Using energy source rankings (data from Capers Jones), we propose three ways to analyze the data and prioritize which energy sources will be right for 2050.

1. Deciding Which Energy Sources to
Develop for 2050
Data from Capers Jones
Data File: ElectricRankings2013.xlsx

2. The Energy Sources Data Set
 The data set consists of 24 energy sources
 Each energy source is evaluated against the following attributes with ranks
assigned to each attribute:
 Cost in 2013
 Cost in 2050
 How green the source is
 How reliable the source is
 How safe the source is
 How amenable the source is to being a high capacity energy source
 The energy source’s risk of attack
 Whether the source is good for Rhode Island
 The ranks go from 1 to 24. For all attributes, we assume that the lower the
numerical value of the rank, the better.
 NOTE: The analysis below uses the ordinal ranks; however no real decision
can be made until we have cost information and a ranking system that is not
just ordinal but also on a ratio scale.
 THE CONCLUSIONS IN THIS REPORT ARE PRELIMINARY; ACTUAL
COST AND RELATIVE RATIO OF DIFFERENCE BETWEEN RANKS ARE
REQUIRED TO FINALIZE THE ANALYSIS.
2

3. Three Potential Approaches
1. Sequential Filtering: In this approach we begin with the
most important attribute (say, being green). We filter
using this attribute discarding sources that have low
green ranks. Then we filter with the next most
important attribute (say, the cost in 2050), and so on
until we arrive at a set of energy sources that survive all
the filters. These then are the sources for further study
and development.
2. Global Optimization: In this approach we take all the
attributes at once with each attribute rank set above a
given threshold. Think of it as a multi-dimensional Venn
diagram. The sources that are in the overlap space of
this Venn diagram are the sources for further study and
development.
3. Hybrid: In this approach we start with one or more
sequential filters and then use global optimization to
make recommendations about how to proceed. This is
the approach used in this analysis.3

4. How do the sources compare on cost and
greenness?
4
The scatter plots above show a source’s green ranking (stays constant from one plot to the
other) compared to costs in 2013 (left) and costs in 2050 (right). Only a handful of sources
are green; some of these sources become more expensive in 2050 (e.g. Hybrid) while some
become cost effective in 2050 (e.g. Solar Organic).

5. Relative Differences
in Cost Rankings
o For each energy source, the rank for cost in
2013 is below the axis and the rank for cost
in 2050 is above the axis.
o The chart allows us to easily see which
sources have the most drastic change in
their costs.
o The cost of Fusion (the rightmost bar) goes
from being the most expensive in 2013 to
least expensive in 2050.
o Let’s pick the 12 sources with the lowest
cost ranks (1 to 12) in 2050 as well as the 5
sources that have the most dramatic drop
in costs (6 rank drop or lower) from 2013 to
2050.
o These sources are the ones that survive
our first filter and are circled in the legend
below left.
5
2013 Cost Rank
2050 Cost Rank
Sequential Filter 1: Cost

6. Sequential Filters 1& 2 & 3: Low Cost &
Green & Good for Rhode Island
6
The energy sources that pass through filters 1, 2
and 3 are the following:
o Hydro
o Geothermal
o Solar Silicon
o Small Land Windmills
o Solar Organic
o Tides
o Waves

7. How do the sources compare on reliability &
high capacity and safety & risk of attack?
7
The scatter plot on the left indicates sources outside the yellow rectangle as ones whose
reliability and capacity require improvement. On the right we see that except for Waves all
the sources are already good with respect to safety and risk.
Action 2: Increase
the prevalence of
these energy
sources
Action 1: Improve
the capacity and
reliability of these
energy sources
Action 3: Improve
the safety of Wave
energy