INDUSTRIAL ENERGY EFFICIENCY CASE STUDY
Energy Management - Assembly & Injection Molding Plant, Bridgeport, CT
Situation: CT-based division of $2 billion publicly traded company, hired Design with Nature, LLC (DwN) as energy manager to implement energy conservation measures across three facilities in CT over two year period. Cumulatively the three facilities have over 150,000 square feet of production floor space, and use 14 million kWh of electricity per year.
Measures implemented include: "low hanging fruit" such as air compressor leak analyses, pressure regulation, electricity demand reduction, power factor correction, motor, lighting and heating upgrades, air-side economizer installations.
More advanced projects included: air use timing retrofits, energy management software and sub-metering installations, production machinery retro-fits and replacements.
Outcome: $638,000 in cost savings, including $45,000 in utility rebates and incentives, garnered over a 27 month period. Net reduction of 2.3 million kWh over baseline (16.7% decrease), and an 8.7% reduction over current use when accounting for increases in production output during that time.
Lessons Learned: The Value of Good Recordkeeping. There was no existing baseline and no direct responsibility for energy conservation on-site, so considerable effort was required to gather archived bills and match usage to various production and support machinery.
One of the factories had 800 hp of compressed air capacity; we found $30,000 of air leaks per year that once fixed, reduced the load on this system. Further work with the production machinery maintenance team resulted in another $50,000 per year of compressed air savings through the use of solenoids and timers to shut-off air flow.