Turning waste into watts a boon for environment
Waste… it has been generated by humans since the dawn of time. The Roman Empire perfected the early art of waste management, using sophisticated aqueducts and waste removal systems.
But the world has grown quite a bit since then, and despite our best efforts to reduce, reuse and recycle, the world now has more municipal solid waste than ever before. In the U.S. alone, we generate nearly 300 million tons of waste a year, a number that will only get bigger as our population continues to grow.
Waste in the U.S. is managed in three ways: Treatment and disposal primarily by landfilling (52.5%), recycling and composting (34.7%), and waste-to-energy (12.8%).
While recycling has jumped leaps and bounds over the last few decades, there are a number of limiting factors. For example, the economics of recycling have declined due to reduced demand for recyclables, and the cost of producing marketable products from recycled materials has increased due to a changing waste stream and more expensive processing. And in a big move, China has recently stopped accepting U.S. recyclables as well. As a result, the number of methane-producing landfills continues to rise.
That is why there is a new push to enhance Waste-To-Energy efforts. Currently the smallest percentage of waste management, WTE is the process of generating energy from the primary treatment of waste, or the processing of that waste into a fuel source.
And a new report on Waste-To-Energy released by the City College of New York looks closely into decades of research on WTE and how it can be beneficial for recycling efforts and the reduction of greenhouse gases.
According to the study, Waste-To-Energy reduces the amount of waste that would otherwise be landfilled by up to 90%. WTE is also more environmentally sound, reducing greenhouse gases and providing a viable alternative to methane-producing landfills. But not every community practices WTE, and the study also suggests that those who do consistently have greater rates of recycling than those who don’t.
Stony Brook Professor and Director of the Waste and Reduction Management Institute Frank Roethel reviewed this new study, and shares his thoughts:
“I think the report represents all of the facts. All the data on the issues of greenhouse gas emissions and landfills are totally valid, and need to be embraced by decision makers across the nation. While a lot of people find some of the data hard to digest, it is pretty clear.”
There are 76 WTE facilities in the U.S. – 19 of which are in the tri-state area - that process nearly 94,000 tons of solid waste per day. That’s 13% of all waste generated in the country! This in turn produces 2.5 GW of electricity and 2.7 GW of combined heat and power. This is enough to power the equivalent of 2.3 million homes!
One of those facilities is on Long Island in the Town of Hempstead. I recently got a chance to take a tour of the plant and experience all that goes into the WTE process. Truly a fascinating process. First, garbage is trucked into a warehouse, where it is then loaded into a massive storage room. The room currently houses about 17,000 tons of garbage. Each day around 3,000 tons are processed, which amounts to over a million per year! The garbage is then loaded into an incinerator via giant cranes. The steam produced from the burning trash powers a giant turbine, which then powers a generator to produce thousands of megawatts of power every day. The remaining metal materials that cannot be burned off are separated by a giant magnet so that they can be used to create energy in other ways.
Ed Sandkuhl, the Covanta Facility Manager, says that they are always looking for new ways to squeeze more energy out of every last piece of trash. “We’re working on going from 90% reused to 100%. In a perfect world, there would be zero waste, and that’s what we strive for every day. Our mission statement is ‘to ensure that no waste is ever wasted’.”
While Waste-to-Energy is a feasible technique in our area, it isn’t for all areas of the country.
“When WTE first came online, it wasn’t a cheap waste management option,” explained Roethel. “Today, however, it is much more cost effective. The other side of the coin is that urban areas, especially on the East and West coasts, no longer have the available locations to bring solid waste to landfills. Other areas of the country do, but to ship our waste out to them is incredibly expensive, not to mention the immense risk of moving solid waste by truck over the roads between accidents and added congestion. I think we really need to give some serious thought about managing our solid waste dilemma, especially for an area like Long Island with the potential closure of the [only remaining] Brookhaven landfill in a few years.”
Now interestingly enough, the CCNY report comes after the United Nations recently released a study on mitigating methane that confirms landfills as a major contributor to emissions and climate change. As more data and studies are released, there is optimism that those still using landfills will shift towards Waste-to-Energy.
“My hope is that we will continue to develop new technologies that will enhance recycling,” says Roethel. “But will it ever get us all the way there? Not in our lifetimes.”