FPB 78-1 Cochise: Now Running Air Conditioning With Solar Energy

We are anchored at Cape Lookout, North Carolina. It has been a very warm humid weekend, the type of weather that typically finds us in cooler climates. We’ve been waiting for the arrival of six new Sunpower 360 watt solar panels, the most efficient available, and very much in demand. Cory and Angela McMahon’s Triton Marine Team have just completed installation, and we are watching as the Outback Mate controller adds up the day’s power creation.

Cory is aboard today fine-tuning the solar charge controller parameters. The Mate controller is prematurely reducing output. Yet the total for the day still comes to 33.4kW hours. That’s 1317 amp hours of electricity for our 24 volt DC system: sufficient to run our air conditioning in normal summer weather, as well as the usual life aboard loads like cooking, lights, fridge and freezer, etc.

These six panels are mounted in a more efficient unshaded position, on top of the Matrix deck roof, which provides accelerated air flow keeping them cooler. We do not like the weight aloft, and just tolerate the appearance. But these six new panels effectively double solar output, making the trade-off worthwhile.

Although the numbers come in as expected, we are just beginning to digest the impact this will have on our cruising. Imagine…34kWh of clean, silent power.

Posted by Steve Dashew  (June 26, 2018)

7 Responses to “FPB 78-1 Cochise: Now Running Air Conditioning With Solar Energy”

  1. Carl E. Says:

    Hi Steve,

    If I understand correctly, FPB 78-3 (Iron Lady) has solar panels on the Matrix Deck roof as well. Do the installations differ very much (other than the fixed ladder on 78-3 :)) and are you happy with the access for cleaning and other maintenance?

  2. Steve Dashew Says:

    Howdy Carl:
    Iron Lady’s panels were designed in from the start to be part of the Matrix deck roof structure.It was their very impressive output that got us to taking a second look. We are going to build a ladder to the Matrix roof for solar panel maintenance, and then use a light weight plank between the edge of the roof and the panels. We put our panels onto a tubular ladder truss so as to keep the weight down and provide separation sufficient to create a wind acceleration zone between panels and Matrix roof. The panels have a slight positive angle of attack relative to the roof to help with air flow. As to the cleaning process, we think this can be achieved using hose with nozzle and a deck brush with an extended handle.

  3. Andy Says:

    34kWh means around 8 – 17 litres of diesel saved per day, depending on efficiency of generator – multiply that to get litres per month, and you can only say: Very impressive!

  4. Steve Dashew Says:

    Hi Andy:
    Monday we had rain or 100% cloud cover for most of the day.We somehow managed to put 16.8kWh on the meter.

  5. Juergen Says:

    Steve glad to see/hear that the thoughts of Solar on the Matrix roof has been amended..

    If you had to adjust for the added weight up there what ratio of Extra fuel/water weight do you feel is needed to keep the same center of Balance..

    Personally I have currently have 1200w’s of solar on the Roof of my bus and once my system has been fully installed, I to shall enjoy my own Domestic Air-conditioning system Plus all other electrical systems..

    Overall I’m glad to see that the 83’s have joined the solar age.

  6. Steve Dashew Says:

    Hi Juergen:
    Th VCG trade off with solar panels aloft is more of absolute need for stability rather than something we can trade off. That said, we very much like the feeling that comes with all the solar power we now produce.

  7. Andy Says:

    Actually 17 kWh gathered on cloudy rainy day is even more impressive!

    Remind me how many 360W panels you had again?

    With this much solar output, you could consider disconnecting at least some of your alternator (2 x 2?) drive belts from main engines, if you are getting enough power anyways they are just there heating up for nothing and wasting (many litres of valuable) diesel, and they are very quick to reconnect if/when needed. Or even consider installing a belt clutch / disconnect so you could do this – with fancy model even remotely from the bridge anytime needed. Or replace them with (much) higher efficiency permanent magnet models that can take be freewheeled without damage.