I recently read an interesting article about 'Range Anxiety' that can be experienced by electric car owners and can't help but wonder if this translates across to electric boat owners too? There is actually a lot of research that you can find online, from the likes of Tesla, that want to curb the fears/anxiety that their customers have that their electric car won't make the journey from A to B and instead run out of juice somewhere enroute.
'Range anxiety' has it's own Wikipedia page and in a survey it was the number 1 reason for people not to choose an electric car! Once you unplug from your house with a fully charged battery in your car are you going to make it to the next place to plug in and charge...or not...? Welcome to the world of 'Range Anxiety'!
There is an increasing trend & popularity in electric motors for boats: why not enjoy clean & quiet power from an electric motor (inboard or outboard) instead of a noisy, dirty diesel engine or gas outboard. There are now many lakes and waterways in the USA that are becoming 'electric motors only', restricting the use of anything non-electric to help keep the waters clean & quiet.
Some popular brands of electric outboards are from Minn Kota, EP Carry, Elco, Torqeedo & E-Propulsion Some have batteries built into the outboard whilst others require an external battery aboard. With either option you can't help but wonder how long will my battery last and will I be able to make it safely to shore, preferably somewhere that I can plug in and recharge my battery.
Solution - why not just charge with SunPower flexible solar panels aboard your boat and help top up the battery bank whilst underway.
Extend your range & time on the water
With SunPower solar panels aboard your boat you can avoid the 'range anxiety' and charge your batteries while underway and help extend your range & time on the water. The power from solar can help directly offset what your motor is using whilst underway and then when you're at anchor enjoying some fishing or cocktails then the solar is charging up those batteries and powering the stereo.
Something I read on the Torqeedo website that I think was important to note is that "it takes 8 times the power to go twice as fast". Electric motors need a lot of power (amps) when you have the throttle wide open and are blasting around the lakes & waterways at full speed. You will likely get 1 hour or less of use from a fully charged battery and the solar power being generated will not even make a dent in the power you're using. However, if you ease back on the throttle and start cruising at half throttle, or idle speed, then you are using much less power and come into the range of what the solar panels aboard can help directly offset.
"It takes 8 times the power to go twice as fast"
Example: Below is a photo we received from a customer that had an Elco EP-20 outboard on his Bennington pontoon boat. They added 6x170W SunPower E-flex solar panels, 3 wired in series, 3 wired in series and then paralleled together to a Victron Energy SmartSolar 150|35 charge controller and on to the 48V battery bank that the Elco motor requires.
The Elco EP20 is an 8,880W motor at 48V (nominal) which means at full throttle it would be using around 185Amps (8880W / 48V = 185A) Wowsers, that's a lot of juice and on the recommended 2x 48V, 168Ah li-ion battery bank (2 batteries in parallel to keep the voltage at 48V but increase the amps to 336Ah) that would be around 1h 45m of use!
Slow things down a little a go half throttle then we need 8 times less power so 185/8 = 23Amps. This comes into the range of what the solar panels can directly offset 6x170W panels = 1020W / 48V = 21.25Amps. Any slower/idling speeds then the solar will for sure be directly offsetting your usage helping avoid 'range anxiety' and putting extra power into the battery bank.
Most MPPT charge controllers will only go up to 48V battery banks but some of the larger electric outboards/inboards require higher voltage battery banks, maybe 96V or 108V. Should you have a higher voltage battery bank then don't worry there are options available to you to charge with solar. Simply email us and we can help size your system in terms of the number of panels and high voltage MPPT charge controller required.
We look forward to helping you go solar with SunPower aboard your electric boat.