Changing to an Eco-Friendly World (Large-Scale Changes): Energy

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No matter what kind of remodeling you are doing, whether it is a kitchen, bathroom, or guest room, you should first think about reducing energy use. Over the past 6o years, our access to inexpensive energy has allowed building design to ignore location and orientation. Unfortunately, this tradeoff of historical design wisdom for standardized building comes at great cost to the environment.

We are using our natural resources at an unsustainable rate. According the book The Ecology of Commerce, “Today’s population uses in one day what it took nature 10,000 days to create.” To say it in another way, we are living on our energy capital (stored petroleum and coal) and squandering our income (solar energy). If you ran your company on your capital savings and ignored current income, you wouldn’t be in business very long. Green building is a step toward reversing that trend.

Based on 1998 figures, the heating, cooling, and lighting of buildings consumes 36 percent of the energy consumption in the U.S. A significant portion of this energy is in the form of electricity: residential buildings alone consume 35 percent of all electricity in the US. However, the energy that buildings require starts accumulating long before the buildings and homes are even in existence. The energy required to extract, transport, manufacture, and then re-transport materials to the point of use requires a substantial amount of energy at a significant cost to the environment. The sum of all the energy required by all the materials and services (including the costs of upkeep and maintenance) that go into constructing a building is called the embodied energy. The unit of measure for embodied energy is British thermal unit per pound (Btu/lb.). It is highly dependent on factors such as geographical location and the technology used during the manufacturing process. For example, stones excavated from a nearby hillside for a new patio have lower embodied energy than stones that must be transported from another state. Embodied energy figures give us a realistic base for comparison as we assess different products or technologies for use in our homes.

To better understand embodied energy; let’s consider a brick in your exterior wall. Where did it come from? First, clay had to be extracted from the earth. Then it was transported to the brickworks where the clay was molded into a brick form and fired in a kiln. Eventually the brick was again transported twice more — to a retailer and then again to your building site before the brick was put into place. But this is only the direct embodied energy of the brick. Embodied energy also includes indirect energy, including mining equipment to extract the clay, trucks to transport the clay, and kilns — anything that had a proportion of its energy invested in that brick.

The embodied energy in recycled building materials is generally much less than the embodied energy in materials produced from raw, or new, materials. Although using recycled materials can involve transporting, cleaning, and sorting, the total energy requirements are still far less than the energy used in extracting and refining a virgin resource.

This section will help you assess the embodied energy that goes into your home, the products you use, and the way you live. In this way you can understand and appreciate the complexity of construction, and its profound affect on everything around us. Our goal is to help you make appropriate choices when planning your remodeling project.

Energy Required to Produce from Virgin vs. Recycled Materials:

 

Energy required to produce from virgin material (million Btu/ton)

Energy saved by using recycled materials (%)

Aluminum

Plastics

Newsprint

Corrugated Cardboard

Glass

250

98

29.8

26.5

 

15.6

95

88

34

24

 

5



Is Global Climate Change Really Happening?

Have you stepped outside of your air-conditioned homes lately? The fact of the matter is that we have had the hottest temperatures in decades over the last ten years. We hove also seen erratic weather patterns, where we have had extreme cold, flooding in eastern Europe, severe drought in the western United States for at least five years, and major tropical storms. In Nicaragua, 40,000 people died as a result of mudslides and extreme weather; 10,000 people died during heat waves in France. These extreme weather patterns are characteristic of global climate change.

Effects of Fossil Fuel Use

Green building will help wean us off our dependence on fossil fuels. Currently, the US relies on fossil fuels — oil, coal, and natural gas for 86 percent of its energy needs,’ despite their polluting effects. Burning these fuels spews tons of fine particles, sulfur dioxide, toxic metals, and other pollutants into the air. The Union of Concerned Scientists (UCS) estimates that fine particles alone may cause 64,000 deaths a year, or more deaths than result from auto accidents. In addition, drilling for oil and natural gas and mining for coal harms the environment by polluting natural surroundings and disrupting local wildlife populations. Given that the building sector is the second largest user of energy, changes in current building behavior are critical to reducing fossil fuel emissions and environmental damage, including the larger international issue of global climate change.

Global Climate Change

Green building directly addresses the single most significant challenge of our generation — global climate change. The greenhouse effect is primarily a function of the concentration of water vapor, carbon dioxide, and other trace gases in the atmosphere that absorb the terrestrial radiation leaving the surface of the earth. Atmospheric concentration changes in these gases can alter the balance of energy transfers between the atmosphere, space, land, and the oceans. With everything else constant, when greenhouse gas concentrations in the atmosphere increase, there is a net increase in the absorption of energy on the earth. This causes a rise in surface, ocean and air temperature as more heat is transferred to the ground.

Water vapor, carbon dioxide (CO) methane (CH) nitrous oxide (N2O) and ozone (O3) are all naturally occurring greenhouse gases, but can increase to destructive levels as a result of human activities, such as construction. Over the last 250 years, carbon dioxide concentrations have increased by 31 percent, methane by 131 percent, and nitrous oxide by 17 percent. Moreover, each greenhouse gas differs in the way it absorbs heat in the atmosphere: methane traps over 21 times more heat per molecule than carbon dioxide, and nitrous oxide absorbs 270 times more heat per molecule than carbon dioxide. That said, the global mean surface temperatures have increased between 0.5 and 1 degree Fahrenheit since the late 19th century, which further correlates to a four- to eight-inch rise in global sea level. This current trend will likely accelerate the rate of climate change over the next centuries. Some climatologists expect the average global surface temperature to increase between 2.2 and 10 degrees F (1.4 and 5.8 degrees C) in the next 100 years.

Scientists explain that some of the heat due to the greenhouse effect raises the air temperature a bit, but more of it causes increased evaporation of water. As a result, the extra moisture may disrupt weather patterns, producing stronger, longer-lasting, more frequent storms in some areas and droughts in others. Even in the short term we can expect to see these more extreme weather patterns directly caused by global climate change.

“Great!” you may be thinking. “If we keep burning fossil fuels to build homes and provide for our energy, maybe I can wear my swim suit in December!” Think again. Even in the short term, global warming is predicted to destroy coastal wetlands. It will cause unusually frequent but long-lasting bouts of severe weather: flooding in central Europe, vicious cyclones in South Asia, and freak spring snowstorms on the American plains. Global warming may also stress crop production, increase the frequency of diseases like malaria carried by airborne insects, threaten wildlife species, and disrupt entire ecosystems around the world. Low-income communities have the fewest resources to cope with climatic changes, and unfortunately, those communities are often situated near toxic, greenhouse-gas emitting facilities.

In the eyes of most of the world, U.S. leadership and integrity on issues of global climate change have disappeared. Concern with only those issues that are of specifically American interest has replaced historical global concerns, and that is costing the United States an enormous amount of good will. A former U.S. Congresswoman thinks that this will result in higher tariffs on some American goods. In other words, the average American will have to pay more for various goods and services because the Europeans, Japanese, and others may eventually say, “All right, we are going to levy a tax on these goods coming from the U.S. because they are using more resources and more energy, and that is creating more of a problem for all of us.”

In addition to the cost of political goodwill, there are bottom-line economic costs related to climate change. The US is spending billions of dollars on insurance to cover increasingly devastating weather damage, and also spending more on health care costs related to pollution-induced ailments such as asthma and allergies. As climate change increases, so too will virus-based diseases (such as West Nile disease), for which we have no remedy and which migrate north as a result of weather and habitat changes. Given all the negative ramifications of global warming, even the chief executive of British Petroleum has admitted it would be “unwise and potentially dangerous to ignore” the threat of global climate change.

Green building helps us take personal responsibility for global climate change by clarifying the link between our actions and rises in temperature. Today, confusion masks the problem. For example, the term “global warming” can be misleading because we may still have record low temperature days while the earth is steadily warming. Adding to the confusion, high atmospheric winds carry air pollution long distances: how is someone who lives in the northeastern US supposed to identify their air pollution with Midwestern factories exhausting gases into their air from thousands of miles away? Perhaps even folks next door to coal-fired power plants don’t make the connection: the Environmental Protection

Agency estimates that we spend 90 percent of our lives in temperature-controlled buildings that shelter us from the elements. Furthermore, global climate change is the combined effect of human activities around the world: what difference does remodeling a house with inefficient incandescent lights make if factories are spewing out tons greenhouse gases in Europe?

Keep in mind the warming is global — and therefore everyone needs to take responsibility. This guide helps you to understand the connection between your actions (how you remodel) and their consequences (global climate change). Each person who is remodeling can change the world for the better! In the following sections, you will learn how to remodel your home to save you money and minimize its detrimental energy impact on the environment in two fundamentally “green” ways: use less energy and use renewable resources for energy

Using Less Energy

In addition to investing in renew-able energy sources, as homeowners we can make simple changes to our homes that save energy — always the cheapest and most environmental solution! It is estimated that a whopping 43 percent of American energy use is wasted. The US Department of Energy estimates that we could save anywhere from 50 to 94 percent of our home energy consumption by making energy-saving changes.

Green building reduces energy consumption in many ways. First, we can decrease the embodied energy of the building through efficient design, by using recycled and local materials, and by recycling construction waste. Second, green building design reduces a building’s energy consumption over its lifetime. Installing ceiling insulation and double- glazed windows in every US home can save more oil than the Arctic National Wildlife Refuge can produce at its most optimistic projections, at about 1/20 the cost. Strategically placing windows and skylights can eliminate the need for electrical lighting during the day, which is often when electricity is in highest demand from utilities. A whole house fan can cool the house over night, rather than relying on air conditioning. Additionally, houses can maximize passive heating and cooling. South facing windows with overhangs can reduce heating costs by 20 to 30 percent, and prevailing breezes, shading, and natural plantings can keep houses cool in the summer using the same physics that cause global warming. This list only scratches the surface of the possibilities for reducing a building’s energy requirements. The financial benefits are obvious: less energy leads to a lower energy bill. Additionally, decreasing energy consumption, and thus reducing alterations in the global climate, could help prevent further environmental degradation. Keep in mind that it is the impacts of energy use that we are trying to avoid — not the energy itself. In other words, reducing the use of specific non-renewable, polluting energy sources (for example, coal or oil), should be a higher priority than increasing the use of renewable energies such as solar-generated electricity.

FYI: The US Department of Energy estimates that buildings annually consume $20 billion more energy than would be necessary if the buildings were improved.

Energy Efficient Design Savings

The study, Greening the Building and the Bottom Line by the US Department of Energy and the Rocky Mountain Institute (RMI), highlights case studies of several companies that invested in energy- efficient designs and thereby experienced significant savings.” Further justifying the investment in retrofitting, they found compelling evidence that daylighting (a design feature which allows the use of natural light, rather than artificial light during daytime hours), improved the effectiveness of heating, ventilation, and air conditioning (HVAC), as well as the quality of indoor air. This resulted in increased productivity, fewer worker errors, and less absenteeism in many cases studies. For example:

• Boeing’s “Green Lights” effort reduced its lighting electricity use by up to 90 percent, with a two-year payback and reduced defects.

• Lockheed’s engineering development and design facility saved nearly $500,000 per year on energy bills and gained 15 percent in productivity, with a 1.5 percent drop in absenteeism.

• West Bend Mutual Insurance’s new building yielded a 40 percent reduction in energy consumption per square foot and a 16 percent increase in claim-processing productivity.

Because labor costs are such a large share of total costs (workforce accounts for approximately $130 per square foot, 72 times more than energy), a one-percent increase in worker productivity can result in savings to a company that exceed their total energy costs. There are more and more cases similar to those documented by RMI, and as a result, companies are starting to invest in energy efficiency for the reasons suggested above: reduced energy expenditures and increased worker productivity.

Use Renewable Sources of Energy

Conventional Sources of Energy

When we discuss “renewables,” we are referring to solar, wind, geothermal and biomass energy. Like renewables, nuclear power plants do not burn fossil fuels and therefore do not emit substances that harm air quality or cause climate change. In fact, substituting nuclear energy for fossil fuel energy has significantly reduced US and global emissions of carbon dioxide, the chief greenhouse gas, and other pollutants. Moreover, radiation from nuclear plants is not an issue — nuclear plants produce only a small fraction of the radiation experienced by the US population. One report estimates that New York’s six nuclear power plants cause approximately 0.5 to 1.5 statistical cancer deaths per year. Extrapolated to the US as a whole, this data implies 8 to 30 annual statistical deaths related to nuclear radiation that are concentrated among individuals who work in the power plants.

The primary concern with nuclear energy is disposal. State and federal documents indicate that every dump ever used to store low-level nuclear waste — a total of six — has leaked.’ In addition, the Congressional Research Service (CRS) reports that transporting nuclear waste to the proposed Yucca Mountain storage facility in Nevada could result in 154 truck and i8 rail accidents per year, a small number of which might release radioactivity Given that plutonium is radioactive for 250,000 years, one spill could stay on this earth and cause harm to people for longer than our species has inhabited the planet! Although nuclear power itself does not harm air quality, cause climate change, or emit harmful radiation from power plants, the waste from nuclear power is a serious hazard to human and environmental health — a risk not worth taking, given cleaner alternatives.

Hydropower has both positive and negative aspects associated with energy production, but in general is not a viable alternative. Dams needed to generate the power severely alter physical and chemical characteristics of the water and disrupt ecosystems both upstream and downstream. Scientists at Oak Ridge National Lab hold federal hydroelectric dams primarily responsible for reducing Northwest salmon from i6 million to 300,000 wild fish per year. Furthermore, dams are disruptive to human communities: one million people had to be relocated from an area inundated by the Three Gorges Dam in China.’ Even though the U.S. Department of Energy (DOE) defines hydropower as representing 42 percent of renewable energy production, we do not recommend hydropower as an alter native to fossil fuels.

For building green, we do not need fossil fuels or hydroelectric or nuclear power — we need the services they provide. Most often we want heating, lighting, energy, and fuel, and this we can obtain from other renewable sources — such as wind, sun, and biomass. As Amory Lovins, president of the Rocky Mountain Institute, has said for many years, “People want hot showers and cold beer; they don’t care where the energy came from.” Renewable energy just needs to prove better or cheaper...

Wind Energy

Wind Energy Facts

• Denmark, Germany, and some regions of Spain now have 10 to 25 percent of electricity generated from wind power. A single one-megawatt wind turbine displaces 2,000 tons of CO each year — equivalent to planting a square mile of forest — based on the current average US utility fuel mix.

• To generate the same amount of electricity as a single one- megawatt wind turbine using the average US utility fuel mix would mean emissions often tons of sulfur dioxide and six tons of nitrogen each year.

• To generate the same amount of electricity as a single one- megawatt wind turbine for 20 years would require burning 26,000 tons of coal (a line of ten-ton trucks ten miles long) or 87,000 barrels of oil.

• To generate the same amount of electricity as today’s US wind turbine fleet (4,685 MW) would require burning 6.1 million tons of coal (a line of 10-ton trucks 2,300 miles long) or 20 million barrels of oil each year.

• 100,000 megawatts of wind energy will reduce CO2 production by nearly 200 million tons annually — the amount of wind energy the European Wind Energy Association (EWEA) claims can be installed in Europe by 2010.

 

Wind power is a realistic economic alternative today. Since 1983, prices for wind energy have dropped by an extraordinary 8 percent,’ exceeding the most optimistic expectations from renewable proponents. Current state-of-the-art wind power plants are generating electricity at less than five cents per kilowatt hour and costs are continuing to decline as more and larger plants are built and advanced technology is introduced. According to Stanford University researchers in a 2001 Science article, the direct cost per kilowatt hour of power generated by winds of at least 14 miles per hour is 2.9 to 3.9 cents per kilowatt hour; one quarter of wind monitoring sites are capable of these wind gusts. This price is cost-competitive with new coal plants producing power at 3.5 to 4 cents per kilowatt hour and new natural gas plants producing power at 3.3 to 3.6 cents per kilowatt hour.

The Future of Wind Turbines

Once wind turbines are in wide use, there will be a large, unused capacity during the night when electricity use drops. Turbine owners can turn on the hydrogen generators, converting wind power into hydrogen, idea/for fuel cell engines. John Deere and Company is working on wind turbines that generate hydrogen to use in hydrogen-consuming farm equipment.

Wind is the world’s fastest growing energy source on a percentage basis, growing 32 percent annually for the last five years and on track to grow more than 25 percent in 2003. A modern windmill can produce the energy used for its own production within just three months.” Three wind-rich states — North Dakota, Kansas, and Texas — have enough harnessable wind to meet our national electricity needs.” Globally, windmills can cover more than half of all energy consumption without adding to air pollution, Wind has myriad benefits beyond its ability to supply large amounts clean electricity cheaply, including national security, new wildlife-friendly models, pleasing aesthetics, fast installation, job creation, reliability and predictability. In terms of national security, wind turbines are widely distributed, unlike a nuclear or coal plant where a single location can be targeted. Many people argue that a more distributed power structure such as one relying on wind power might have avoided blackouts in New York and New England caused by an outdated, centralized system. If 30 percent of America’s electric power needs were met by wind, the US would be able to get rid of 6o percent of its coal dependence.’ Today’s larger, slower-turning blades are also less of a hazard for birds, that can be killed while attempting to circumnavigate the smaller, faster turning blades of older models. Turbines are being placed offshore, thereby reducing aesthetic objections (although inland they look and smell better than any power plant). Wind power is the fastest of all technologies to install. The turbines can be built quickly to respond to electricity shortages and are a feasible option for developing countries or rural areas where fossil fuel power plants prove too expensive.

The European Wind Energy Association (EWEA) estimates that every megawatt (MW) of installed wind capacity creates about 6o person-years of employment and 15 to 19 jobs, directly and indirectly. A typical 50-megawatt wind farm, therefore, creates some 3,000 person-years of employment. The wind industry is likely to be one of the largest sources for manufacturing jobs in the 21st century. This is especially relevant for rural areas where it can provide a source of skilled-work income for sometimes hard-pressed farmers.’ In addition, wind offers a “double cropping” benefit for rural communities. In other words, a farmer can grow crops while leasing his wind rights and earn $2,000 to $4,000 per year or more for housing a single utility-scale turbine on his property. The income- generating wind turbine is essentially a second, or double, crop. Reliability has also increased — the availability of utility-scale machines is typically greater than 98 percent. “Wind is also inflation-proof, meaning that once a wind plant is built, the cost of energy is known and is not affected by shifting fuel market prices”. Forecasting is expected to dramatically reduce the impact of wind’s variability on utility operations, making integration into the grid easier. It seems the answer to our energy problems may indeed be blowing in the wind.

Solar Energy

By far the largest part of the energy on Earth comes from the sun. The sun gives off so much energy that it is equivalent to a 180-watt bulb perpetually burning for every square meter (nine square feet) on Earth. This solar energy influx is equivalent to about 7,000 times our present global energy consumption. In other words, there is tremendous potential in solar energy to provide a significant portion of our heating, lighting, electrical, and mechanical power needs — 7,000 times our energy needs. Just by covering an area 291 by 291 miles square with solar cells, this 0.15 percent of the Earth’s land mass could supply all our current energy requirements.

But you don’t need solar cells to take advantage of the sun’s energy for your home. Passive solar heating and cooling represent an important strategy for displacing traditional energy sources in buildings. Anyone who has sat by a sunny, south-facing window on a winter day has felt the effects of passive solar energy. Passive solar techniques make use of the steady supply of solar energy by means of building designs that carefully balance their energy requirements with the building’s site and window orientation. The term “passive” indicates that no additional mechanical equipment is used, other than the normal building elements. All solar gains are brought in through windows, with some use of fans to distribute heat or effect cooling.

All passive techniques use building elements such as windows, walls, floors, and roofs, in addition to exterior building elements and landscaping, to control heat generated by solar radiation. Solar heating designs collect and store thermal energy from direct sun light. Passive cooling minimizes the effects of solar radiation through shading or generating air flows with convection ventilation.


Designing to use natural light can eliminate the need for mechanical heat.

Passive Solar Case Study

Susan Smith is a homeowner in California who has noticed a substantial improvement in comfort and a decrease in energy bills since she incorporated passive solar design into her home renovations. Before, “It would get to be 110 degrees in the house; it was amazing. Our energy bill was about $100 a month.” Susan super-insulated her home, replaced leaky, single-pane windows with double-pane windows, and added a reflective roof. Now, “It can be 30 degrees outside and it stays 60 degrees inside; it is really nice. Our energy bill is only about $10 a month.”

Beyond her comfort and financial gains, Susan feels emotionally fulfilled knowing that she thoroughly researched all the materials in her home to insure that every detail minimally impacted the environment and the health of the products’ manufacturers.

“I feel a new sense of connectivity with nature.... When I started to research conventional building materials and looked at where they came from, who made them, how they were made, I started to look at everything differently.”

Another solar concept is day-lighting design, which uses natural light to illuminate rooms during the day and contributes greatly to energy efficiency by eliminating the need to turn on lights. The benefits of using passive solar techniques include simplicity; low price, and the design elegance of fulfilling one’s needs with materials at hand.

Photovoltaic (PV) cells convert sunlight into electricity for your home. They are usually made of silicon; they contain no liquids, co chemicals or moving parts. Moreover, PV cells require little maintenance, do not pollute, and operate silently. Photovoltaic cells come in many sizes, but most are ten centimeters by ten centimeters square inches), and generate about half a volt of electricity; A bundle of PV cells that produce higher voltages and increased power is referred to as a PV module, solar collector, or array. A module producing 50 watts of power measures approximately 40 centimeters by 100 centimeters (15.75 inches by 39.37 inches). PV modules can be retrofitted on to a pitched roof above the existing roofing, or the tiles replaced by specially designed PV roof-tiles or roof-tiling systems.

PV modules, like flashlights or cars, generate direct current (DC), but most home electric devices require 120-volt alternating current (AC). A device known as an inverter converts DC to AC current. Inverters vary in size and in the quality of electricity they supply. Less expensive inverters are suitable for simple loads, such as lights and water pumps, but models with good quality waveform output are needed to power electronic devices such as TVs, stereos, microwave ovens, and computers. In grid-connected systems, PV supplies electricity to the building and any daytime excess may be exported to the grid. Batteries are not required because the grid supplies any extra demand. However, if you want to be independent of the grid supply you will need battery storage to provide power outside daylight hours.

Photovoltaic Facts

• Worldwide photovoltaic installations increased to 340 megawatts in 2001, up from 254 megawatts in 2000. In 1985, annual solar installation demand was only 21 mega watts. The total on-grid market segment grew to almost twice the size of the off-grid market in 2001.That is the equivalent of one small conventional energy power plant.

• Of the global demand for solar photovoltaics, over 30 percent is accounted for by Japan, 20 percent by European countries, and less than 10 percent by the US.

• Nearly 45 percent of the world’s solar cell production is manufactured in Japan. The US is second with 24 percent (of which 70 percent is exported), with Europe third, at 22 percent.

• Two billion people in the world have no access to electricity. For most of them, solar photovoltaics would be their cheapest electricity source — but they can't afford it.

Between 1987 and 1998, the annual number of US PV shipments in the US grew 640 percent, with a 20.5 percent average annual increase. The cheapest photovoltaic cells have become three times as effective since I978. Back in the 1970s the cost of PV cells was $70 per watt of production; today, residential solar energy system typically costs about $8 to $10 dollars per watt. In some areas, government incentive programs, together with lower prices secured through volume purchases, can bring installed costs as low as $3 to $4 dollars per watt (10 - 12 cents per kilowatt hour). Without incentive programs, solar energy costs (in an average sunny climate) range from 22 to 40 cents per kilowatt hour.” Scarcely a month goes by without another advance in either PV cell design or manufacturing technology — by 2030, the price is expected to drop to 5.1 cents per kilowatt hour. PV demand has been stimulated in part by government subsidy programs (especially in Japan and Germany), and by equipment rebate policies and tax credits for utilities or electricity service providers (e.g., in Switzerland and California). The central driving force, however, comes from the desire of individuals or companies to obtain their electricity from a clean, non-polluting renewable source, for which they are prepared to pay a small premium. The greater the demand for PV, the faster the price will come down.

PV systems are appropriate for electric devices, but water heating or other heating is most efficiently produced by solar water heaters. They convert up to 6o per cent of the sun’s energy into heat used for domestic hot water, pool heating and space heating needs. There are two types of systems: passive and forced circulation. A passive water heater consists of a water tank located above a solar collector. As water in the collector warms, water flows by natural convection through the collector to the storage tank. A forced circulation system requires a pump to move water from the storage tank to the collector. Most solar water heaters in the United States are the forced circulation type.

There are several types of solar collectors. Most consist of a flat copper plate with water tubes attached to the absorber plate. As solar energy falls on the copper plate and is absorbed, the energy is transferred to the water flowing in the tubes. Integral collector and storage systems combine the function of hot water storage and solar energy collection into one unit. Solar collectors are typically roof- mounted, with hot water storage tanks inside the house. They are often connected to a conventional water heater for back-up.

Solar water heating systems are efficient, clean, easy to install, and virtually maintenance-free. and since hot water counts for as much as 40 percent of the energy requirements of an average house, solar water heating systems can cut the costs for heating hot water by 40 to 60 percent. An active, flat-plate solar collector system will cost approximately $2,500 to $3,500 installed, and will produce about 80 to 100 gallons of hot water per day. A passive system, typically used in climates that don’t freeze, will cost about $1,000 to $2,000 installed, but will have a lower capacity. If the monthly cost of financing the system is less than the net savings, a solar water heating system may result in immediate positive cash flow.

Overall, solar energy has a bright future. Passive heating obviously makes economic and environmental sense today, and solar systems are cheaper, simpler, and more reliable than ever for homes. All types of solar applications are expected to become commonplace when and if the true costs of fossil fuel use — including external costs like pollution, health risks, and military protection for foreign oil sources — become reflected in its price.

Biomass Energy

After hydroelectricity, biomass is the most widely used renewable source of energy representing three percent of energy consumption in the US In contrast to other sources of renewable energy that rely directly or indirectly on sunlight and its effects on weather patterns — such as wind power, solar cells and hydro power — biomass energy comes from stored, solar energy in plants. Electricity from burning biomass (crops and crop waste) is also predicted to have substantial growth. Unfortunately, biomass can cause respiratory infections and various pollution problems, including sulfur, nickel, cadmium, and lead pollution. For some places in the world, however, growing biomass may turn out to be sensible since production can take place on poor soils, help prevent erosion, and even help restore more productive soil. Others argue it is not likely biomass will provide a major part of global consumption because the total agricultural biomass production from stalks and straw, constituting half the world’s harvest in mass, only makes up about 16 percent of the current agricultural production. Still, Shell Oil, the most successful company in the oil industry, expects that biomass will provide between 5 and 10 percent of the world’s energy within 25 years, possibly rising to 50 percent by 2050.

Just as the Stone Age did not end for lack of stone, the oil age will not end for lack of oil. Rather it will be the end because of the eventual availability of superior alternatives.

Geothermal Energy

Like biomass energy, geothermal energy can be used at all times. Produced by the earth’s natural subterranean heat, it is a vast resource, most of which is deep within the earth. Geothermal energy can be economically tapped when it is relatively close to the surface, as evidenced by hot springs, geysers, and volcanic activity. (The “ Old Faithful” geyser in Yellowstone National Park is an example of geothermal energy.) In contrast to oil fields, which are eventually depleted, properly managed geothermal fields keep producing indefinitely.

In the home, geothermal energy is used for heat pumps. Pipes are drilled into ground water that stays a relatively constant temperature. That is then used as the heat source for a pump that extracts the heat and blows it into the building or dumps excess heat in summer and cools the home. The cost of geothermal energy is currently priced at five to eight cents per kilowatt hour, and is expected to drop to four to six cents per kilowatt hour with more industry experience and improved drilling technology.

Major Life-Cycle Environmental Impacts of Energy Sources for Electricity Generation

Air Pollution

Climate

Land Use, Degradation

Water Use and Quality

Wildlife

Radiation

Coal

Oil

Natural Gas

Biomass

Wind

PV

Geothermal

Hydroelectric

Nuclear

Very High

High

Very Low - High

Near 0 - Moderate

Near 0

Near 0

Near 0 - Very Low

Near 0

Near 0

Very High

High

Moderate - High

Very Low - High

Very Low

Low

Very Low - Low

Low

Very Low

High

Moderate

Low - Moderate

Near 0 - High

High

Very High

Very Low

Very Low - High

Very Low

Very High

Moderate - High

Near 0 -Low

Very low - High

Near 0

Near 0 - High

Near 0

High

High - Low

High

Moderate - High

Low

Low-Moderate

Near 0 -High

Near 0

Near 0

Very High - High

High

Low

Near 0

Near 0

Near 0

Near 0

Near 0

Near 0

Near 0

High

This table is qualitative, labeling impacts in order from worst to best as high, moderate, low, or near zero. It should be read vertically; it does not attempt to compare the severity of different categories of environmental effects (e.g., air and water pollution).Finally, the life cycle impacts are not only based on power plant operation, but also fuel production and transport, waste disposal, and other operations. Therefore, no cell in the table is empty, because even very clean energy sources like solar and wind require energy at some point in their cycle — for instance, for manufacturing—and this energy itself has environmental impacts.

Oil scarcity may be the weakest reason for making the transition away from oil. Profit, climate protection, security, and quality of life are all more relevant and defensible.

Renewable Energy Outlook

Compare the $50 billion the US spends on safeguarding oil supplies in the Persian Gulf with the $1 billion Americans could save annually by switching just 20 percent of our energy production to renewables. A study by the Economic Research Associates found that by switching to renewables, Colorado residents alone would gain 9,400 jobs and enjoy a $1.9 billion energy savings. Co-op America’s Solar Catalyst Group found that California could create up to 19,000 new full-time jobs by producing up to 900 megawatts of new solar photovoltaics (PVs) per year by 2010.

Given this potential savings, why do fossil fuels still supply 85 percent of US energy needs, and renewable energy sources less than 3 percent? Importantly, there exist powerful economic incentives to “disinvest” in renewables. We don’t have to pay for resource depletion or air pollution, to say nothing about the tax incentives and corporate welfare the fossil fuel industry enjoys; therefore, the true price of fossil fuels is not reflected on our energy bills.

Additionally, the price of fossil fuels does not reflect the heath treatment costs, higher insurance rates, missed work, and lost life resulting from air pollution. Studies by the American Lung Association indicate that annual US health costs from all air pollutants may amount to hundreds of billions of dollars. Until we pay for pollution, waste, carbon fuels, and resource exploitation (all of which are presently subsidized), there is little to encourage us to install unfairly expensive solar panels or other renewables.

Despite economic obstacles, the global wind industry is growing by 25 percent annually while the markets for oil and coal are expanding only 1 to 2 percent per year. Although the oil and coal markets are a significantly larger percentage of our energy use, meaning that, statistically, a one percent growth reflects a significant increase, a 2 percent growth in wind is still substantial growth. People are realizing that if- we are going to approach our future with environmental and economic foresight, it would be wise to reduce our consumption of fossil fuels and invest in renewable energy production.

There are great advantages to using renewable energy: It pollutes less, makes a country less dependent on imported fuel, requires less foreign currency, and has almost no carbon dioxide emissions.

Many of the renewable technologies are cheap and easy to repair. Renewable energies can be the most cost-effective method of bringing electricity to developing countries or remote villages that do not have reliable or wide-reaching energy infrastructure. Surpluses of wind, solar, and geothermal electricity on long-term contracts can guarantee the price, something those relying on oil or natural gas can't do. and , once we get cheap electricity from these renewables, we can use it to electrolyze water, splitting the water molecule into its component elements of hydrogen and oxygen. Hydrogen, an exceedingly environmentally friendly energy-carrier that leaves behind only water, can later be used in electricity production. Although renewables were once refer red to in The Economist as “alternative” pet projects for “bearded vegetarians in sandals,” these energy sources are quickly becoming recognized as economically competitive, more socially just, and environmentally sustainable energy solutions.

Ozone Depletion from Construction In 2000:

• 60 percent of ozone-depleting substances, including chlorofluorocarbon (CFC) and less-destructive hydrochloro-fluorocarbon (HCFC), were used for building and construction systems in the US.

• 7,000 tons of CFCs were used to replace leaking or otherwise emitted refrigerants from older equipment in buildings.

• 120,000 tons of RCFC were used for new and existing building equipment.

75,000 tons of HCFC were used for foam building insulation.

Source: US Green Building Council, “Industry Statistics,” cited September 25,2003.

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