Thursday, October 30, 2008

Passive house through retrofit

Climate Solutions Special Issue
Germany’s Efficient Homes
by Nicole Pillen and Nana Doerrie
German energy agency, dena's, Efficient Homes project is tapping into substantial energy savings through the retrofits of existing buildings.

As energy prices on the world market rise and the debate on how to address climate change intensifies, energy-efficient home retrofits have become a vital issue in Germany. The residential building sector consumes the largest proportion of site energy used in Germany, and the lion’s share—about 75%—of this use is attributable to space heating. Consequently this share has to be reduced radically for overall energy consumption and carbon dioxide (CO2) emissions to decline. Existing buildings are of particular importance. At present, older buildings use on average 225 kilowatt-hours per square meter (kWh/m2) (71,325 British thermal units per square foot (Btu/ft2)) annually—or 3 times the energy required to heat a new building. Yet despite rising energy prices, retrofit projects are still not fully exploiting potential energy savings. Currently, over half of the potential savings that are economically feasible remain untapped after a renovation.

To realize these potential savings, the German energy agency, dena, has initiated the Efficient Homes project. Launched in 2003, this project uses best practices to

* develop, test, and implement cost-effective low-energy standards for retrofits that are superior to the federal requirements for new buildings;

* publicize and improve innovative technologies for increasing the energy efficiency of existing buildings; and

* educate and encourage builders, designers, architects, and the general public to implement all economically feasible techniques for energy efficient retrofits of existing buildings.

Many educational efforts and promotional events have been held to publicize the project. These include workshops for architects, planners, and the housing industry, as well as special events for consumers. Remodeling guidelines have been developed for each of these different target groups. In addition, regional competence networks, which consist primarily of local energy agencies, have been created to increase awareness of efficient retrofitting techniques. The Federal Promotional Bank (KfW Förderbank) has also been doing its part to support project participants by offering low-interest loans and partial payments to reduce the costs of borrowing to finance these retrofits.

These efforts have paid off quite well. Since 2003 more than 140 buildings comprising 2,230 residential units have undergone energy-efficient retrofits (see Figure 1). The project includes every type of residential building—from single-family homes to an apartment building with 295 units, so renovation recommendations and best-practice case studies now exist for almost every residential building type. The buildings represent a mix of commercially and privately owned residences; 49% belong to housing cooperatives and commercial landlords, and 51% belong to private individuals. Of the latter, 24% are private landlords and 27% are owners of single-family and two-family homes.

In many cases, these retrofits employed highly innovative passive-house components, which, until recently, have been used almost exclusively in new buildings. A passive house is an ultra-low energy house that is built according to a rigorous energy standard: the building must not use more than 15 kWh/m2 per year (4,750 Btu/ft2 annually) in heating energy. This is usually achieved by employing superinsulation materials and special windows that combine triple-pane insulation glazing with air seals and specially developed thermally broken window frames, which reduce heat loss through the frame.

To appreciate the accomplishments of the Efficient Homes project, one must first understand the differences between German and U.S. building stock. Most buildings in Germany are not built out of wood; 86% of single-family and two-family homes are built out of concrete, concrete block, or brick, while only 14% are stick built. In the United States, 95% of single-family homes are stick built.

Two-thirds of the residential buildings in Germany were built before 1978. The average rate for new developments has been 1% per year for the past several years. This means that existing buildings dominate Germany’s building stock. Approximately 35% of Germany’s residential buildings must be completely retrofitted now or within the next two decades, with another 28% of them needing to be completely rebuilt for the second time sometime in the next 20 years. Altogether, this means that roughly 50% of Germany’s older buildings will be retrofitted within the next 20 years. It is therefore essential to implement cost-effective low-energy retrofitting standards immediately. Otherwise the energy demand for space heating and domestic hot water cannot be significantly reduced.

Tightening Energy Standards

Until 2006 participants in the Efficient Homes project could choose to meet either of two energy standards—the Efficiency Standard or the Future Standard—both of which are related to the energy requirements for new buildings. The Efficiency Standard requires the energy consumption of a retrofitted building to be 30% less than that of a comparable new building. To meet the Future Standard, the energy consumption of a retrofitted building must be 50% less than that of a comparable new building. Starting in 2007, all participants in the Efficient Homes project have been obligated to meet the Future Standard. (For both standards, “energy consumption” refers to the primary energy demand of the building, which is defined as the energy embodied in natural resources—coal, crude oil, sunlight, uranium—that has not undergone any human-caused conversion or transformation. In the United States, this energy is referred to as source energy.)

These standards do not specify particular materials or technical installations that must be used. This is done to allow for innovative solutions to meet the standard. However, a ventilation system is required in every building. The project has already been such a success that the Efficiency Standard has been incorporated into the Federal Promotional Bank’s regular offers for energy-saving retrofits that are not part of the Efficient Homes project.

The Efficient Homes retrofit projects have proved that it is possible to reduce the energy consumption of old buildings significantly. These energy savings were achieved using only standard construction techniques. Before the retrofit, the average energy demand of these 140 buildings was 336 kWh/m2 (106,512 Btu/ft2) annually. After the retrofit, it was reduced to an average of 44 kWh/m2 (13,948 Btu/ft2) annually. This is far below the minimum requirement for comparable new buildings of 98kWh/m2 per year (31,066 Btu/ft2 annually). These results clearly demonstrate that energy-efficient methods of construction can reduce the energy demand of an existing building by an average of over 80% (see Figure 2).

The Oldest Low-Energy Building

The oldest building in the Efficient Homes project is quite old—344 years old, to be exact. This timber-framed building was built in the small village of Feuchtwangen, Bavaria, in 1663, just 15 years after the end of the Thirty Years’ War. It is a two-story single-family home. The retrofit was completed in summer 2007. The owner, Josef Buckel, said that he wanted to update the building, and he wanted to save energy and protect the environment.

What was done to modernize this house? The most important measure was the installation of superinsulation made of polystyrene to significantly reduce heat leakage through the walls, roof, and floor. A 4-inch (10-centimeter) thermal insulation composite system, with a U- value of 0.31 Watts per square meter times degrees Kelvin (W/m2K), was installed on the facade. The insulation on the roof is now 8 inches (20 centimeters) thick, with a U-value of 0.13 W/m2K. It was extremely important to identify and eliminate the building’s thermal bridges in order to achieve the best possible results. The casement windows were retrofitted with energy-efficient glazing. The energy for space heating and the provision of warm water is now supplied by three different sources: a geothermal pump, a solar-thermal collector, and a mechanical heat recovery ventilation system. Because the new insulation made the building more airtight, it was necessary to install a mechanical ventilation system to prevent condensation and mold.

The results of the retrofit are impressive. The building’s total primary energy supply (TPES) was reduced by 85%. Before the retrofit, the TPES was 572 kWh/m2 annually (181,324 Btu/ft2 annually). It is now just 36.5 kWh/m2 annually (11,570 Btu/ft2 annually), based on modeling of the newly retrofitted building. (These modeled savings will be checked against the actual energy consumption of the building. All project participants are required to report this data for the first two years following modernization.) Mr. Buckel can be proud; by retrofitting his home, he has made an enormous contribution to the overall reduction of greenhouse gases. According to dena’s calculations, his house now saves 39 metric tons of CO2 per year! And he profits directly, too, because the final or site energy—which he pays for—adds up to only 12 kWh/m2 per year (3,804 Btu/ft2 annually). Although the building is more than 300 years old, it is now more efficient than most new buildings in Germany, and Mr. Buckel needn’t worry about rising energy prices.

The Most Efficient Single-Family Home

The project’s most efficient single-family home is a two-story, 2,551 square foot (237 square meter) timber building, with an addition built from concrete. It was built 50 years ago on the banks of the beautiful Lake Bodensee, one of Europe’s biggest lakes in the south of Germany. When the house was originally built in the 1950s, no one was paying attention to energy efficiency. When it came time to retrofit, the current owner, Andreas Koch, wanted to reduce the building’s extremely high annual energy demand of 255 kWh/m2 annually (80,835 Btu/ft2 annually). Koch is an architect specializing in energy-efficient construction who works for the European Institute for Energy Research. His objective was to preserve the building’s typically ’50s style while significantly reducing its energy demand. He was extremely careful in choosing the measures he wanted to apply, so the building would still resemble the family house that he and his mother and sister had inherited from his grandparents.

What was done? Again insulation played a major role. A thermal insulation composite system made of polystyrene with a thickness of 12 inches (30 centimeters) and a U- value of 0.102 W/m2K was installed on the timber construction part of the building. New wooden cladding was installed over the polystyrene. A thermal insulation composite system was installed on the concrete addition as well, with the roof and basement getting 12 inches (30 centimeters) of polystyrene. The side of the house facing the lake underwent the most dramatic changes. The balcony was torn down and the windows were replaced with larger, highly efficient, three-pane thermal units.

The result is remarkable: a beautiful view of the lake and the mountains; brighter, more spacious rooms; and outstanding energy efficiency. You wouldn’t know that you were standing in front of a window if you were standing blindfolded just 12 inches away—proof of the windows’ superb thermal quality. The building is now extremely airtight, so much so that to ensure good air quality, a mechanical ventilation system had to be installed. But Mr. Koch is not wasting energy with his ventilation system. He chose a system that recovers 80% of the heat that would normally be lost while exhausting the indoor air.

The heating system was completely retrofitted as well. The old-fashioned oil heating was replaced by an innovative geothermal heat pump that uses brine and water to produce 7.8 kilowatts, enough to provide a constant supply/system temperature of 95ºF (35ºC). A 101 square foot (9.4 square meter) solar-thermal collector was also installed on the roof of Mr. Koch’s house. It is one of the new, efficient vacuum tube units, with an output of 3.75 kilowatts. The energy provided by the geothermal heat pump and the solar collector warm the water in a storage tank that is then distributed throughout the house for heating and domestic hot water. The solar collector supplies 51% of the energy needed to heat the domestic hot water, and 8% of the energy needed to heat the house.

To complete the energy-efficient heating system retrofit and to improve the residents’ comfort, Mr. Koch installed an underfloor radiant heating system. Instead of wasting energy by heating a room at ceiling height as some forced-air systems do, underfloor heating warms the air at floor level, and that warm air then rises through the living space, warming its occupants and losing heat as it rises. Very little energy is therefore wasted, and Mr. Koch’s rooms are heated in a way that makes them more comfortable—warm feet and a cool head, rather than cold feet and a hot head.

The result of all these changes is that the annual TPES of 255kWh/m2 annually (80,835 Btu/ft2 per yr) before the retrofit was reduced by 86% to just 34kWh/m2 annually (10,778 Btu/ft2 annually) after refurbishment. That’s a third of the regularized minimum requirement for a comparable new building, which would be 107 kWh/m2 annually. Like Mr. Buckel, Mr. Koch has become almost independent of rising energy prices. The building’s final or site energy demand is now calculated to be as little as 11kWh/m2 annually (3,487 Btu/ft2 annually). And Mr. Koch has done more than his share to protect the environment and the climate. With the improvements to the building, his home now emits 30 metric tons of CO2 less per year.

Success All Around

The Efficient Homes project has been a great success. By the middle of 2007, more than 1,300 owners had applied for the program and are now committed to highly energy-efficient retrofits. The two examples described above—the Buckel and Koch homes—show that these renovations are not miracles. Standard measures and technologies that are readily available in the marketplace were used to attain these exemplary energy standards.

Nicole Pillen is a project director and Nana Doerrie is a staffmember at dena.

For more information:

For more information on these projects, visit and or contact

Friday, October 24, 2008

Helping 'green' products grow - From Mc Kinsey

The impulse to go “green” is spreading faster than morning glories. Organizations of all types are launching green campaigns—from London’s congestion charge on automobiles to Wal-Mart Stores’ push to sell organic foods. In almost every opinion poll on the subject, consumers say they are very concerned about climate change, and they connect the dots back to their own purchases, according to a 2007 McKinsey survey of 7,751 people in Brazil, Canada, China, France, Germany, India, the United Kingdom, and the United States. Indeed, the poll shows that 87 percent of consumers worry about the environmental and social impact of the products they buy.

But when it comes to actually buying green goods, words and deeds often part ways. No more than 33 percent of the consumers in our survey say they are ready to buy green products or have already done so. In a 2007 Chain Store Age survey of 822 US consumers, only 25 percent of them report having bought any green product other than organic foods or energy-efficient lighting. Indeed, most of the green goods on the market have tiny market shares. In 2006, green laundry detergents and household cleaners accounted for less than 2 percent of US sales in their categories. Hybrid cars, though trendy, made up little more than 2 percent of the US auto market in 2007, according to a report by J. D. Power and Associates.

Consumers in the United States and other developed countries have therefore done little to lighten their carbon footprint. Some of this lag between talking and walking could reflect insincerity, laziness, or posturing. But much more of it stems from the failure of businesses to educate consumers about the benefits of green products and to create and market compelling ones. A 2007 Climate Group study discovered that two-thirds of US and British consumers cannot name a single green brand. Similarly, the 2007 National Technology Readiness Survey of 1,025 US adults found that though more than two-thirds say they prefer to do business with environmentally responsible companies, almost half add that it is difficult to find green goods and services.

Corporations can reap a number of benefits by going green. Consider the success of compact fluorescent lightbulbs (CFLs), for example. In 2005, sales of CFLs accounted for less than 5 percent of the total lightbulb market. Only two years later—in 2007, the year the public woke up to the looming threat of climate change—they captured an estimated 20 percent of it, according to the US Environmental Protection Agency (EPA). Companies, such as GE, that sell CFLs have increased their revenues, enhanced their brands, and strengthened their competitive positions.

To realize the green market’s true potential, businesses must help consumers change their behavior by removing the hurdles between intentions and actions.
Breaking down the barriers

Our 2007 study of 7,751 consumers around the world identifies barriers to buying green at all five stages of the purchase process. In the first stage, awareness, consumers must be aware that a product exists before they can buy it, but many of them don’t know about the green choices in a number of categories. Next, consumers must believe that a product will get the job done. Many, however, think the quality of green products is lower than that of their more traditional, “browner” counterparts. Consumers must then decide whether or not a product lives up to its green reputation. Many are skeptical about environmental claims, partly because they distrust corporations and the media. Finally, in the fourth and fifth stages, consumers must decide if a product is worth the expense and the effort needed to purchase it—consumers often believe that green goods cost too much and are difficult to find. To increase sales of environmentally sensible products, companies must remove these five barriers—lack of awareness, negative perceptions, distrust, high prices, and low availability.

The importance of each barrier varies by product, industry, and geography. More than 90 percent of the consumers who participated in the McKinsey global survey know about CFLs, so there is no lack of awareness about them.1 Nonetheless, many think CFLs are too expensive and of dubious quality. Such concern about the price and quality of goods varies across regions and across product categories. For example, 14 percent of US consumers say they would pay a premium for green products in the retail sector, compared with 26 percent in Brazil. Seven percent of French consumers are willing to pay a premium for green products in the petroleum sector, compared with 26 percent in India.

Companies first need to figure out which customers would probably want which products and then examine how people in each market segment make their purchasing decisions. No matter which barriers prove most important for a given product, industry, and region, businesses must ultimately address barriers in all areas before consumers will change their behavior. In other words, companies have to move customers through every stage of the purchase process—from becoming aware of eco-friendly products to finding them.
Educate consumers

Because consumers are largely unaware of green products, a business that sells them must see itself first as an educator, not a sales machine. Our study shows that more than one-third of the consumers who want to help mitigate climate change don’t really know how. The top three ways for them to reduce their own emissions are to drive more fuel-efficient cars, improve the insulation of their homes, and eat less beef (exhibit). Yet when we asked the consumers in our study to name the top three, they fingered recycling, energy-efficient appliances, and driving less. Few consumers knew how eco-friendly it is to shun beef.
Back to top

This lack of knowledge means that companies must explain not only their own products but also the larger issues of pollution, climate change, overfishing, and other environmental problems. Nonprofits and government agencies should also take up the cause of green education. Energy Star provides a model. This program, a joint effort launched by the EPA and the US Department of Energy in 1992, educates consumers about the way suitable products can cut energy use, save consumers money, and protect the environment. Every appliance that meets government energy-efficiency standards can carry the Energy Star label, which has gained widespread consumer recognition and trust. Because federal regulations mandate energy labels for certain kinds of equipment, almost half of the air conditioners sold in the United States during 2005 carried the Energy Star sticker. In the same year, nearly 30 percent of all US homes had energy-efficient refrigerators and washing machines, according to the Vermont Department of Public Service.

To cite another example: P&G’s Future Friendly campaign provides consumers with specific tips on how they can have a positive impact on the environment by making their homes more energy efficient, using less water, and reducing household waste. A number of environmental nonprofits, including the Waterwise Project, Waste Watch, Energy Saving Trust, and Global Cool, endorse this information. The campaign’s print, television, and online messages tell consumers not only what they can do to protect the environment but also how P&G’s energy-efficient products can help them do so. P&G benefits because it refreshes its brand, enhances its reputation, and protects its market share from new green competitors. The campaign didn’t pick up steam until 2007, so its impact on sales is not yet conclusive.
Build better products

Even when consumers can identify environmentally sound choices, the green label is sometimes the kiss of death. Certain green products—such as Toyota Motor’s Prius—have become status symbols, but many others have image problems. According to the 2007 GfK Roper Green Gauge study of more than 2,000 Americans, 61 percent believe that green goods perform less well than conventional ones. Indeed, that often used to be true: early hybrid cars had less power than nonhybrids, for example, and early CFLs couldn’t fit properly into most normal fixtures, were slow to turn on, and shined weakly once they did.

Consumers will not think better of green products until companies make them equal to, or better than, their conventional alternatives. It's no surprise: most people value performance, reliability, and durability much more than ecological soundness. Eventually, GE succeeded with CFLs, which have overcome their teething problems and now pay for themselves in five months (Wal-Mart committed itself to selling 100 million of them in 2007, thus helping to surmount another barrier—availability). Toyota dealt with early perceptions of the Prius by increasing its horsepower and mounting a campaign that promoted the car as “quick, roomy, and economical.”
Be honest

Consumers doubt not only the quality but also the very greenness of green products, according to the GfK Roper survey. In this area, they trust scientists and environmental groups, not the government, the media, or businesses—and justifiably so. A 2007 study by TerraChoice Environmental Marketing examined 1,753 claims about green products and found all but one misleading or just plain false.

In the misleading category, some companies tout features that are actually mandated by law (for example, labeling products as free of CFCs, the ozone-eating propellants the US federal government banned almost three decades ago). Other companies mislead consumers by highlighting a single positive product feature while ignoring the negative ones. Paper and lumber products tout their recycled content, for example, without noting the air and water emissions of their manufacturing processes or the impact on global warming. In the just plain false category, a dishwasher detergent boasted of its environmental virtue in using 100 percent recycled paper—on its 100 percent plastic container.

To rebuild public trust, companies must come clean about the true environmental impact of their products and their attempts to reduce it, and many will need to address historical concerns about specific products or operations. Only then will consumers believe a company’s green claims. In 2005, GE launched its Ecomagination initiative with the broad objectives of meeting environmental goals such as clean water, renewable energy, and reduced emissions, as well as increasing its investment in sustainable technologies and its revenues from sustainable products, like lower-emission aircraft engines, efficient lighting, wind turbines, and water purification equipment. As part of the Ecomagination campaign, GE also undertook to make its own operations more environmentally sustainable. Since then, the company has managed to sustain positive growth for its portfolio of energy-efficient and environmentally advantageous products and services—with revenues forecast to rise 21 percent from 2007 to $17 billion in 2008—while reducing greenhouse gas emissions from its own operations, which are projected to be down by about 8 percent in 2008 from the 2004 baseline.
Offer more

A consumer who gets past the sometimes checkered history of eco-friendly products may well encounter a fourth barrier: they often cost more. Indeed, price is the largest obstacle to purchases of green products, according to a 2007 survey of 3,600 consumers by the UK Department for Environment, Food, and Rural Affairs. Close to half of the participants want a two-year return when they pay a premium for a product, yet 70 percent of green appliances (including energy-efficient televisions, washers, and dryers) take longer.

Companies must ensure that consumers understand the financial and environmental returns on their investment in green products, for they are more willing to try new ones—especially those that cost more—when they find it easy to track the savings. Sales of such products may also rise if their design stands out and signals their owners’ commitment to the environment.

The value of the Prius, for instance, goes well beyond traditional functionality. The car caught the attention of consumers because of its unique and contemporary style and its innovative dashboard, which, via an onboard computer, displays the various energy-efficient functions of the car. By enabling the driver to determine how much and what kind of energy the car is using at any given time, the dashboard communicates the vehicle’s energy efficiency, thereby broadcasting its environmental benefits. By contrast, Honda Motor’s Accord hybrid, which looked more conventional and did not toot its environmental horn, languished (and was eventually dropped, in 2008). In 2006, the Prius held 76 percent of the US hybrid market; the Accord hybrid, which functioned just as well, held only 12 percent.
Bring products to the people

Having decided to buy green products, many consumers encounter a last hurdle—finding them—either because manufacturers don’t keep up with demand or advertise where they can be bought, or because wholesalers and retailers don’t stock them or display them prominently. Biofuel enthusiasts, for example, must often drive out of their way to fill up. Many energy-conscious homeowners have no choice but to buy high-emission power because their local utilities don’t offer green energy. Many contractors don’t know where to buy green building materials. In 2007, we undertook an informal survey of 23 retailers in Chicago and in the San Francisco Bay area. Fewer than half sold green products other than organic foods and CFLs, and among the minority that did, only about 10 percent stocked more than one brand option.

Companies with successful green products ensure that they are available and easy to find. Wal-Mart and GE have promoted the fortunes of CFLs, for example, by making them easy to buy. Wal-Mart put the bulbs in the most coveted place in retailing—at eye level, on the top two or three shelves; an educational display from GE complements the attractive placement. Toyota communicates its determination to make the Prius widely available by running ads that say, “We’ve significantly increased production on the hard-to-find, easy-to-drive Toyota Prius.” According to AutoInsight, the company has increased its output of the cars by an average of 50 percent a year since 1999.
The green imperative

Businesses by themselves can’t lead consumers from intentions to actions; as the success of Energy Star shows, the government and nonprofits must often participate actively to achieve long-lasting changes in consumer behavior. Nevertheless, businesses should play a leading role in the green movement in order to shape their market opportunities and manage potential regulation of their industries.

Today, green products and services are only a niche market, but they are poised for strong growth. Already, 33 percent of consumers say they would pay a premium for green products, and 54 percent care about the environment and want to help mitigate climate change. Entry into the green market can also improve a company’s reputation, thereby increasing the value of its brands. Some 70 to 80 percent of the valuations of public companies in US and Western European stock markets depends on expectations of cash flows beyond the next three years. A company’s reputation strongly shapes those expectations, and corporate citizenship is its top driver, according to the Reputation Institute’s 2007 global survey. In short, green activity can raise the bottom line.

In addition, companies that have a strong position in the green market can protect their market share from competitors. More than 80 percent of 2,192 executives in a McKinsey Quarterly survey2 conducted in 2007 expect some form of climate change regulation within the next five years in countries where their companies operate. The most active businesses will try to shape these regulations and may even push for stricter ones that would disadvantage their less environmentally savvy competitors. Newcomers, in turn, can steal market share from established companies through appeals to the ever-growing legions of green consumers. Whole Foods Market, with double-digit sales growth in the essentially flat supermarket industry, is a powerful example of a new entrant that has used a green offering to win share not only in the green market but also in the premium segment.

Going green while staying competitive can be challenging, and companies may rightly ask whether cultivating green consumers is worth all the trouble. We believe that it is more than just worthwhile—it is imperative for success. Once businesses remove the obstacles that now make it hard for consumers to act on their environmental beliefs, sales of green products could explode. What’s more, a company that builds a reputation for eco-friendliness can do much more than increase its revenues. The better its reputation, the more talented the employees it can attract, the more loyalty it can inspire in its customers, and the more it can charge for its products.
About the Authors

Sheila Bonini is a consultant in McKinsey’s Silicon Valley office, and Jeremy Oppenheim is a director in the London office.

This article is adapted from “Cultivating the green consumer,” which appeared in the fall 2008 issue of the Stanford Social Innovation Review.

The authors wish to acknowledge the contributions of John Forsyth, Nadeem Sheikh, and Jessica Weisz.

Not that consumers know everything they should. Only half of the participants in this study know about carbon credits, a way for individuals or businesses to lighten their carbon footprint. Companies that sell these credits invest the money in renewable energy, reforestation, and other activities that reduce carbon emissions, thus offsetting those of the individuals or businesses purchasing the credits.

Monday, October 13, 2008

Fun Facts about water

• If all the world’s drinkingwater were put in one cubical tank, the tank
would measure only 95 miles on each side.
• People currently lacking access toclean drinking water: 1.2 billion.
• % of world’s households that must fetch water outside their homes: 67
• % increase in the world’s population by mid 21st century: 100
• % increase in the world’s drinking water supplies by mid 21st century: 0
• Amount of water Americans use every day: 340 billion gallons.
• Number of gallons of water needed to produce a car: 100,000
• Number of cars produced every year: 50 million.
• Amount of water annually required by a nuclear reactor: 1.9 cubic miles.
• Amount of water used by nuclear reactorsevery year: the equivalent of
one and a third Lake Eries.
Sources: Der Spiegel, May 25, 1992; and Annals of Earth, Vol. 8, Number 2, 1990; Ocean Arks International,
One Locust Street, Falmouth, MA 02540.

Sunday, October 5, 2008

Greening America’s Schools costs and benefits

“This carefully documented study
conclusively demonstrates the financial, environmental, and other benefits of
using green technologies in schools. In fact, failure to invest in green technologies is not financially responsible for school systems; the study uses conservative accounting practices to show that investments in green technologies significantly reduce the life-cycle cost of operating school buildings. And the public benefits of green schools are even larger than those that work directly to the financial advantage of schools. These include reductions in water pollution, improved environmental quality, and increased productivity of learning in an improved school environment.”
LINK to the full document