Comparing Support and Opposition
The survey we created and distributed regarding solar development in the California desert provided a lot of raw data, which had to then be processed using a range of statistical methods. This section provides details regarding the types of statistical analysis that we employed and how this analysis allowed us to compare the responses from those who support utility-scale solar in the California desert and those who oppose this type of development.
A series of two-sample t-tests allowed us to determine the issues for which the two groups’ opinions were statistically different, the degree of those differences, and the directional orientation of each group with respect to the median (Table 1). In our analysis, statistical significance was determined by the two-tailed p-value. Degree of difference was measured by difference between the two mean values. Orientation was measured by where the mean response fell with respect to the median option, in other words, greater than or less than three on our 5 point scale. For instance, mean responses below three for the third question — “How likely do you think the following outcomes will be if a utility-scale solar facility is constructed near your town?” — denotes “not likely to happen.” In this example, a zero would indicate “will not happen” and a three would indicate “equally to happen as not to happen.”
| Two Sample t-Test Results | ||||||
|---|---|---|---|---|---|---|
| Supporters | Opponents | |||||
| Likelihood | Value | Likelihood | Value | Differential* | P-Value* | |
| Construction Jobs | 4.45 | 4.41 | 3.51 | 3.54 | -0.87 | 2.42 x 108 |
| General Jobs | 4.33 | 4.41 | 3.3 | 3.61 | -0.8 | 3.29 x 107 |
| Less Fossil Fuel Use | 3.59 | 3.89 | 2.87 | 3.32 | -0.57 | 5.74 x 104 |
| Bigger Budget | 3.61 | 3.95 | 3.14 | 3.29 | -0.65 | 3.06 x 105 |
| Increased Business | 4.07 | 4.34 | 3.31 | 3.47 | -0.86 | 1.39 x 108 |
| More Energy | 4.34 | 4.59 | 3.44 | 3.67 | -0.93 | 1.07 x 109 |
| Supporters | Opponents | |||||
| Likelihood | Concern | Likelihood | Concern | Differential | P-Value | |
| Less Housing | 1.81 | 1.63 | 1.97 | 1.85 | 0.22 | 0.0956 |
| Less Habitat | 2.42 | 2.68 | 3.35 | 3.64 | 0.96 | 1.45 x 108 |
| Poorer Air Quality | 1.56 | 2.53 | 2.45 | 3.38 | 0.85 | 2.18 x 106 |
| Less Recreation | 1.95 | 2.16 | 3.05 | 3.25 | 1.09 | 1.08 x 109 |
| Less Water | 2.01 | 2.89 | 3.15 | 3.79 | 0.89 | 2.75 x 107 |
| More Traffic | 3.31 | 2.25 | 3.75 | 3.15 | 0.9 | 6.56 x 108 |
| Site Damage | 1.92 | 2.37 | 2.82 | 3.46 | 1.09 | 9.3 x 1010 |
| Viewshed Impact | 2.05 | 2.12 | 3.14 | 3.31 | 1.18 | 1.1 x 1010 |
Across every category, those who were classified as supporters of solar believe that the positive outcomes are more likely to happen than do those who oppose solar, and vice versa. The most divisive issue was water, where opponents believe utility-scale solar might lead to less water (3.15 out of 5) and supporters believe it is far less likely (2.01 out of 5). Water was followed by viewshed impact, where opponents believe that the scenery might be impacted (3.15 out of 5) and supporters believe it is far less likely (2.04 out of 5). Less housing was the only outcome option that did not show statistical significance in opinion between the two groups. The questions that followed asked respondents to rate their degree of concern for and degree of value placed on potential outcomes: supporters were far less concerned about the potential negative outcomes and place more value on the potential positive impacts. In terms of greatest concern, the biggest differential was viewshed impact, where opponents consider it somewhat concerning (3.30 out of 5) and supporters of solar were less concerned (2.12 out of 5). However, the issue of greatest concern to opponents remained water (3.78 out of 5). In terms of value, supporters and opponents disagreed most on the value of more energy to their communities. Neither group, however, reported to find little value in any of the potentially positive impacts — all mean responses were greater than three.
Given these results, it seems as if opponents of solar differ the most from supporters in their concern over water resources. Habitat and viewshed appear to be close behind. For their part, supporters seem to value the potential increase in the availability of energy, more jobs, and greater commercial activity. Given that all mean responses to issues of concern fall below 3 on a 5 point scale, supporters appear to be generally optimistic whereas opponents tend to be more cynical of the positive outcomes.