We present a methodology to determine and model actual condenser performance in ammonia refrigeration systems. Insights from real system performance tell us how to improve system efficiency. This paper can help designers and operators determine applicable efficiency strategies for their refrigeration systems!

When a facility has variable occupancy, attempts to predict monthly energy use based strictly on weather fail. We document a genetic based model to characterize monthly energy use in variable occupancy buildings with improved correlations compared to a weather-only prediction.

We discuss a path to zero energy for the Akron Zoo as a case study that includes aggressive efficiency, on-site renewable energy with limited space, implementation constraints, and some unexpected conclusions.

Through multiple case studies, we discuss real flaws in the implementation of energy efficiency and some necessary preventative steps that could be taken to avoid these flaws. (optional 2nd sentence) This paper became the foundation for multiple other publications and presentations, and has helped the Go team evolve our commissioning, energy, auditing, and measurement & verification services.

The industrial sector must pursue full decarbonization like other economic sectors. We discuss definitions, real attempts by manufacturers, methods for examining industrial processes, and implementation costs and associated economics.

Robust models of building energy use can be created as a function of outdoor air temperature, production and other variables. We found that regression models of monthly energy use can be used accurately to predict daily energy use of the same facility in some cases, but not all.

Prolonged electrical grid outages can have disastrous effects on industry, especially where cooling fluid is critical to avoid the catastrophic destruction of equipment. We explore the use of energy efficiency to reduce the need for emergency power generation during grid outages as a strong co-benefit to implementing certain energy efficiency measures.

This paper describes a method of performing and comparing lifecycle costs for standard, CO2-neutral and net-zero energy buildings.

In 2007, considering greenhouse emissions trading programs internationally, we investigate the economics of efficiency compared to other options. Results show that, at current prices, energy efficiency remains more cost effective than purchasing renewable energy certificates or CO2 emission reduction credits as long as the simple payback is less than the life of the energy efficiency project.

We review historical and program-induced rates of energy efficiency improvement and we estimate improvement rates needed to mitigate long-term risks from fossil-fuel supply instability and global warming. We also review concepts that could be useful in meeting necessary energy efficiency improvement rates, including: theoretical minimum energy use, energy bandwidths, Lean Energy, and Whole-System Inside-Out methodologies.

This paper describes a methodology for calculating net energy savings from skylights as a function of skylight area, the required lighting level, and type of lighting. Results show that the optimum skylight to floor area ratio and net energy cost savings increase as the target lighting level increases.

We present a conceptual and mathematical framework for determining energy savings from productivity improvements in manufacturing.