IS THERE AN ELECTRIC SKI BOAT IN YOUR FUTURE?  Written 9/20/2008

Right now, we have the technology and the actual parts to put together an electric powered ski boat.  Tesla Motors currently sells an electric powered sports car powered by a 118 pound, 248 HP electric motor powered by Lithium Ion batteries.  This car can go from 0 to 60 in 3.9 seconds (which is faster than almost every production car on the road) and will hit a top speed of 120 mph with a range of roughly 150 miles.  A rechargeable battery weighing close to 1,000 pounds powers it.  Add the battery and motor weight together and it’s almost identical to that of a conventional PCM 349 HP engine with a full tank of gas.  If we increase the size of the motor by 25%, we’ll have 310 HP (at the output shaft of the motor from 0 through 8,500 rpm) and increased the motor weight by only 30 lbs.   

The battery size can remain the same as the motor can run at close to 25% efficiency, as it’s capable of spinning a constant 14,000-rpm.  Ski boats typically run at 3,500 RPM for 30 seconds, then idle for a minute and then repeat until the end of the set.  At each end of the lake, this boat would use no energy at all as the motor can stop spinning entirely.  There’s no need to idle.  These factors will allow the boat to run for hours in between charges just like the Tesla roadster.  Docks in the future will have quick chargers where you will plug in your boat in between sets and/or overnight. 

Utilizing this current technology, we could put one of these motors and battery packs in a boat, replacing the gasoline engine and still have all the performance we have grown accustomed to but without burning any petroleum based products period!  No exhaust fumes at the transom.  No noise complaints from the neighbors.  Ski boats might then be allowed on lakes, rivers and places where they have never been before. 

In the end, we have a fully powered ski boat that is noiseless, pollution free and will operate all day for pennies.  One of the drawbacks is that our current technology limits the battery pack life to only last 3 to 5 years.  If the battery pack costs $10,000.00, then the cost per year for the batteries is $3,333.00 per year ($64.00 per week) for a 3 year replacement and $2,000.00 per year ($38.46 per week) for 5 years.  Right now, with gasoline at $3.79 a gallon, we can ski about 16 short sets on this amount.  For anyone skiing 20 sets per week, the savings should the equivalent of about 4 gallons of gas per week plus all of the associated oil and filter changes that go along with this wear and tear.  This equates to $15.16 (4 gallons of gas per week x 52 equals $788.32 per year plus 5 oil and filter changes with Mobil 1 equals another $150.00 for a grand total of $938.32 in savings per year not including the cost of the electricity to recharge the batteries which is ridiculously low and not including any labor for the oil and filter changes.  Add to this all of the positive economic factors (like keeping our money circulating within our own economy rather than sending it offshore) and the environmentally friendly facets which can reduce emissions to zero through the purchase of green energy credits and you are looking at the future right NOW.

It’s up to each and every one of us to help clean up this beautiful planet we call home.  Its up to us to make sure the thoughts and words become things.  In doing so, we will all be doing our part, contributing to a more beautiful, peaceful and cooperative world. 

Sincerely,

Schnitz!



Notes;

PCM Engine weight = 950 lbs

HP 343

Torque 430 at 5,000 RPM through 1.23 to 1 transmission

Gasoline weight = 25 gallons x 6.216 = 155.40 lbs

Total weight for both = 1,105.40

Add the weight of the gas tank also. 

HP = Torque x RPM ÷ 5252

Weight of Tesla motor = 118 lbs

Weight of fuel (batteries) =

HP 248

Torque 276 at 0 thru 4,500 RPM x 1.23 trans = 339.48

Right now, the Tesla battery pack weighs about 975 lbs.  Add to this a 150 lb motor and the net weight is 1,125 lbs.  The gasoline-powered boat on the other hand carries a 950 lb engine and 155 lbs of fuel for a net total of 1,105 pounds, a 20-pound difference or basically no difference