Anyone experimented with boosting solar panel output with a mirrored surface?

[magentawave]

I have two 100 watt Renogy panels mounted on the top of my Toyota Sienna minivan that charge my Ecoflow Delta 1300’s. I wish I had room for more panels but with a Thule cargo box on one side of the racks, 2 surfboards on the other side, and the two panels in the middle, theres just no more room.

PROBLEM: It’s 11:00 AM as I type this and very cloudy and both panels are producing a measly 23 watts total. (If the sun was blazing I would be easily pulling 130+ watts.) Also, the days are getting shorter and the sun is at more of an angle relative to my flat fixed panels which means less energy thru the winter.

QUESTION: Has anyone experimented using a mirrored panel (or maybe just a white panel?) that’s about the same size as my solar panels to reflect light on to the solar panels? What were your results?

Thank you!

 

[sunshine_eggo]

 

[glandpuck]

"The Ivanpah system consists of three solar thermal power plants on 3,500 acres (1,400 ha) of public land near the California–Nevada border in the Southwestern United States."

This all mirrored system that heats a liquid extremely hot and uses the steam pressure to turn generators.

 

[thebeavesknees]

Very excellent results, and there's a how-to video on how they made the concentrators.

 

[DIYrich]

QUESTION: Has anyone experimented using a mirrored panel (or maybe just a white panel?) that’s about the same size as my solar panels to reflect light on to the solar panels? What were your results?

If you have room for a mirrored panel, why not make it a solar panel?

 

[thebeavesknees]

If you have room for a mirrored panel, why not make it a solar panel?

Mirrors can be cheaper and lighter than another panel, and can be used in cases where another panel might not fit.

 

[mvonw]

My solar array is on a hill overlooking a meadow. In winter, the combination of snow and cold dramatically increases output of my panels. Unfortunately it’s not nearly compensating for the much shorter days..

 

[pollenface]

Are your panels mounted flat? If you can set them up to be tilted towards the sun wherever you are parked it will increase production.

My flat planels on my 4wd don't produce much unless it's midday in summer

 

[Tomthumb62]

I have two 100 watt Renogy panels mounted on the top of my Toyota Sienna minivan that charge my Ecoflow Delta 1300’s. I wish I had room for more panels but with a Thule cargo box on one side of the racks, 2 surfboards on the other side, and the two panels in the middle, theres just no more room.

PROBLEM: It’s 11:00 AM as I type this and very cloudy and both panels are producing a measly 23 watts total. (If the sun was blazing I would be easily pulling 130+ watts.) Also, the days are getting shorter and the sun is at more of an angle relative to my flat fixed panels which means less energy thru the winter.

QUESTION: Has anyone experimented using a mirrored panel (or maybe just a white panel?) that’s about the same size as my solar panels to reflect light on to the solar panels? What were your results?

Thank you!

We have 400W of panels flat mounted on our trailer and another 200W Renogy folding suitcase. In the fall like this, the suitcase panels produce about 60% of the power when all 600W are connected. For example, if I just have the 400W flat mounted panels connected, I might be getting 100W on a day like today, but if I then add in the 200W suitcase (angled to the sun), I’ll get about 290W. During July, those same 400W panels will produce over 300W, because the sun is so high in the sky and blasting directly onto the flat panels.

Are you in a location that you could set up some suitcase panels on the ground? It can make a huge difference.

 

[magentawave]

Very excellent results, and there's a how-to video on how they made the concentrators.

The polished and coated mirrored panels he used are exactly what I’d like to buy. I tried to find the company, Aremet, in Canada he mentioned but couldn’t find the site. Will look for a source in the US.

Thanks

 

[magentawave]

We have 400W of panels flat mounted on our trailer and another 200W Renogy folding suitcase. In the fall like this, the suitcase panels produce about 60% of the power when all 600W are connected. For example, if I just have the 400W flat mounted panels connected, I might be getting 100W on a day like today, but if I then add in the 200W suitcase (angled to the sun), I’ll get about 290W. During July, those same 400W panels will produce over 300W, because the sun is so high in the sky and blasting directly onto the flat panels.

Are you in a location that you could set up some suitcase panels on the ground? It can make a huge difference.

I really wanted to buy a 200 watt folding panel to supplement the 200 watts of flat fixed panels on my roof to charge my Ecoflow Delta 1300’s. Everyone at the Ecoflow FB page said it can’t be done because the voltage would exceed what the Delta 1300’s can handle.

 

[magentawave]

Are your panels mounted flat? If you can set them up to be tilted towards the sun wherever you are parked it will increase production.

My flat planels on my 4wd don't produce much unless it's midday in summer

Nah, can’t tilt them. Maybe next build I will do that though.

 

[magentawave]

If you have room for a mirrored panel, why not make it a solar panel?

I don’t have room for another panel on the roof which is why I am considering a portable and folding mirrored surface that I can quickly set up and take down and easily stow away because it’s thin.

Just for the heck of it I put my front windshield cover on the roof next to my solar panels at about 3pm recently on a sunny day and it produced about 3 more watts of input into my Ecoflow Delta 1300.

That floppy dull medium gray fabric windshield cover is not at all a very reflective surface and wasn’t nearly as long as the two panels are. It was haphazardly placed at about 90ish degrees to the drivers side of the flat panel with the sun at 3 pm on the passenger side.

Three watts of boosted input isn’t much for two 100 panels, but what if the panel was a highly mirrored aluminum surface like the ones in the video and covered the entire length of the two solar panels? For example, it’s sunny and clear and 3PM now and I’m only getting *9 watts of input and the days are getting shorter. I’m thinking it could make a huge difference.

*Before 10ish AM and 1ish PM, a big part of the problem is due to shading because I have two surfboards stacked on the drivers side of the panels and a Thule rooftop cargo box on the passenger side of the panels.

So, I’m thinking of making a panel out of those mirrored aluminum panels shown in the video. Mine would fold so I can store them. I just have to figure out a way to connect them at each fold and make em rigid while in use. The key is to do this in a way that I can set them up or take them down in just a minute.

I’m open to ideas on how to do this!???

 

[Tomthumb62]

I really wanted to buy a 200 watt folding panel to supplement the 200 watts of flat fixed panels on my roof to charge my Ecoflow Delta 1300’s. Everyone at the Ecoflow FB page said it can’t be done because the voltage would exceed what the Delta 1300’s can handle.

You can sell the Ecoflow and build your own, if you're into that kind of DIY (being that you're on a solar DIY site...). It will be much cheaper, much more versatile, more powerful, flexible. You can even make it look fairly pretty, but you won't get the curb appeal that companies like Ecoflow, Anker and Jackery have spent a lot of money on to try to lure you to buy their product based at least 50% on looks. Then you could hook up five 200W folding suitcases if you wanted. It would be worth your while. Will Prowse even has a video on it and then there are others on this site who have done the same but put theirs in pretty boxes. Will just puts his in a milk crate, because it's cheap, DIY'rs often have one around, sturdy and you can easily see how the build is done. In a more finished-looking build, you can't see the internal build, but that's probably what you'd like to see and just know that the whole thing works like you want it to. $1000 could build you an excellent solar generator like this and you could do it for much less or $1500 would get you a ton more more battery capacity.

 

[magentawave]

You can sell the Ecoflow and build your own, if you're into that kind of DIY (being that you're on a solar DIY site...). It will be much cheaper, much more versatile, more powerful, flexible. You can even make it look fairly pretty, but you won't get the curb appeal that companies like Ecoflow, Anker and Jackery have spent a lot of money on to try to lure you to buy their product based at least 50% on looks. Then you could hook up five 200W folding suitcases if you wanted. It would be worth your while. Will Prowse even has a video on it and then there are others on this site who have done the same but put theirs in pretty boxes. Will just puts his in a milk crate, because it's cheap, DIY'rs often have one around, sturdy and you can easily see how the build is done. In a more finished-looking build, you can't see the internal build, but that's probably what you'd like to see and just know that the whole thing works like you want it to. $1000 could build you an excellent solar generator like this and you could do it for much less or $1500 would get you a ton more more battery capacity.

I probably will sell my Delta 1300's after I buy and build out my bigger van, but for now I need to figure out the cheapest way to make a portable, foldable panel(s) that will reflect light on to my two panels.

 

[KITROBASKIN]

Can’t help thinking mirror reflection will be irregular radiance on panels. Might that cause hotspots? Asking because I do not know.

 

[Warpspeed]

Can’t help thinking mirror reflection will be irregular radiance on panels. Might that cause hotspots? Asking because I do not know.

Its the same as the shading problem, but in reverse.
Any individual cells missed by the reflected solar energy will very likely drag down the output of the whole panel to what it would be without the reflector.

I agree with earlier poster DIYrich, if you have the space for a reflector, arguably better to just fit more panels.
An active tracking reflector might work, but cost and complexity pretty much rule that out, compared to just installing some extra panels.

 

[peakbagger]

You may not be aware of ancient solar history and the Cerrizo Crispy Panels. Arco Solar built a solar farm that used reflectors to up the amount of light to the panels. They turned brown quickly and eventually the farm was disassembled by a scrapper that rated the damaged panels and sold them. Some of the names were quadlams, new panels were in the $10 a watt range so people snapped up the Carrizo panels that still put out power but at a diminished rate. I, saw a set for sale once at a solar garage sale that long term dealer in VT held. They were dark brown and stamped with Carrizo on the back.

 

[Warpspeed]

These days solar panels are not expensive, especially used ones.
The most cost effective way to get the most from some pretty extreme sun angles is to electrically combine the outputs of panels facing in very different directions.

This is also extremely effective when there is total cloud cover and extremely diffused grey light, where it makes little difference which way the panels point. While total output will still be pathetic, at least every panel is adding its very small share.

 

[Doggydogworld]

I assume your two panels are connected in series. You should be able to connect a 3rd panel on the ground in series with the two on the roof. Or a second pair of panels in parallel (2S2P configuration). You might even find a single 200W panel with the right voltages you could parallel with the series pair on the roof. Just don't exceed the 1300's input ratings (65 Vdc and 10A, I think, but double check your particular unit's specs).

Reflectors really need to track the sun, otherwise they reflect the sun the wrong way much of the day. Even when they reflect onto the panel they tend to concentrate in a small area. That's bad for output and can damage your panel. Take a mirror outside and experiment with different angles to simulate the sun crossing the sky. You'll see how the reflection moves around and changes shape.

I'd first look at a portable panel or two. I'd also try to figure out a way to raise the existing panels out of the shade. Maybe if you post a pic of your roof people will have some good suggestions.