Gov. Chris Christie signed legislation Monday aimed at encouraging the continued growth of New Jersey's solar industry while protecting ratepayers from increased costs.

The measure, which had strong bipartisan support in the Legislature, increases the percentage of the total power utilities must derive from solar energy from about 2 percent a year to more than 4 percent by 2028. The state goal overall is to generate 23.5 percent of New Jersey's energy from solar.

Proponents said the law should help increase prices for the solar subsidy credits, which utilities buy from solar producers, and keep the solar industry healthy by saving thousands of jobs and making it a more attractive venture. The state Division of Rate Counsel estimates the law will save ratepayers about $1.1 billion over the next 15 years.

After the bill-signing ceremony at the Statehouse, Christie said the law also would "help maintain New Jersey's position as a national leader in the solar industry." He said the industry has created thousands of jobs in the state and "helped businesses thrive and grow" while generating more than 800 megawatts of clean energy.

In recent years, New Jersey has built more solar projects than any state, except California. But the plethora of projects contributed to a glut of solar subsidy credits, driving down prices. The market also grew stagnant when utility companies started producing more of their own solar energy, sharply dropping the value of the credits, a major source of revenue for independent solar developers.

Environmental groups, who have been at odds with the governor over some key issues, praised the new law and its goals but said more still needs to be done.

"The recent boom in solar development demonstrates our state's potential is much greater than previously anticipated," said Matt Elliott, clean energy advocate for the Environment New Jersey group. "Moving forward, longer-term state policy must keep up with that potential. We should be increasing the state's overall clean energy requirements and ensuring more of our clean energy goals are carved out for solar specifically.

"In the short term, however, this bill will ensure that New Jersey continues to be a solar leader," Elliott said.