Solar Panel Installation & Experience

It's now been ten months since we installed solar panels on Mowzer and so here's a more technical post on the details of the installation and our experience with it so far.

One of our primary goals when we moved aboard Mowzer was to be as energy self-sufficient as possible with solar and/or wind power generation.  If nothing else, our five years of visiting the boat in it’s charter configuration had taught us that the last thing we wanted to do was to have to run the engines or a generator for a couple of hours a day, both from a noise point of view but of course also from a desire to use as much renewable and free energy as possible.  Of course the energy is not really free because you have relatively high setup costs for both systems, but once up and running, they have relatively low operating/maintenance costs.

For solar, we mapped out the cabin top and bimini top space, documenting where all our lines, blocks, cleats and other sailing paraphernalia lie and while still at home, mapped out a plan to add thin, flexible solar panels to the tune of 345 watts.  The flexible panels are a bit less efficient than rigid but much lighter and they don’t require a frame to support them so there is pretty much a weight/installation cost vs. efficiency equality in our minds.

We ordered four Solbian panels for delivery to St. Thomas:  two square 90W panels and a rectangular 40W panel for the bimini and one rectangular 125W panel for the cabin top.

Once in St. Thomas we played around with the configuration to get maximum sun exposure with the assumption that most of our time will be spent in the Caribbean sitting at anchor with the wind blowing from the east which puts the best energy producing sunshine on our mid-line in the summer months and slightly to starboard in the winter months.  The one disadvantage of mounting on bimini and cabin-top is that they both tend to sweep upwards from fore to aft which results in the panels being more angled away from the sun in the later afternoon hours - pretty much after 4pm there is little solar production.

Three panels sewn to our bimini and one affixed to the cabin top.

To mount the panels we used two different methods:

For the cabin-top we first tried sticky-back Velcro but this quickly succumbed to the wet conditions and the adhesive really only lasted a couple of weeks.  We toyed with using a 3M adhesive product to stick either the panels or the velcro down but really didn’t want to deal with the mess and in hind-sight, we ended up moving the panel a bit so we were glad we did not go with a fully permanent solution in the beginning.  Our final installation used 3M Lock-Tite which holds the panel solidly in place even in 35 knot winds.

Cabin top panel affixed with 3M Lock-Tite under the leading edge.

For the panels on the bimini top we used the placket and velco method described here http://www.bruceschwab.com/uploads/solbian-to-canvas-guidelines.pdf .  The only addition we made was to provide a little more rigidity for the panels by inserting a piece of corrugated plastic board between the solar panel and the bimini.  I used my SailRite machine to sew the Velcro to the panels in a long, wide zig-zag stitch.  As with the cabin-top panel, these panels have remained in place through 35 knot winds but if we felt the need, any or all of the panels are easily removed and stored inside.

To protect wires from sun, they run under a flap of Sunbrella on top of the bimini.

Profile showing the thin solar panel with velcro, the corrugated plastic board and velcro on the bottom.

Velco plackets sandwich the two layers together and hold them to the bimini.

I didn't make my flaps quite big enough to give full coverage and protection so the exposed Velcro will eventually break down in the sun.

Each panel has two wires that we connected to longer wires with MC4 connectors which we routed around the bimini and above the main cockpit door.  We drilled two holes into the port bulkhead directly below the bimini where we installed gasketted conduits to pass the wires into the cabin, and then routed them down behind the navigation station and into the berth below.  We mounted four MPPT controllers each protected by a 15 amp fuse, on the wall in the berth where they are easily visible and monitored.  The outputs are then combined, with the negative run through a shunt to measure real-time amperage and then connected to the negative bus in the electrical box under the port berth.  The positive runs through a switch under the berth which in turn is connected to the house battery bank in the port engine room.

Conduits in the bulkhead feed the wires inside the cabin.

MPPT controllers and 15 am fuse.

When sitting at anchor, we pull the boom as far to port as possible so that all four panels get full sun.  We also ease off lines that cast shadows on the panels and tie them off at the mast.  At maximum sun, we routinely see 15 to 18 amps at the shunt but lower if the battery charge exceeds 85%.

We installed our solar panels in November and they were our only means of renewable energy production through the winter months in the north-eastern Caribbean.  We have a house battery bank of 500 amp-hours and in general we found that on a good sunny day we still needed to run our generator or engine for approximately an hour a day.

To give you an idea of our energy use, our main consumers of power are our refrigerator and freezer and for much of the time we do not turn on our freezer, opting to shop more often.  We do not use our big anchor light since that consumes 5 amps, instead opting to hang a 0.1 amp LED ‘anchor light’ in our rigging.  (As an aside, we will be upgrading our main anchor light to LED once in Grenada.)  All of our inside lighting has been converted to LED bulbs so very little power draw there, we have our propane gas solenoid that gets its workout at dinner-time.  We have an electric water pump for the galley and heads, and then there are the electronics that need a daily charge - two tablets, a phone and a laptop computer.  Underway, we have one chart plotter, various navigation instruments and Sulu, our trusty electronic auto pilot.  In busy anchorages the VHF radio is on all of the time.

What have we learned and what would we do differently?  What are we going to change?  Well, we definitely need either additional panels or to add a wind generator to this configuration since 345 watts is just not enough for us.  We also find that given the angle of the cabin and bimini we really only have good power production between about 9am and 4pm - six to seven hours on a good day.  That leaves 18 hours when we are losing the power struggle with our batteries and without a boost on the batteries at about 9pm our morning levels are just too low to maintain good battery health.  If we turn on the freezer we have to add more generator time.

So, in April we bit the bullet and decided to add a wind generator (more on that in a separate article) and are still toying with the idea of adding more solar.  We will most likely upgrade our bimini so that the entire surface is solid rather than the current configuration of the solid central area with canvas on the sides.  This would give us a more secure attachment point and more water-proofing for the cabin below.  The bimini has lost its water-proofing over the years and having the sewn plackets has greatly reduced it further since water pools against the Sunbrella ridges and finds it’s way through the stitching holes.  We would also consider adding a rigid panel on a frame over the dinghy davits that would allow us to angle it toward the later afternoon sun and therefore extend our hours of solar production.  For the moment we will hold off on more solar panels until we have completed a full year in the Caribbean since we fully expect that the summer months (hurricane season) will be more cloudy and therefore would not gain us as much solar production anyways.

Overall impression:  we love the Solbian panels and the option that the thin plastic and slight flex gives for easy mounting options.  The only maintenance we’ve had to worry about is to clean them with fresh water after a salty crossing or when in an anchorage with dust blowing from land (or the Sahara).  Where wires are exposed to the harsh sunlight we have installed Sunbrella sleeves to protect them.  We are careful not to walk on the panels and in the course of ten months we have only one small mark on one that we can only assume is from a rope slap when a genoa line flogged.

Danny & Erika

Since the early days of June its been nice and quiet down here from a weather watch point of view.  However, in the last two weeks, in quick succession we have watched the development of two hurricane systems.

Danny caused quite a stir while we were still in Carriacou and we watched and listened to the buzz as we waited for the storm to turn north and take Grenada out of it's intended path.  The downgraded tropical depression hit the northern leeward and virgin islands but passed on relatively harmlessly.

Erika came up quickly on Danny's tail and while the storm was quite a bit larger it appeared to be tracking north and therefore not a risk for us.  Over the last few days however, Erika stalled with a more southerly track and by yesterday was unleashing her strength on the island of Dominica that we love so much.  We were saddened to hear of flash flooding and resulting deaths and hope that as she moves on, Erika softens or moves away from the islands.

Just to give an idea of the size of the storm that hit Dominica - here's a satellite image from Weather Underground:

While we sat here relatively unscathed in Mt. Hartman Bay on the south coast of Grenada, about 200 miles away from Dominica, the storm was doing her best to make it uncomfortable.  Wind, being sucked up into the system from as far away as South America, blew straight into the anchorage from the south, turning it rocky and rolly for about 24 hours.  Nothing to worry about but I can't imagine what it would be like sitting through 50-60 mph winds or more.

Wind and swell blowing in directly from the south, thankfully there are reefs outside Hartman Bay that broke up the worst of it.

Today we sit serenely at anchor with the winds back out of the protected east.

Back on Grenada - Let's Take an Island Tour

We returned to Mt. Hartman Bay from Carriacou and took up our same position in the anchorage just as before, and just as before the social whirl of activities encircles us.  Today we'll be getting on with putting together the plan for our new hard bimini and some other projects but before that we put in some fun on the weekend and included an all-around-the island tour yesterday with a small group of fellow cruisers.

Cutty was our driver in his brand new air-conditioned (OMG - haven't been this non-sweaty since our visit to Canada in June) taxi van, so we started off the morning with a plan of what we would cover.

Cutty reviews the itinerary.

For the first part of the drive we made our way high up above St. George's where we saw the prison and some old forts, and beautiful views of the Caranage down below.

Old Fort George on the hill with the Carenage fronting the harbour below.

As we made our way through numerous little villages perched on the steep hillsides, everyone has a way of expressing their national pride and taking part in the annual community beautification projects to win the coveted prize.

Just a small glimpse of the display in front of one house as we zipped by.

Ancient and new petroglyph carvings in the cliff face - If Cutty hadn't pointed these out we would never have seen them here on the road side.

Our first organized stop was at Concord Falls.  If you remember we did the hike from Grand Etang a couple of weeks ago and ended up at the falls in a torrential downpour.

Three weeks ago the river was swollen with rainfall and we couldn't get near the falls.

Today, after a few dry days, the falls are much more hospitable.

We even watched some local guys test their (our) nerves with some dives.

Ready to take the plunge?

Moving on up the west coast to Gouyave (pronounced Guave) we entered a much more rural area where tourism takes a back seat to fishing and farming.  Grenada's nutmeg crop is returning after the devastation of hurricane Ivan in 2004, and they now produce one third of the world's supply (2nd after Indonesia), all of it passing through this little production facility with a total of 80 workers.  It operates as a farmer's co-operative and the majority of its employees are women.  The pictures capture the sights but what you cannot begin to imagine is the heady aroma of nutmeg that saturates the air.

To fulfill her daily wage Manasee must sort and grade 170 lbs of nutmeg each day.

All the ladies' hands flew through the cracked shells and kernels.  All parts of the nutmeg are used but the largest, most dense kernels fetch the highest price.

Our guide Cristine showed us the huge drying racks full of nutmegs.

I wish you could smell the heady nutmeg scent filling the air.  The only automated machinery in the factory is the nutmeg cracker from which the workers (I believe all ladies) sort the results.

Sorted, graded, bagged nutmegs, ready for labelling and shipping.

Labelling is done with a dye akin to shoe polish and hand-cut stencils.

Where is that next bag headed?

Can you believe that ONE THIRD of the world's nutmegs come from this little factory???

On to our next stop at the Diamond Chocolate factory.  Unfortunately because cocoa is in low season at the moment, no production was actually going on but we got to see the machinery and had an explanation of the process.  Of course we couldn't leave without sampling the wares and purchasing a few bars to enjoy later.  Perhaps further on in the season we'll make our way to the larger Grenada Chocolate Company factory and see a bit more of this process.

Just one of the many thousands of blooms along the way - Grenada always seems to be in flower.

 Finally, just before we passed out from hunger we stopped for lunch at the north eastern end of the island at the River Antoine rum factory.  This rum factory has been in production since the early 1700s and is one of the few remaining where they still grow their own sugar cane (most now use molasses as the starting point).  We sat for lunch overlooking the cane-field, watching the seaside palm trees waving in the distance.

A delicious lunch and a cooling breeze complimented the wonderful view.

This is the oldest functioning waterwheel in the western hemisphere - still pressing the watery syrup from the sugar cane.  There is no operating manual for this mill - all working knowledge is orally passed down from father to son.

Cut cane awaiting the mill.

The actual press was build 235 years ago and is still in full operation!

The bagasse (remains of the cane after pressing) is used for fuel or compost.

Pulling the bagasse from the mill.  Bet he's wearing regulation flip-flops for this job!

By the first furnace we chuckled - they burn bagasse, and boxes from the competition.

They recently had to replace one of these ancient copper boiling pots.  They can only be acquired from collectors or the remains of other rum distilleries, to the tune of about $6,000 USD.  Got any lying around??

The final product is knows as Rivers Rum.

Two large stills where the wood burning furnaces are fed 24/7 by hand.

And finally, the tasting.

Rivers Rum comes in two white varieties:  75% alc/vol for the local market and 69% alc/vol "tourist rum" so that those with airplane tickets can fly with the less flammable version.  Whichever you buy is likely to strip paint if not careful.  They also produce two "ladies' drinks" at about 19% - passionfruit punch and guava punch.

We finished up the remainder of our tour with a drive down the old airport strip (replaced in 1994 to be closer to St. George's after the U.S. "intervention")

Driving down the old airport runway, which now gets used for drag racing.

Would you buy a "Swiss" watch from this guy?  Actually, it's the old duty-free shop at the airport.

The Prime Minister's plane (one of the ones left at the end of the runway) landed here the day before the Intervention.

The final leg of our drive was over the middle of the island and past Grand Etang lake that we had been unable to see in the mist three weeks ago.  The trail we took that day rises above the lake up the central ridge.

Another one to look at carefully - this is a  Rainbow Eucalyptus with bark of brilliant colours.  Sorry for the photo quality but we were zipping by on the road.

What a day - we arrived back at Secret Harbour at 5pm, happy, exhausted and full of local knowledge.  Cutty was a wonderful guide with an abundance of local knowledge both of the island and also of the botanical environment as well.

We concluded our day with dinner and drinks at the marina to the soulful sounds of Gary on the sax and another great couple of cruiser singers whose names escape me at the moment.

We're all definitely ready for bed!

And lastly, you know I always like to get to the stats:  we traveled 60 winding, hilly miles around this little 21 x 12 mile island, crossed the central mountains at an elevation of about 1900' (580m), pretty much missed the south-western parish of St. David's and made 6 great new friends from Tempo, Shameless and Moody Mistress!

Danny

An update on tropical storm Danny as of this morning:  it looks like Danny is going to reach H-status in the next couple of days and will pass into the Caribbean at the northern end of the island chain.  This is good news for all of us down in Grenada, but not so good for friends up-island.  For those that are affected - please stay safe!

Perhaps we won't rush back down to the big island, but we'll definitely be following the forecasts.  There are a couple more hikes we'd like to get in, now that our main chores are done.