San Jose Mercury News: Even as a state rebate is shrinking, the price of residential solar power is dropping, thanks to lower installation costs and a glut in the supply of key components. That’s putting it in reach of more people and prompting solar advocates to say the day is coming when rebates and tax credits won’t be needed to spur the growth of the renewable energy industry. The cost of a typical 4,000-watt home solar system has dropped as much as 10 percent in the last year – falling below …