Module #37

Conservation, Efficiency and Renewable Energy

Module Introduction:

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• In any discussion of energy use, whether renewable or nonrenewable, energy conservation and increased energy efficiency rank among the most crucial factors to consider.
• We begin our discussion of renewable energy with a look at conservation and efficiency.
• We will then explore the range of renewable energy resources that are available.

Module #37: Conservation, Efficiency and Renewable Energy

Essential Knowledge

5.12 Introduction to Sustainability (Modules 1, 2, 29, 33, 37, 66)

• Sustainability refers to humans living on Earth and their use of resources without depletion of the resources for future generations. Environmental indicators that can guide humans to sustainability include biological diversity, food production, average global surface temperatures and CO₂ concentrations, human population, and resource depletion.
• Sustainable yield is the amount of a renewable resource that can be taken without reducing the available supply.

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Essential Knowledge

6.2 Global Energy Consumption (Modules 34, 35, 37)

• The use of energy resources is not evenly distributed between developed and developing countries.
• The most widely used sources of energy globally are fossil fuels.
• As developing countries become more developed, their reliance on fossil fuels for energy increases.
• As the world becomes more industrialized, the demand for energy increases.
• Availability, price, and governmental regulations influence which energy sources people use and how they use them.

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Essential Knowledge

6.13 Energy Conservation (Module 37)

• Some of the methods for conserving energy around a home include adjusting the thermostat to reduce the use of heat and air conditioning, conserving water, use of energy-efficient appliances, and conservation landscaping.
• Methods for conserving energy on a large scale include improving fuel economy for vehicles, using BEVs (battery electric vehicles) and hybrid vehicles, using public transportation, and implementing green building design features.

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Case Study: Energy From Wind

• William Kamkwamba was a 14-year old boy living in a small village the nation Malawi in Africa.
• William’s family was too poor to send him to school, but he attended a local library sponsored by the U.S. government.
• Using recycled parts and “junk” William was able to construct a windmill and generate electricity.
• After becoming a local hero William graduated Dartmouth College and co-wrote the book The Boy Who Harnessed the Wind.

See pages 431-432 of the textbook for the full text.

Using Less Energy

• Energy conservation and energy efficiency are the least expensive and most environmentally sound options for maximizing our energy resources.
• Energy conservation: Finding and implementing ways to use less energy (e.g. walking/biking instead of driving).
• Energy efficiency: Finding ways to use less energy to perform the same task (e.g. replacing an older device with an Energy Star one).

Reducing Energy Use

Home

• Weatherize (insulate and seal gaps).
• Turn the thermostat down in winter and up in summer.
• Reduce the use of hot water (do laundry in cold water and take shorter showers).
• *Replace incandescent light bulbs with compact fluorescents or LEDs that are more efficient.

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Transportation

• Walk or ride a bike to reduce vehicle use.
• Take public transportation.
• Carpool.
• Consolidate trips.

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Electronic Devices

• *Buy Energy Star devices and appliances.
• Unplug when possible or use a power strip.
• Use a laptop rather than a desktop computer.

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We can reduce energy consumption through changes in energy conservation and energy efficiency. Conservation strategies emphasize using less energy, while efficiency strategies (*) focus on using less energy to perform the same task.

Incentivizing Conservation

• Governmental approaches to incentivizing energy conservation include:
• Providing walkways and bike paths to encourage walking/biking instead of driving.
• Providing public transportation to discourage automobile use.
• Taxation of electricity, oil and natural gas to discourage use.
• Rebates for retrofitting homes and businesses with more advanced heating and electrical systems/devices (e.g. Energy Star devices or LED lights) to use less energy.
• Electric companies can use a tiered rate system to discourage electricity consumption during peak demand and avoid black outs.
• Tiered rate system: A billing system used by some electric companies in which customers pay higher rates as their use goes up.
• Peak demand: The greatest quantity of energy used at any one time.

The OPEC Oil Embargo (1973-74)

• The OPEC Oil Embargo was an embargo by Arab members of OPEC against the U.S. and other nations supporting Israel during the Yom Kippur War, causing a severe global energy crisis, quadrupling oil prices, sparking inflation and recession (stagflation), leading to gas rationing and long lines, and highlighting global energy dependence.
• The crisis prompted energy conservation (e.g. the CAFE Standards), the search for alternative energy, and a shift in geopolitical power dynamics.
• This was arguably a major turning point in US foreign policy and the starting point of the ‘Energy Dominance’ movement and the push to geopolitical security through the development of domestic energy fuel sources.

Incentivizing Efficiency: The CAFE Standards

• The Corporate Average Fuel Economy (CAFE) Standards were enacted in the US in 1975 in response to the OPEC oil crisis (73-74).
• Focused on efficiency of automobiles, raising standards → less dependence on oil and greater economic security.
• Hybrids and electric vehicles help bridge the gap between nonrenewable and renewable energy sources.
• The CAFE standards represent an improvement in efficiency rather than conservation.

Sustainable Design

• Sustainable design improves the efficiency of the buildings and communities in which we live and work.
• A sustainable building design incorporates proper solar orientation to maximize sun exposure, native landscaping including shade trees to help regulate temperatures as well as insulated windows, walls, and floors with high thermal mass that can maintain internal temperatures.
• In the Northern Hemisphere, a southern exposure allows the house to receive more direct rays from the Sun in winter when the path of the Sun is in the southern sky. This maximizes passive solar design.

The goal of sustainable design is to reduce consumption of non-renewable resources, minimize waste, and create healthy, productive environments → environmental equity.

Sustainable Design (Continued)

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• Both passive solar design and the use of building materials with a high thermal mass help to improve the sustainability of a building’s design and reduce energy consumption as depicted in the next slide.
• Passive solar design: Construction designed to take advantage of solar radiation without active technology.
• Thermal mass: A property of a building material that allows it to maintain heat or cold (i.e. insulator).

Passive Solar Design

• Passive solar design uses solar radiation to maintain indoor temperature.
• Roof overhangs make use of seasonal changes in the Sun’s position to reduce energy demand for heating and cooling.
• In winter, when the Sun is low in the sky, it shines directly into the window and heats the house.
• In summer, when the Sun is higher in the sky, the overhang blocks incoming sunlight and the room stays cool.
• High-efficiency windows and building materials with high thermal mass are also components of passive solar design to maximize sustainability. These material absorb energy during the day and release it at night, regulating temperatures.

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Passive solar design: A form of sustainable design in which construction is designed to take advantage of solar radiation without active technology.

Green Roofs

Green roofs offer numerous economic and environmental benefits:

• Plants not only provide food, but also shade, cooling the building, reducing temperatures and stress of air-conditioning systems while simultaneously improving insulation and efficiency of mechanical equipment.
• Ecosystem services: Plants produce oxygen, sequester carbon and provide habitat for local species including birds that can control pest insects and cultural services including urban amenities.
• Control stormwater runoff and retention, especially in urban environments that lack permeable surfaces.
• Reduction of urban heat islands and improved air quality.
• Improved life expectancy of roofing systems by protecting the roofing materials from direct ultraviolet radiation and extreme temperatures.
• Reduced greenhouse gas emissions.

Green roofs: roofs made with soil and growing plants.

Renewable Energy

• Fossil fuels and nuclear fuels are nonrenewable energy resources.
• Renewable energy: Energy collected from renewable resources, which are naturally replenished on a human timescale, including carbon neutral sources like sunlight, wind, rain, tides, waves, and geothermal heat.
• Renewable energy is either potentially renewable or nondepletable.
• Potentially renewable: An energy source that can be regenerated indefinitely as long as it is not overharvested.
• Nondepletable: An energy source that cannot be used up.

Current Use of Renewable Energy

• (Top) Renewable energy resources provide about 13 percent of energy worldwide.
• (Bottom) Only 7 percent of the energy used in the United States comes from renewable energy resources.

Do The Math: Energy Star

• See page 436 of the textbook.
• Make sure to review the math problem and make sure you understand the set up, especially the dimensional analysis.
• Your Turn answer =
• $109.50/year
• $328.50 savings

If you have questions or need further explanation with ‘Do The Math’, you need to come in for extra help before school.

Module Review:

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• In this module, we have seen that to achieve energy sustainability we should begin with conserving energy and increasing energy efficiency.
• Energy conservation refers to finding ways to use less energy. Increasing energy efficiency means achieving the same amount of work from a smaller quantity of energy.
• Sustainable design of buildings and communities can decrease energy use.
• We also looked at different categories of renewable energy resources.
• Potentially renewable energy sources can regenerate if we do not consume them more quickly than they can be replaced.
• Nondepletable energy resources such as the wind cannot be depleted no matter how much we use.