Did you ever think for a minute when you threw that banana peel away months ago that it might find a new life somewhere? Well, if you’re a Granger trash customer, much of your trash serves another purpose once it hits the landfill. Sound intriguing? You have no idea! Read on to learn more about this process, step by step.
Your banana peel (and your other trash) is picked up at your home or business by a Granger truck. If you’re in the greater Lansing area, it gets dumped at Wood Street Landfill. (In our northern or southern service territories, it will still end up at the landfill. It will just make a stop at one of our transfer stations first.)
- Once it’s in the landfill, your banana peel starts to break down. It’s eaten by these tiny organisms called methanogens. Methanogens live to eat trash and expel methane gas. The first transformation, from banana peel to methane, has taken place.
- Your banana peel, now disguised as methane, joins with other substances in the landfill to form landfill gas. We capture the landfill gas, which is about 50 percent methane, through a system of perforated pipes. The gas is drawn out of the landfill using vacuum pressure.
- When it was just a banana peel, your trash never cared how it looked, but now that it makes up landfill gas, it requires a lot of primping. The gas travels to a room in our electric plant where it is cleaned up to get ready for its date with the engine. Landfill gas is quite vain, so it goes through a number of different steps that compress it, cool it, filter it and remove moisture. (You definitely don’t want your landfill gas to feel bloated!)
- Once the gas is ready, it’s used as fuel in an engine-generator set. At Granger, we use two main types of engines, Caterpillar 3516s and Caterpillar 3520s. They both work similarly to the engine in your car or the generator you use to power the lights in your camper. They’re just a lot bigger and use landfill gas for fuel instead of gasoline. The landfill gas powers the engine, which turns the generator to create electricity. And voilá! That banana peel that was smelling up your kitchen trash is now something that can help power a light bulb or a flat screen TV.
- Electricity is sold to a local utility (here in Lansing to our project partner Lansing Board of Water & Light) and goes out from our electric plant directly to the grid.
Granger produces electricity using this process at 14 locations in Michigan and several other states. (To see descriptions of all our renewable energy projects, click here.) And we’re not just making a tiny bit of electricity, either. From our two electric generating stations in the Lansing area alone, we’re making enough electricity to power about 6,700 homes.
There’s also another way we use banana peels (disguised as landfill gas) to make renewable energy, but that’s a story for another day.