Thank you for this excellent discussion with thoughts as how to incorporate data collection/analysis to help inform future investment decision-making.
I would suggest, however, that the thinking needs to broaden. In essence, what I see here is only a bit past the stove-piped ‘we invest in energy efficiency and we will save energy, what is the ROI’ sort of discussion that is too prevalent both in government policy-making and in private business. The rebound effect element that you highlight merits understanding. However, there are very large arenas for additional consideration — arenas that quite likely overwhelm, in robust cost-benefit analysis, the implications of direct energy savings. Let me provide two small examples:
1. In the office environment, ‘greening’ programs can lead to productivity improvements of 5 / 10 / 15+%. (see: http://getenergysmartnow.com/2009/09/25/new-study-green-buildings-generate-more-green/) As the typical US office spends roughly 100x on people as it does on energy/water resources, a 5% productivity improvement has 25x the value of a 20% reduction in the energy/water costs. While it is a more serious challenge to do a clean before/after with schools (changing cohorts, changing curriculum, etc …), there is strong evidence of similar gains. Thus, the question, what energy efficiency investments might have an impact on student/teacher performance (such as daylighting) and how does one include that improved (or, possible, worsened) performance in the valuation equation of energy efficiency investments?
2. Many school systems are seeking to foster improved STEM education programs and all school systems expend significant resources on textbooks and other tools (for STEM and otherwise). Solar PV panels, for example, are quite easy to integrate into educational programs. (See:http://getenergysmartnow.com/2013/09/03/thinking-past-stovepipes-solar-electricity-on-roof-and-classroom/) To what extent can energy efficiency investments contribute to the educational program and how would one incorporate that ‘learning value’ into the cost-benefit calculation?
For a perspective as to the systems-of-systems benefits from greening schools, see: http://www.senseandsustainability.net/2013/10/18/greening-schools/