Solar Bimini: System and Costs

Previous Solar Post: Solar Bimini

Summary

We are slloooowwllyyy installing solar power on our 1989 Catalina 36 sailboat.  Nathan designed and built a new bimini from 1″ stainless steel tubing, to accommodate the large rigid panels.  I spec’d the solar install itself, so if anything goes wrong on that end–it’s all my fault :-).

In the previous post, I talked a bit about the bimini.  In this one, I’m talking a bit about the system design, the equipment I selected based on our budget and the system requirements, and costs.  Feel free to contact me or leave a comment below with questions or corrections.  We’ve done all the labor to date, so cost is comprised of transport to and from Anchorage, shipping, and materials.

System Design

Basically, we took a measuring tape into the cockpit and tried to tetris the maximum wattage of solar.  After a while, we tired of this (and all the extra wiring we’d have to do), and sized the largest solar panels we could fit forward and aft of the backstay.  Then we found the few places selling solar panels within 500 miles of us, and bought the cheapest decent ones we could find, to last us a few years before we resell them and revise the system.

This drove the rest of the design.  I did estimate our power consumption, but it was purely for informational, rather than guidance, purposes.  On a sailboat, the primary drivers of the size of the solar system are going to be unshaded space, then aesthetics, followed closely by budget.

Technically speaking, we COULD fit 800-1000W of solar atop the bimini, another 200–300W atop the dodger, and 400W of lifeline mounted panels–if necessary.  Not currently necessary, or in the budget.  (Inasmuch as we budget.)

I had the choice of selecting a charge controller for peak loads, or cloudy day minimums.  I chose cloudy day minimums, and went with a 30A Midnite Solar Kid with HyperVOC, and future install of an overcurrent shunt to a DHW heating element.

Solar costs
Table 1: Solar components and costs.  Finding, buying, and transporting the solar panels was another $100.

Sourcing

I am not a person who is adept at finding bargains, or arranging shipping to out of the way places.  Sam and Jesse Osborne of Seven Seas Sailing Logistics, friends of mine whom I admire greatly, are excellent at both of these things, but since I am not  prone to asking for help, I puzzled through this on my own.  I’d have been better off asking their assistance, for certain :-).  I am, however, a slow and persistent turtle!

The Silfab solar panels came from Lime Solar in Anchorage.  Purchasing large panels online and shipping them to Seward proved difficult because we are in a small town in Alaska, have a P.O. Box, and live in a marina.  While we could have found a reasonable workaround (such as purchasing 100w Renogy panels through Amazon), we were satisfied with the options available at two locations in Anchorage.  Alaska Home Living sells mostly Canadian Solar panels in a few sizes.  Lime Solar had in stock Silfab, Samsung, and a GoalZero suitcase panel.  Both had panels in the size, voltage, and power range I wanted.  Alaska Home Living also sold a selection of the system components such as charge controllers and inverters.  Both are aimed more towards larger home or commercial systems.

I tried to get panels through a box store, but none permitted the panels to be shipped to the store.  Of course, RIGHT AFTER we bought the Silfab panels from Lime Solar, Home Depot started their ‘anything online is shipped for free to the store’ policy.  including solar panels.  Argh.

Honestly, price and availability drove selection of the Silfab panels.  They were rated for 20-30 more watts per panel than the comparable Canadian Solar option, while being 25% less expensive.  The spec sheets, although specs are often deceiving because you cannot see the quality control of the factory by looking at numbers or the panel, were virtually identical.  Where they were not identical, the Silfab panels seemed superior.  The Silfab company itself seems to be a well-known Canadian manufacturer, but with limited availability in retail.

There’s a little risk management as well.  If we don’t like the solar bimini configuration, we can back out of it–sell the panels, revise the frame, try again.  Or, fatalistic view that it is, if we hit heavy weather and the panels get damaged, we can soldier on with a slightly improved iteration ;-).

References

I go a little overboard on researching, because I like it so much.  But the problem is, I research so much, that the individual sources begin to blur together.  As long as I vet sources before I accept their data into the maw of my brain, I don’t mind.  But I am on a constant quest to keep track of what I learned where, so as to share the information and/or pay appropriate tribute.  So, this section, on any post of mine, will get updated long after the post is published, as I discover a reference that had shaped my thinking, and deserves attribution (oops!).

 

 

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