renewable energy

Energy Efficiency and Renewable Energy

Chapter 18Living in the Environment, 14th edition, G. Tyler Miller

-What is energy efficiency?Miller says we waste about 43% of our

energy unnecessarily.-Why worry about it?

-Do you consider energy conservation and/or efficiency in your house?

“Tired of heating or cooling an empty house while you're away? In about an hour, you can be on your way to a more comfortable home. Depending on the model you select, you can program day and night temperatures and even a setting for every day of the week. You'll be more comfortable with your heating and cooling bill too. Lowe's is happy to provide this information as a service to you.”

http://www.lowes.com/lowes/lkn?action=howTo&p=Improve/ProgramThermostat.html

What’s a renewable energy source?

What are some examples we can think of?

http://rredc.nrel.gov/ http://en.wikipedia.org/wiki/Renewable_energy

Making our homes & offices more efficient

• Sears tower consumes more energy in a day than a city of 150,000 people! (Miller)

• Super insulation, plug leaks!• Use heat from the sun• Energy efficient windows• Landscaping, roof top gardens• Miller gives lots of other ideas in our text• The ING Bank in Netherlands, uses 92% less energy than a conventional building of its size

http://www.rmi.org/images/PDFs/BuildingsLand/D92-21_NMBBankHQ.pdf

http://www.eere.energy.gov/consumer/

How can we fuel our cars?• Hybrids?

– Gasoline, diesel or natural gas & battery– 30-300! mpg– Lower emissions

• Fuel Cells? http://world.honda.com/FuelCell/ – H2 will have to be generated– Efficient, 2H2 + O2 → 2H2O– No moving parts, low maintenance– Get the costs down– http://www.howstuffworks.com/fuel-cell.htm

• E85 1)http://www.gm.com/company/onlygm/energy/index.html

2) http://www.e85fuel.com/e85101/faqs/e85.php?topic=E85101

More about ethanol…• CH3CH2OH

• Made from sugar, corn & other grains by fermentation

• Have you heard of gasohol? (10-23%) reduced emissions of CO2 and CO potentially renewable net energy loss, higher cost may compete with growing food corrosive, harder to start car in cold weather

• Also read about methanol CH3OH

• http://www.open.ac.uk/T206/photos/220594-1f1.24.jpg

Renewable energy for heat and electricity

• Passive solar• Active solar• Solar thermal• Solar cells• Hydropower• Wind power• Biomass• Ethanol• Geothermal• Hydrogen

http://www.fi.edu/guide/hughes/images/renewable.gif

Renewable energy provides 16% of world’s energy in the world and 6%

in the U.S.• Miller says renewable resources haven’t

received tax breaks, subsidies and R & D funding as fossil fuels and nuclear power have.

• Prices we pay for fossil fuels & nuclear don’t include environmental & health costs

http://www.eere.energy.gov/femp/technologies/renewable_fedrequire.cfm

Wind Energy!• Mendota Hills Wind Farm

http://www.windpower.com/projects_detail.cfm?ProjectID=19

• Global Wind energy• http://www.windpower.com/windpower.cf

m• http://cr.middlebury.edu/es/altenergylife/

windpower.htm

Solar energy…a myriad of possibilities

• Passive solar…absorbs and stores heat directly…use with good insulation

• Need access to the sun• Need heat storage system• Back up system?

Active solar heating….

• Uses heat absorbing fluids and pumps

• Popular for heating water in homes• High set up costs, high maintenance

and unappealing appearance

http://www.greenenergy.org.uk/sta/solarenergy/howwork.htm

• Solar thermal systems– Collect and transform radiant energy

from the sun into heat, used directly or converted to electricity. Used in desert areas.

– Sunlight collected and focused on solar collectors. High temps produce steam to run turbines for electricity.

– These need backup systems or storage, high cost of installation, high land use

Photovoltaic cells (PV)• You’ve seen them in calculators• Quick installation and can be moved;

installed on roofs so little land use

• Low environmental impact, no CO2

• Long lasting, no moving parts

need backup systems high costs currently

http://www.schools.sandwell.net/emu/bowater/bowater2/Primary/solarcells.htm

http://www.co.monroe.fl.us/solar-cells-op.jpg

Hydropower• Works based on water flowing from high to low

elevations • Controlled by dams and reservoirs and used to

spin turbines & produce electricity• 20% of world’s electricity • Very efficient, low cost electricity• No air pollution or waste disposal• High construction costs• Alters animal habitat• Danger of collapse• Large dams high environmental impact

http://water.usgs.gov/watuse/graphics/hymap.st1.color.gif

»

http://www.tva.gov/power/hydroart.htm

http://www.brattle.com/_documents/Expertises/Expertise67.gif

http://ga.water.usgs.gov/edu/hyhowworks.htmlAnimation at this site! Go there!

Energy from biomass

• Plant & animal wastes burned to provide heat or electricity

• Wood logs, pellets, wood chips, branches• Agricultural waste• Animal dung• “Urban waste” = garbage; cardboard and paper,

wood waste• Used for heating, cooking, industrial processes or to

create steam to power turbines for electricity• Some argue that that the wastes should be left to

feed livestock, recycle into the soil, prevent erosion• Biomass can also be converted to biogas (methane

and CO2) use bacteria and chemical processes to do this.

http://www.gocpc.com/Images2/Biomax/Biomass%20Residues.jpg

Geothermal: energy from the earth

• http://www.enecho.meti.go.jp/english/energy/geothermal/images/43.gif

http://www.eia.doe.gov/cneaf/solar.renewables/page/geothermal/geothermal.gif

more on geothermal….http://www.eia.doe.gov/cneaf/solar.renewables/page/geothermal/geothermal.gif

•Low environmental impact; we’re tapping natural heat sources such as volcanic rock, geysers and hot springs.

•Energy efficient and cost effective

•1% of world’s electricity

Cost is high so source must be concentrated and accessible

Reservoirs can be depleted if heat is removed faster than resupplied.

•Chevron graphic to see how geothermal works…. http://www.chevron.com/stories/#/stories/re_geo/geo_ov/?gclid=CNWv7LKYy48CFQM-IgodE0nX0w/ another animation http://www1.eere.energy.gov/geothermal/gpp_animation.html

Hydrogen…a fuel of the future?

• 2020-2030

• 2H2 + O2→ 2H2O

• We’ll need to make the H2

high costs right now no fuel distribution system in place

No green house gasesSafe, nontoxic, nonpolluting, itself.

http://www.bmwworld.com/pics/7er/7350_1024.jpg

So what of the future?• Wide variety of sources…no one answer• http://www.pdm-group.co.uk/renewable_energy/

energy_generation.html

• What’s the energy policy in this country?• How does politics play into this?• Aging electrical grid system• What can YOU do? • www.campaignEarth.org• http://www.eere.energy.gov/consumer/