Solar Panels Start Fire on Sailboat!

--Blogpost written by Bob

At approximately 12:30 PM on March 17, 2018, people in the restaurant in Marsh Harbor's Jib Room noticed that a bimini on a sailboat at the end of the dock had caught fire.  Six or 8 people ran out with fire extinguishers and water hoses to extinguish the blaze--it was extinguished very quickly.  The following photographs document what I observed after the fire was already extinguished.  I saw the blaze from the restaurant and went out to help extinguish the fire.  I returned to the restaurant to get a cell phone so that I could take the following photographs.

Fire damage viewed from astern of s/v Wildflower III,
a Beneteau 41.1.  No one was aboard
when the fire started.

The fire started at one or more of four 100-watt flexible
solar panels that were mounted on
the sailboat's bimini.

One of the solar panels is still on top of the
damaged bimini at this point.

More removing of solar panels.

The solar panels were removed after the fire was
extinguished because of the potential
for the fire to restart.

More effort in removing the solar panels

The last of the four solar panels
being taken off the bimini.

The voltage controller and related wiring was
removed from the cockpit.  The cables
from the solar panels were actually
entangled in the stern pulpit.

The front of the removed voltage controller.
No brand was evident.

The bottom of the removed voltage controller.  Note
that the red lead to the battery was taped
with black electrical tape.

The fire damage to one of the 100-watt solar panels.

The brand and model number of one of
the four identical solar panels.

To me it was clear that the voltage controller was NOT professionally installed.  There may have been serious flaws in the wiring that were covered by black electrical tape (which should never be used on a boat!).  It is also possible that the voltage controller was faulty, overloaded, or otherwise inadequate to handle the 400 watts of solar panels.  However, the fire started at the interface between the solar panels and the bimini at a time in the day when solar energy production would have been at a maximum.

It is noteworthy that two loose propane tanks sat in the cockpit of the sailboat, a very small one plus a 10-pound aluminum tank.  If these had caught fire, the people who extinguished the flame would have been in danger from explosion.

When I got back to my boat I looked up the Go Power! website and found out that they use (one size fits all) 30-amp PWM controllers (one of the least efficient) which by my calculation should nominally handle 360 watts at 12 volts.  However, four 100-watt panels were used in this case for a total of 400 watts, assuming ratings are accurate.  In any case, the controller's rating was probably marginal for four 100-watt solar panels plus some of the wiring that I observed between the voltage controller and the batteries would never meet ABYC standards.  I couldn't determine where the solar panels were actually manufactured but they were a lot less costly than my Solbian-brand flexible solar panels (made in Italy).  I would roughly estimate the damage to the sailboat at somewhere between $25,000 and $50,000 based on my experience--that amount of money would have purchased high-quality solar panels and good MPPT controllers many times over.



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