When we committed to building off-grid in Oaxaca, we knew it would be harder than building conventionally. We did not know how much harder, or in what specific ways, or how many of the lessons would come from mistakes rather than planning. This is the practical, unglamorous account of what it actually takes to create a functioning off-grid property on the coast of Oaxaca — the power, the water, the waste, the logistics, the communication, and the human side of construction in a remote part of Mexico.

We are writing this from Montserrat Reserve, our eco retreat near Chacahua, where every system we describe here is running right now. Some of them took three attempts to get right. None of them work exactly the way we originally designed them. All of them work, and that distinction — between the plan and the reality — is what this post is about.

What Off-Grid Actually Means on the Oaxaca Coast

Off-grid means different things depending on where you are. In the mountains of Colorado, it means cold. In the Australian outback, it means heat. On the Pacific coast of Oaxaca, it means humidity, salt air, intense sun, torrential seasonal rain, months of drought, insects that eat everything, and a tropical environment that accelerates corrosion, rot, and biological growth at a pace that temperate-climate builders cannot imagine.

It also means no municipal water line, no sewer connection, no reliable electrical grid within practical connection distance, limited cell signal, and roads that become impassable during the rainy season. The nearest town with a proper hardware store is hours away by a combination of boat and unpaved road. The nearest electrical supply distributor is in Puerto Escondido, and even that is a significant trip when you factor in the boat crossing.

Off-grid on the Oaxaca coast is not a lifestyle choice layered on top of existing infrastructure. It is the only option. There is no grid to opt out of. You either build your own systems or you do not build at all.

Power: Solar Panels, Batteries, and the Things You Learn the Hard Way

We went solar. On the Oaxacan coast, where we receive roughly 5.5 to 6.5 peak sun hours per day for most of the year, solar was the obvious choice. But “going solar” is a phrase that hides an enormous amount of complexity.

Panel Sizing

Our initial system was undersized. We calculated our expected loads — lighting, kitchen equipment, water pumps, a few fans, phone and laptop charging — and sized our array to cover that with a modest buffer. What we did not account for was the gap between theoretical output and real-world output. Panels lose efficiency in extreme heat, and our coastal location regularly hits 35 to 40 degrees Celsius on the panel surface. Dust, pollen, salt spray, and bird droppings reduce output further. Rainy season cloud cover can cut production by 60 to 70 percent on heavy overcast days.

We ended up expanding our array by about 40 percent beyond our original calculations. Our current system runs approximately 4.8 kilowatts of panel capacity across the property, mounted on secondary structures rather than the villas themselves to keep the aesthetic clean and to allow better airflow beneath the panels. If we were starting over, we would have sized for 150 percent of our calculated load from day one. The cost difference is small relative to the labor of retrofitting.

Battery Storage

We use lithium iron phosphate (LFP) batteries for storage. Our first battery bank was lead-acid — cheaper upfront, widely available in Mexico, and familiar to local electricians. Within eighteen months, the salt air and humidity had accelerated corrosion on the terminals, and the cycle depth we were running them at (regularly below 50 percent state of charge during rainy season stretches) degraded the cells faster than expected. We replaced them with LFP, which cost roughly three times as much but handles deep cycling without degradation, tolerates the heat better, and requires almost no maintenance.

Our current storage capacity is approximately 19.2 kilowatt-hours, which gives us roughly two days of autonomy at our average consumption rate. During extended cloudy periods in the rainy season, we have occasionally dipped below our comfort threshold, but we have never run the system to zero.

Inverter Choices

We use a hybrid inverter system that can handle both the solar input and, when absolutely necessary, a backup generator. The inverter was one of the most important decisions we made, and also one where we made an early mistake. Our first inverter was a modified sine wave unit — cheaper and easier to source in Mexico. It ran our lights and fans fine, but it produced an audible hum in certain appliances, and it damaged a water pump motor within the first year. We replaced it with a pure sine wave inverter, which runs everything cleanly and quietly.

What You Can and Cannot Run

Off-grid solar on the Oaxaca coast can comfortably run LED lighting throughout the property, ceiling fans, water pumps, a commercial blender, a small refrigerator, laptop and phone charging stations, a sound system at reasonable volume, and our satellite internet router. It cannot practically run air conditioning, electric water heaters, conventional ovens, hair dryers, or anything with a heavy resistive heating element. We designed around those limitations from the start — our villas use cross-ventilation and thermal mass for cooling, we use gas for cooking, and our showers are heated by solar thermal tubes. You can read more about how these systems integrate in our sustainability page.

The honest truth is that an off-grid solar system on this coast is not about abundance of power. It is about discipline in consumption. Every watt matters. You learn to think about energy the way you think about water in a drought — as something precious that you do not waste.

Water: Rainwater, Storage, and the Dry Season Problem

Water is the system that keeps us up at night more than any other. The Oaxacan coast has a dramatic wet-dry cycle. From June through October, it rains heavily — sometimes 200 millimeters in a single day. From November through May, it barely rains at all. Building a water system here means capturing enough during five months of abundance to last through seven months of scarcity.

Rainwater Harvesting

Every roof on the property is a collection surface. Rain flows from the roofs into gutters, through first-flush diverters that discard the initial dirty runoff, and into underground ferrocement cisterns. We have a total storage capacity of approximately 80,000 liters across multiple tanks, which sounds like a lot until you calculate the daily water needs of a functioning hospitality property — showers, kitchen, cleaning, garden irrigation, and the natural pool top-up during evaporation season.

Our collection system works well during the rainy season. The tanks fill reliably by late August in a normal year. The challenge is making that water last. By April, in a dry year, we are watching levels closely.

Filtration

Rainwater is not automatically safe. Bird droppings on roofs carry bacteria. Organic debris decomposes in storage tanks. We run a multi-stage filtration system: sediment filters to catch particulates, activated carbon filters to remove taste and odor compounds, and ultraviolet sterilization for the water that goes to kitchen and drinking taps. The UV system runs on solar power and consumes very little energy, but it requires regular bulb replacement — and those bulbs have to be ordered from the city and shipped in, which means planning ahead by months.

Dry Season Challenges

In a bad dry year, rainwater alone is not enough. We have a backup: a deep well that accesses the local aquifer. We use it sparingly and only when cistern levels drop below a critical threshold, because the aquifer is a shared resource, and over-extraction on this coast has real consequences for the mangrove ecosystem and the communities downstream. Balancing our needs against responsible water use is an ongoing ethical negotiation, not a solved problem.

Waste: Composting Toilets, Septic, and Greywater

Waste management off-grid requires you to confront things that conventional construction hides behind a flush handle and a pipe to the municipal sewer.

Composting Toilets vs. Septic

We evaluated both options extensively. Composting toilets eliminate the need for water in the waste stream and produce usable compost over time. They are the environmentally superior choice. They are also, in a hospitality setting, a guest experience challenge. We tested several models during the construction phase and found that modern batch-composting units, when properly maintained, are odor-free and comfortable to use. But they require consistent management — turning, carbon additions, and monitoring — that adds a daily task to operations.

We ultimately went with a hybrid approach. The common-area facilities use low-water-flush systems connected to a small biodigester that processes waste anaerobically and produces effluent clean enough for subsurface irrigation. The villas use composting units. Guests are given a simple, honest explanation when they arrive, and in practice, the response has been overwhelmingly positive. People who choose to stay at an off-grid eco retreat on the Oaxaca coast are generally not the people who are bothered by a composting toilet.

Greywater Recycling

All greywater — from sinks, showers, and the kitchen — passes through a constructed wetland system before being reused for landscape irrigation. The wetland uses gravel beds and native aquatic plants to filter out soaps, food particles, and organic matter. It works remarkably well, but it requires that every product used on the property be biodegradable and plant-based. We provide all soaps, shampoos, and cleaning products to guests and staff. Nothing petrochemical goes down any drain. This is a non-negotiable constraint of the system, and it is one we explain clearly on our sustainability page.

Material Delivery: Boats, Tides, and Patience

This is the part of building off-grid in Oaxaca that no planning document can fully prepare you for. Our property is accessed primarily by boat. Heavy materials — lumber, stone, cement for the limited concrete we used, cistern components, solar equipment, batteries, plumbing supplies — all arrive by boat across the lagoon, and boat access is tide-dependent.

A delivery that misses the tide window waits until the next day. A delivery that arrives during a storm does not arrive at all. A pallet of solar panels that ships from Oaxaca City to Puerto Escondido in six hours can take another two days to reach our property, and that is in good conditions. During the rainy season, when the lagoon swells and the channels shift, delivery logistics become genuinely unpredictable.

We learned to stockpile. If a material was critical and available, we bought it early and stored it on-site, even if we would not need it for months. The cost of storage was always less than the cost of a construction crew standing idle because a shipment did not arrive.

We also learned to source locally in ways we had not initially considered. Stone from the property itself. Clay from deposits nearby. Palm fronds from established groves in surrounding communities. The less we needed to bring in by boat, the less the tides controlled our schedule.

The nearest well-stocked hardware store is hours away. Forgetting a single fitting or connector means losing a day or more. We kept a running inventory and ordered in bulk. The crew learned to improvise with what was on hand rather than stopping work for a missing part. That kind of adaptability cannot be taught in advance. It develops out of necessity.

Communication: Satellite Internet and Signal Realities

Cell signal at our location ranges from weak to nonexistent, depending on the carrier, the weather, and apparently the mood of the nearest tower. During the construction phase, communication with suppliers, consultants, and the outside world was one of our biggest operational bottlenecks.

We now run satellite internet, which provides a reliable connection for the property. It is not fast by urban standards, but it handles email, messaging, video calls, and the basic connectivity that guests expect. The hardware was expensive, the monthly cost is significant relative to terrestrial internet, and the dish requires a clear view of the sky that dictated where we could mount it. But it works, consistently, regardless of what the cell towers are doing.

For day-to-day communication during construction, we relied on a combination of satellite messaging devices, occasional trips to areas with cell coverage, and a lot of face-to-face coordination. There is something clarifying about not being able to send a quick text. You plan your communication more carefully. You make decisions on-site rather than deferring to someone on a phone call. In retrospect, the limited connectivity during the build phase may have actually improved the quality of our decision-making, even as it slowed it down.

The Construction Crew: Local Knowledge and Natural Building

We hired locally. The workers who built Montserrat Reserve are from communities along the Oaxacan coast — people who understand this climate, this soil, and these materials in a way that no imported crew could. Many of them had experience with conventional construction — concrete block, rebar, corrugated roofing — and were initially skeptical of our approach. Clay plaster? Parota wood frames without steel reinforcement? Composting toilets? Some of them thought we were building something that would not last.

We invested time in training. We brought in specialists in natural building techniques — rammed earth, clay plastering, traditional palapa roofing — and ran workshops with the crew before construction began in earnest. The skepticism faded as the workers saw the techniques in practice and recognized elements of older building traditions that their own grandparents had used before the concrete era took over.

By the end of the project, the crew had become advocates for the methods. Several of them have told us they plan to use natural building techniques in their own homes. That transfer of knowledge — from the project back into the community — is one of the outcomes we are most proud of.

Permits and Regulations

We will be direct: navigating permits and regulations for an off-grid property in rural Oaxaca is not straightforward. The regulatory framework is designed around conventional construction connected to municipal services. When you are building off-grid with alternative materials and independent utility systems, you are working in spaces where the rules are unclear, where local authorities may not have encountered your type of project before, and where the process requires patience, transparency, and a genuine willingness to explain what you are doing and why.

We obtained all required permits. We worked with local authorities rather than around them. We hired a Mexican architect to stamp our plans and an environmental consultant to ensure our systems met or exceeded all applicable environmental standards. The process took longer than it would have for a conventional build, and it required more documentation, but it was not adversarial. Local officials were generally curious and supportive once they understood the project.

The one piece of advice we would give to anyone building off-grid in Mexico: do not try to shortcut the regulatory process. The temptation is real, especially in remote areas where enforcement is light. But cutting corners on permits creates legal vulnerability that can surface years later, and it undermines the trust between builders and communities that makes projects like ours possible.

What We Wish We Had Known

If we could go back to the beginning, here is what we would tell ourselves:

Size your solar system for 150 percent of your calculated load. Panels degrade, conditions vary, and your actual consumption will be higher than your estimates.

Buy LFP batteries from the start. The upfront cost is higher, but the total cost of ownership is lower, and you will avoid the frustration and waste of replacing degraded lead-acid batteries in a salt-air environment.

Build more water storage than you think you need. Climate patterns are shifting. The dry season is getting longer and less predictable. An extra 20,000 liters of storage capacity costs relatively little during construction and provides enormous peace of mind during a drought year.

Stockpile critical materials early. If it has to come by boat, buy it when it is available, not when you need it.

Invest in your crew. Training takes time and money upfront, but a crew that understands and believes in natural building techniques works faster, makes fewer mistakes, and produces better results than a crew following instructions they do not understand.

Be honest with yourself about costs. Building off-grid is not cheaper than building conventionally. In many cases, it is more expensive, especially in the short term. The savings come over decades, in reduced operating costs, in systems that maintain themselves, and in a property that does not depend on external utilities that can fail or become unaffordable. But the upfront investment is real, and pretending otherwise helps no one.

The Result

Montserrat Reserve runs entirely on its own systems. The sun powers our lights and fans. The rain fills our cisterns. The garden feeds our kitchen. The waste returns to the soil. The buildings are made from materials that were here before we arrived and will be here long after the buildings themselves have returned to the earth.

It was not easy. It was not fast. It was not cheap. But it works, and it works in a way that does not extract from the land or the community around it. That matters to us more than anything else.

If you want to see these systems in person — to understand what off-grid living on the Oaxacan coast actually looks and feels like — Montserrat Reserve opens in 2027. You can learn more about us and join the waitlist to be among the first to experience what we have built.