Complex sentence: Waste heat has lower utility (or in thermodynamics lexicon a lower exergy or higher entropy) than the original energy sourcheat include all manner of human activities, natural systems, and all organisms.
Split into simpler sentences: Waste heat has lower utility (or in thermodynamics lexicon a lower exergy or higher entropy) than the original energy source. Sources of waste heat include all manner of human activities, natural systems, and all organisms.