Conservation vs. renewable energy: Cases studies from Hawaii

State of Hawaii generates about 90 percent of its electricity from imported fossil fuel sources. Thus, there is pressure from both public and policy makers to reduce the State dependency on foreign fossil fuel sources. To this extend, there are incentives created at State and Federal level for both residential and commercial buildings to install photovoltaic (PV) systems. Although such incentives are necessary for long-term objectives, it is shown in this study that retrofitting inefficient old building-equipment is another viable source to reduce the State of Hawaiiʹs electricity demand. Four case studies are presented to illustrate that building-equipment retrofitting is a viable and necessary tool for increasing the energy efficiency of buildings. Each case study presents an equipment retrofit project electricity savings with its payback periods, and compares with equivalent electricity capacity and economics PV systems in Honolulu, Hawaii. The case studies show that energy savings from retrofit projects ranged from 28% to 61% for individual equipment retrofits. These results indicate that equipment retrofitting with energy-efficient alternatives is about 50% or more cost-effective than installing PV systems. This is so even when large renewable energy tax incentives provided by the Federal and State Governments are taken into account.