What kind of footprints do you want to leave?

SOLAR POWER

When we decided to move into an RV full time and become nomads we knew that in order to have the freedom to explore the places we wanted to see we’d sometimes be without electric hookups (power).  Since the RV was our full time home we wanted to make sure we’d have enough power to provide the creature comforts of home when boondocking or dry camping.  With no intent to return to the dark ages we needed options to create our own power to sustain us while in off-grid locations.

 

4 Solar Panels on Roof, 4 on Portable Stand

 

So how did we do this? Five easy steps (it’ll be easy they said, just put in solar panels they said):

  1. Assess how much power we were currently using
  2. Determine our energy goals
  3. Design the system
  4. Install the system
  5. Tweak the system

1)  Assess how much power we were currently using: In order to decide on how much power we would need we had to assess our power consumption levels.  This meant taking an honest, hard look at how much power we used.  We did this by performing an energy audit.  We went through and identified every electronic device (lights, appliances, laptops, etc) we needed and wanted to run.  The basic math:

The number of amps the device uses x how long you use it = how many amp hours the device uses

We created a spreadsheet of all our devices and used the equation above to figure out how much power we needed per day.

We found that we needed about 217 amp hours per day

2) Determine our energy goals:  Next we had to discuss our energy wants and needs. We had a few goals:

  • Be able to generate enough power (those pesky 217 amp hours per day) to sustain us for up to two weeks living off grid using conservative energy methods
  • Be able to charge electronics, use the internet and watch TV
  • Be able to run some of the high-demand electronics (e.g. microwave, hair dryer) sparingly
  • Be able to run the air conditioner when it got too hot

3) Design the system: This is where Brendan really started digging into things.  He did months of research about solar power systems to design one that could meet our goals/requirements and fit our budget (oh yeah, did we mention we had a budget?) Our purchases included:

  • Four 6V 225 amp hour AGM batteries (450 total amp hours)
  • Battery Meter
  • Inverter
  • Eight 100 Watt Solar Panels we could put in portable ground array that we could tilt and move with the sun
  • MPPT Solar Charge Controller
  • Cables and Connectors
  • Gas generator (because our 15000 BTU air conditioner would require more solar than we could provide on our budget)

4) Install the system: A lot of work went into installing the new solar components.  There’s far too many steps to list, but here are a few of the highlights:

  • Unbox all the new, shiny toys
  • Fit and install all components into the available space
  • Make all the cables the correct length and gauge for maximum efficiency (and safety so we don’t burn down the house)
  • Install new circuit breakers and fuses to protect the new circuits
  • Wire the new inverter to work with our current RV electrical system
  • Configure the solar arrays for maximum output and minimum voltage drop
Brendan spending time in the crawlspace

5) Tweak the system: You didn’t think we got it perfect right out of the gate did you?  After taking our solar show on the road we learned a few ways we could make things better:

  • Put the solar panels on the roof! Our portable ground array was a bit of an inconvenience.  Having to put out the panels every morning and take them in at the end of the day was a lot of work. We were also wary of leaving the solar panels sitting out all day when we left the RV because nice things tend to walk away. By putting the panels on the roof they’re not accessible (or really even noticeable) to thieves and they start generating power when the sun comes up and don’t stop until the sun goes down. They’re hard workers! And because the panels are now generating power all day we’re able to run our refrigerator using solar power during travel, keeping our beer cold.  And when we’re boondocking or dry camping we can run the fridge on solar power instead of gas saving us money on propane. #winning
  • Ditch the generator. Seriously. It’s on the bubble about to be sold. The only reasons we have it are to run that 15000 BTU air conditioner and to charge the batteries if it’s cloudy. Our thought is that if it’s so hot we can’t stand it (and it has to be pretty damn hot for that) we’ll go find somewhere with electrical hookups to ride out the heat wave. And if it’s too cloudy to charge our batteries using the solar array we can plug into the truck and charge the batteries with the truck alternator. Also our generator is so much less effective at charging the batteries than the solar panels, so a cloudy day might still charge the batteries better than that 100 pound generator.

So is our system working for us?  Yes!  And as we wind on down the road our solar power system will keep evolving.  This project has touched almost every system of our tiny RV home on wheels and has given us a better understanding of how to best utilize our resources. We’ve learned that we can get by on much less power than we originally thought so we’re feeling pretty good about that.

We’re happy to answer questions about our setup!  Please comment on this post or email Brendan for more details.


2 thoughts on “SOLAR POWER”

    • Great question Rod! Every system setup is different so the best battery bank configuration is the one that best meets all your particular requirements. For this system install, we utilized 6 volt tanks because;

      • Capacity: the 6 volt tanks individually offered a higher ampere hour capacity leading to an overall battery bank with a higher 50% usable ampere hour capacity than if two 12 volt tanks were used.
      • Size: the 6 volt tanks are smaller, individually easier to maneuver and fit into tight compartments. Moving boxes of lead is just friendlier when the boxes are smaller.
      • Availability: the 6 volt AGM deep cycle tanks, or “golf cart batteries”, are readily available. We looked into lithium tanks but logistics complications with delivery and the added Lithium system requirement of rewireing existing DC systems to isolate them from common frame grounds made it cost and time prohibitive on this project.
      • Fault tolerance: it is easier to obtain and swap out a 6 volt tank if one of the cells in the battery bank is failing.
      • Cost: at the time there were great deals for 6 volt AGM tanks. This tends to be the norm but you can sometimes find 12 volt deep cycle deals.

      I hope that helps and please let us know if you have any questions or would like assistance with a solar project.

      Thank you,
      Bren

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