Alternative Energy Onboard – Exploring the Options

Alternative Energy Onboard

Every boater knows that redundancy onboard is a good idea – especially when it comes to keeping your batteries charged. With industry advancements, renewable energy options for onboard charging are not only vastly improved, but also becoming more affordable for boaters – so this Navigator will explore the pros and cons of adding Solar, Wind, Hydro or Fuel Cell technology to help you decide what makes the most sense on your boat.

Before You Start

The most important factor to help determine what will work best for you onboard is to determine what exactly are you trying to accomplish. Are you simply trying to keep your battery bank topped up without plugging in to shore power when not onboard? Or are you trying to offset normal power usage while cruising without relying on a genset or running your engine? Once you've determined what you're trying to do, you can figure out the number of amps you'll need to replace and which system (or combination of systems) will work best for that purpose.

Two additional aspects to consider are how you might install each system and what kind of weather conditions you're likely to experience where most of your cruising takes place. Installation limitations could easily make the decision for you – so think carefully about these things while doing your research.

By adding one (or more) alternative energy solutions onboard, you increase the reliability of your power supply while potentially realizing substantial savings by not burning fuel to recoup the energy lost – so it's worth exploring. With that in mind, let's look at the pros and cons of each of the best renewable energy option currently available for boats.

Solar Power

Solar PowerOver the last decade, the cost of installing solar power on a boat has dropped substantially, while the efficiency of panels and monitoring has greatly improved, and installation has never been easier – making solar power a highly feasible option for many boaters. Once installed, solar panels quietly convert sunlight into electrical current – putting amps into your batteries and replacing the amps you've used with almost zero interference. Additionally, they are a perfect way to safely top up batteries when you're away from your boat as the “float” cycle can take a ridiculously long time.

What's the downside? Mainly finding enough real estate onboard to create the total power needed. If you're just interested in topping up the batteries – solar power is a great option, but if you want to replace all the amps you're using while cruising – you'll be needing a fair amount of space for large panels, and that space should be shadow-free throughout the day to keep the panels at their most efficient. For more a more in depth look at installing solar power – check our Solar Power Basics Navigator.

Solar Power Pros

Solar Power Cons

Works at anchor or underway Only effective for part of the day
With optimal conditions a 100W panel will produce 33 amps/day Small amounts of shading can greatly affect efficiency
Low maintenance Can take up a lot of space
Long lasting Less efficient the hotter they get
Safe operation More power equals more panels/space
No noise Needs good air circulation to operate efficiently

Wind Power

Wind Generator OnboardHarnessing the wind to create power has been around for over a thousand years – so the idea is not exactly new. With fields of giant wind generators cropping up across the USA, it's not surprising that it makes sense to harness that power on our boats too, and marine wind generators have come a long way from the high-pitched noise makers that originally entered the market. These days, technology has vastly improved bringing smoother rotation and lightweight carbon blades – which equals far less noise along with increased efficiency of power production, even in lighter winds. If you live and cruise in an area where winds are consistent – you could potentially be creating energy 24 hours a day – so wind power may be a great option. But if a perfectly quiet anchorage is what you seek, perhaps you should look elsewhere.

Wind Power Pros

Wind Power Cons

Can produce power 24 hours a day Can vibrate at certain wind speeds
Long lasting Can be noisy
Low maintenance Potential danger of blades
Works at anchor or underway No power in a calm anchorage
Produces a lot of power in high winds Low power generation sailing downwind

Hydro Power

Hydro Generator Watt & Sea Generators

A newer player on the alternative energy marine market are Hydro generators, such as those made by Watt & Sea. The idea with Hydro (water) power is to create energy by towing something that spins as water moves past it, while creating the least amount of drag possible. Most Hydro power units are fastened to the transom of the boat and can be deployed or stowed depending on the power generation needs. The faster the boat moves through the water, the more amps the generator produces – but you'll want to be cruising at a minimum of 5 knots to get meaningful power production (the Cruising 600 model will produce 8 amps/hour at 5 knots of cruising speed – but at 8 knots it will produce almost double that). If you have a small boat and travel under 4 knots, Hydro power is not the option for you – but if you normally cruise in the 5-8 knot range, it's definitely worth considering.

Hydro Power Pros

Hydro Power Cons

Excellent power generation underway Power production underway depends on boat speed
Minimal drag at higher speeds No power generation at anchor
Stows neatly when not in use More expensive than solar or wind power
Silent operation Vulnerable to damage
Higher maintenance

Fuel Cell Power

Efoy Comfort 210

Finally – the newest alternative energy option for boaters is a fuel cell generator by Efoy Comfort. Like a gas or diesel generator, the Efoy can come on automatically and charge as much as you need it before shutting off again – all on its own. But unlike those generators, there is virtually zero noise or heat produced – and the byproducts of running it are water and carbon dioxide – making it a very “green” way to generate power. Empty fuel canisters can even be recycled!

The only real downside of Fuel Cell technology is the price for the amount of power it produces – which can be as low as 3.3 amps per hour, or as high as 8.8 amps/hour depending on the unit you choose. For those boaters that have smaller power needs, the Efoy is an excellent option – running quietly in the background with very little maintenance or attention – whether it's sunny, raining, windy or calm. But if you're looking to replace more than 150 amps a day while at anchor, the unit will be running almost constantly and you'll potentially go through “fuel” quickly – making it a more expensive option over the long run unless you supplement it with additional power from one of the other options above.

Fuel Cell Power Pros

Fuel Cell Power Cons

Clean burning, by-products are water and carbon dioxide Maximum capacity of 80-210 amps/day depending on unit size (running 24/7)
Automatically starts and charges when batteries get low Slow amp hour production (3.3 – 8.8 amps per hour)
Very quiet Need to carry/store “fuel”
Easy installation Fuel available in limited locations
Can run 24/7 if needed Most expensive option per amp
Runs efficiently at any temperature
Low maintenance

What's the Best Choice?

Wind and Solar OnboardAt the end of the day, the decision on what's best completely depends on the kind of boating you do and where you do it. Are you cruising in the Northwest where there's a fair amount of cloudy days, but good wind and lots of moving from anchorage to anchorage? Or are you in the tropics where there's a ton of sun but you could stay in one spot for weeks? Most likely, the perfect installation will be a mixture of the options above – such as wind AND solar power, or solar AND fuel cell – which gives you solid coverage for different conditions and ensures you can stay away from the dock for as long as you like while still enjoying cold beverages, music, movies and everything else we've become accustomed to on land.

We hope you've found this Navigator on Alternative Energy Options helpful, but if you need more information, please don't hesitate to give our knowledgeable staff a call at (800) 426-6930.