1. Alternative energy

2. Solar Heating and cooling  Passive solar-  1. no outside energy is used to run fans or pumps.  2. the building itself along with landscaping help to collect store and distribute the sun’s energy  Active solar-  1. heating system that has flat plate collectors installed on the sunny side that is covered in transparent glass or plastic  2. Water or air is circulated through collectors to absorb captured heat and carry it to storage tanks

3. Active solar  3. Heated air and water can be pumped through out the house.  4. Initial cost to install is still quite high. Storage must be added for sunless days. These can only store enough for one or two days. A back up heating system must be used and adds to the expense.

4. Solar electricity  1. concentrating solar power is a collection system that concentrates enough sunlight to generate a large amount of steam  2. The steam is used to spin a turbine and rotates the coil of a generator to produce electricity.

5. Geothermal  Geothermal energy – uses the natural heat of the earth as an energy source  1. Geothermal reservoirs provide hot water or steam that can be used for heating and cooling buildings, processing foods and other goods, and generating electricity  2. Currently used in about 20 different countries. The Geysers geothermal instillation in San Francisco is the largest in the world

6. Geothermal  https://www.youtube.com/watch?v=sbiq_yd- znM&list=UU3LlvEUT4Bc9jKG8Xrmuf_g https://www.youtube.com/watch?v=sbiq_yd- znM&list=UU3LlvEUT4Bc9jKG8Xrmuf_g

7. Wind power  1. The winds energy originates from the uneven heating of the earth’s surface.  2. The sun’s rays heat the poles at an angle which creates large scale currents in the atmosphere.  3. Early wind mills were used to pump water for cattle.

8. Wind power  4. Inexpensive electricity put most windmills out of business.  5. Like solar wind as a resource is erratic.  6. Wind generated electricity can be stored in batteries.  7. Most effective systems have interconnected machines that averages power over a large area.

9. Water power  Water power- we are already using a large percent of our available hydropower.  1. Growing interest in using the energy available from small dams and from undammed flowing water.  2. Would use small turbo generators

10. Biofuels  1. The energy released by the direct combustion or the conversion of biofuels into solid, liquid, or gas fuels.  2. The by-products can be used for food, fertilizer, and chemicals.  3. Biofuels can be used to produce electricity, heat, steam, and transportation fuels.  4. Sources of biofuels include- forest products, agriculture and food processing wastes, municipal sewage and solid waste

11. Biofuels in our future  1. Most biofuels are made from sugar cane and corn.  2. The process is that sugar is converted by yeast to produce ethanol and carbon dioxide  3. Corn is not a practical source since it competes with food crops  4. cellulose is a good source and is found in biomass waste from forests and fields, fast growing hays like switch grass, and woody crops like poplar.  These crops can grow in areas that don’t have to be plowed and help with soil erosion  5. Bio enzymes break these down and yield more energy then corn

12. Biofuels in our future

13.  https://www.youtube.com/watch?v=QegyXo5u9uI