Lyall Burgess
- Apr 18, 2020
- 6 min read

Our Top 7 Boatshow Questions

We are missing the BoatShow life

We all know where we would rather be right now - yep at the Pacific Boatshow in Richmond CA, we had such a great time there exhibiting last year. Not only is it a great show it's in a building that's powered by over 1 megawatt of SunPower solar panels - how's that for advertising!

Katie & I both really look forward to our few days of #boothlife and chatting solar & sailing with everyone that stops by. As we're an online business working from our off-grid home it's certainly nice to get out in front of people, answer their questions & show just how accessible solar is. Solar can be a great solution for providing clean & quiet renewable energy to your boat, why listen to a noisy engine/generator just to charge your batteries?

Despite the show being cancelled you can still head to their website www.pacificboatshow.com and see who is giving a virtual seminar or click on their link to download the e-show guide. All of the vendors who had plans to exhibit are still out there and available to answer your questions and might even be running show specials - we are!

Use promocode PACBOATSHOW for 10% off the SunPower E-flex panels in our store

Our Top 7 Boatshow Questions

So over our morning coffee we have been reminiscing about being at the booth and have put together our top 7 boatshow booth questions (with answers!)

1. So are these made in China? No, the SunPower solar cells are made in a SunPower factory in the Phillippines then the flex panels are assembled in a SunPower factory in France. SunPower is a huge global corporation headquarted in Silicon Valley but they have control of the whole process and can ensure a high quality flexible solar panel.

2. I heard that if one cell gets shaded a third of the panel will shut down? No, with SunPower they stand up to shading issues really well and that doesn't happen. Only the shaded cell is going to stop producing power but it still allows the flow of power from the cells around it so that the panel doesn't shut down. Please watch some of the shading videos on our homepage that highlight the SunPower advantages really well. In testing with just one shaded cell a SunPower panel dropped to 89% power production whereas a conventional panel dropped to 66% power production.

3. That's it, where's the rest of it? Yes, this is the SunPower flexible solar panel unboxed and ready to go. Lightweight, flexible & powerful. You have all the solar cells (32 on a 110W panel) which are connected and come together at the junction box (small black box in the top right corner) and that has a positive and negative cable coming off it. The junction box is robust & durable with a high protection from water & dust ingress (IP67) and has a built-in bypass diode. There's 17" of cable for the positive and negative 12AWG wires with MC4 connectors on the end.

4. What would this 110W panel power? Good question, don't forget we're not plugging stuff straight into the panel it's always going to be sending DC power to your DC battery bank and then that's where you're getting the power from (either DC or AC via an inverter). So rather than ask what will this solar panel power maybe think of it as what will this solar panel help offset across a day. A neat trick you can do with SunPower panels is divide the panel wattage by 3 to get an estimated daily yield in terms of amp hours (at 12V).

So for example 110W / 3 = 36 amp hours in a day (at 12V) You can then look at what that powers, so if my cell phone charges at 1.8A and is plugged in for 5 hours that's 1.8A x 5 = 9Amp hours, and my laptop charges at 3.4A and is plugged in for 3 hours that's 3.4A x 3 = 10.2Amp hours. So for those two things I need 19.2 Amp hours, well my solar panel covers that and leaves me 16.8Amp hours to offset the power of other items, nav lights, interior lights, VHF etc

5. How many panels will I need? It's possible to look at how much power you use aboard (do a power audit) and then doing some maths on how many panels it will take to offset this power usage. However more often with a boat you have a limited amount of "roof space" available for solar panels (the bimini, dodger or deck space) and so it's simply a case of looking at the dimensions of the SunPower E-flex panels, deciding which one physically fit the best and maxing out that space with solar. It's better to have too much solar to account for cloudy days or low winter sun and so you will never hear someone on the dock say I've got too much solar and I'm thinking of taking a panel off!!

6. Can I walk on these panels? I wouldn't lay the panels in a high traffic area but yes you could stand on them, however it's not recommend and for the vast majority of installs the panels are up out of the way on the bimini or dodger. Some catamarans or power boats installing onto a hard top may occasionally have to stand on the panels but they could be slippery and hot so watch out! You may see some other flex panels advertised as "walk-on", but these are not high efficiency panels, so won't produce a lot of power, and there are questions about whether the non-skid used will actually trap dirt and salt and block the active solar surface even more!

7. What else do I need to make this all work? The solar panel is just one component of the solar system as a whole. To make it all work you will need a few more parts including (but not limited to):

Y-branch connectors - if you are connecting two or more solar panels in parallel you will need some Y-branch connectors (you don't need these for series wiring as the panels daisy chain together)

PV extension wire - Your solar panel(s) is likely up on deck, or on the bimini, and so you will need a length of PV extension wire to get down from the panel into the boat. PV wire has a thicker jacket to protect it from UV & other elements from being outside

Deck gland fitting - At some point you will likely have to send the wire through the boat to get inside to the charge controller so will need a watertight fitting to go through the deck, bulkhead etc.

MPPT charge controller - The MPPT charge controller will regulate the flow of power from the solar panels to the battery bank. Most charge controllers are 'buck' controllers so taking a higher voltage from the panel (18V) and decreasing it (bucking it) to charge your 12V nominal battery bank (say 13V-14V). An MPPT will use this difference in voltage and turn it into 'more' amps to send through to the battery whereas a PWM will not do this. An MPPT charge controller will prevent overcharging of the battery.

Circuit breaker - We suggest having a circuit breaker after the charge controller and before the battery bank rated at the same size (or slightly larger) as the output of the charge controller so a Victron 100|20 can have a 25A circuit breaker. The circuit breaker is there as overcurrent protection to protect the wiring from overheating.

Have a question you would like to ask us? We're here to help just give us a call +1 808 825 2670 or send us an email info@sunpoweredyachts.com or click on the little chat icon on the bottom right and if we're available we'll answer straight away. We certainly are looking forward to 2021 and making plans to exhibit again at the Pacific Sail & Power Boat Show. Until then we will be exhibiting at a couple more shows in 2020, you will find us at: