedback and ideas! Maybe I can pick your brain for an unrelated problem that my brother has challenged me with.
He has a farm in Brazil and he needs to make sure the water pumps keep on working when the grid is down (he has greenhouses). I need an affordable controller/inverter that would use both the grid and solar panels at the same time. No batteries. Basically it would use the Solar Panel when there is sun, supplementing with the grid power. When the grid is down it would run the pump with the Solar panel when it has enough production. It needs to work on the Brazilian grid.
Thanks

 

[caki]

Backup generators are interesting, but mine seems to work using Murphy' law of physics. Its a Generac whole house 20KW Natural Gas fed system. It tests itself once a week.

BUT, EVERY time I have actually needed it, it had an issue. One was a bad control board, another time a bad transfer switch, a third time bad gas valve. It got to the point where I bought a little Honda 2100i, which works every time. I bought the propane conversion kit for that also. Works great. That being said, its only for the fridge and some lights via extension cords. That is why I am building some big ass batteries charged via solar and connected to two MPP LV6548's. I want to be able to run my entire house off Solar if needed, long term.

I had my generator on storage, so I'm dreading when I try to use it. I followed all the instructions on the manual to winterize it, but Murphy Law is applicable to that too

 

[Hedges]

I'm not sure if the M215 support frequency-watts, or if Enphase uses some other scheme.

A Sunny Island at 140 lbs weighs a lot less than an Onan generator. It would fit in the same space but probably flat, not upright. So convection wouldn't work, but fan running more should take care of cooling.
If the M215 do frequency-watts, they could be fed through Sunny Island so you would have UPS grid-backup for downstream loads.


For water pumping, I imagine a VFD running 3-phase pumps. PV string with Voc not too high for the VFD wired into its DC rail (given how 6 diodes are wired to 3 input phases, have to bypass or rewire if fed by single phase, or bypass if fed by 3 phase.)
With lower voltage AC coming in, PV should hold up the DC rail as best it can, and if it droops below AC, that picks up some current. Not ideal MPPT, but simple. To make this work when grid is down, implement a control loop that keeps DC rail at 400VDC or whatever by varying pump speed.

Alternative is grid-tie inverter after the switch for the pump. If peak PV is below motor consumption it should never export. Two PV arrays of different orientations wired in parallel to inverter flatten the production curve. But this does not operate when grid is down.

Start pump in the motor when PV begins to produce, and run into the evening off AC if you need more water. That should maximum PV use.