I have been a fan of solar power as long as I have been living on the road.
One of the first projects I tackled when I first became nomadic way back in 2006 was adding 130W of solar to the back of my tiny Tab Clamshell. I think it was my abundance of sexy solar power that helped me win Cherie’s heart – our first date I let her plug into the sun and the rest was history.
When we had our Oliver custom made for us, we designed 200W of solar in from the get-go – and it was an essential enabler for our style of life on the road.
Many of our first four years on the road were spent unplugged, and relying on solar energy with very little generator use.
So how is it that we have gone over three years without adding solar to Zephyr, our absolutely awesome vintage 1961 bus?
A few reasons:
- Eastcoast bound – Moving into Zephyr coincided with a desire to be based primarily out of Florida for family reasons. Which meant we’d be staying in RV Parks with electrical hook-ups anyway. This pushed the priority of investing in solar way to the back burner, as we knew the longer we waited the more technology would evolve.
- Increased Energy Appetite – Back in our trailer days we relied on propane appliances, the bulk of our electrical needs were carefully optimized to run off of DC 12V power, and we spent our workdays staring at power-efficient laptop screens. All that has changed.In Zephyr we have gone propane-free, and thus rely on electric for our refrigeration needs – we have a Danfross compressor based DC fridge from Vitrifrigo, a convection/microwave oven, and an induction cooktop. We spend our workdays staring at big beautiful 27″ & 30″ monitors. And while we have kept power efficiency in mind, our systems are a mix of AC and DC powered and we often keep our inverter on 24/7 to power it all.
In other words – our power demands have gone way up. 130W or 200W isn’t going to cut it anymore – we need substantially more power up on top. It is going to take an elaborate and carefully planned out full-roof system to keep on top of most of our power needs.
- Sweet Sexy Curves – Then comes the bigger challenge… We absolutely love Zephyr’s vintage 1961 classic curves, but her gently rounded roof leaves very little flat space suitable for traditional thick, flat, framed solar panels. Only thin panels that can meld with the roof lines will look good on our girl. But there just aren’t many thin and flexible options out there!
Every year I’d spend a week or two researching the latest state of the art in solar, hoping to find the perfect companion to tie into our sweet Lithium Ion battery setup, only to end up not ready to jump yet.
There just wasn’t any affordable and attractive way to fit the amount of solar power that we wanted onto Zephyr’s roof, and we didn’t like the idea of investing in half-measures that would still keep us dependent on regularly finding hookups or spending excessive amount of time listening to a generator drone.
We knew that ultimately only thin and flexible panels would be able to mesh nicely to our curved roof – and every year we’d decide that none of the options felt worth investing in.
Until now… perhaps.
Is 2014 the year that Zephyr at last goes solar? Has solar technology at last caught up with the needs of our 53 year old bus?
We’re in the midst of a major investigation…
The Solar Challenge: The Goal
Our goal is to design a system for Zephyr capable of powering the bulk of our typical energy needs for several days without needing to regularly resort to a generator.
We expect that this will require somewhere between 500W to 1000W of solar, with the ultimate goal being to install as much power as we can while still looking good. Because when it comes down to it, you really can never have too much power.
With such a major investment planned – we wanted to do it right the first time. That means a lot of design and research work up front picking the ideal components – and especially picking the best panels.
And of course – cost is a consideration. It is not necessarily the top concern, but overall value of the system needs to be balanced with the desire for peak performance.
RV Solar Resources
A ton has been written online about solar, but not a lot has been written from the RVers perspective. And a lot of what has been written is not in-depth and often actually incorrect about a lot of important details.
The best online resources we have found, and we have consulted personally with them all:
- Jack Mayer’s RV Electrical & Solar Page – Jack has compiled an incredible online resource about RV solar and electrical systems.
- HandyBob Solar – Bob is strongly opinionated, but he has seen it all and shares a lot of great information and real-world examples.
- AM Solar – AM Solar has probably installed more solar systems on RV’s than anyone else, and they have an excellent reputation for quality work, products, and advice. Their “RV Solar Education” series is a must-read.
But despite all this information available, we haven’t found anyone who has done much head-to-head testing of different setups and scenarios. Actual real-world data, especially comparative data, is almost impossible to come by.
And when it comes to thin and flexible panels, there just isn’t much solid unbiased information available out there at all. Some folks have written about the system they installed, but we haven’t found anyone who has published much comparative analysis of the options available.
Solar Challenge Preview
As we began the research on this project, I reached out to several solar companies to ask if they would be interested in participating in some no-strings-attached unbiased head-to-head testing.
To our delight, so far we have gotten gear to evaluate from:
- Victron – Victron (the maker of our awesome MultiPlus Inverter) has sent us a pair of BlueSolar 50A MPPT Solar Charge Controllers, and I have set them up to allow for direct head-to-head panel testing.
- Go Power – Our dear friends the Wynn’s have written about their experiences with Go Power panels, and they put us in touch with the company who agreed to send us 2x 100W Solar Flex panels for testing, as well as their basic PWM charge controller.
- Grape Solar – Grape Solar was also excited by the project, and sent us 2x 100W Photo-Flex panels for testing.
- HighFlex Solar – HighFlex Solar was the first to pioneer high-efficiency thin and flexible panels, and now they are the first to design panels with integrated MPPT chips directly on the panel to optimize power output. We were very excited when they agreed to send us one of their 156W panels, and we are eager to see if it lives up to its potential.
We hope to add a few more contenders to the mix as well, but this collection of gear has given us some great data already.
With the capability of testing panels head-to-head under identical real-world conditions, we aim to be able to actually measure the differences in performance between these panels under a range of testing scenarios.
The testing will continue over several months to give us time to conduct a range of experiments, and to try and observe how durable and scratch-resistant the panels are as well. We will be sharing all our results in a series of blog posts here.
What have we learned so far?
You’ll just have to stay tuned here to find out…
Solar Quest Questions
We’ve fielded a lot of questions about solar over the years.
Along with sharing our testing results, we are also setting out to answer a bunch of key questions through a mix of research and actual real-world measurement and experimentation.
Some of the questions we hope to address over the coming months of blogging about this project include:
- How much solar is really needed? How should an RV system be properly sized?
- What are the classic mistakes commonly seen in RV solar installations? What are key tips to avoid them?
- What is the difference between a PWM and MPPT controller? Is MPPT worth it? Is there any advantage to integrating an MPPT controller directly into the panel, like High Flex Solar has?
- What are the downsides of thin and flexible panels versus traditional glass panels?
- What is the impact of wire size and length on a solar system install?
- What are the trade-offs of wiring panels in series versus in parallel?
- What are the impacts of mixing-and-matching non-identical panels?
- How much does shade, shadows, and clouds effect solar panel power output?
- How much does flat roof mounting impact power output versus being tilted towards the sun? What impact does bending along a roof curve have?
- Is it possible to run an air conditioner off of solar power?
- And critical for us – what are the best thin and flexible solar panel options out there?
- And finally – is investing in solar really worth it?
Along the way while answering all these questions over a series of blog posts, we aim to explain the basics of solar power – and the keys to designing a great system – whether using thin panels or traditional.
We hope you will follow along – you will be able to access all of our solar related posts from our new RV solar page.