Are Fully Electric Boats The Way of The Future?

With more and more cars on the road comprising of Electric Vehicles (EVs) I was curious how electrification was going for the boating industry. There are quite a few manufactures getting their toes wet (pun intended) in the Electric Boat (EB) market. How realistic is it to assume that boats will follow the same path as cars when it comes to electrification? Generally speaking, the energy required to operate a boat is far greater than to operate a car. This is because boats, among other factors, operate on the water where they generate much more drag against their hulls compared to the rolling resistance that tires generate on the road. I am excluding large ships from this discussion, which are actually quite fuel efficient, and focusing on the recreational boat market. So, let’s take a look at some Pros and Cons to EBs.

Pros:

· Environmentally friendly

· No fuel cost or engine maintenance & no emissions generated

· Reduced vibrations & elimination of engine noise

· Low power electric motor weigh less than equivalent internal combustion engine (ICE)

Cons:

· Energy density of batteries is much less than gasoline or diesel

· Reduced range for same weight in fuel (gas vs batteries)

· Lower speeds required for energy conservation

· Cost of EBs are higher than their fossil fuel counter parts

One of the biggest draw backs for EBs is the fact gasoline is 50 times more energy dense than lithium-ion batteries. This means the energy contained in 1 Kilogram (kg) of gasoline is equivalent to the energy contained in 50 kgs of lithium batteries! Of course, electric motors are much more efficient than ICEs so ratio isn’t quite that large. In order to keep weight and prices down for EBs manufactures are expecting consumers to change their boating habits. “We think there will be a shift in attitude from owners of small sportsboats from travelling at 30-40 knots to cruising at 15-25 knots,” a boat manufacture said in a Motorboat & Yachting article. I don’t know if this a realistic assumption, but the article also discusses using hydrofoils to reduce drag forces buy lifting the hull of the boat out of the water. Just for fun I wanted to do a quick calculation to see how much weight in batteries it would take for a 200 horsepower (hp) electric motorboat to cruise at wide open throttle for 4 hours.

With a 200 hp = 150 kW motor and boating for 4 hours = 600 kWh of storage capacity required. Assuming that lithium-ion batteries weigh about 6 kg per kWh, then the battery packs would weigh 3600 kg = 7936 lbs. That’s a lot of weight to haul around for a small motorboat and may even weigh more than the boat itself! You could expect to burn about 80 gallons of gasoline when running a motorboat with an ICE under the same conditions.

Image curtesy of MotorBoat &Yachting

Stipulate Energy Efficiency – Policy is Key

This blog is the final of my Three Things to Combat Climate Change Today series. If you have been following these were my three things that we should be taking action today that don’t require new technology to implement. The other two previously discussed were to curtail methane emissions and electrify everything reasonable.

Energy Efficiency, the topic of this post is not a glamorous field, particularly in the US where we much rather tout new technology in solar, wind, and storage while energy savings takes the back seat. With the instability of oil supply announced this week energy efficiency might become exponentially more recognized in the coming months. The International Energy Agency recently released their 2021 World Energy Report driving towards a 2050 Net Zero energy goal[1]. They have calculated that worldwide we need to improve our energy intensity by 4.2% annually to meet their 2050 goal. Unfortunately, we are only accomplishing about 2% per year since 2010 and the 2020 pandemic slapped us down to 0.5% as we retreated to work from home. Reading this detailed 100+ page report might sound depressing, but there are nuggets of hope. One particular section nested more than 50 pages in didn’t jump out until my second reading: “standards and labels are a keystone of energy efficiency policy”. They go on to report that standards and labelling saved over 1500 TWh of electricity consumption in 2018. This is the same amount of wind and solar electricity generated worldwide that year.

Turing to data specifically in the US, last week the US Annual Energy Outlook report from the EIA was presented forecasting energy use through 2050[2]. Reviewing their presentation provided insight like this chart showing the growth of wind and solar assuming their costs continue to decrease. The chart also corelates to my last post showing no decrease in natural gas use over the next 3 decades. It wasn’t until I listened to the recorded presentation and subsequent Q&A did it strike home that these data are based on current policy and not claims and projections made by car manufactures setting goals to eliminate ICE vehicles by 2035, and corporations pledging 100% renewable energy. These claims are no guarantees and subject to change at the next quarterly financial report so they are not modeled by the EIA. Recognizing that each administration also imparts changes, the bottom line is it takes policy, standards, and metrics to enact change.

Reading these two reports recapped the importance of energy efficiency in our efforts to combat climate change with both stressing the importance of policy, standards, and metrics. If we can achieve a 4% annual reduction in energy intensity it quickly scales to 3,500 TWh of electricity reduction (the equivalent of half of China’s total electricity consumption)[1].

[1] K. Sadamori and B. Motherway, “Energy Efficiency 2021,” Energy Effic., p. 103, 2021.

[2] “Annual Energy Outlook - U.S. Energy Information Administration (EIA).” https://www.eia.gov/outlooks/aeo/index.php.

What does the term “Sustainability” mean to you?

The term sustainability has been gaining popularity in recent years and seems to have as many interpretations as there are trees in this world. So, what is the definition of sustainability anyway? According to Cambridge Dictionary to be sustainable is the “ability to continue over a period of time”. That sounds like a pretty broad definition as a “period of time” could entail infinite possibilities. Some examples of not being sustainable include: spending more money than you earn requiring one to take on a large amount of debt and consuming natural resources at a greater rate than they can be replenished. However, I would like to talk about what sustainability means to me through the use of the three pillars or triads of sustainability: the environment, society, and the economy.

The diagrams below depict two ways to interpret the triads of sustainability. The diagram on the left, the Sustainability Venn Diagram, depicts overlapping environmental, societal, and economic needs. For example, if a system is optimized for sustainable societal and economic growth, equitable conditions are attained. If the conditions are optimized for the three pillars, sustainability is achieved. However, this method makes it seems that all three triads of sustainability are equally taken into account when determining a sustainable process, which is generally not the case. I like to use the diagram on the right, the Nested Sustainability Triad, which shows more of hierarchy of how each of the sustainability pillars interact with each other on Earth. Planet Earth supports a wide variety of environments, which in turn provides for a diverse group of societies and cultures to flourish, and societies allow for the development of economies.

I am going to go one step further and relate the nested sustainability triad to the concepts of objectivity, which I came across while reading a book on the topic of anthropology called Sapiens: A Brief History of Humankind by Yuval Noah Harari. An objective phenomenon exists independently of human consciousness and human belief; trees, rocks, and solar radiation all existed before people discovered or understood them. The Subjective is something that exists depending on the consciousness and beliefs of a single individual. Our societies are comprised of billions of people that have individual values, attitudes, feelings, and beliefs. The inter-subjective is something that exists within the communication network linking the subjective consciousness of many individuals. Many of history’s most important drivers are inter-subjective including: money, nations, law, governments.

My interpretation of sustainability is hierarchal. While we should do our best to make sure our economies continue to grow, the continual progress of our societies can only be achieved if the environment remains intact for future generations to meet their own needs.