FPB 78-1 Cochise: Solar Update


We continue to be impressed with Cochise’s solar array. From ten solar panels we are generating within spitting distance of 20 kWh. Twenty kWh is enough power to run the great room air conditioning during the middle of the day.

We are just beginning to understand how important this level of solar energy is to the efficiency and enjoyment of cruising.

And it’s fun seeing how well you are doing or have done, and comparing with other cruisers.

The 20kWh referred to in the photo above is generated by ten 340 watt panels. The layout of these panels is such that some of them are shaded at certain times of day. Our original estimate was that we’d see a 30% loss from rated output due to shading, angles, etc. This number seems to be right on.

During the midday sun, say 1000 to 1400 hours, output is averaging about 110 amps. We have seen as much as 150 amps on a momentary basis. The norm is 110/115 amps.

Posted by Steve Dashew  (October 20, 2016)

12 Responses to “FPB 78-1 Cochise: Solar Update”

  1. Pete Says:

    I couldn’t understand how you were getting 20kW from 3.4kW of panel – thought I must have dropped a power of ten somewhere, and the difference between 3.4 and 2 was the efficiency loss.

    Light finally dawned when I looked properly at the picture, and realised you didn’t mean 20kW at all but 20kWH 🙂

  2. Kees Says:

    Why do you keep referring to 20 kWH as 20 kW? You’re mixing up energy and power.

  3. Andy Says:

    Thanks for great writing. But small correction, above should be 20kWh for amount of energy as is indicated in the display screenshot. 20 kW would be unit of instant power, which obviously would be much bigger PV-system.

  4. Shannon Says:

    Do you think this amazing solar output will affect your thought process on where you drop the hook and/or using a stern anchor to keep the angle to the sun at optimum?

  5. Steve Dashew Says:

    Hi Shannon:
    Probably not going to change our approach to anchoring. But we are thinking about more panels.

  6. Shannon(TheShaz) Says:

    How durable are the panels? I know Cochise is brand new. But I assume some research went into the system. Are you going to have to cover the panels up while going thru the canal locks?

    Thanks again for the amazing pictures and commentary.

    I again highly recommend a 360 camera. Between Gear VR and Google Cardboard Virtual Reality (VR) is the way to go. You record from the Salon or Matrix deck and we poor unfortunate folks can actually see what it is like to be on a FPB.

    Only thing missing would be the actual motion and salt air, but a wobbly chair and a squirt bottle & fan fixes that.

  7. steve dashew Says:

    Hi Shannon,
    Engine room air comes in via a pressurized system which originates in the BBQ box aft face. There is an outlet on the starboard side, aft of the mast and wet locker.

  8. steve dashew Says:

    Solar Panels have (from memory) a 20/25 year warranty. We have a 360 degree camera but have not had time to learn how to use it.

  9. RobS Says:

    You seem to consistently use the term “kW” when you mean “kWh”. A 3.4kw solar array can’t produce 20kW of instantaneous power, it can average ~3kW of instantaneous power over the course of a 7 sun hour day which will equal ~20kWh of generated energy which is precisely what you are seeing.

  10. admin Says:

    Yep, accidentally left out the “h”.

  11. James Masters Says:

    given weight’s an issue — and you want more panels — what have you found to use — other than roll-panels — and where would you place them …?

  12. steve dashew Says:

    Hi James;
    There are lighter panels, but they cost about four times what these do. There are several options for adding panels, and we could probably squeeze in six more without too much hassle.