Period 25: Energy from Wind and Biomass

Transcription

1 Name Section Period 25: Energy from Wind and Biomass Activity 25.1: Causes of Winds 1) The Earth s winds a) What causes wind circulation from the equator to the high latitudes? b) What causes these north-south winds to be deflected to the east or west? c) On a sunny day, which surface heats more quickly land or water? Which surface cools more quickly at night? d) What causes land and sea breezes? What role do convection currents play? e) Your instructor will demonstrate land and sea breezes. Does this demonstration represent a daytime breeze or a night time breeze? Activity 25.2: Generating Electricity from Wind Power 2) Generating Electricity from Wind Your instructor will demonstrate a model windmill electric generator. a) How can the moving blades of a windmill generate electricity? b) What types of locations can provide the most wind power? 1

2 c) What are the advantages of generating electricity using wind power? d) What (if any) are the environmental concerns about using wind power? e) Group Discussion Question: Why are there often objections to the installation of wind farms from local residents? Activity 25.3: Payback Time 3) Payback Time for the Cost of Electricity Some locations have sufficient wind power to use a windmill to generate electricity for home use. a) If a backyard windmill could generate an average of 628 watts of power (0.628 kilowatts), how many kilowatt-hours of energy could this windmill generate each year? b) Suppose that you have been given the choice of purchasing electricity or generating your own electricity using a backyard windmill. Answer the questions below to find how much money could you save in 10 years by using the windmill as your only source of electric power. 1) If electricity costs $0.12 per kilowatt hour and you use 5,500 kwh per year, how much would you pay for purchased electricity for ten years? 2) If the windmill costs $3,000 to purchase and install and $200 per year for upkeep, how much would it cost you to generate your own electricity for ten years? 3) How much money (if any) would the windmill save you after 10 years? 4) Is the payback time for the windmill more or less than 10 years? 2

3 Activity 25.4: Energy from Biomass 4) Using Biomass for Energy a) What is biomass? b) What are the common types of biomass used as biofuels? c) How can biofuels be produced from algae? d) How can biofuels be produced from animal waste? 4) Bioethanol and biodiesel used for transportation a) What is bioethanol? b) Much gasoline contains some ethanol; for example, E85 is 15% ethanol. What advantage does E85 have over straight gasoline as a vehicle fuel? c) What economic consequences are there to using large quantities of corn to produce ethanol for vehicle fuel? d) How does biodiesel differ from bioethanol? e) Group Discussion Question: Does the combustion of biodiesel and bioethanol produce greenhouse gases? 3

4 Activity 25.5: The Carbon Cycle 5) The Carbon cycle a) What is the carbon cycle? b) Where is carbon sequestered (stored) in the environment? c) What activities add carbon to the atmosphere? d) What activities remove carbon from the atmosphere? 6) The Carbon Budget a) What is the Earth s carbon budget? b) What are carbon dioxide sinks? c) What are carbon dioxide sources? d) What role do the oceans play in the carbon budget? e) Group discussion Question: How have human activities changed the balance of the Earth s carbon budget? 4

5 Name Section Period 25 Exercises: Energy from Wind and Biomass 1. Explaining land and sea breezes: a) If you visit a beach on the sunny day, would you expect to feel a breeze blowing from the shore out to the water, or from the water into the shore? Draw a diagram that explains your answer. b) At the same location at night would you expect to feel a breeze blowing from the shore out to the water, or from the water into the shore? Draw a diagram that explains your answer. 2. Calculating payback time for a hybrid vehicle: A fuel-efficient hybrid car costs $3,000 more than a less efficient model. The hybrid car gets better gas mileage and saves you $600 per year in fuel. In how many years will you be paid back in fuel savings for the extra $3,000 you spend to purchase the hybrid car? 3. Calculating payback time for a windmill: Suppose you live in such a windy place that a windmill attached to your house can generate all of your electricity. a) Purchasing electricity from the electric company would cost you $600 per year. Maintaining your windmill costs $100 year. How much money do you save each year by using your windmill? b) Suppose the windmill costs $5,000 to purchase and install. How many years must you use the windmill before you are paid back for the purchase and installation cost of the windmill? 5