Energy Efficiency PPT
- Efficiency is the effective operation as measured by a comparison of production with cost (as in energy, time, and money)
- The term energy efficiency refers to the measure of the useful energy
- Entropy is the measure of randomness or disorder in a system and is also a measure of unusable energy within a closed or isolated system
- Input is all components (matter and/or energy) entering the system.
- Throughput is the flow of all components within the system.
- Output is all components leaving the system.
- The efficiency of a product can be measured by: % efficiency = (output ÷ input) x 100
- A feedback loop is a circular process
- A feedback loop is how the output becomes input and affects the system.
- Positive Feedback: A feedback loop in which output of one type acts as input that moves the system in the same direction. The input and output drive the system further toward one extreme or another.
- Negative Feedback: A feedback loop in which the output of one type acts as input that moves the system in the opposite direction. The input and output essentially neutralize each other’s effects and stabilizes the system.
- A high throughput economy is one that has a high output.
- A Low Throughput economy is one that has a balance of input and output
- Fuel-efficient vehicles powered by a fuel cell that runs on hydrogen gas are being developed.
- We can save energy in building by getting heat from the sun, superinsulating them, and using plant covered green roofs.
- Strawbale is a superinsulator that is made from bales of low-cost straw covered with plaster or adobe. Depending on the thickness of the bales, its strength exceeds standard construction.
- Photovoltaic (PV) cells can provide electricity for a house of building using solar-cell roof shingles.
- Solar cells can be used in rural villages with ample sunlight who are not connected to an electrical grid.
- Water flowing in rivers and streams can be trapped in reservoirs behind dams and released as needed to spin turbines and produce electricity.
- Ocean tides and waves and temperature differences between surface and bottom waters in tropical waters are not expected to provide much of the world’s electrical needs.
- Wind power is the world’s most promising energy resource because it is abundant, inexhaustible, widely distributed, cheap, clean, and emits no greenhouse gases.
- Wind turbines can be used individually to produce electricity. They are also used interconnected in arrays on wind farms.
- Plant materials and animal wastes can be burned to provide heat or electricity or converted into gaseous or liquid biofuels.
- The scarcity of fuelwood causes people to make fuel briquettes from cow dung in India. This deprives soil of plant nutrients.
- Biodiesel is made by combining alcohol with vegetable oil made from a variety of different plants
- Biodiesel has the potential to supply about 10% of the country’s diesel fuel needs.
- Methanol is made mostly from natural gas but can also be produced at a higher cost from CO2from the atmosphere which could help slow global warming.
- Geothermal energy consists of heat stored in soil, underground rocks, and fluids in the earth’s mantle.
- Dry steam: water vapor with no water droplets.
- Wet steam: a mixture of steam and water droplets.
- Hot water: is trapped in fractured or porous rock.
- Hydrogen is chemically locked up in water an organic compounds.
- ENERGY STAR is a joint program of the U.S. Environmental Protection Agency and the U.S. Department of Energy helping us all save money and protect the environment through energy efficient products and practices.