Bio Chapter 10
reducing energy has economic as well as environmental advantages
most energy analysts, reducing energy waste is the quickest, cleanest, and usually cheapest way to provide more energy, reduce pollution and environmental degradation, slow climate change, and increase economic and national security
hidden are the costs of illness from air and water pollution
of higher medical bills and health insurance premiums Consumers pay for these hidden cost not always at the gas pump
A smarter electrical grid would involve a two-way flow of energy and information between producers and users of electric- ity. Such a system would use smart meters to monitor the amount of electricity use
patterns of use for each custome
The next step in the evolution of more energy-efficient motor vehicles will probably be
plug-in hybrid electric vehicle—a hybrid with a second and more powerful battery that can be plugged into a conventional electrical outlet and recharged running primarily on electricity, plug-in hybrids could easily get the equivalent of at least 100 mpg for ordinary driving and up to 1,000 mpg
The other 43% is wasted unnecessarily, mostly due to the inefficiency of many devices and
processes that we use.
Walls and floors of concrete, adobe, brick, stone, or salt-treated timber, and metal or plastic water tanks can store much of the collected solar energy as heat
release it slowly throughout the day and night
Another way to save energy and money in industry is to
replace energy-wasting electric motors, which use one- fourth of the electricity produced in the United States and 65% of the electricity used in U.S. industry these motors are inefficient because they run only at full speed with their output throttled to match the task—somewhat like keeping one foot on the gas pedal of your car and the other on the brake pedal to control its speed Replacing them with variable speed motors, which run at the minimum rate needed for each job, saves energy and reduces the environmental impact of electric motor use.
One of these vehicles is the energy- efficient, gasoline-electric hybrid car
small, traditional gasoline-powered engine and a battery-powered electric motor used to provide the energy needed for acceleration and hill climbing. Cur- rent models of these cars get up to 50 mpg
A fourth way for industry to save energy is to
switch from low-efficiency incandescent lighting to higher-efficiency fluorescent lighting compact fluorescent bulb uses one- fourth as much electricity as an incandescent bulb and can last ten times as long, saving at least $30 in replacement costs during its lifetime Even better, light- emitting diodes (LEDs) use about one-seventh of the electricity required by an incandescent bulb and can last about 100 times longer
These hidden costs include government subsidies
tax breaks for oil companies, car manufacturers, and road builders and the costs of pollution control and cleanup, military protection of oil supplies in the Middle East and time wasted in traffic jams
Since 1985, despite government-mandated corporate average fuel economy (CAFE) standards,
the average fuel efficiency for new vehicles has generally declined while standards and efficiencies in other countries rose
2007 UN study, better architecture and energy savings in buildings could reduce
the energy used globally by 30-40%.
energy efficiency
the measure of how much work we can get from each unit of energy we use. best way to cut energy waste
About 41% of this energy is unavoidably lost because of the degradation of energy quality imposed
the second law of thermodynamics
U.S. consumers do not realize that gasoline costs them much more than the price
they pay the pump
Energy-efficient windows or attached greenhouses face the sun
to collect solar energy directly
fuel efficiency for all types of cars could nearly double if car bodies were made of
ultralight and ultra-strong composite materials such as fiberglass and the carbon-fiber composites used in bicycle helmets and in some racing cars.
U.S. Department of Energy, roughly 84% of all commercial energy used in the United States is
wasted
2005 study by the International Center for Technology Assessment, the hidden costs of gasoline for U.S. consumers were about
$3.18 per liter ($12 per gallon)
There are many ways to save energy and money in existing buildings. Surveys of energy use in older houses typically result in some or all of the fol- lowing recommendations:
1. Insulate the building and plug leaks. About one-third of the heated air in typical U.S. homes and other build- ings escapes through holes, cracks, and closed, sin- gle-pane windows. During hot weather, these win- dows and cracks let heat in, increasing the use of air conditioning. Adding insulation to walls and attics, plugging air leaks, and sealing heating and cooling ducts are three of the quickest, cheapest, and best ways to save money and energy in any building. 2. Use energy-efficient windows. Replacing single-pane windows with energy-efficient double-pane windows or highly efficient super windows that have the insulating effect of a window with three or more panes can cut heat losses from a house by two-thirds, lessen cooling costs in the summer, and reduce heating-system CO2 emissions. 3. Heat houses more efficiently. In order, the best ways to improve efficiency in space heating are to use: superinsulation; a geothermal heat pump that transfers heat stored in the earth to a home; passive solar heating; a high-efficiency, conventional heat pump (in warm climates only); small, cogenerating microturbines fueled by natural gas; and a high- efficiency (92-98%) natural gas furnace. The most wasteful and expensive way to heat a space is to use electric resistance heating with electricity from a conventional power plant. 4. Heat water more efficiently. One approach is to use a roof-mounted solar hot water heater. Another option is a tankless instant water heater fired by natu- ral gas or LPG. It heats water instantly as it flows through a small burner chamber, providing hot water only when it is needed, and uses less energy than traditional water heaters. 5.Use energy-efficient appliances and lighting. Accord- ing to the U.S. Environmental Protection Agency (EPA), if all U.S. households used the most efficient frost-free refrigerator now available, 18 large power plants could close. Microwave ovens use 25-50% less electricity than electric stoves do for cooking and 20% less than convection ovens use. Clothes dryers with moisture sensors cut energy use by 15%. The best compact fluorescent lightbulbs are four times more efficient and last up to ten times longer than incandescent bulbs. Figure 10-5 summarizes ways in which you can save energy in the place where you live.
why is there so little emphasis on improving energy efficiency?
1. fossil fuels and nuclear power are artificially cheap because of the government subsidies and tax breaks they receive and because their market prices don't include their harmful environmental and health costs 2. there are few tax breaks, rebates, and other economic incentives for consumers and businesses for investing in energy-efficiency improvements
four widely used devices that waste large amounts of energy:
1. incandescent lightbulb uses only 5-10% of the electricity it draws to produce light, while the other 90-95% is wasted as heat. 2. The internal combustion engine, used in most motor vehicles, wastes about 80% of the energy in its fuel. 3. A nuclear power plant used to produce electricity wastes about 75% of the energy in its nuclear fuel, and probably closer to 92% when we consider the energy used to deal with its radioactive wastes and to retire and close up, the highly radioactive plant. 4. A coal-fired power plant wastes about 66% of the energy that is released by burning coal to produce electricity, and probably 75-80% if we include the energy used to mine and transport the coal and to transport and store the toxic coal ash.
If renewable energy is so great, why does it provide only 15% of the world's energy and 7% of the energy used in the United States? Reasons why:
1. since 1950, government tax breaks, subsidies, and research and development funding for renewable energy resources have been much lower than those for fossil fuels and nuclear power, although subsidies and tax breaks for renewables have increased in recent years 2. prices we pay for nonrenewable fossil fuels and nuclear power do not include their harmful environmental and health costs
Studies show that with increased and consistent government backing, renewable energy could provide 20% of the world's electricity by 2025 and 50%
2050
growing interest in developing superef- ficient, ultralight, and ultrastrong cars that could
300 miles per gallon
Industry accounts for about 30% of the world's energy consumption and
33% of U.S. consumption, mostly for production of metals, chemicals, petrochemicals, cement, and paper.
Superinsulated houses in Sweden use
90% less energy for heating and cooling than typical American homes of the same size use
Major advantages of using passive or active solar heating systems for heating indoor spaces
Advantages: Net energy is moderate (active) to high (passive) Very low emissions of CO2 and other air pollutants Very low land disturbance Moderate cost (passive)
Major disadvantages of using passive or active solar heating systems for heating indoor spaces
Disadvantages: Need access to sun 60% of time during daylight Sun can be blocked by trees and other structures High installation and maintenance costs for active systems Need backup system for cloudy days
Amory Lovins
Energy analyst estimates that in the United States "we could save at least half the oil and gas and three-fourths of the electricity we use at a cost of only about an eighth of what we're now paying for these forms of energy."
cogeneration, or combined heat and power (CHP) systems.
In such a system, two useful forms of energy (such as steam and electricity) are produced from the same fuel source. The energy efficiency of these systems is 75-90% (compared to 30-40% for coal-fired boilers and nuclear power plants), and they emit one-third as much climate-changing carbon dioxide (CO2) per unit of energy produced as do conventional coal-fired boilers.
many ways for industries to cut energy waste
Some companies save energy and money by using cogeneration, or combined heat and power (CHP) systems
24-story Georgia Power Company building in the U.S. city of Atlanta, Georgia, uses 60% less energy than conventional office buildings of the same size
The largest surface of this building faces south to capture as much solar energy as possible and each floor extends out over the one below it. This blocks out the higher summer sun on each floor to reduce air conditioning costs but allows the lower winter sun to help light and heat each floor during the day. In the building's offices, energy-efficient compact fluorescent lights focus on work areas instead of illuminating entire rooms.
smart grid
This energy-efficient, digitally controlled, ultra-high-voltage grid with super- efficient transmission lines would be respon- sive to local and regional changes in demand and supply
Adding this to an $.80 per liter ($3 per gallon) pump price of gasoline
U.S. consumers would yield a true cost of about $4 per liter ($15 per gallon)
passive solar heating system
absorbs and stores heat from the sun directly within a structure without the need for pumps or fans to distribute the heat
active solar heating system
absorbs energy from the sun by pumping a heat- absorbing fluid through special collectors, usually mounted on a roof or on special racks to face the sun. Some of the collected heat can be used directly. The rest can be stored in a large insulated container filled with gravel, water, clay, or a heat-absorbing chemical, for release as needed.
Replacing them with variable speed motors, which run at the minimum rate needed for each job, saves energy
and reduces the environmental impact of electric motor use. recycling materials is a third way for industry to save energy and money. For example, producing steel from recycled scrap iron uses 75% less energy than producing steel from virgin iron ore and emits 40% less CO2. Switching three-fourths of the world's steel production to such furnaces would cut energy use in the global steel industry by almost 40% and would sharply reduce its CO2 emissions.
fuel cells
at least twice as efficient as internal combustion engines have no moving parts, require little maintenance, and use hydrogen gas as fuel to produce electricity essentially eliminate emissions of CO2 and other air pollutants if the hydrogen was produced from noncarbon or low-carbon renewable sources of electricity such as wind turbines and solar cells Unlikely to be widespread until 2020 will probably be very expensive because they have a negative net energy yield
Green architecture
based on energy-efficient and money-saving designs makes use of natural lighting, solar energy, recycling of wastewater, and energy-efficient appliances and lighting green buildings have living roofs, or green roofs, covered with soil and vegetation, which helps to keep the buildings warmer in winter and cooler in summer.
According to the U.S. Department of Energy (DOE), building such a smart grid would cost the United States from $200 billion to $800 billion,
but would pay for itself in a few years by saving the U.S. economy more than $100 billion a year.
Chinese company is now selling the world's first plug-in hybrid
called the Build Your Dreams (BYD) car.
energy conservation
energy we save by cutting energy waste, as a largely untapped, abundant, clean, and cheap source of energy
energy-efficient diesel car, which accounts for 45% of new passenger car sales in Europe
energy-efficient diesel car, which accounts for 45% of new passenger car sales in Europe.
biodiesel
fuel that energy-efficient diesel cars run on
Another form of renewable energy is
geothermal
unnecessary energy waste still costs the United States a
great deal of money
There is a lot of room for reducing energy waste in transportation, which accounts for about 28% of the energy consumption and two-thirds of the oil consumption in the United States. What is one problem with government efficiency standards for motor vehicles?
has been low for years
superinsulation
important element of energy-efficient design house can be so heavily insulated and airtight that heat from direct sunlight, appliances, and human bodies can warm it with little or no need for a backup heating system Such houses typically cost more to build than conventional houses of the same size, but the cost is paid back within years by energy savings.
Energy analysts say that if these economic handicaps inequitable subsidies and inaccurate pricing—were eliminated then
many forms of renewable energy would be cheaper than fossil fuels and nuclear energy, and would quickly take over the marketplace
