Boat Systems Solar Panels

I is for Investing in the Future: Solar Panels

Monday, April 11, 2016S.V. CAMBRIA


During the month of April, we're participating in the Blogging From A to Z Challenge where every day (excluding Sundays) we'll be posting to the blog . . . alphabetically. The overall theme we've chosen to tie all the entries together is living aboard a boat and cruising – things we've learned along the way: our thoughts, reflections, and tips for those just starting out or who are interested in this lifestyle.



If anyone tries to tell you that investing in solar panels in the Pacific Northwest is a waste of money (like they did us) they're completely wrong. And we can prove it.

Six years ago we added a solar panel array and have been tracking the benefits ever since. At the time, we only carried a single 32 watt panel (original to the boat and dating back to 1999) on top of our radar arch which put out a whopping 2 amps, if that – basically a trickler. Along with our wind generator, which is quiet but equally as unproductive, we could hardly call ourselves self-sufficient: It was time to make a change.

After months of research, we purchased three Kyocera 135 watt panels measuring 60 by 26 inches and weighing approximately 30 pounds. Needless to say, the installation required a bit of thinking . . . and engineering. The dodger and bimini on Cambria are canvas and would have required substantial stainless work to accommodate the weight of the panels, one of which would have been shaded by the boom most of the day. 

In lower latitudes, shading wouldn’t make such a big impact; but here where the sun is at a 30° angle in the height of summer and approximately 65° in the winter, it does. So we opted for the easier and (in our opinion) more practical installation and changed out two sections of lifelines (port and starboard) for a solid stainless bar which the panels are mounted on. When conditions are rough, they lie flat and can be secured (not to offshore standards, however). But at other times of the day, we’re able to adjust them with several different props cut to different lengths to maximize their output. 




To control the system, we chose a Xantrex 60 amp MPPT with a battery temperature sensor, not because it was our first choice or that our system required the capacity (it’s much bigger than we need and has the ability to add other panels later on). But because the company manufacturing the one we had originally wanted (a Morningstar 45) was experiencing difficulties sourcing components from their Chinese suppliers. In the end, we were glad for the change and are very happy with the Xantrax’s performance.

Using the specifications provided by Kyocera, under optimal conditions the panels should generate 120 amp hours of power – 30 amps shy of our average daily consumption. But we generally see more than that. During the summer months, they can produce 140 to 150 amps, with approximately 15 to 20 amps coming in during the peak hours (noon to four). On our best day, we banked 172 amp hours and on our worst day, none at all. But more important than the numbers, we’re not burning fossil fuels to compensate for our desire to watch movies, use the computer whenever we like or power a freezer. 

We estimated that we’d recoup the cost of the system after three years, but our expectations were, once again, surpassed. By the middle of 2012, the savings on fuel exceeded the price tag and we’ve been living free (give or take) since then. One of the greatest expenses to recover was the MPPT, with the materials for mounting coming in a close second. The panels themselves were the least expensive components, costing around $330 a piece. If we were to buy the same equipment today, it would cost a little less but take longer to recoup the costs due to lower fuel prices. Of course, there are better, more efficient panels on the market today and our choice might be different.

David has a meticulous personality and has been tracking their performance for the past six years: Over the period, they produced a total of 72,125 amp hours (970 kWh). To date, we estimate that we saved over 2400 hours of engine/generator use and approximately 2200 gallons of fuel – a savings of roughly $9,000. An excellent investment . . . for the boat as well as the environment.

 Click on the graph for a larger view.







Note: Looking at the graphs, you can clearly see the days it rained, particularly late in the season.  The mid-range days were generally ones in which we were moving.

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14 comments

  1. It's wonderful that you proved them wrong and great to know how well the solar panels have worked. I'm amazed just how much you've saved (not to mention the hassle of dealing with the fuel).

    Mason
    Alex's Ninja Minion

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    1. We were a little surprised too for a couple of reasons: we move around a lot so the engine recharges the batteries, we spend a lot of time in higher latitudes (52+) and the general climate of the rain forest.

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  2. Solar power is awesome - and your graphs are incredible! It's amazing to see the savings in dollar amounts.

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    1. That's because David is crazy about keeping records (I think he considers it entertainment). But I have to admit, it is really cool to see the results graphed out.

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  3. Okay, can I admit I'm even more impressed by the record-keeping than by the effectiveness of your solar installation in a higher-latitude foggy place? It's a no-brainer for us having solar in Florida!

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    1. I know. David's completely anal when it comes to keeping records (you should see our log!). But it really is interesting to see how well the panels performed even during months when we had a lot of rain or were on the west coast where there's a lot of fog.

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  4. Very informative post! We have three Kyocera 85-watt panels. I don't think it's going to be enough power for us. It's something we're going to have to think about - upgrade our panels? Add wind? Not sure what we'll do.

    Cheers - Ellen

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    1. He really wants to add another one to keep up with our demands (we added a portable freezer to the boat after the solar panel installation), but we really don't have a place to mount it without making the boat look like the Flying Nun.

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  5. This is so fascinating! Thank you for sharing such detailed information! I will have to look into this for our boat!

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  6. Excellent data! Thanks to David for that! We've just begun to develop a solar system on Sionna, which right now consists of one 100w panel and a 30amp controller. Instead of expanding production (since we'll be motoring down the ICW for our first year) we've spent our money on reducing consumption: LED lighting throughout, low draw fridge and double the fridge insulation, minimal electronics, etc. After the first year we'll decide about adding solar.
    Great info!

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  7. Solar panels... such a great invention and the perfect alternative to fossil fuels. Once we installed ours on Irie, they did not need any maintenance or work. We would have loved to have more, but didn't have the space for it. On our next boat... :-) I liked having a wind generator as well - it provided us with a lot of power on windy days as well - but my husband would have easily swapped it for more solar panels if we could.

    Liesbet @ Roaming About – A Life Less Ordinary

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  8. Very interesting!! And I am also a data enthusiast so I am loving the graphs!!

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  9. I don't know much about solar panels but hubby is impressed with your engineering. He asked "LED lighting as well?"

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