CH 13: Achieving Energy Sustainability

Renewable Energy “The use of solar energy has not been opened up because the oil industry does not own the sun.” - Ralph Nader

What are Renewable Resources? Renewable energy can be rapidly regenerated, and some can never be depleted, no matter how much of them we use. Ex) Biomass Renewable/non depletable = refer together as renewable.

Nondepletable Energy sources that cannot be depleted no matter how much we use them The amount available tomorrow does not depend on how much we use today EX) Solar, wind, geothermal, hydoelectric, etc. EX) No matter how much wind energy we capture there will always be more

Potential Energy Renewable as long as humans do not use it faster than it can be replenished EX) Biomass

Renewable Energy The greatest renewable source of electricity production currently in use is hydroelectricity.

How Can We Use Less Energy? Energy conservation- finding ways to use less energy. For example, lowering your thermostat during the winter or driving fewer miles. Energy efficiency - getting the same result from using a smaller amount of energy.

The Benefits of Using Less Energy Many energy companies have an extra backup source of energy available to meet the peak demand, the greatest quantity of energy used at any one time. Important to REDUCE peak demand hours Variable price structure- utility customers can pay less to use energy when demand is lowest and more during peak demand. Example: Use the Clothes dryer before 10 am and after 7 pm in the summer.

Sustainable Design Improving the efficiency of the buildings we live and work in.

Passive Solar Energy Using passive solar energy can lower your electricity bill without the need for pumps or other mechanical devices. Building the house with windows along a south- facing wall which allows the Sun’s rays to warm the house during the winter, yet let indirect light in to save on lighting costs in the summer.

Sustainable Design Building houses close to where people work means reduced reliance on fossil fuels for transportation Use materials that have high thermal inertia Ability of a material to retain heat or cold Building a house into the side of a hill or roofing a building with soil and plants= provide insulation and reduce need for heating and cooling Use of recycled building materials is another method of energy conservation EX) Earthships in New Mexico

Sustainable Design Techniques Passive Solar design Radiant Heating Solar Panels Skylights Uses 30% less energy than the federal code requirement Natural Light fills 90% of office & public areas Window, louvers & skylights open as needed to allow for air circulation Recycled denim jeans insulated the walls Rooftop garden insulate the roof Water collected from the roof recharges the groundwater Efficient radiant heating system carries warm water through tubes in concrete floor.

Biomass is Energy from the Sun The Sun is the ultimate source of almost all types of energy Most Common form of Renewable energy Wood, Charcoal and Manure- used to heat homes throughout the world. Ethanol and Biodiesel (biofuels)- used as substitutes for gasoline and diesel fuel.

Modern Carbon vs. Fossil Carbon Many people are confused how burning biomass such as wood is better than burning coal. The carbon found in biomass was in the atmosphere as carbon dioxide, taken in by the tree, and by burning it we put it back into the atmosphere Burning coal is carbon that has been buried for millions of years and was out of circulation until we began to use it. This results in a rapid increase in the concentration of carbon dioxide in the atmosphere.

Biomass Wood, Charcoal and Manure - used to heat homes throughout the world. Ethanol and Biodiesel (biofuels) - used as substitutes for gasoline and diesel fuel.

Hydropower Hydroelectric power plants use running water to spin a turbine and generate electricity. Hydroelectricity is very economical, with costs per kilowatt-hour similar to coal. No pollution is produced.

The Kinetic Energy of Water Hydroelectricity - electricity generated by the kinetic energy of moving water. This is the second most common form of renewable energy in the world.

The Kinetic Energy of Water Run-of-the-river systems - water is held behind a dam and runs through a channel before returning to the river. Water impoundment - water is stored behind a dam and the gates of the dam are opened and closed controlling the flow of water. Tidal systems - the movement of water is driven by the gravitational pull of the Moon.

Tidal Power Hydro Power

An issue with dams is that they produce a constant, steady stream of electricity that cannot be easily adjusted to meet demand. Some dams have pumped storage, where water will be sent and stored during low-demand times, then returned back through the dam’s turbines when demand is higher. Kinzua Dam and Seneca pumped storage generating station, Mead, PA

Wind Energy Similar to hydroelectricity, except that moving air provides the force to spin the generator. Wind turbines are able to orient themselves to face the oncoming wind. As the air passes through, the blades rotate. These are attached to a shaft, which connects to the turbine.

Wind farms are large numbers of wind turbines clustered together. A single wind turbine can generate 1-7 megawatts of energy per year, not enough for a large population. Wind farms are large numbers of wind turbines clustered together. The Gansu Wind Farm in China produces 6 billion kilowatt-hours of electricity per year!

Wind power is comparable in cost to coal. Possible negative impacts of wind turbines include: Disruption of bird and bat migration pathways. Noise. Disruption of scenery.

Geothermal Energy Like nuclear and coal, works by boiling water to steam. Naturally-occurring heat from the Earth is used in place of fuel. At a geothermal plant, two wells are drilled. One injects cold water towards the underground heat. The second directs steam to the turbine.

Geothermal Energy

Solar Energy An enormous amount of energy (over 1,000 watts per square meter) hits the Earth every day. This energy is very diffuse, spread out across the entire surface area of the planet. Two separate technologies have been developed to convert solar energy into electricity.

Parabolic solar collection involves using curved reflective surfaces that collect light and focus it onto a concentrated point. The heat is absorbed and used to boil water into steam, which spins a turbine.

Photovoltaic cells capture solar energy and convert it directly to electrical current. Solar electricity tends to be 1.5-2 times the cost of electricity from coal or other renewable sources. Not available on overcast days or at night.

Iceland Uses the more per capita energy than other nation Most of that energy = local and renewable Very expensive to import to Iceland Abundant fresh water= Hydroelectricity Geysers and hot springs= Geothermal energy Generate enough electricity for almost every on the country Trying to develop hydrogen energy to power cars First filling station hydrogen-fueled cars

Hydrogen Fuel Cells Fuel cell - a device that operates like a common battery where electricity is generated by a reaction between two chemicals. What are some advantages and disadvantages of a Hydrogen fuel cell car?

Biofuels A fuel derived directly from organic, or living matter. Used as an alternative to gasoline or other fossil fuels. The Navy Goes Green - Daily Show Segment

Before Lord of the Rings…

Geography of Nonrenewable Resources Electricity generation by solar, wind, hydrokinetic, or geothermal plants is restricted by the natural geography of the United States.

The Great Plains have the highest average wind speeds and the greatest potential for wind power.

Areas with significant elevation differences and river courses are ideal for hydroelectricity generation.

The western states are the most favorable for geothermal energy production.

The deserts of the southwest are ideal for solar electricity generation.

PBS NOVA - Making Stuff Cleaner

Unit 5 Concept Mapping Spend 20 minutes creating a concept map for Unit 5: Energy Resources and Consumption on a separate sheet of paper. You must create a multi colored (4+ colors), in depth map. The topics include: Non Renewable Resources Methods of Electricity Production Energy Efficiency Energy Sustainability Renewable Resources - Methods of Electricity Production Energy Conservation

Example Concept Map