Ask The Sietch- Solar Powered Trailer

question markA million years ago (or at least it seems like such a long time ago) when this website was nothing more than a collection of very ugly pages that didn’t do much there was a feature called “Ask The Sietch” in which people could send in their renewable energy questions and I and the members would do our best to answer. While I am not formally restarting this handy feature I do from time to time get some interesting questions and try and answer them. Here is one such question from Ed.

He Writes:

How would I go about creating a Mobile Solar Generator trailer, to run some power tools off it and use it for emergency power? I bought a small trailer and am looking at a Solar Kit that comes from England, that claims “Simple DIY Installation – no special tools or skills required” and I was wondering if there was something in the USA? (See Web Sites Below)
1) Trailer
2) Solar Kit

Here is what I would do Ed…

First off your trailer is going to need a bit of work. You should install a small enclosure on the back big enough to hold a couple of lead acid batteries, some tools, and a charge controller (about the size of your average electrical panel). You are going to need to be able to keep your batteries dry and out of the elements.

What you propose actually makes perfect sense. Power tools run on DC current, Solar panels make DC current, its a match made in heaven. However if you want to store up some solar energy and use it later you are going to need a batter backup system.

The way it would work is this.

solar battery system

You use your solar panels to charge up your storage batteries and then you can use the energy latter for whatever you want (including but not limited to charging your power tools). If you have a suitable fancy charge regulator you could also plug your power tool battery charger directly into the charge regulator and charge the power tool batteries directly from the sun.

If you wanted to use your stored solar energy for anything that doesn’t need DC current you are going to have to use an inverter. Inverters turn DC into AC. It would look something like this.

battery system with ac

So as you can see you will need some panels, a charge controller, some batteries and an inverter if you want to use AC loads. Many companies make kits that have a lot of these features wrapped up into one. SMA makes a nice inverter called the Sunnyboy, I have used them before and they are reliable, Outback makes nice inverters for battery backup systems, and I am sure you can get some panels from anywhere. You might even be able to find a solar battery charging kit on the net. The one you sent me looks a little small but it might work. Battery charging with solar is easy, but like anything else has a slight learning curve.

You have to have a charge controller or your batteries can get overcharged, and you need to take care of your batteries (some models need you to vent them, or to fill them with chemical solutions every once and a while). With a little net research you should be able to find all the parts you want for under $1000. But just think no matter where you go, so long as there is sun you can have power.

You might also want to give homepower magazine a look they always have good stuff about battery backup systems.

Hope this helps, if anyone else has any tips for Ed leave them in the comments.

10 thoughts on “Ask The Sietch- Solar Powered Trailer”

  1. I gotta say I like the idea. The problem is the industry is not where you are. The manufacturers are thinking on a much larger scale. I don’t know how large that trailer is (I saw the picture with dimensions but but I have no feel for these things, it’s really a math exercise) most PV panels for rooftops are pretty large. I think you are looking for the “home improvement store” size. I presume you would build a structure on the trailer and mount the PV panels to the structure with the batteries inside it.
    I did find this place but I know nothing about them. They just, allegedly, have something in the size I believe you would need.
    http://kingsolar.com/catalog/mfg/package/basicssys.html
    What I think would be really neat would be to add a small wind powered generator to to charge the batteries while you drive to the site. But if you think finding small PV kits is hard there’s nothing I can find for wind. Of course there is the home-brew option, but you talk about learning curve!!!

  2. I worked for a guy last year who built his own version of this, it has solar pv, solar thermal (you can take showers from it, it’s great), and a small wind turbine. You can see pictures of it in the background for the 2005 junior solar sprint.

    It was built basically the same way I describe above. Like you said, I really don’t think you are going to find any commercial product that does what Ed wants. But if you want to take the time to learn, and want to make a really nice setup, its very doable with products on the market. Wiring up solar panels is pretty easy, they come with snap together fittings on them now and days.

    I don’t know if you would want to put the wind turbine up while you are driving your gas mileage would go waaaay down. But if you set up the turbine after you stop some place (and had a tall enough poll) you could use the turbine to charge the batteries as well.

  3. I would highly reccomend AGM batterys and an Inverter fro “OUT BACK” I have installed many on boats. Great inverters.

  4. the laptop battery should be invisible to the user and deliver enough power to endure a five-hour flight from Toronto to Vancouver. In reality, a typical laptop battery provides only about 90 minutes of service. Many users complain of much shorter runtimes.

  5. Hi, i wonder if you can help me to build a circuit to charge a little 12 volts battery with solar photovoltaic cells,
    Thanks a lot,
    Mauricio

  6. me and my sis r trying to see if it is poesible to make a car that runs by wind fans and solar energy. do u have any comments?

    please rite back
    fan 393

  7. Dear Sir,
    Good day to you. Kindly give us the quotation for 20pcs of 45A, 12V Solar Charge Controllers including the freight cost to Dakar International Airport,Senegal asap.

    We are Lambub Enterprises located in Dakar , Senegal West Africa and we deals in Solar Equipments and installations.

    We hope to read from you asap.

    Thanks
    Lamin Buba General Manager
    Lambub Enterprises
    15, Youff Fish Beach
    Dakar, Senegal
    Tel 00221777395002.
    E-Mail lambub_enterprises@yahoo.co.uk

Comments are closed.