Currently, the federal government provides a 30% tax credit on photovoltaic and hot water systems. The state of Hawaii gives a 35% tax credit. Combined, these incentives can take care of roughly two-thirds the cost of the system. Haleakala Solar will guide you step by step on how to capitalize on these generous (and limited-time) programs.
A solar hot water system can be paid off in 2-3 years and over the long haul, savings can be quite substantial. Move away from dirty, fossil fuels and move towards energy independence and sustainability.