Cob Building Tutorial

Chapter 11: Utility Considerations

As long as you’re exploring the freedom of building your own home out of natural materials, why not think about going all-out and getting off the grid altogether? The smaller size of cob homes, combined with their extra thermal mass, makes them very energy efficient. Using passive solar design can make them even more energy efficient. The savings in energy requirements for your new home put solar and wind systems within reach.

A solar power system produces DC power directly from the sun using panels of photovoltaic cells. When the sun isn’t shining, solar panels don’t work. That's a problem for homeowners, who are usually away from home in the daylight hours. This problem is solved by battery packs. The solar panels generate electricity while the sun is out, then this power is stored in batteries for use in times when the sun isn't shining. One of the major expenses of installing a solar power system in your home is the purchase of an inverter. Inverters convert DC power to AC power. Although photovoltaic cells and battery packs produce and store DC electricity, most home appliances run on AC power; therefore you’d have to convert from DC to AC to use solar power in most commercially available appliances. A typical inverter runs anywhere from $3000-$5000. There are smaller inverters that can be used for each individual appliance for around $150, but the problem here is that you would have to purchase an inverter for every appliance you intended to run.

It may be that you are not ready to take the plunge and go completely off the grid. If that is the case, there are still many alternatives available to you that would reduce your need for non-renewable resources. One possibility is to use your local power company as a storage facility for your solar home. In this arrangement, you are still on the grid, but you have access to your local power company for peak times when your usage may exceed your energy production capacity. Conversely, during your downtime when you're not using much electricity, a federal mandate requires that your local power company buy from you any electricity you produce but don't use. Unfortunately in many states, you have to pay the retail rate for their electricity, but they purchase any you sell to them at wholesale rates. Check with your local company if you're interested in this approach.

How much would a good stand-alone solar power system cost? The prices vary greatly depending on available sunlight in your area, consumption demands, and system options, but as a ballpark figure, if you’re planning to buy a solar power system based on the average power consumption of an American home (8900 kwh), plan to spend anywhere from $25,000 to $30,000 for a stand-alone system. If you can reduce your consumption to the 900 kWh range, you can expect to pay as little as $5000 to $10,000 for the system. So you can see that it pays to make as many cuts as you can. This may sound expensive up-front, but when you consider that you’ll be eliminating your monthly power bill, it can actually be less expensive in the long run.

It's up to you to decide where you can make cuts and how much you're willing to invest in sustainable power. One thing is for certain, on-the-grid power rates will continue to rise, and so any changes you can make will pay off over time, not only by decreasing your power bills but also by reducing our demand on non-renewable resources that damage the environment. 

Speaking of making changes, one of the changes you can easily make is to use compact fluorescent lighting. Compact fluorescent lamps (CFLs) can greatly reduce the amount electricity used to light your home. An average CFL uses only 15 watts of energy to produce the same amount of light generated by a 100-watt incandescent bulb. However, several readers of this column have written to express their concern about the fact that CFLs contain mercury.

While it is true that CFLs contain mercury, and that mercury is toxic, there is no danger of the mercury escaping as long as the bulbs remain intact. That means that unless you break the bulb, the mercury is safely contained. In the event that a bulb breaks, a few basic precautions should keep your family safe: first, open doors and windows in the room so that any potential mercury vapors may escape; next, sweep up the fragments (don’t vacuum, as the blower in the vacuum will vent the mercury into the room and disperse it into the atmosphere); finally, secure the fragments in an airtight container (a tied plastic bag works well) until they may be properly disposed of.

To reduce danger of mercury contamination, never dispose of your CFLs in the trash. Instead, find a recycling center that will accept CFLs for reprocessing. If you are unsure if there are CFL recycling centers in your area, Earth 911 maintains a database of recycling centers at: www.earth911.org.

How serious is the danger from mercury contamination in CFLs? A standard CFL contains about 5 milligrams (mg) of mercury. There are several other common household items that contain more mercury than a CFL. Here are some examples:

A standard lithium watch battery contains about 25 mg of mercury. That’s equivalent to 5 CFL light bulbs.

Older dental fillings contain about 500 mg of mercury. That’s equivalent to 100 CFL light bulbs.

Old-fashioned home thermometers contain up to 2000 mg of mercury. That’s equivalent to 400 CFL light bulbs. If you use the new battery-powered ones, these usually run off of lithium batteries, so you’ve cut the mercury down to the equivalent of 5 CFL light bulbs.

Automatic safety shutoff switches in steam irons (the ones that shut off the iron if it’s accidentally knocked over) contain about 3500 mg of mercury. That’s equivalent to 700 CFL light bulbs.

Some other common household items that may contain mercury include greeting cards that play music, shoes with lighted soles, pilot light sensors, electric switches, barometers, analog blood pressure devices, stoves, ovens, water heaters, space heaters, clothes dryers, furnaces, ball point pens, latex paint manufactured before 1992, pesticides manufactured before 1994, older children’s chemistry sets, batteries, and anything with a safety shutoff switch.

This is not to suggest that mercury is a safe thing to have around your household, but if you are concerned about mercury contamination, there are plenty of other items around your home that pose a greater risk than CFLs. If CFLs are properly handled and properly disposed of, there is less risk of exposure to mercury than posed by other household items.

One final thing to consider with CFLs is the energy savings. Since CFLs generate the same amount of light as a 100-watt bulb for only 15 watts of power, they save a tremendous amount of energy. Most energy generated in the United States comes from coal-burning power plants. Burning coal releases mercury into the atmosphere. So it is conceivable that using incandescent bulbs poses a greater risk of mercury contamination than using CFLs,

Wind generators are a viable alternative to generating power by burning fossil fuels. Wind generators produce clean electricity by using only the wind as a power source. There are only two potential problems associated with wind generators. One is the claim that they kill birds. The other is the claim that they damage the looks of the landscape.

Let’s start with the myth that wind generators kill birds. This probably got started in the days of the Altamont Pass, California windmills. These wind generators use shorter blades and must therefore rotate at a much faster rate to generate electricity. Today’s generators use much longer blades with a much greater surface area. Because of this, they rotate at a much slower speed. This slower speed makes it much easier for birds to avoid them. These new blades are a recent development. Therefore any bird mortality study done prior to 2000 would not have incorporated data from the new blade design and is therefore useless in predicting bird mortality with current wind generator designs. Unfortunately this old data is what gets quoted the most often in the media, so people automatically think ‘bird mortality’ when they think of wind generators. In actuality, far more birds are killed by automobiles than wind generators, so the next time someone tells you that “wind generators kill birds,” ask them if they’ve sold their cars.

The most recent study concerning deaths caused by wind generators is the 2001 National Wind Coordinating Committee study, “Avian Collisions with Wind Turbines: A Summary of Existing Studies and Comparisons to Other Sources of Avian Collision Mortality in the United States." According to this study, wind generators cause 2.19 bird deaths per turbine per year.

In contrast, an estimated 10 to 12 million birds are killed each year by automobiles, and up to 1 billion birds are killed each year by colliding with windows. Obviously the new turbine designs are far safer than other avian hazards in the environment.

Now to address the question of whether wind turbines harm the ‘look’ of the landscape; as the adage goes, “beauty is in the eye of the beholder.” I’ve seen wind farms. I’ve also seen coal-burning power plants and oil refineries spewing out smoke and pollution. If those are the two choices I have for my landscape, I’d far prefer the former to the latter.

There may come a time when wind turbines are commonplace. There may even come a time when they are viewed as an aesthetic component of the landscape. I wonder…when they started building windmills in Holland centuries ago, did the people complain about them “ruining the landscape?” Yet now those old windmills are looked upon with nostalgia and are seen as works of art. Maybe there will be a time when wind turbines achieve the same status.

If you’re planning to use a wind turbine for your home, which is better for you, a stand-alone wind generator, or one that is connected to the grid? That would depend on several factors. For a stand-alone system, your home would have to meet the following criteria:

§ Is the average wind speed at or above 10 miles per hour?

§ Are you prepared for the intermittent nature of wind-generated power, and do you have a backup plan for when the wind isn’t blowing (e.g., battery backup or alternative stand-alone power source)?

§ Are you in a remote location where attaching to the power grid would be expensive or impossible?

If you are interested in a wind generator, but would like to connect to the grid, you would have to meet the following conditions:

§ Your average wind speed is less than 10 miles per hour, necessitating the occasional purchase of supplemental power from a utility company

§ The expense of connecting your wind generator to the grid isn’t cost-prohibitive

§ Local codes allow such a connection

If you’re not sure of the average wind speed in your location, you can find out by checking with the U.S. Department of Energy’s Wind Energy Resource Atlas of the United States, which is available online at: http://rredc.nrel.gov/wind/pubs/atlas/.

The average home would need a wind generator in the 5 to 15 kilowatt-hour range. Depending on service contracts, installation costs, battery backup, and maintenance, such systems would be in the $5,000 to $20,000 range. Average system life is about 20-30 years. While this might seem expensive up-front, when you divide the cost over the life of the system, it works out to be between $20 and $85 per month…far less than the average monthly utility bill, and there’s no threat of price increase!

To learn more about how to determine if a wind turbine generator is practical for you, visit the Alternative Energy Store at: http://howto.altenergystore.com/The-Basics/Wind-Power-How-to-Determine-if-it-is-Practical-for-You/a30/.

The ultimate in energy independence is to live without electricity, just as humankind did for thousands of years before Thomas Edison came along. Some groups, like the Amish, have always lived without electricity. Others ‘dropped out’ in the 1970s during the ‘back to nature’ movement. Still more have come to more recent decisions to live off-the-grid by living without electricity. Today it’s called ‘homesteading.’

Why on earth would anyone want to live without the modern convenience of electricity? In the words of Marci Lilly of the High Lonesome Ranch in Birch River, West Virginia, “Living without electricity is actually a lot easier than most people think.  How can I not have tv, or the blender, mixer, lights? Well, many people still choose to live without all the hassle, electric bills, etc. And life actually becomes easier, slower, even more serene. You go to bed earlier, so you get up earlier in the morning.”

“We lived for over five years without electricity, and had very little adjustment. We never even missed tv.  But it probably takes a week before the habit of switching it on, diminishes. Just think of the silence... sometimes that takes getting used to!”

I know from my own personal history that living without electricity puts you into a whole other world of experience. I lived without electric power for nearly a year back in the late 1990s. After a while you realize just how annoying all these electronic gadgets can be. Without a television or computer or a video game to distract you, you begin to notice the world around you. You pay attention to the details. You learn to listen to the silence.

Living without electricity doesn’t have to mean living a life of austere asceticism. Don’t forget, ancient Rome’s palaces didn’t have electricity, nor did all the kings and queens of Europe in days gone by. It is quite possible to live a life of luxury without electricity. The secret lies in learning the alternatives to electric appliances.

For one example, let’s look at refrigeration. Think about that big energy-guzzling appliance in your kitchen. It’s there to preserve food, but could there be another way to do so? Could there be several alternatives to food preservation by refrigeration that have stood the test of time? The answer, of course, is ‘yes.’

Are you a vegetarian? Then you can preserve most of your food by learning how to do home canning, or by storing it in a root cellar, or by drying it on a line in the sun or in a solar-powered food dehydrator. Do you eat meat? Then a backyard smokehouse can add flavor to your meats while preserving them. I can still remember my grandfather’s smokehouse, and strings of dried apple slices strung across my grandmother’s kitchen. Sometimes the old technologies are the best technologies. These tried-and-true methods worked for the human race for centuries before refrigerators came along. If you don’t want to give up the convenience of refrigeration just yet, there are solar-powered fridges. Vegas Trailer makes one, designed for use in a travel trailer. It could just as easily be used in an electricity-free cabin or home, assuming you can get by with a small fridge. For product information, visit their site at: www.vegastrailer.com/sundanzer.

Another energy guzzler is your kitchen range. Before the days of electric ranges, people cooked on an open fire or in a wood-fired stove. Unless you live near a forest, you probably won’t have a ready supply of kindling for a wood-fired stove. Then of course there’s the work of chopping wood and lighting a fire every time you want to cook. But there is a new alternative. Aga Cookers of Telford, Shropshire, Great Britain, manufactures a cook stove that can be run on biodiesel (http://www.aga-web.co.uk/index_334.htm). Biodiesel is a cleaner-burning alternative to wood-fired stoves.  As biofuels become more readily available, these stoves will be more convenient to operate using a sustainable fuel source. In the meantime, they can be operated using regular diesel fuel or by making your own biodiesel. If you’re interested in the latter option, you can learn the details of making your own biofuels at Journey to Forever’s Web site: Handmade Projects. Make Your Own Biodiesel! at: http://journeytoforever.org/biodiesel_make.html.

On the other hand, if you don’t mind a little extra work on occasion, maybe an earth oven would be right for you. Earth ovens are just what they sound like: ovens made of earth. Such ovens are made of a mixture of clay and sand. You can make coils to shape the oven, or alternately you can stack balls of the mixture in a circular pattern to form a dome. Some people have also made such ovens out of cob: a mixture of clay, sand and straw. The straw adds structural support and makes it possible to actually sculpt an oven into an ornamental piece for your lawn that is both attractive and functional. As fires are built inside, the oven solidifies, much like pottery being fired. For instructions on building an earth oven, visit: http://katipo.co.nz/gallery/oven. If you’re interested in the sculptural effects that can be achieved by using cob to build an oven,  and don’t mind cooking outdoors on occasion, the Low-Impact Living Initiative site at: www.lowimpact.org/courseoutlinecobbuilding.htm has some interesting photos.

There is also the option of using a propane cook stove, but propane isn’t a sustainable fuel. I once read about a hydrogen-powered cook stove, but I can’t seem to find any more information about it. If such a stove is ever offered to the public, it would have the advantage of operating on a sustainable fuel.

What about home heating? Is it possible to forego electricity without freezing in the winter? If you’re building your own home, you can use passive solar to help to some extent. ‘Passive solar’ means aligning your home so that you have a lot of glass facing to the south during the winter months (assuming you live in the northern hemisphere) to maximize heat from the winter sun. Planting deciduous trees on the south side of the house will help in this regard. When the leaves are on the trees in the summer, they provide shade. In the winter, when more sunlight is needed for warmth, the trees have shed their leaves, allowing for more sunlight. Overhangs can also be strategically placed to block the summer sun while maximizing the winter sun.

Passive solar design can go a long way towards meeting your heating needs, but what do you do when it isn’t enough? One option is a wood-fired heating stove or fireplace. You can’t beat a warm hearth fire for coziness and romantic atmosphere! Today’s wood-fired heating stoves and fireboxes are much more energy efficient and less polluting than your grandparents’ wood stoves. Since they are designed to burn hotter than their counterparts of yesteryear, more of the wood burns, so less carbon and other pollutants are released into the atmosphere. Of course, you’d have to have a ready wood supply and now mind chopping wood on occasion. If that’s not a problem for you, visit the Wood Heat Organization at: www.woodheat.org.

A newer home heating alternative is the biodiesel stove. These stoves can burn either biodiesel or regular diesel fuel if biodiesel isn’t available in your area. And as with the biodiesel cooking stove, you can always make your own fuel. For more information on biodiesel heating stoves, visit Kuma Stoves at: www.kumastoves.com/bio_diesel.

If you have a biodiesel heater, you may also want to consider attaching a water line to it to heat water for showers and baths during the winter months. In many cases, such a system will supply all of your hot water needs when it’s cold outside. During the summer months you can place a solar collector on a south-facing roof. Such collectors can be made inexpensively yourself using PVC pipe painted black. You can find detailed instructions on how to build a collector at Build it Solar: www.builditsolar.com/Projects/WaterHeating/water_heating.htm. The water can be heated the roof solar collector during the summer and by the home heating system during the winter, eliminating the need for an electric water heater altogether.

If such a system seems too elaborate for you, you might also consider tankless water heating systems. Such systems attach to the water line and heat the water as it flows, eliminating the need for a tank. While some of these run on electricity, most run on propane or natural gas. If you’re interested, House Needs offers a wide variety at: www.houseneeds.com. So far I haven’t been able to find a manufacturer that offers a biodiesel tankless water heater, but as demand for green products continues to increase, rest assured that there’s probably one on the horizon.

Speaking of water, getting it to your home without electricity doesn’t have to be a problem. If you have a well, you can use a good old-fashioned hand pump. Another alternative would be to install a cistern and a rainwater catch system. With a cistern, all the rainwater that usually goes through the gutters and out into the ditch is instead captured for later use. By installing a filtration system, this captured rainwater can be used in the home. Such a system is gravity-fed by installing a valve in the bottom of the cistern. This means that the bottom of the cistern would have to be situated above the water tap.

Using a cistern as your primary water supply would require careful planning and conservation. If you have a garden or plan to water your lawn, it helps to route the gray water from your showers, baths, and sinks into the ground by installing a piping irrigation system. That way you’re using the water twice. I wouldn’t recommend using a cistern without a well or city water backup unless you live in an area with a lot of annual rainfall. Even then I’d be cautious. As global warming continues, weather patterns are changing all over the world. Regions that have had a lot of rainfall in the past may no longer be as wet in the future.

Would you like to get rid of that electric washing machine without having to by a washtub and a scrub board? The Laundry Alternative (www.laundry-alternative.com) has a solution that doesn’t require scrubbing by hand. Their portable washing machine, the Wonder Wash, is hand-operated and can wash five pounds of clothes in minutes. The secret is its pressurized laundry compartment. The pressure forces the detergent through the fibers in the fabric, getting them clean in record time. It uses a fraction of the water a traditional washing machine uses, so a Wonder Wash is indispensable if you’re practicing water conservation. The best part is that the Wonder Wash can be had for less than $50!

There are still quite a few electronic gadgets in the average home, but many can be substituted for battery-operated alternatives. Battery-powered radios have been around for decades. Even televisions and computers have become compact, portable, and battery-operated. Cell phones have virtually eliminated the need for a home telephone. If you’re living electricity-free, you can always charge your cell phone in the car. If you go to the extreme of living without a car as well, you can buy a charger for your cell phone that works on solar power. Solar Style offers one for less than $60 at: www.solarstyle.com.

About the only major electricity-using device that we haven’t covered yet (except for compact fluorescent lights) is lighting. There are several approaches to dealing with lighting in an electricity-free home. For daytime lighting needs, you can always make strategic use of skylights. Even on cloudy days, skylights can supplement your lighting needs. Until recently, skylights were a problem for homes with more than one floor; however, a new product is being researched that would use fiber optics to redirect sunlight to the lower floors of a multi-story building. In these units, a solar collector reflects sunlight into a bundle of fiber optics. This bundle terminates on the ceiling of an interior floor. The sunlight is conducted by the fiber optics to a fixture placed over the end of the bundle. The fixture functions to diffuse the light evenly. The problem so far with these systems is that the sun has to be at the proper angle for them to work at all. One approach to solving this problem to add a motor-driven reflector to track the sun as it moves across the sky. The motor would be solar powered as well, so no external energy source would be required. The problem with any sort of sunlight-driven system is that it will only work during daylight hours, so if you need lighting in the evenings, you’ll have to come up with an alternative plan.

The oldest of these options are, of course, lamps and candles. While the amount of light emitted from the average candle hasn’t changed much over the centuries, there are propane lamps on the market now that give off far more light than their older kerosene counterparts. If the small amount of illumination available from kerosene lamps is an issue for you, you might want to step up to a propane lantern. A Coleman lantern generates about as much light as a 100-watt light bulb. I’ve used Coleman (www.coleman.com) lanterns for years, and have been satisfied with their quality and performance.

The final option for lighting a home without electricity is battery-powered lighting. This requires a little homework and a lot of planning. There are a wide variety of choices in battery-powered lighting. Some of these will work better than others, so it’s better to investigate the quality of the products you intend to buy before furnishing your entire home with them. In order to avoid going broke buying batteries, I would suggest purchasing rechargeable batteries. These may be recharged using a solar powered charger. Several companies offer solar powered battery chargers. A good place to start would be Battery Stuff’s line of products at: www.batterystuff.com/solar-chargers. The method I have used in the past is to buy two sets of batteries for each light; one to use and one to recharge. That way you’ll always have fresh batteries available. If you have children, you might want to buy some extras to hide around the house as well. For some reason, batteries seem to grow legs and walk off when kids are around!

A great resource for electricity-free living is Lehman’s Products for Simple and Self-Sufficient Living at: www.lehmans.com. This company caters primarily to Amish communities and carries a wide variety of products for people interested in a simpler lifestyle.

You don’t have to go totally without electricity to benefit from any of the ideas listed above. You can use as many of them as you think you will be comfortable with. The more you can do, the more you’ll save on your energy bill. Minimizing your energy consumption will also make it easier to install an off-the-grid power system. The less wattage you need, the less your alternative power system will cost.

So would it be possible to live your life totally without electricity? Two-thirds of the Earth’s population already does. With the technology available today, going electricity-free doesn’t have to be an ordeal. In fact, it can be quite rewarding. I think back on my little cabin in the woods and I remember the nights most of all. I’ve always had a bit of insomnia, but it wasn’t as much of a problem when I lived without electricity. There were no appliances humming through the night; in fact, there were no electronic noises at all. I fell asleep listening to the crickets and the wind in the trees. There was also no monthly electric bill to worry about. After about a month or so, I really didn’t miss the electricity much at all.

We live our lives according to what we’re accustomed to. We’re accustomed to the convenience of electric appliances, but what have we sacrificed for that convenience? How much freedom and independence have we traded away when we chain ourselves to the power company? Maybe it’s time to grow accustomed to something better.

Chapter 1	Chapter 8	Chapter 15
Chapter 2	Chapter 9	Chapter 16
Chapter 3	Chapter 10	Chapter 17
Chapter 4	Chapter 11	Appendix A
Chapter 5	Chapter 12	Appendix B
Chapter 6	Chapter 13	Appendix C
Chapter 7	Chapter 14	Appendix D

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