Human impact on ecosystems

Kingston fossil plant Ash spill (2008)

Carbon cycle

Pros Cons

Non-renewable finite resource

Environmental pollution

Dependence on foreign supply

Global climate change

Fossil-fuel based infrastructure

Cheap fuel = social stability

Pre-industrial revolution anyone?

The instability of a fossil fuel economy

Novel innovations for alternative energy

Wind energy Solar energyCellulosic ethanol

Electric carsHydrogen fuel cells

Group activity:Rank the following alternative energy technologies

from most promising (best) to least promising (worst)

• Biodiesel• Hydrogen fuel cells• Electric cars (Lithium ion batteries)• Cellulosic ethanol• Wind • Geothermal• Solar

One problem with electric cars

Lithium is also a finite resource that is mined from salt flats

Nissan LeafChevy Volt Lithium ion battery

Lithium salt mining in Bolivia

>50% (estimated) of the world’s lithium lies in Salar de Uyuni

Evo Morales: President of Bolivia

Ethanol as a renewable fuel?

MTBE

Government support for more E85 pumps (85% ethanol, 15% gasoline)

• Government announced Friday 10,000 more E85 pumps in the next 5 years

• "Flex-fuel pumps will give Americans a choice to purchase domestically produced renewable transportation fuels.“- US Agriculture secretary Tom Vilsack (Friday, April 8, 2011)

Overview of Brazil sugarcane ethanol• ~8 million hectares• Supplies 40% of

Brazil transportation fuel

• Brazil wants to expand to 40 million hectares

• Currently only the sugar part of cane is used (14% of mass)

• Brazil will likely become an ethanol powerhouse

1 hectare = 2.47 acres

Plants are mostly made up of sugars

Why Cellulosic Ethanol?

Why Switchgrass?• Native grass to US• Perennial crop• Requires little to

no fertilizer• Can be grown on

marginal land• Use hay bail

machinery• Farmer income• No erosion• Large fleet of E85

vehicles on road• Pilot biorefinery

in Vonore, TNhttp://www.wbir.com/news/local/story.aspx?storyid=112598

Miscanthus giganteus stand growing for 10 years never fertilized or irrigated

Ethanol: The bad news

• Food vs. fuel vs. feed agricultural land• Absorbs water – 2006- present many complaints

about engine damage with E10 (found to exceed)• EtOH requires 42X more water than gasoline• Energy density is 2/3 that of gasoline• Logistics of moving large amounts of biomass• Calculations of cost-benefit are VERY complicated– However, technology is so IMMATURE that these

numbers are meaningless

Algae as a renewable source of ethanol and biodiesel

Algae for ethanol and biodiesel: infrastructure costs too great

Survival of the human species depends on our ability to capture energy in a way that is sustainable

We should start planting fields of switchgrass everywhere so we can fuel our cars on renewable fuel

• Without talking to your neighbor, do you agree or disagree?

• Write all of your reasons for your position (one per sticky note) No talking!

It is BETTER for the U.S. government to invest more money into DEFENSE than into ENERGY

• Without talking to your neighbor, do you agree or disagree?

• Write all of your reasons for your position (one per sticky note) No talking!