Solar – Is The Power Worth The Price?

A lot of people have asked us if we will be transferring our solar panels from our bus conversion to the Winnebago diesel pusher motorhome we just bought. Quite a few have been surprised when we told them we don’t plan on doing so. Terry and I have discussed it at length, and we just don’t see any reason for it.

Our MCI bus has five solar panels, totaling 540 watts of power, an 2,000 watt Magnum Energy pure sine wave inverter, and a bank of three 8D Lifeline absorbed glass mat (AGM) batteries. For the bus, and for our lifestyle while we were building the bus, it was a good setup. But nothing ever stays the same in life, and our needs have changed.

We used to do a lot of boondocking, and I am an admitted power pig. The bus has a residential refrigerator, and we use a lot of power running our computers, internet connection, watching television and such. We never turned our inverter off. Because the bus onboard electrical system was 24 volt, and our house system was 12 volt, we could not easily charge our batteries while driving down the highway, like most RVs can do. The solar system did just fine, and on a good day we could easily put over 30 amps an hour into our battery bank from our solar panels. If we had cloudy days, we could always fire up our Onan 5500 watt generator and top off the batteries.

But with the Winnebago, we have an RV refrigerator, so we don’t need to have an inverter on while traveling. And with the 7500 watt Onan Quiet Diesel generator and our inverter, we have plenty of power when we pull into a place without hookups for the night.

I have always said that solar is a good supplement to an RV generator, but it is also a very expensive supplement. In my opinion, AM Solar is the best company in the country for RV solar needs, and owner Greg Holder is the acknowledged solar expert in our industry. Even Greg would agree with me that solar is an expensive addition.

So is it worth it? Let’s do the math – according to the AM Solar website, a 100 watt panel with the mounting kit, which usually retails for $795, is currently on sale for $499 per panel. Four panels (which I would consider the minimum for serious dry camping), come to $1996 under the sale price. A Heliotrope HPV-22B charge controller, which usually retails for $325, is currently on sale for $275. Size 27T AGM 12 volt batteries are $245 each, and if you step up to the 8D size we have in our bus, they sell for $540 each. Just for the sake of this example, let’s assume you use three of the size 27T batteries, which will set you back $735.

Then you will need an inverter. A Magnum Energy 2,000 watt modified sine wave inverter will cost $1519, and the ME-RC50 remote control from Magnum is $183. If you step up to Magnum’s pure sine wave inverter, add a couple hundred dollars more. And then you need to factor in the cost of installing all of these goodies, unless you’re handy enough to do the job yourself, or have a friend who is!

So you’re looking at a minimum investment of $4,758 if you do your own installation, based upon AM Solar’s current pricing in this example. And remember, solar is a supplement to a generator, at best! While there are a few die hard boondockers who get by just on solar, they usually go to bed with the chickens and spend a lot of their time monitoring their power usage and solar input.

By comparison, our 7,500 watt Onan diesel generator uses less than a gallon of diesel per hour. Let’s assume I run the genset three hours a day, and that diesel fuel is currently selling for $2.75 a gallon (a high figure in most parts of the country right now). That is $8.25 a day.

Based upon these figures, I would have to run my generator 576 days to break even on the cost of the solar setup. If I had a fifth wheel or travel trailer and used a Honda portable generator, it would cost even less! Let’s assume you spend 45 days a year dry camping, which is much more than most RVers I know ever do. It would take you over 12 years to recoup the cost of your solar system!

Of course, if you have a trailer and have to purchase a generator, you have to factor that cost in. Most RVs have a generator onboard as standard equipment.

So, while we have enjoyed making our own electricity from the sun, is solar a good investment? Obviously not, just in terms of dollars and cents.

Even already having the panels and other equipment in the bus, which we could transfer to the Winnebago, we have decided that we probably won’t do enough long term boondocking in the future to make it worth the time and expense of having the solar system removed from the bus and installed on the Winnebago. We’ll be able to get by a few days just fine on our generator.  

Thought For The Day – Don’t ever take a fence down until you know the reason it was put up.