BY C KOHN, WATERFORD WI

Choosing the Better Fuel: Life Cycle Assessment

Saltwater Power?

Watch: http://www.youtube.com/watch?v=JiKa4nOkHLw&feature=player_detailpage

So, are we good? Do we even need petroleum, biofuels, or other sources of energy?

Why hasn’t this changed our lives already?

What Powers Saltwater Power?

Watch again: http://www.youtube.com/watch?v=JiKa4nOkHLw&feature=player_detailpage

This time, ask yourself the following: What powers the “Radio Frequency

Generator” that cause the saltwater to burn?Are the energy gains from this ‘fuel’ greater

than the energy losses?What makes a good fuel, and is this a ‘good

fuel’?

Saltwater Bust

Clearly the energy to create the “Radio Frequency Generator” must be a lot, given the size, noise, and intensity of the machines used.

It might be safe to say that if the energy needed to power the machine comes from fossil fuels, this may not be such a great method for creating energy.

Case in Point: wouldn’t it be more energy-efficient just to put the fluorescent bulb into a standard light fixture rather than power it with the big honking machine?

Life Cycle Assessment

For a fuel to be a “good” fuel, it should produce more energy than it consumes. In other words, the energy needed to make a fuel should be

less than the energy produced by the fuel. Reminder – we don’t “create” energy – we only change it into a

different form. Energy is not the only concern – we must also

consider the following: Is it sustainable – i.e. can we continue to use it year after year

without harming our society, planet, or bodies? Is it economical – can we make money producing it, or will it

ultimately harm our economy? Is it practical – can we use it without completely changing the

way our society functions?

Life Cycle Assessment

Life Cycle Assessment is the process in which we examine and measure all the inputs and outputs of a process. Input – what we lose in making a product Output – what we gain in making a product

Life Cycle Assessment is simply a way to measure the value or harm caused by using a product

For example, if you spent $10 to buy supplies for your lemonade stand but only made $5 selling your lemonade, a Life Cycle Assessment(LCA) would indicate that this was probably poor choice. Inputs in exceeded Outputs gained i.e. Total Cost exceeded Total Benefit

Life Cycle Assessment

LCAs can be used for just about any product. For example, you could perform an LCA on a DVD

LCA in a Nutshell

LCA Exercise

Briefly, perform an LCA Exercise to determine which is better – bottled water, or tap water?

For each option, list the following: What material inputs are necessary for each to be

consumed? What transportation inputs are necessary? What energy or electricity inputs are necessary? What are the hazardous outputs of each? What are the nonhazardous outputs of each? Which is better? How do you know?

LCA of Tap vs. Bottled Water

Inputs – Tapwater Freshwater Pipes (materials,

energy to manufacture, pollution from extraction).

Pumps (energy) Filtration & treatment

(energy) Dirty glass (energy to

wash)

Inputs – Bottled Water Freshwater Filtration & treatment

(energy) Petroleum for plastic

in bottle Energy to produce

bottle Pumps (energy) Transportation

(energy)

LCA of Tap vs. Bottled Water

Outputs – Tapwater Greenhouse gases

from energy used to filter, pump, and move water

Possible pollution from detergents used to wash drinking glass

Water

Outputs – Bottled Water Greenhouse gases from energy

used to filter, pump, move, transport, and refrigerate water

Greenhouse gases from production of bottle

Greenhouse gases from movement of petroleum needed for the bottle

Landfill waste from 4/5s of bottles that are not recycled

Pollution from dyes, treatments, and packaging used to produce, sell, and market bottled water.

Water

LCA Exercise II

Perform the same analysis for Ethanol and Gasoline

LCA –Ethanol (energy)

Figure 1—Life Cycle Assessment of Energy for Ethanol Production and Consumption. (GLBRC.org)

LCA – Ethanol (carbon)

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