Sustainability has been defined as meeting the needs of today without sacrificing the ability of future generations to meet their own needs.  The needs within this definition are further broken down into three categories:

1. Environmental
2. Economic
3. Social

I began with this basic concept in an attempt to evaluate the sustainability of nuclear power to support my fellow bluetape.org writer B. Ellis’s article Nuclear Issues in N. America.  As an engineer by training, instinctively I attempted to calculate and quantify a ranking for eight alternative energy sources.  This seemed like a great idea until it was time to find a way to quantitatively analyze each source for each sustainable category (environment, economic, social).  Using environmental needs as an example, I began by looking at CO2 emissions as an environmental sustainability indicator and ranked each source on their emissions of CO2 per unit output of energy.  Subsequently, by referencing the World Energy Report as a source, I was able to form the following list:

1. Nuclear
1. Solar
1. Hydro
1. Biomass
2. Natural Gas
3. Oil
4. Coal

This seems like a reasonable analysis if CO2 emissions are considered as the governing environmental concern.   However, if the disruption of natural ecosystems was considered the governing environmental concern the list could look as follows:

1. Nuclear
1. Oil
1. Natural Gas
1. Coal
2. Biomass
3. Solar
4. Wind
5. Hydro

Both of these lists could be considered equally accurate, making it difficult, if not impossible, to create one, quantitative sustainability ranking.  This difficulty forced me to suppress my engineering mindset and to look for another form of analysis.  I decided to unburden myself of this difficult task and pass the problem to a panel of experts.  This diverse panel of 22 experts consisted of professionals, students, politicians, teachers and engineers from many parts of the world including Sweden, Finland, Canada, USA and Korea.  The panel was asked to call upon their personal expertise and consider the following question:

“Considering Sustainability to be defined as:

meeting the needs of the present without compromising the ability of future generations to meet their own needs.

 The needs to consider within this definition are:

1. Environmental
2. Economic
3. Social

Give the following energy sources a rank from 1 to 8 with 1 being the most sustainable and 8 being the least.  Please do not tie any of the sources.”

An example response (mine) is as follows:

The results of all the expert’s opinions were tallied to give each energy source a “Sustainable Score”.