Ground mounts for second set of panels for Winter use only

[SenileOldGit]

My 12kW of ground mounted Canadian Solar 595W panels don't give out enough kWh to get me through a day during the Winter months, if it's a cloudy day. I was thinking of buying another 8kW of panels (you can now buy 8kW of new solar panels from BimbleSolar for £1,200 plus delivery) to use with a couple of extra Voltacon V5 inverters, but only during the Winter months. I would put the solar panels out in the garden on some sort of temporary mount - I was thinking of some sort of metal spike that fits onto each corner of a panel (so four per panel), and is then hammered into the ground. The angle of the panels would be about 30 to 45 degrees from the horizontal.
It would need to be something that isn't permanent, so that I can take all the panels up in the Spring - because otherwise I would have even more potential spare electricity than I do with 12kW of panels during the warmer months. (I have a big garden and I don't spend much time in it when it's cold, so this would be an ideal situation for me.)

 

[timselectric]

If just temporary for winter, you don't need anything except panels.
Configure the strings, similar to existing, and just parallel to the same MPPT's.
Overpaneling is great for winter.

 

[42OhmsPA]

Following this to steal ideas, I've been thinking about the same thing the past few weeks.
One of my ideas involves IBC totes (filled with water and some RV antifreeze) along with strut.
Another one involves an A frame structure that can double as a greenhouse in early spring.
The last one is I beams sunk in the ground on a steep angle (and concentrated) along with some high tension cable to mount the panels on. It would double as a clothesline, hammock station and/or shade structure in the summer with some of those parachute material sun shades.

 

[timselectric]

With solar panels being so cheap, now.
Overpaneling for winter is very appealing.

 

[JRH]

Following this to steal ideas, I've been thinking about the same thing the past few weeks.
One of my ideas involves IBC totes (filled with water and some RV antifreeze) along with strut.
Another one involves an A frame structure that can double as a greenhouse in early spring.
The last one is I beams sunk in the ground on a steep angle (and concentrated) along with some high tension cable to mount the panels on. It would double as a clothesline, hammock station and/or shade structure in the summer with some of those parachute material sun shades.

I’m doing the same thing now …panels came in last week. …….im paneling for winter with only an expected 20% power production of summer ……

unless it just awful weather I can generate enough to get by…

unless it’s cloudy and raining or snowing ( 5-10%), …..after keeping track this winter , I should be able to maintain at least 20% of summer power..probably more if averaged out …
If i find what I bought isn’t enough I will keep adding panels Untill it is enough…at some point it will be enough ….haaa, …..
In my RV I don’t need a ton of power to be fine offgrid…in the summer I will be able to run about anything as much as needed and then trim it back a little at night…. No prob…

Winter is what I’m trying prepare for…with location and total power…winter is the big unknown to work toward..I have good back up , but would like to get where I don’t need it…hope it works as planned.

J.

 

[SenileOldGit]

If just temporary for winter, you don't need anything except panels.
Configure the strings, similar to existing, and just parallel to the same MPPT's.
Overpaneling is great for winter.

Thanks for that info, I never thought of that! If they're paralleled then the voltage won't be higher than 400V odd, as long as I use the correct number of panels per string.

 

[SeaGal]

Thanks for that info, I never thought of that! If they're paralleled then the voltage won't be higher than 400V odd, as long as I use the correct number of panels per string.

Few thoughts...

If you parallel the panels, the current will increase (double if same type of panels). You will need to look into the max current capability of your inverter and see what it will handle.

Do you actually need to physically remove the panels in the Spring? Sounds like a lot of work, rather than just not turning the new inverter on. Or is it to do with not needing planning permission if they are a temporary feature? - I don't know whether there are time limits or not regarding PP

Regarding mounting, you could also consider Renusol tubs.

 

[timselectric]

If you parallel the panels, the current will increase (double if same type of panels).

That's the goal, since winter production is reduced.

You will need to look into the max current capability of your inverter and see what it will handle.

Amperage isn't pushed, it must be drawn.
There's nothing to handle.
Your phone charger doesn't have to handle the 20a available at the receptacle it's plugged into. It just draws what it needs from the available current.

 

[Bongbong]

Hello SenileOldGit,

Have you considered mounting the panels vertically along the fence? It might be ok for winter use, although on a cloudy day you might want horizontal. As a fence they don't take up much room and personally I quite like the ascetics of the solid black panels.

In a somewhat related question since panel prices are so low they can be used as a building material, how much over-panelling can we do? Double, triple, or something as extreme as twenty fold since panels on cloudy days seem to produce 5%.

 

[SeaGal]

Amperage isn't pushed, it must be drawn.
There's nothing to handle.
Your phone charger doesn't have to handle the 20a available at the receptacle it's plugged into. It just draws what it needs from the available current.

Sure... but if the inverter can't make use of the additional current, then the additional panels will be underused. For example, my Solis has a max current of 13A, so it would be a waste paralleling two (say) 11A strings if it can only use 13A of the available 22A.

 

[SenileOldGit]

Sure... but if the inverter can't make use of the additional current, then the additional panels will be underused. For example, my Solis has a max current of 13A, so it would be a waste paralleling two (say) 11A strings if it can only use 13A of the available 22A.

No it won't, if in the Winter you are only getting 5A off each string... That's why the strings are in parallel - the inverter will be blown up by more than its maximum voltage (in my case, 500V per inverter), but the inverter will decide how much it wants to draw in amps.

It is only additional current in the Winter, in the Summer the inverter will easily take as much as it can handle because there will be more than enough available.

I have decided against removing the panels in the Summer, it's too big of a job to do every year.
I am thinking about putting two strings of 15 x 400W panels out permanently. First I will see how much power I get from my panels this Winter, and see how much grid electricity I have to use to supplement it, then decide if it's worth getting more panels.

Bimblesolar (and I expect other sellers) have 400W panels for £49+VAT if you buy 10, I would need two strings of fifteen panels (or maybe fourteen) to match my existing two strings of ten 595W panels, so only £1,800 odd for another 12kW - incredibly cheap.

As Bongbong said, you could use them structurally now they are so cheap, and build outbuildings from them - the only problem I can see is that you would ideally want all the panels in a given string to be facing the same direction. I suppose if you have a long shed and cover one side and the roof with panels, that would work well. The prices are unbelievably low nowadays though, and the panels' quality is also better than it has ever been, as well as the efficiency.

I see people are still trying to sell crappy old panels on Ebay (UK) for more than these brand new panels cost! Crazy! I couldn't find any used panels (in quantities of more than two or three) that were a reasonable price (I would say maybe a third of the price of these panels would be reasonable, seeing as the used panels' original efficiency was probably only 15%, then take away ten years or more of use which takes it down to maybe 12% efficient, and you immediately need twice as much surface area of panels to generate the same as new panels would generate - which means twice as much spent on mounting materials. So screw that!

 

[fourtytwo]

I see people are still trying to sell crappy old panels on Ebay (UK) for more than these brand new panels cost! Crazy! I couldn't find any used panels (in quantities of more than two or three) that were a reasonable price (I would say maybe a third of the price of these panels would be reasonable, seeing as the used panels' original efficiency was probably only 15%, then take away ten years or more of use which takes it down to maybe 12% efficient, and you immediately need twice as much surface area of panels to generate the same as new panels would generate - which means twice as much spent on mounting materials. So screw that!

Dead right there reckon Ebay have gone right off the boil on solar......greed!
Have you looked at city plumbing, good panel prices & free delivery over £80ish, very handy especially if you just want a few extra for filling in or some mounting rails. If I had the space completely agree with your over-paneling scheme.

 

[timselectric]

Sure... but if the inverter can't make use of the additional current, then the additional panels will be underused. For example, my Solis has a max current of 13A, so it would be a waste paralleling two (say) 11A strings if it can only use 13A of the available 22A.

If it was summer, yes.
But this is just for winter help.
I'm guessing that it still won't be clipping, in winter.