How to Build a Green Home

Of the many components which you can add to the house you are building, to make it more environmentally friendly and to give yourself a more sustainable lifestyle, Solar Power is probably the major one. There are two types of solar energy to consider. One, called passive solar design, is the direct interplay of your house and the sun in terms of heating, cooling and lighting. The other is the collecting of solar energy, by means of photovoltaic solar panels, and converting that energy to electricity, with or without batteries.

Passive solar designing lets you decide how to use the sun for lighting and heating; and it gives you options to keep the house cooler, by protecting it from the extremes of summer. When building your house, the orientation of the building lot, the path of the sun, and modifications to the design of the house should be considered at the earliest stages. As stated in an earlier article, the ideal orientation of a house on a lot—that is, for those living above the Equator—is just East of South, with most windows on the southern and eastern sides of the house. This allows for maximum use of the sun’s light and heat in the winter, when its path is following a lower arc across the southern sky. It also protects the house from too much sun during the summer, when its path is directly overhead.

If you have yet to purchase the lot upon which you are planning to build your home, look for land which slopes moderately, dropping southward. Not all lots give you the option of a gentle south-facing slope. If your lot doesn’t have a southern slope, even if it is graded in the opposite direction, the house can still be designed to capture the southern exposures. In building our homes in Mexico, one of our houses was built on a gentle south-slope. Orientation was easy and we made the necessary modifications to our house design to both accommodate the winter sun and protect against an overabundance of summer’s heat. The lot for our other house slopes mostly to the west. The house is still oriented to just east of south but, to capture more sunlight and heat, we have more and larger window on the south. The second house is also built around an interior patio, which allows light to come into more of the house from different angles.

Besides the benefits of cooling and heating and light, some passive solar components can be used to give a house a green space, a niche or room that has a mini-climate, like a greenhouse. In a two-story house we lived in in California, the design included a small balcony outside of the second floor master bedroom which was glass-enclosed all the way to the first floor. By opening and closing the balcony doors, we could regulate the temperature of the room. The bottom floor surface was covered in bricks and had a planter box, a sink and counter. The room was like an indoor patio and studio, with plenty of light for both the plants and other projects, such as painting and clay. Insulation is a key factor in passive solar design. Besides make modifications to allow or prohibit light, keeping the heat in our out is accomplished by good insulation.

Passively using the sun for light and caloric energy is only one of the two ways to harness the sun. Photovoltaic cells, in solar panels, collect the sun’s energy. There are various ways to use the solar energy that has been collected by these solar panels. With the use of a converter, which changes the power to alternating current (AC), the energy can be used immediately. If one chooses, the energy can be stored in batteries and “saved” for use when needed. At this point, the energy can be converted and used as AC or used directly from the battery, as direct current (DC). The advantage of DC is that you don’t need the converter to process, to change the energy into AC. When purchasing a system for solar power, a converter is, along with the solar panels themselves a major expense. The disadvantage to DC is that you need to find and purchase special outlets and find and purchase special, and relatively expensive, equipment, especially lights and kitchen implements.

If you decide on the more preferred AC choice, there are decisions to be made. Stand-alone systems require batteries. Battery-life can be as long as ten (or, in some cases, more) years; but, there is a replacement factor looming, at some point, in the future. Here in Mexico, we are completely off the grid, so we have chosen the battery option. After 5 years, with the regular required maintenance that we have given them, they are performing as well as we when first set the system up. When the time arrives for the batteries to be replaced, it is important to replace them all, as used batteries will skew the load usage, in a mixed battery assemblage. One final note on batteries: because of advanced technology, batteries can be nearly 100% recycled; an environmental factor to consider with this option.

The alternative to the battery option is to be connected to the local power grid and use the solar panels, as a supplemental system. This can produce smaller electric bills as well as a more environmentally friendly lifestyle. In some areas, the power companies will “buy back” power that your system has generated during the day. This can mean even more savings. A final alternative to the above is to add a limited battery system. This insures that when all else fails, you will have lights when, up and down the streets, your neighbors are searching for their tucked away candles and flashlights.

The last question to consider, as with the other issues in previous articles regarding gray-water usage and rain-water harvesting, is “How much should you get?” As with the other systems, the answer lies in two calculations: figuring out how much you use/need; and figuring out, given the various systems and their components, how much you can afford. The answer to your first question can be found by averaging your monthly electric bills. When planning your home, you can use this figure as a baseline and predict whether your new home will use less or more. Given that you are planning to build and live a more sustainable lifestyle, chances are you will use less, but it is a factor only you can estimate.

Panels come in shapes and sizes and powers to collect. After calculating your usage, you can then calculate how many panels, the size of the converter, how many batteries, if any, and the other supplementary costs (such as cables) there are. In our one house in Mexico, we have a small, efficient 24 Volt system: 3 panels which generate 550 Watts of power, a charge controller, eight batteries and a 1500 Watt converter. This serves our needs and provides electricity to both the main house and the guest/studio room. While this system is fine for people who don’t use a lot of electrical energy, most would find it limiting.

One last factor to consider about solar power, that we discovered after we had installed the system, was getting the proper sized converter. Our 1500 Watt converter is fine for running the lights and appliances, the refrigerator, the video player and screen, and the stereo system. All of these require low wattage. There are some products that require more watt usage, such as a hair dryer. With products like these, there are lower wattage alternatives; their higher wattage ones can cause problems for the converter, as it struggles to keep up. The safest choice is a higher wattage converter. To that end, in the second house we built, we installed more panels and a larger converter to accommodate more and heavier usage.

Whichever type of Solar-harnessing systems you decide to use, passive components, solar electric components in the different modes of application, you will be contributing to the health of the environment. Sustainability practices, on any scale, have the twin benefits of lessening the stress of the overuse of ecological resources, and the lessening of the need for dependence on overtaxed community resources. Each step the individual takes is, ultimately, good for everyone.

It's important to also make sure that your home is toxin free.  Here's a company I highly recommend who have been around for over 50 years and has pioneered the "Green Movement" before it was "hip".  

http://youarewell.myshaklee.com/us/en/category.php?main_cat=HomeCare&

Have a great "Green and Healthy" day!  :)

Richard Cooper