EDISON -- Aside from the subtle smell of methane, it is hard to tell that the undeveloped mound of dirt, rocks and patchy grass on the Raritan River in Edison is just a giant garbage can.
At its peak of operation, more than 400 garbage trucks would roll through the now Heller Industrial Park each day to dump thousands of tons of local trash next to the river.
Soon, the 21-acre site will power 1,200 homes for the next two decades, turning a chunk of unusable property into a renewable energy site.
Close to 24,000 solar panels currently sit on top of the plateaued landfill, making it the 10th solar farm built in New Jersey as part of Public Service Electric and Gas's $500 million investment into its Solar 4 All program.
"The best part of this is you really get to take unproductive land and put it to good use," said project manager Andrew Powers, who said there is limited use for the land since any construction could not penetrate the landfill's 14-inch clay cap.
The Edison solar farm alone will also reduce the utility company's yearly emissions equal to pulling 800 cars off the road.
It took roughly five months for crews to construct hundreds of concrete stands to support the rolling lines of panels and run thousands wires connecting the farm to the grid.
The finances surrounding the lease or construction of the projects have not yet been disclosed. According to Powers, the utility company funds these type of projects through customer fees after state approval. The 20-year lease on the site has the option for 10 years of extensions, according to Powers.
Once the Edison solar farm turns on, the utility company will power around 8,500 homes annually in New Jersey through the reusable energy source.
"Through this program, everybody receives the subsidies that are provided with solar energy," Powers said.
The privately owned Edison landfill, which stopped taking garbage in the 1980s, was eventually capped and pumped of toxic liquids, also known as leachate, in 1989 following a suit from the owner of the nearby industrial park and others citing environmental violations.
For years, natural gas has been pumped out of the site to power a local sewage-treatment plant, but the landfill has been otherwise undisturbed.
PSE&G generally only looks at potential landfill sites that have been capped for at least 20 years with a good history of environmental compliance, according to Powers. The program also looks to its former gas manufacturing sites, or brownfield spaces, for solar farms.
Since 2010, the company has also built farms in Eastampton, Bordentown, Deptford, Kearny, West Deptford, Trenton, Hamilton, Linden and Hackensack.
The utility company has already identified a number of former landfills and brownfields that if lined with panels could power around 16,000 more homes.
Earlier this month, the New Jersey Board of Public Utilities gave PSE&G the green light on a third of those projects, allowing an additional investment of $80 million in the program.
By 2020, the power will be turned on at the new solar farms.
In addition, the company is also working on a pilot program, which will equip solar panels with batteries to extend power at hospitals, warming stations and other local services in case of another Superstorm Sandy-like event.
Craig McCarthy may be reached at CMcCarthy@njadvancemedia.com. Follow him on Twitter @createcraig and on Facebook here. Find NJ.com on Facebook.