For using your fireplace. You can probably guess that a wood burning fireplace is the worst type of fireplace for the environment. Sigh. That’s what we have.
I just found these Java-Logs. Yes, they are made out of recycled coffee grounds. So, not only do they burn cleaner and better for the environment, they keep coffee grounds out of landfills. (And you can keep your own grounds out of the landfill by composting.)