Beautiful, graphic rich slides to engage students based on Essential Environment by Withgott and Laposota. Slides cover Chapter 16 Renewable energy resources
2. Germany Goes Solar
• Germany gets less sun than Alaska
• World’s largest solar technology user
• Feed-in tariff system, where utilities are required to buy power from
anyone who can generate power from renewable energy sources and
feed into the grid
• Premium prices for this power under contract
• Germany also world leader in wind power
• Per person, Germany is #1 for all renewable power sources
• CO2 emissions in Germany have fallen 24%
3. • Only 9% from
renewables
• For electricity, 12.9%
is renewables
• Hydroelectric power
already well
established
4. “Perpetually
Renewable” Sources
• Sun
• Wind
• Geothermal
• Relatively new technologies
• Will be more important in future
• Already established renewables include:
hydropower and bioenergy- mostly wood
5. Renewables are good for our climate, release
far fewer greenhouse gas emissions
6. “Green Collar Jobs”
• 6.5 million people work in renewable jobs around the world
• Sweden decreased fossil fuel use, with 60% of its energy
from non-greenhouse gas polluting sources
• Germany
• Wealthy and advanced economies can thrive with switch to
renewables
7. Gov’t Policies can
accelerate transition… but
will it ever happen?
• Feed in tariffs like those in Germany can speed
the transition to renewables
• As of 2014, 29 states had set targets for
renewables use
• Economics of renewables is erratic
• Markets are volatile, policies vary place to
place
• Oil and gas received 75 times more subsidies,
nuclear 31 times more subsidies than new
renewables
8. Solar Energy
• Daily solar energy per roof
per day could power most
homes
• Passive solar collection-
buildings designed to
maximize absorption of
sunlight in winter, but stay
cool in summer
• Overhangs, south facing
windows, vegetation, thermal
mass materials that trap and
store heat to release later
(straw, brick, concrete)
• Conserve energy, reduce
costs
9. Active Solar Collection
• Devices focus, move, or store solar energy
• Example: Flat plate solar collectors consist of
dark heat absorbing plates
• Water, air, antifreeze run through tubes that
pass through collector and transfer heat to
building or water tank.
10. Concentrated
Solar Power (CSP)
Plants
• Large centralized facilities
generate electricity
• Transmit to homes and
businesses through
electric grid
• High environmental
impacts- land cleared,
maintenance requires
water
• Huge potential for energy
production
11. Photovoltaic (PV) Cells:
Sunlight to Electricity
• Sunlight strikes pair of plates made of silicon,
a semiconductor
• Light causes one plate to release electrons,
attracted to opposite plate by electrostatic
• Wire connects the two plates, allowing
electrons to flow back to original plate,
creating a current (DC) converted to
alternating (AC) for residential and
commercial electric power
• Experimenting with thin sheet- cheaper but
less efficient
• But good for many surfaces including highways
12. Net Metering
• Homeowners sell power to their utility
• Value of power is subtracted from utility bill
• In Germany, a feed-in tariff pays producers
MORE than the market price, so producers
may turn a profit.
• Or PV can be connected to a battery to store
the charge.
13. Solar Benefits
• Have another 4-5 billion years of
sunlight
• Sunlight is enough to power all
society if we harness it
• PV cells are quiet and safe, last
20 to 30 years
• Decentralized, local control over
power
• New jobs! Employ 2.3 million
people worldwide
• No greenhouse gas emissions or
pollutants
• Manufacture does require fossil
fuels, but once running, no
emissions
14. Drawbacks:
Location, timing,
cost
• Not all regions are equally
sunny
• But Germany is successful
• Intermittent- daily or seasonal
variation in sunlight
• Cost of equipment is high-
most expensive way to produce
electricity right now
• Prices are declining and pay for
themselves in 10 to 20 years,
then provide free energy
15. Solar Energy Expanding
• Now just 0.33% of US energy supply
• 0.2% electricity generation
• Even in Germany, only 5%
• Grown by 30% a year.
