• Ian Sutton

Evaluating Alternative Energy Sources

There seems to be no end in the number of ideas that are trotted out for generating “green energy”, for storing energy and for capturing greenhouse gases from the atmosphere. We need a means of evaluating them using some type of Pareto analysis, i.e., some way of differentiating the important few from the unimportant many. We all have limited time, energy, resources and enthusiasm. Some type of screening process is needed.

One approach would be to assess each proposed alternative energy source in the following five ways:

  1. Reality Check

  2. Assessment

  3. Project Phase

  4. Energy Properties

  5. HSE

Reality Check

The first step in an evaluation is to conduct a basic reality check, referred to colloquially as the “red face” test. Does the proposed idea make sense? For example, hydroelectric power from dams is clean, available 24/7 and has low operating costs. However, there are very few suitable sites available for new construction so it is unrealistic to expect hydropower to meet our vast appetite for energy in the coming years. So, in this sense, hydroelectric is not a realistic option.

Other energy sources do, however, pass this test. For example, ammonia as a fuel is certainly a realistic option. There is already a world-wide infrastructure for this chemical and industry has plenty of experience in handling it.


As assessment provides a high-level overview of each energy source. Factors to consider are shown in the following Table.

Evaluation of alternative energy sources

We will discuss the parameters in this Table in future posts.

Project Phase

The alternative energy sources to be considered are all at different phases of technical and commercial development. In order to understand their status and to manage their ongoing development it is useful to place each of them within the framework of a Phase-Gate diagram.

A very simple example of such a diagram is shown below. Once more, we will discuss the elements of this sketch in future posts.

Project evaluation of alternative energy sources

Energy Properties

In order to provide a rational means of evaluating the energy choices it is useful to summarize the chemical and physical properties of each, thus allowing them to be readily compared with one another.

The following Table provides an example of such a summary for the base fossil fuels.

Properties of alternative energy sources


Each potential energy source needs to be evaluated for Health, Safety and Environmental issues. A convenient and sensible way of doing this is to use the NFPA 704 Safety Diamond.

NFPA 704 Safety Diamond for evaluating safety of alternative energy sources.

Energy Sources

The above techniques can be used to understand the opportunities and limitations of the following energy sources and energy management technologies.

  • Biofuels;

  • Solar;

  • Wind;

  • Hydrogen;

  • Ammonia;

  • Nuclear (fission and fusion);

  • Hydroelectric;

  • Geothermal;

  • Ocean energy;

  • Carbon capture and sequestration;

  • Geoengineering; and

  • Energy storage.