Green Analysis

An increasing number of corporations and government organizations are undertaking sustainability initiatives including green building design and operations intended to reduce greenhouse gas emissions. Virtually all of these initiatives involve reductions in energy use. For instance, reduced building energy use is a major component in achieving the U.S. Green Building Councils LEED (Leadership in Energy and Environment Design, http://www.usgbc.org/) certification. Organizations are also investing in energy efficiency to qualify their buildings with an Energy Star rating from the U.S. Environmental Protection Agency (http://energystar.gov/)

The case study application described in the Energy Cost Analysis section of this website and detailed in Energy Budgets at Risk: A Risk Management Approach to Energy Purchase and Efficiency Choices illustrates EBaR carbon and other emissions analysis. Table 1 and Figure 1 show emissions before and after the case study efficiency investments.

Table 1. Emissions Baseline and Impact of Efficiency Investment

Figure 1. Emissions Baseline and Impact of Efficiency Investment (lbs/year)

EBaR analysis also provides estimates of emissions at alternative confidence levels. Figure 2 shows expected carbon emission reduction at various confidence levels. As indicated in the figure, a worst-case result provides CO₂ reductions of 808,721 pounds per year or a reduction of 24.6 percent of baseline use. This worst-case result would occur only with extremely warm winters, extremely cool summers, and extremely poor performance of the investment options as defined by the input distributions developed in the analysis.

Figure 2 CO₂ Reductions at Alternative Confidence Levels (lbs/year)

The case study lighting and efficiency investment programs can be expected to provide a net cash flow of $58,300 per year, an internal rate of return of 42.3 percent, and a reduction in the building's carbon footprint of 37.4 percent.