Solar Electric Houseboat Stands the Test of Time
Solar Electric Houseboat Stands the Test of Time
After a year in build on the 4th July 2014 Mothership Marine launched its first solar electric boat. This project was perhaps very much before its time. Apart from a beautifully finished interior crafted by Kanga, Shaun and the team it had, with the help of the University of New South Wales a groundbreaking electrical system consisting of two state of the art electric motors, batteries and a 4kW solar array. A shout out aswell to Don Pulver of Eniquest for his advice too.
Trip 1
The first trip we did was 130 miles up the coast from Jervis Bay to Sydney Harbour. It was quite a trip, particularly as there was a gale blowing from the west.
Trip 2
Fast forward to today the boat is currently owned by Hawkesbury River Charter and has just been moved up from the Hawkesbury river to Lake Macquarie. Directions, go to the Pacific Ocean turn left and head north 60 miles, turn left again. Don’t forget this coastline is world famous for its big swells and surfing!
Brad and Jane, owners of Hawkesbury River Charter, set off at 5am from Americas Bay near the mouth of the Hawkesbury River. The weather was calm but a swell of 2 metres was uncomfortable, waves of up to 1.2 metres were reported later in the day.
They ran the whole day at full power with the DC generator from Eniquest running constantly. There was plenty of sun too. (Slip Slap Slop if you’re an Aussie). They cruised approximately 2 miles off this scenic coastline and had the added attraction of sighting several pods of whales migrating north.
Propeller Size and Pitch
There’s been a lot of discussion lately about the size of propellers and their pitch and how they affect the performance of electric motors. When we first launched the Houseboat in Jervis Bay she was fitted with sixteen inch propellers with a fourteen inch pitch. On our trip north up to Sydney the motors were set at half speed and risked overheating. Elco Motors are air cooled, AC induction motors and need to revolve fast so that the air can cool the motor. We reduced the pitch of the propellers, this allowed faster rotation, meant a faster airflow around the rotator and the motors kept cool. Brad and Jane ran their motors at full power all day and their motors stayed at 30 degrees centigrade all the way.
PMAC vs AC Induction
There’s nothing wrong with AC induction motors, they’re a real workhorse. But permanent magnet motors are more efficient, produce less heat and have a greater torque. These are the types of motors that we fit these days. Unfortunately they do come at a higher price.
Brad and Jane had between 1 and 2 knots of current against them and arrived at their marina at Lake Macquarie at 5.30 in the afternoon. 12 solid hours of cruising on the Pacific Ocean. Nicely done.
If you are visiting the East coast of Australia you can hire The Watershed as she is now called. Please see below for details, and say hi from me.
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