Massachusetts is soaking up the sun.

A $68 million state fund that provides rebates to homeowners and businesses who install solar panels had been entirely disbursed in October after a mere 22 months, though the funds were expected to last up to four years.

Denise Jillson, executive director of Harvard Square Business Association, said she was not surprised by the ambitious investment in energy efficiency.

“The fact it took only about half the time for the funds to be used up is indicative of how this issue really is important to all people,” Jillson said, adding that several Square businesses have contributed to sustainability through a solar Wi-Fi mesh network and solar panels.

Since the program—financed through surcharges on utilities and electricity usage—was met with such overwhelming demand, Massachusetts officials are preparing a new plan that is expected to be available on Jan. 1. This successor project, dubbed Commonwealth Solar, is the preliminary phase of the clean energy initiative—championed by Gov. Deval Patrick ’78—geared toward achieving 250 megawatts of solar-generating capacity in Massachusetts by 2017.

Jenny Harvey, the program coordinator for sustainability at Harvard Real Estate Services, said she attributes the state’s pursuit of a robust renewable energy policy both to the affordability of renewable options and the desire of institutions to increase their sustainability in the public eye.

Harvard has recently undertaken several measures to reduce its carbon footprint. A 500-kilowatt photovoltaic solar array—approximately 2 1/2 football fields long—is in development for the rooftop of The Arsenal, the largest building at the Harvard-owned Watertown office complex. Harvey added that this project would not have gone forward without the $1.1 million grant from the state’s Commonwealth Solar rebate program.

“There is a great effort to promote more solar in Massachusetts,” said Mary H. Smith, an energy strategist for Harvard’s University Operations Services. “The incentive programs are changing.”

Harvard’s other recent efforts to improve sustainability include its agreement made on Nov. 2 to purchase 10 percent of its annual electricity usage in the form of wind power, making the University the largest institutional buyer of that type of energy.

University President Drew G. Faust had previously announced a campus-wide initiative in the summer of 2008 to curb greenhouse gas emissions by 30 percent from 2006 levels by 2016.