43% reduction of state's business and occupation (B&O) tax
Senate Bill [http://www.leg.wa.gov/pub/billinfo/2005-06/Pdf/Bills/Session%20Law%20200... 5111], signed by Washington's governor in May 2005, created a reduced business and occupation (B&O) tax rate for Washington manufacturers of solar-electric (photovoltaic) modules or silicon components of those systems.
In May 2009, Washington enacted [http://apps.leg.wa.gov/documents/billdocs/2009-10/Pdf/Bills/Session%20La... SB 6170], effective July 1, 2009. This bill reduced the B&O tax rate to 0.275%, effective October 1, 2009. This tax rate is 43% lower than the standard manufacturing B&O tax rate. This reduced tax rate applies to manufacturers of photovoltaic modules, solar grade silicon, silicon solar wafers, silicon solar cells, thin film solar devices or compound semiconductor solar wafers to be used exclusively in solar energy systems.
Businesses claiming the credit under this program are required to file annual reports with the Washington Department of Revenue (DOR), detailing employment, wages, and health and retirement benefits. The DOR must conduct a study from existing sources of data and report the impacts of this incentive to the Washington State Legislature by December 1, 2013. This incentive was originally scheduled to expire on June 30, 2014, but was extended to June 30, 2017 by SB 5882 of 2013.