It's "just" carbohydrates - in theory it's no worse than burning oil or gas for heating/electricity, if you make sure everything burns at high enough temperature to burn cleanly and have filters at the exhaust to catch anything that survived the processes.

I'd say it's a positive, we use oil to produce plastics, if that oil is used to produce energy after its plastic form is no longer needed....that's a plus in my book. But maybe on the other hand it's better if it stays in the landfill instead of being burnt and releasing the bound carbon into the atmosphere.