Living Off The Grid

Guest Post By L. Fred Roensch, PhD

In addition to the expected, e.g. high level of insulation, caulking, double glazing, smoke and carbon monoxide monitors and security systems – the following features are suggested for any “off the grid” home. Most of these features are well known and widely used in energy efficient homes – some are not!

1. Minimize total enclosed square footage
   The smaller the enclosed space the lower the heating and cooling energy demand.
2. Minimize footprint by using two stories.
   A two-story home requires a smaller lot size, reduces impact on the surrounding environment, and is easier and more efficient to heat and cool. It also can be designed to appear from the north side as a very conventional home. The home I built was in a “planned community” where the design had to be approved by an architectural review committee adhering to the covenants. It was built among other conventional homes on a cul-de-sac.
3. Eliminate windows, or install a limited number of small fixed windows on north, east and west sides.
   All windows, regardless of the design, and even with shutters, increase the heat and cooling demand.
4. Backfill or build north side of first floor below grade.
   The greater the direct contact with the ground the larger the earth tempering (energy storage and latent heating and cooling during the transiting from summer to winter and from spring to summer.
5. Install a passive solar trombe wall on south side attached to a green house on west end.
   This is the primary source of passive “solar gain” heating for the home. The trombe wall also hopefully, provides most of the heat for the greenhouse.
6. Collect water from the roof in a cistern for yard, plants, garden, greenhouse, and toilet flushing.
   Any water collected from the roof reduces water required from other sources, is very pure, therefore it requires little or no treatment for most uses. This water quality is ideal for laundry, and, if there is enough collected, is also ideal for the yard, plants, garden, and greenhouse because of the extremely low dissolved solids.
   Incidentally, collecting water from the roof will not allow installation of a grass or other living roof. Furthermore, I do not recommend a “living roof” because soil is a very poor insulator and the vegetation requires careful monitoring and care.
7. Recycle potable water (except from toilets) for toilet flushing and use the remainder for garden, greenhouse, yard, and plants.
   Any recycled water reduces the water demand from other sources. Potable water is not required for toilet flushing.
8. Compost organic waste for garden and yard fertilize.
   Composting reduces waste and provides an excellent organic mixture for the yard, garden, greenhouse and plants.
9. Place fireplace on second floor in or near center of home on an inside wall.
   A fireplace can provide the primary neutral carbon heat source. The fireplace can be designed to also provide hot water during the winter and heat for cooking and baking. The unique innovation fireplace design is discussed in a recent article.
10. Place hot water heater behind fireplace.
    The nearer the hot water heater is to the fireplace the easier it is to use the fireplace to efficiently heat water.
11. Place backup furnace on first floor below fireplace.
    This permits the furnace fan to distribute heat from the fireplace. This is discussed in a recent article by me concerning including a fireplace or a stove in the home.
12. Combine all vents:
    from bathroom, bathroom exhaust fans, kitchen appliances, clothes dryer (if present), and heat rejection from any compressor used for home cooling, refrigeration, or freezer. Pass the combined airflow through a thermostatically controlled fan driven reversible air/air heat exchanger.
    An air-to-air heat exchanger with a thermostatically controlled fan controls the air quality by maintaining an adequate interior air exchange with the outside air and simultaneously conserves heat or cooling depending on the outside temperature. This is particularly important during the transition period from fall to winter and winter to spring.
    The home otherwise should be as air tight as practical by sealing all windows, doors, and any other sources of outside air.
13. Install D.C. (direct current) pumps on cistern water and active hot water solar collector.
    When the sun is shining, D.C. pumps can be powered directly by a photovoltaic panel without an inverter or battery.
14. Use an open floor plan with great room with fireplace.
    An open floor plan improves air circulation and is easier to heat and cool. The fireplace will heat the great room primarily by radiant heat where people will spend significant time when they are awake.
15. Slope the ceiling of rooms on top floor.
    A sloped ceiling (towards the north) improves air circulation. Sloping the ceiling also adds some character and style to the home.
16. Install a small, hinged, insulated outside access door adjacent to the fireplace on the north side.
    This makes it easier to bring wood to the fireplace and helps to keep the home clean.
17. Install internal insulated shutters on rails to cover the windows and any sliding glass door on the south side.
    The heat can be conserved at night by closing the shutters in the winter and opening the shutters (depending on the outside temperature) during the day. To reduce cooling demand, during the summer, the shutters are closed during the day and (depending on the outside temperature) opened at night. The shutters also provide additional protection during severe storms.
18. Provide an extended eave on south side of roof.
    During the summer the extended eave on the south side shades the south wall and reduces direct heating by the sum. During the winter the sun is lower in the sky and permits maximum passive heating using the trombe wall coupled with operation of the window shutters. This is an important factor in passive solar home design.
19. Plant or maintain deciduous trees on south side of home – evergreen trees on other sides.
    Evergreens on the east, west and north side reduce the effect of wind during the winter and shade the sides of the home conserving cooling during the summer. During the winter the deciduous trees on the south side permit the sun to help heat the home, using the trombe wall, windows, and shutters. During the summer the deciduous trees shade the south side of the home keeping the home cooler.
20. Place deck or screened porch above greenhouse.
    Ideally, the top of the greenhouse would be glass and neither a deck nor a screened porch would be the top of the greenhouse. However, the option to have a deck or screened porch is present and if present does little to decrease the function of the greenhouse. It’s strictly an option but efficiently adds additional convenient living space to the home.
21. Maximize earth tempering by building lower floor directly on the ground.
    The more the home is in direct contact with the earth the greater the earth tempering (energy reserve storage) and extends the latent cooling during the transition from spring to summer and similarly extends the latent heating during the transition from summer to fall.
22. Use stained wood for siding.
    The staining is strictly a personal option and but it does reduce maintenance cost, and potential environmental concerns compared to painted siding. Of course using, preferably recycled wood siding, is preferred because wood is a renewable neutral carbon building material.
23. Use space rugs though out home – no wall-to-wall carpeting.
    Wall to wall carpeting reduces significantly the earth tempering latent energy storage effect. Personally, I like it in the bedrooms but it would reduce total energy demand if it could be avoided.
24. Install active or photovoltaic panels on the ground.
    Placing the active hot water heating solar panels and photovoltaic panels on the ground provides easy access for cleaning and the inevitable maintenance required. Furthermore, every drop of water can be collected from the roof.
25. Use solar clothes dryer, i.e. a clothesline.
    When the sun is shining, the energy used to operate a clothes dryer is eliminated.
26. Use skylights and “solar pipes” for natural lighting.
    Solar light is free; electric lights require energy.
27. Install micro hydro turbine in near by stream.
    It is generally agreed, a reliable energy source other than wind or solar, even if a wood fireplace is used, is required to meet basic energy needs for most “off the grid” living. This is because inevitably there will be extended periods of clouds and inadequate wind. Unless the cost drastically lowers for solar photovoltaic panels, batteries, inverters  and controllers, it is prohibitively expensive to install a larger enough system to cover these periods of cloudiness and lack of wind.
    Of course, if you are capable of synthesizing (or willing to buy) enough bio diesel, then a diesel generator could be used to provide temporarily the energy for basic needs during these periods of clouds and inadequate wind. I don’t recommend a gasoline or propane fueled generator because both contribute a net increase of atmospheric carbon dioxide compared to bio diesel. This topic is covered in detail in William H. Kemp’s book (see below).
28. Install bio diesel emergency backup electrical generator.
    Bodies or vegetable oil is carbon neutral and renewable.
29. Have the home built inside, in module form in a controlled environment, all system tested, and then placed on the foundation.
    Construction in a controlled environment offers many advantages. It assures quality construction, ease of inspection at each stage, and reduced waste. Weather related delays, weather damage to the structure eliminated, security, and other typical problems related to construction is minimized or eliminated.

Many, but not all, of the features listed above are discussed in detail in the following books:

“Earth-Sheltered Homes: How to Build an Affordable Underground Home” by Rob Roy

“The Renewable Energy Handbook: A Guide to Rural Energy Independence Off-Grid and Sustainable Living” by William H. Kemp

“Solar Living Source Book-Special 30th Anniversary Edition: Your Complete Guide to Renewable Energy Technologies and Sustainable Living” by John Schaeffer

“Microhydro: Clean Power from Water” by Scott Davis

More books for off grid living…