Final answer:
To access stored energy from biomass, humans can convert it via burning for heating and cooking, or through processes like fermentation to produce biofuels. Biomass consists of plant or animal matter, including waste products. The energy derived from biomass originally comes from the sun through the process of photosynthesis.
Step-by-step explanation:
To access the stored energy in biomass for human use, we must convert the biological material into a more useful form of energy. This can involve processes like burning, gasification, fermentation, or anaerobic digestion, depending on the biomass source and intended use. Burning wood or other plant matter, including waste products like sawdust, sludge, or even animal feces, is the one of the primary and traditional methods of accessing energy from biomass. Wood, for example, provides about 4 kcal of energy per gram when burned. The energy stored in the form of carbohydrates or proteins within the biomass can then be utilized for heating, cooking, or even generating electricity.
Additionally, other methods, such as converting biomass into biofuels like ethanol, can provide a liquid fuel substitute for transportation needs. The energy from biomass ultimately originates from the sun, as plants capture solar energy through photosynthesis and store it in organic matter which we can later convert and use.