Honolulu-based solar energy company RevoluSun has launched a new division to help its commercial customers reduce their electric bills through efficiency and conservation measures.

Energy efficiency improvements can allow some companies with older, inefficient buildings to cut their energy bills by up to 50 percent even before installing a rooftop photovoltaic system, said Eric Carlson, RevoluSun co-founder.

The new division will be headed up by David Sungarian, an engineer and certified energy manager who previously operated his own consulting business.

The return on investment for energy efficiency projects is often high because customers are able to realize immediate cost savings through low-cost, and in some cases no-cost, measures, Carlson said.

Once an energy audit is done and improvements are made, a company is able to get a better idea of how large a photovoltaic system it needs to meet its energy requirements, Carlson said.

"Then RevoluSun designs a custom solar system that can offset the remaining energy bill, which is smaller in scale thanks to the reduced power consumption," Carlson said.

Conservation and efficiency measures include installing newer air-conditioning and lighting systems, upgrading system controls and improving a building’s "envelope" by adding insulation and tinting windows.

Taking steps to improve energy efficiency is also a good way to reduce electricity bills for companies that are unable to take full advantage of PV systems for various reasons, Carlson said.

For example, the more floors a building has, the higher its energy consumption will be in relation to the amount of rooftop space it has to install a PV system.

"As a rule of thumb, as a building goes vertical, the chance to zero out its electricity bill with a PV system is reduced," Carlson said.