Note: the following post describes, step by step, how my wife & I went from total solar neophytes, to living completely off grid and harnessing the power of the sun for its help with much of the daily work and comfortable lifestyle we enjoy here in Mexico. I’ve included a fair amount of techno speak for those who, as I once was, are craving the empowerment of understanding and implementing solar, but are struggling though some of the initial phases. Readers are encouraged to post questions or comments about the systems or processes described here in that all questions, no matter how basic, may be of some help to others that follow…
The first couple of winters visiting the property we had purchased near Puerto Vallarta on the Pacific coast of Mexico (2005-2007), my wife Holly & I were still in the process of securing title, and thus reluctant to put any money into infrastructure improvements. The modest, one bedroom mexican ranch house we occupied had one existing 15 watt solar panel direct wired to a 12v marine battery and running one long string of 12v incandescent lights when we bought it. Despite twelve hour days of cloudless skies, we had, at best, an hour of light once the sun went down. For refrigeration we parked our faithful old pickup truck camper next to the house and used the onboard dometic gas refrigerator. Around that time I had launched and was chairing a municipal energy commission back in the states, and was growing increasingly interested in sustainability in general, and solar in particular.
By the second winter, we hand carried down three Sunsei 17w panels and I began learning about charge controllers, inverters, and the always dreaded “voltage drop”. At that early stage of learning, it took quite a while to figure out that voltage drop inherent with using the existing #12AWG house wiring for 12v, combined with a tired old marine starting battery, far too small solar panel array, and energy sucking incandescent bulbs, were all conspiring to keep us literally “in the dark”.
“Poco a poco” (little by little) is a favorite expression of our mexican neighbors, and poco a poco it was learning the ins and outs of solar. Around the second year in, a mexican neighbor told me he knew of someone with some panels, and soon four Sharp 175‘s, of unknown origins, were purchased for a good price, and stored safe & sound in our rickety goat shed. Using the SEI guide “Photovoltaics Design & Installation Manual” plus help from Lee Consavage, an engineer friend, and other input from online chat groups such as Arizona Wind & Sun, I began designing our first real PV system. Finally, after stumbling int the dark – literally – we were well on our way to a brighter future! On the next trip SOB (south of the border), Holly and brought down in our carry-on luggage an Outback MX60 Charge Controller, a 1000watt Go-Power inverter, and miscellaneous fuse blocks and cable connections. Three sweaty days later, much of which was spent crouching gingerly atop spanish roof tiles, drilling holes through cement walls, and making numerous, nervous, electrical decisions well above my pay grade, I flipped the switch, and lo-and-behold, “the miracle of the ranch” had finally occurred! Truly; seeing that little green light go on for the first time, hearing the gentle hum of the inverter, and realizing that we were now sucking power, real power, 120v power sufficient to run ample lights, a small 7cubic foot refrigerator, blender for margueritas, play music, and charge computers, right out of the sky, right out of the either, felt as close to something miraculous as I expect I’ll ever experience!
Since those early days, we have upgraded our batteries from the original 4 trojan T 105’s and now have 8 Trojan L-16’s for over 700amp hrs @ 24volts DC, plus a larger, 1500watt Xantrex inverter to run a heavier duty washing machine than we had originally. Still, even with the larger battery capacity, we rely on a small, portable gen set to top off the batteries from time to time in extended periods of rain during the summer months.
A note on inverters: 1500watts with a 2000peak load capacity seems to be the break point providing enough amperage to run a decent size washing machine and virtually any home power tool except a welder. Pure sign wave inverters run quieter and provide cleaner power, while the more economical modified inverters tend to hum, both the unit itself, as well as through stereos and certain other electronics. We have also experienced two appliances that wouldn’t run at all on the Xantrex modified sine wave inverter; a yogurt maker, and also a dehydrator which actually burned out as a result.
Fast forward another year from building the original house system, and I had completed my NABSEP coursework from the AltE learning center in Hudson Massachusetts, and I was ready to take on much more significant solar project. By this time Holly and I had also expanded our vision for the ranch to include an off-grid campground, solar water pumping & heating, and various other projects. In the fall of 2009 we both sold our companies (I had been a commercial architectural photographer and Holly had a financial planning firm) and we committed ourselves to the dream of living and promoting sustainability full time. Currently we rent out our house in New England most of the year and we’re forging ahead with creating a broader scope, regional, sustainability center. Our ongoing projects include building with stone, compressed earth block, & other local material, organic farming & gardening, goat cheese production, composting, tree planting, water recycling, biofuels experimentation, and numerous other initiatives.
In the winter of 2009/2010 we learned to mix mud for adobe, and with much help from visiting family & friends, and our mexican neighbors, we built the campground bath house and solar shed which houses showers, bathrooms, a laundry room, a workroom, the 2.4kw solar array, an Outback 3600w pure sine wave inverter, sixteen Trojan L16 batteries for 700amp/hrs at 48volts, and the balance of the electrical system. Our campground “Camping Sol y Mar” (Camping Sun & Sea) is, as far as we know, the first completely off grid campground with RV hookup sights in the americas, if not the world. This winter are building on a new backpacker bunkhouse, and with that in place will begin hosting workshops and work exchange Volunteers.
The entire project has been a huge learning curve but we have an increasingly steady stream of adventure campers and wonderful volunteer work exchange participants using the facilities. In addition to the solar which produces up to 15kw per day (enough to budget 2kw for each of the 5 hookup sites – sized for small to mid-sized campers – plus a couple more kw for a modest sized cheese cooler for Holly’s goat cheese making operation, the building also boasts solar hot water showers, and grey & black water recycling systems. The increasingly “edible” campground also features an herb spiral, rapidly growing fruit trees (see “Eat This Campground! post below) and a natural wood fired pizza oven coming online soon Thank you Katy & Alex, our amazing summer caretakers this year! ).
I wish I could say it’s been easy and smooth getting this far. Sometimes it feels as though every step is a battle. Attempting to cut costs, I opted for creating my own array racking. Big mistake! The thousand dollars saved cost me countless hours piecing together a custom aluminum framework on a completely uneven roof made from timber milled with a chain saws and machetes. Simple tools like a drill bit and bolts long enough to through-bolt the 6” timbers all had to be brought down from the states as needed. After my experience of working atop spanish tiles on our home system, I opted to leave off having tiles under the bath house array, and instead lay down a roofing of clear polycarbonate laminate. Constructing this, and making it all waterproof and structural enough for potential hurricane force wind loading turned out to be incredibly tedious, and much more of a project that I had ever bargained for. Still, the roof works really well, in that it provides nice passive daylight to the workroom below where the rest of the system is housed, as well as the fact that the laminate stays perfectly cool under the panels, even on the hottest of days.
Yet another error I made was the purchase of the Outback FX inverter rather than GV model. The FX series won’t accept the voltage vagaries of supplemental charging from generator backup (a subtle distinction missed by both myself, and the sales agent that recommended the FX unit for my specific application). Outback was kind enough to supply me with a replacement board to convert the FX model since bringing the inverter back to the states for replacement was impossible. Still the changeover meant dismantling the guts of the system after it had been already been completed.
Occasionally my wife and I ask ourselves, “if we had it all to do over, would we simply have tied in to the power lines less than 100 yards away?” That definitely would have been the easier, less expensive route to take. But
then we realize that if we’d wanted easy, we would’ve been better off just staying in the states. Rancho Sol y Mar increasingly is our home now anyway. A crazy, inventor friend of ours just finished building us a fuel alcohol still, so tackling renewable transportation is the next learning curve looming. We also have 100‘s of fruit & coconut trees planted, a small, first crop of corn coming up, and loving, productive, adorable animals on all sides, Our dream of 100% independent living is increasingly becoming a reality. We realize we’re a little crazy, and a more normal life would be easier, however were strapped in now, and taking the ride. I guess that as long as the sun keeps shining, we’ll be here in Mexico seeking to sustain ourselves and others from it!