Vintage Solarex PV Panel

James Solar Expert Posts: 250 ✭✭
Hello Folks, I came across an item at a estate sale I thought might give you a kick ... I couldn't help myself, I had to grab it as a collectable. It is a "vintage" Solarex PV panel. It was encased (sandwiched) in a homemade overglaze frame with polycarbonate on front and rear of panel.

I removed the overglaze mounting frame and polycarbonate, and cleaned up the panel. I found the unit to be quite intact, without any looseness in the frame. The rear white encapsulation (EVA?) layer is somewhat "sticky", so I'm guessing it is starting to breakdown.

 It is labeled Solarex Solar Energizer type 2400 EG Size is 22.25" x 22.25" x 0.75" thick aluminum frame.
36 cells, 3.25" diameter
In full sun I measured 19.96 VDC @ 0.97 amps
 Im curious, does anyone have a clue as to when this panel was manufactured? Early 1980's?
Based on the size of the cells, Im guessing the unit is actually producing just about full power.
I believe the cell size is a clue as to aprox. manufacture date. Check out the photo of the "state of the art" output wiring method!

 Anyone know about this panel and what the original output wattage spec would have been?


  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,044 ✭✭✭✭✭
    Looks like the cells are about 3" by the dimensions of the panel. The oldest of my panels have 2 1/2" cells. This is a really cool old panel. Haven't seen one like this before. I have a collection of vintage panels myself. This would make a nice addition to my collection. LOL
     I found this online as well as some patent applications and other Solarex/J.P.L./Nasa reports. The first patents were made in the mid 70's. I would guess this panel to be early 80's vintage.
    Solarex “Solar Energizer” solar panel | Smithsonian Institution (

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.

  • James
    James Solar Expert Posts: 250 ✭✭
    edited May 2023 #3
    I never thought about collecting vintage panels, but this one dropped in my lap.
    I actually bought a large 40 vdc 300 watt panel at the sale ($30) and this little guy was sitting on the ground nearby. I asked about price and the folks said I could have it for free because I bought the big one.

    My google search yielded the same Smithsonian link, but not much else. I was actually interested in some more history of Solarex Corp. I remember they were a rather large supplier in their day. I also remember that I believe BP bought into the company, and maybe even bought them out completely. I'm going to try to research some history.

    I'd love to find a trade magazine ad or article about this panel to use as part of a wall display.
    The panel almost looks artistic to me.

    My avatar photo is a Bell Labs 1956 National Geographic ad page.
  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,044 ✭✭✭✭✭
    Here's a rather long and pretty boring report I came across.
    19780016677.pdf (
    You are correct about BP eventually buying out Solarex. Sad that BP produced some very high quality solar panels but had a massive problem with faulty Strain relief and J-box connections around 2004 that cost them dearly in panel warranty replacements.

     Here's a couple pictures of some of my older panels. The first two shots are of what I understand to be the first panel to be available for sale to the general public. It has a rubbery silicone front and fiberglass board backing. The next pics show a panel that was made with TecStar cells that were used in early satellite use. Notice the different and advanced looking radial traces on the cells. These are the 2 1/2" cells I mentioned. The last couple shots are ancient Arco panel. I wish I knew more about this one. The enclosure supporting the cells and glass is open air and box like. These cells seem to be the crudest of all the panels I have

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.

  • karl_solarmuseum
    karl_solarmuseum Registered Users Posts: 1
    @James, thanks for sharing! Yes, that is from the early 1980s. Size of the wafers is one indication but the other is how the traces are done. Earlier wafers had soldered top traces and later are screen printed in general. I believe I have some individual cells that are the same pattern sold by RadioShack under the Archer brand. I have yet to upload them to

    Also, if you want to learn more about Solarex, one of the founders wrote a fun read called Sun Above the Horizon: Meteoric Rise of the Solar Industry by Peter Varadi. It's in my top 5 solar books currently.