Steps To Identify And Prioritize Possible Energy Efficiency Measures

Opportunities for incorporating greater energy efficiency into commercial buildings can occur in many stages of the building cycle, including:

  • New building design and engineering
  • Acquisition and leasing
  • Asset valuation
  • Operations and facilities management

This handbook focuses primarily on the final stage, operations and facilities management, and suggests measures that are suitable for retrofitting or replacing existing building technologies. The following outlines the basic steps for identifying and prioritizing energy efficiency opportunities. Note that Climate Corps fellows will be primarily involved in steps 4–6.

  1. Estimate baseline energy use intensity. High-level calculations of baseline energy use intensity (EI) can be performed by dividing annual purchased electricity and fuel by office space square footage. In order to perform this analysis, obtain documentation of purchased energy (e.g., monthly electric and natural gas bills) from the previous fiscal year and square footage figures for office space. Baseline estimates of EI can be compared to benchmark energy use intensity figures to provide a rough estimate of possible gains to be accomplished through energy efficiency measures. For more information on estimating baseline energy use and benchmarking, see Chapter 5: Interpreting energy bills and benchmarking energy use.
  2. Commission an energy audit. If initial energy intensity benchmarking calculations reveal that an office space is not maximally efficient, the next step is to commission a professional energy audit. The findings of an energy audit will detail opportunities for increased efficiency in systems throughout the office, ranging from low- to no-cost improvements in system settings and use to full system replacements. Energy audits often reveal obvious inefficiencies such as faulty HVAC controls. Correcting these problems should be a first priority, and is likely to yield quick returns. The energy engineering firms that perform these audits sometimes offer a guarantee that their audit will yield investment opportunities with a certain low payback threshold, or the audit will be free. For more information on energy audits, consult the Flex Your Power energy audit guide at [].
  3. Consider interactions between systems. It is important that evaluation of possible efficiency upgrades be conducted with a holistic focus - a change to one system may alter the conditions of other systems throughout the office space. For example, efficiency upgrades to a lighting system will result in reduced releases of heat and will lower the cooling load of the air-conditioning (AC) system. Reductions in cooling load because of increases in efficiency of lighting or office equipment can sometimes be significant enough to reduce the cooling load of an HVAC system. The energy engineer(s) should be able to provide good estimates of the probable collateral effects of a given efficiency upgrade, and these should be factored into financial analysis and prioritization.
  4. Perform financial analysis of possible efficiency investments. For each potential project, one should forecast the initial incremental investment plus the expected annual savings and costs. Reduction in energy usage will likely be the main financial driver, but changes in labor and replacement costs may also be significant. Tax incentives and utility rebates should also be included in the calculation. The Climate Corps financial analysis tool can be used to estimate the net present value (NPV) as well as the expected payback period.
  5. Prioritize options for investment. Investments should be ranked based on the NPV as well as the size of the initial investment and feasibility. Small and easy NPVpositive investments should be implemented immediately. Larger investments will often create greater energy savings but need to be budgeted and managed with greater resources.
  6. Evaluate financing options. Investments can be paid for in cash, financed with a loan, leased or financed through a performance contract (see Chapter 12: Energy efficiency finance). The best option for a given company will depend on the company’s cash position, budget cycle, availability of incentives and purchasing policy. It is a good idea to work with the chief financial officer and managers to make recommendations based on all of these elements.
  7. Post-implementation follow up. Once the recommended efficiency upgrades have been completed, it will be important to follow up with post-project energy monitoring to quantify and document the effects of the efficiency upgrade. Environmental Defense Fund plans to follow up quarterly with host companies to monitor progress and reductions in energy usage.
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