Anyone who lives in a big city may have dreamed of moving elsewhere and living isolated, in a house among the trees or on a deserted beach. During the pandemic and the endless months of quarantine, many more may have had this same idea. As romantic and seductive as this may seem, however, living deep in nature comes with some important practical challenges. Rarely would anyone give up the little comforts they are used to, like turning on a faucet or charging their cell phone. If the location is, in fact, remote, it may not have electricity, drinking water, gas, sewage, or solid waste collection. But there remain several possibilities for a life with comfort and without neighbors. What are the main solutions to enable this and how can an architectural project provide an off-the-grid life?
Living off-the-grid requires an awareness of everything that the house consumes and produces, an ecosystem that, preferably, should be a closed cycle. The balance can never be negative. In other words, if the house consumes more than it produces, there is no possibility of paying for the excess, as we are used to in cities. At the same time, if something is left over, it means it was underutilized and resources were wasted. Without the urban infrastructure that provides us with daily facilities, a self-sufficient house or community must be able to provide all the means for living locally.
Water
Although electricity may come to mind at first as the most important utility, water supply is vital for our survival. For this, it is necessary to identify one of the three most common sources of safe water: a nearby body of water (a lake or the source of a river), a well, or collected rainwater. Water from artesian wells or rainwater systems should preferably go through a filtering system before being used for consumption. To pump water from an underground cistern, a lake, or to feed some filtering devices, however, electrical energy is indispensable.
Electricity
To generate electricity in off-grid systems, the sun and wind are the primary renewable sources available. Residential wind systems are still relatively expensive, but they can be good options when weather conditions are favorable. This system consists of a wind turbine, which captures the kinetic energy of the wind through its propellers, transforming it into electrical energy. Batteries store the energy and supply it in the absence of wind. Another essential component is the inverter, which transforms the direct current (DC) of this energy stored in the batteries into alternating current (AC), suitable for use in household appliances and other equipment. Small aero generators generate up to about 100 kW.
But the most common way to obtain electricity off the grid is through solar energy. According to GOGLA (Global Association for the Off-Grid Solar Industry), the off-grid solar industry has grown tremendously over the past 10 years, becoming a vibrant $1.75 billion-a-year market that remains in business with a solid growth curve, currently serving 420 million users. Of course, this doesn't just encompass would-be hermits. There are 840 million people in the world who still lack access to electricity, and more than 1 billion live connected to unreliable networks. Off-grid solar energy could also serve a variety of productive uses for these populations, powering solar water pumps (SWPs), refrigerated storage, or food processing machinery.
A photovoltaic off-grid system is made up of a few parts. First, the array of solar panels captures the sun's radiation and converts it into electrical energy. This energy will go to a charge controller, which serves to extend the life of the batteries, making them always receive adequate charges. The controller is also responsible for charging and discharging the batteries. Both the batteries and the photovoltaic panels must be connected to the inverter, which will allow for the use of the electrical energy in alternating current, since the plates all produce energy in direct current.
Regardless of the system, it is important that an off-grid construction has adequate space for all these equipment and devices, so that they are accessible and allow for easy maintenance.
Garbage and Sewage
Another concern in off-grid construction is related to waste. Organic solid waste can be composted and recyclable solids must be sent to the appropriate destinations. Without urban collection to gather and distance us from our garbage, occupants will face the enormous amount of waste produced in a building.
The concern over waste generation is crucial, especially to prevent the pollution of the same water sources that are used to supply water. In relation to sewage, there are some options for adequate treatment. The most common choice for sewage treatment in places where there is no network is the septic tank. The operation is simple: sewage enters the pit, where solid waste will settle, a crust will form on the surface and wastewater will remain between the layers, flowing to a sink. Bacteria that live inside the septic tank digest the organic fraction, helping to eliminate solids and remove most of the odor. Wastewater slowly leaks out into a bed of gravel and soil below. Despite being able to carry out this primary treatment, the septic tank's efficiency is low and limited, and it can pollute the soil and generate unpleasant odors. Also, it may require periodic emptying, which can be complex in remote areas.
One possibility for treating the effluents from the pit in a more adequate way, using a highly ingenious system but with little technology, is through the Root Zone System. In this case, filtration is done by stones and also by plants that, with their roots, capture the nutrients from the sewage and return clean water to the soil. The sewage, previously filtered by the septic tank, travels along the paths of the tank, passing through stages with different sizes of stone and sand, until it ends up being returned to the air as water vapor, already clean, returning to the water cycle and making itself a friendlier option for the environment.
Another option widely used in remote locations is the dry toilet, or composting toilet. In this case, the residue is transformed into a compost that can be used to fertilize plants. In more traditional dry pots, at each use, the container must be covered with sawdust so that, when full, it can be placed in a composter, which will decompose the organic matter through the bacteria present. There are already modern compost toilets on the market, which are odorless and very efficient.
There is also the possibility of recycling the sewage. To do so, users must first separate the gray waters from the black ones. The first refers to the effluent that comes from washing machines, showers, and bathroom sinks; the second is that from toilets. Through a physical, chemical, or biological treatment, which removes most of the impurities in grey water, this first type of effluent can be reused for non-potable uses, such as irrigation and for toilets.
To deal with black waters, users can use biodigesters, which work through anaerobic microorganisms (in the absence of oxygen). A biodigester consists of a hermetically sealed chamber in which organisms consume water-diluted organic matter through fermentation, breaking it down. As a result of this biodigestion, biogas and biofertilizer are generated. The first can even be used to feed stoves. Of course, each of the solutions presented here must be designed according to the needs and possibilities of each project and accompanied by the recommendations of experienced professionals.
The Voxel Quarantine Cabin exemplifies these concepts well. This was a project developed by a team composed of students, professionals, and experts from the Master in Ecological Buildings and Advanced Biocities (MAEBB) of the Institute of Advanced Architecture of Catalonia (IAAC) Valldaura Labs. Designed as a quarantine cabin, the house can accommodate one occupant for 14 days, providing for all material needs during isolation. The water system incorporates rainwater collection, which filters through vegetation on the terraces, and recycles gray water and treats black water in an autonomous biogas system that generates usable fuel for cooking and heating and produces sanitary fertilizer as by-products. In addition, it produces all its electricity through solar panels, and its structure is made of wood from the land itself.
In off-the-grid and self-sufficient constructions, both the designer and the occupant must be much more careful and aware of environmental impacts. The project must necessarily be energy efficient so that it does not need numerous and costly energy capture systems. For the thermal comfort of the building (heating or cooling), natural and renewable solutions should be sought if possible. The occupant of a project of this type also needs to be aware of all systems running and fully connect to the functioning of the building, including the generation of energy, its consumption, the water cycle, and the waste generated. The house becomes a resilient ecosystem and the occupant an important part of the balance.
This article is part of the ArchDaily Topic: Automation in Architecture. Every month we explore a topic in-depth through articles, interviews, news, and projects. Learn more about our monthly topics. As always, at ArchDaily we welcome the contributions of our readers; if you want to submit an article or project, contact us.
