Why the need for Alternative Energies?

• Based on known oil reserves and the worldwide consumption rate, most estimates suggest this reserve has only 50 more years of production left in it.

• In the US, 89% of our total Energy Budget is Fossil Fuel Based

• Fossil Fuel combustion represents a global environmental problem

• Most alternative energy sources have little polluting side effects

Energy Needs:

Electricity Generation, Space Heating, Transportation dominate our uses of energy. Most traditional Energy production comes about via steam driven turbines so the heating of water is what is essential.

• Coal Fired Steam Plants
• Nuclear Fired Steam Plants
• Oil/Natural Gas Fired Steam Plants

The choices are:

• Invest in discovery of new oil reserves (e.g. Off-shore, shale oil)
• Invest in Clean Coal Technology as 20% of the worlds supply of Coal is in the US
• Invest in Alternative Energies

Every form of energy generation has environmental fall-out. Can we pick the best one globally and or locally. As long as the decisions are driven by "voodoo" economics (i.e. heavy subsidy), intelligent decisions are not likely to occur.

Most forms of alternative energy genearation require much less of an organizational infrastructure. This means that a shift to alternative energies means a loss of jobs.

Objective Evaluation Criteria for Alternative Energies:

• Capital Costs
• Operating Costs
• Efficiency
• Is it renewable?
• Energy Storage Requirements
• Pollution
• Environmental Modification
• Levelized cost to the consumer
• Feasibility on Large Scale
• Individual Homeowner Independence
• Unit Capacity

Forms of Alternative Energy:

Note: Currently we have no significant production line alternative energy source operating anywhere in the US!

• Solar (PV or Thermal)
• Hydro
• Wind
• Geothermal
• Ocean Thermal Energy Conversion (OTEC)
• Tidal Energy
• Biomass Burning
• Nuclear Fusion: --> Forget it, we aren't smart enough yet.

  Comparative Table
  

  Evaluation	Solar Thermal	PV	Hydro	Wind	OTEC	Tidal	GEO	Biomass
  Capital Costs	Large	Large	Enormous	Moderate	Enormous+	Enormous	Small	Small
  Operating Costs	Moderate	Small (replacement panels)	25--30% of Coal fired steam plant	Small	Unknown	Small	Neglegible	Small
  Efficiency	15%	5--10%	80%	42%	7% +	25%	100%	0--25%
  Renewable	Yes	Yes	Yes	Erratic	Yes	Yes	NO	unclear
  Storage	Not Needed	Unclear	Built-IN	Essential	Not Needed	Unclear	Not Needed	Not Needed
  Pollution	None Really	Waste Heat	None	Visual	None	None	Steam Plumes	Smoke and Particulates
  Levelized Costs	25 cents KWH	16 cents KWH	4 cents KWH	4.5 cents KWH	Unknown	Unknown	Low	Unknown
  Environmental Impact	Moderate	Large	Enormous	Small	Unknown	Outrageous	Small	Moderate
  Large Scale	Too Expensive	Possible but Expensive	Proven already	Very Possible	The Solution	Discrete Locations	Discrete Locations	Possible but Expensive
  Small Scale	Rooftop Water (heating)	Difficult (shingles)	Low Head --> Legal	Definitely	NO	NO	NO	Definitely
  Unit Capacity	1000 MW	Depends on Acreage	2000-6000 MW	Highly Variable	As large as you need	250 MW	1000 MW	A Few MWs

What about Energy Storage?

Options:

• Battery Farms:
  • Acres of batteries; charged by transmission lines during periods of low demand
  • Returned to transmission lines during periods of high demand
  • Designed for load levelling
  • One Acre could store about 400 MW-hours of energy and deliver 40MW of power (for 10 hours)

  We need better batteries period (also for electric vehicles): US is investing in this

• Pumped Hydro:
  • Not many locations lend themselves to this
  • Process is 64% efficient which is pretty good

• Flywheels:
  • Need to optimize energy-to-mass ratio which is material dependent
  • Fused Silica has 25 times the energy storage per kg than lead-acid batteries
  • Flywhees are promising

• Hydrogen
  • Very high energy density storage per kg
  • No naturally occuring sources
  • Separate H from H₂0 is energy intensive
  • Not economically viable unless shipped large distances from point of production

• Compressed Air
  • Thermodyanimcs tells you that when you compress air the temperatur goes up --> melts the pressure containment vessel
  • Have to cool the air as its compressed --> energy intensive
  • Not very practical

Bottom line(s):

Wind energy coupled with advanced battery design has real promise.

OTEC provides a truly large scale solution

Solar PV does not look economically viable

As of 1997 there remains little incentive to not look for new oil reserves