Solar Panel Rover




Introduction: Solar Panel Rover

If you would like to build a 8.64 kWh Solar Panel Rover, then this is the instructable for you! Operating descriptions will also be included in this instructable as well as brief assemblage directions. Originally this solar panel rover was made to bring electricity to Pomona College's Organic Farm which did not have access to the grid. Now the rover is used to power a large variety of outdoor events on the campus.

The rover features three solar panels, for a total of 570 W (each panel is 190 W), that are wired in parallel that are connected to a power controller that then charges six interstate batteries. The batteries are wired in parallel and are wired to a 1000W, 12V inverter with two electrical outlets. Between the batteries and the inverter is a fuse.

This Solar Panel Rover includes:

  • 4 Solar panels, 24 V and 8A each
  • 6 12 V, 120 amp Interstate batteries
  • 1000 W inverter
  • Outback systems Charge Controller
  • Two wheeled trailer with metal frame

Product List:

NOTE: If any part of this instructable is incomplete or you have suggestions please provide comments!

Step 1: Mounting the Solar Panels

You want to make sure that you purchase the panels and the trailer together because the panels are the largest component of the solar rover and it is imperative that the panels fit on the trailer.

In order to decide what angle you would like to fixate your panels, the following website provides suggestions depending on your location in the world. It mostly depends on your latitude:

The panels were purchased as a module and were screwed onto a metal frame and then wired in parallel to have 200 W optimum (24 V*8A) per panel. Between the charge controller and the panels is a disconnect that has a switch accessible for turning the rover on and off.

This disconnect is flipped "on" (connected) second when the rover system is turned on, and first when the rover system is being shut down. This is to prevent any potential overloading in the system.

Step 2: Charge Controller

The Outback systems generally come with a pretty detailed manual installation, in this solar panel rover the charge controller was mounted to apiece of ply wood and wiring connections followed a manual that can be accessed here:

The mounting on plywood directions start on page 12 and are specific for mounting photovoltaic arrays. It will tell you exactly where to mount the positive and negative wires of the battery and solar panel. Be sure to do this on a cloudy day or with the solar panels covered up so that you are not at risk of electrocution when performing the installation.

The above pictures show the charging status of the charge controller.

TROUBLESHOOT: Be sure to check the resistance between all the wires to ensure that they are connected and functioning. Especially when the solar rover has spent a considerable amount of time in the outdoors corrosion can begin to occur at exposed areas and the charge controller will show a presence of voltage but not enough current to charge the interstate batteries.

Step 3: Interstate Batteries

Six interstate batteries are mounted behind the solar panels and within the triangular space that the metal frame creates. They are connected in series with car battery cables that have soldered gauges at either end. The cables at the end of the batteries is then threaded through the back of the ply wood panel and connected to the charge controller. These cables can also corrode over time so ensure that there is complete coverage of metal wires and that connections are tight. An ohmmeter can be used to check the resistance of the wires.

In this particular set up there are six interstate batteries, each is 12V and 120A such that they have the capacity of 8.64 kWh. They are wired in parallel. If the batteries were completely dead the 200W panel (this system has 3) would take 15 hours to charge the batteries at full capacity.

There is a DC disconnect between the battery and inverter that is turned on first (connected) when the solar rover system is turned on and turned off (disconnected) second when the solar rover is turned off.

Step 4: Inverter

This system has a 1000 W inverter, although it could probably have a larger inverter. It has two 120V outlets that any device can be connected to, make sure you don't go over the 1000W because then the fuse could blow in the inverter.

Also in order to prevent damage to the inverter on the battery side a Go Power inverter/battery fuse was purchased. Its installation is pretty straightforward as all the electricity is wired through battery cables.

Step 5: Theft Proofing the Rover

The Solar Rover has several expensive components and sometimes will be used for evening events that extend past the bedtime of the solar rover keeper. Therefore tamper proof screws and bike chains can be used to fortify the solar panels and the trailer. Unfortunately a way other than the strapping down of the batteries has not been created (will be trying to install square tubing over the batteries in place of strap).

McMaster Carr Tamper Proof:

Bike Locks:

Bike Lock

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    26 Discussions

    Do you know the approximate cost of this project? Thanks!

    2 replies

    depending on what you already have laying around, this project turned out to be over two thousand dollars, the most expensive parts being the solar panel and batteries. But it is definitely possible to downscale that cost.

    This is why fossil fuel is currently king. For the cost, a low noise Honda generator is lighter, quieter and more reliable solution.

    nice work. you should really weather proof that expensive outback charge controllers, inverter and batteries. Also, LifePO4 are vastly superior to the lead acids: my home has its lifepo4 bank operating for the past 2 years when the previous lead acid lasted only 10months.

    this is tom from solar china

    we provide you the solar panel for 6 years

    may we know if you need it?

    You have stated twice in your instructions that your batteries were connected in series. This is NOT CORRECT. Your batteries are connected in parallel. If your batteries were indeed connected in series you would be putting out 72VDC to your 12VDC inverter. Of course this would let out all the magic smoke, and you would be replacing the inverter.

    1 reply

    Thank you for the notification, I made the changes in the instructable, so thank you again!

    Check the total max wattage of the PVs - should be 3 * 190 = 570W (not 200) or else specify the conditions for the 200W. See sentence:

    "The rover features three solar panels, for a total of 200 W, that are wired in parallel that are connected to a power controller ..."

    1 reply

    I see you have good intentions and a pair for at least pursuing building and sharing your project. Most nae sayers would be quick to point out your flaws and mis statements and though they may be correct about the former they themselves rarely if ever have the courage to build themselves. Perhaps next time have someone who knows a little something about your work proof read before you post. Otherwise, by all means keep up the spirit and good post.

    I designed and built a Solar Trailer for power and training purposes in 2009

    This system will work as is but it is not safe. Sorry to be so harsh but this is a horribly put together system especially if you plan to use this where people can see it. The NEC (National Electric Code) has a section ( 690 ) on how to wire up PV safely.

    Battery cables have to be a minimum of 2/0 (which looks like you have ) which are not regular car battery cables.

    All the wires need to be inaccessible ( and safe) and you have equipment that is not supposed to be out in the weather (mainly the inverter).

    I am very happy to see you have a fuse for the inverter but you need to have fuses between each major component as it is so much cheaper to replace a fuse than other parts.

    If this is a College system you want to showcase the solar in a safe and appealing manner. Adding labels explaining the system is great!!

    #GetEnergized w/Renewable Energy

    Give a call to help you out with the materials side, you don't want to buy a solar panel from a company that is out of business like Evergreen. Get one with a fresh 25 year warranty that can been upheld. They can also help with custom tailoring the system for your specific needs.

    When you make a post these days its a simple option to select a site as a link and makes it easy for anyone ,even the disabled to see what a person is refering too without messing around . Are you a masochist or something?

    Wow,this is really good! I'm saving the semantics for a later project. Thanks for posting!

    Run a piece of 1 inch square tube over the top of the batterys drill both ends and through the trailer sides . Run a long bolt down from the top and put a nut under . Couple of hammer taps on the exposed threads will slow down a theif or a weld tack will help . Takes the place of the blue tie down

    1 reply

    Cool will try to do that. I would have to probably drill through the square tube to mount it to the frame so that it cages in the batteries?