Talk:Energy systems language

What is the essential difference between "productions" and "transformations" in the presence of "sources". In general terms (without "sources") a production is something like a source, different to transformations. But in the presence of sources, a production seems to be nothing but a special type of transformation, doesn't it?

I believe this should be somehow clarified. Marble machine (talk) 08:50, 25 October 2016 (UTC)