Biomass Energy Costs

Electricity is a basic necessity without which we cannot imagine our lives. Isn't it? But how is the electricity generated? From natural resources that include hydro (water) and thermal sources (like coal and fossils). Right? But if the natural resources start getting depleted, what will happen in future? How will the electricity be generated then? The answer is biomass energy. So, what is biomass after all? Forest residues such as dead trees, wood, wasted gases, yard clippings, all wasted organic matter (including dead plants and animals) constitute biomass. Biomass also includes biodegradable waste that can be burnt further to source fuel. Biomass energy (one of the alternative energy sources) implies generating electricity, using biomass as fuel.

Cost of Production and Process for Biomass Energy

Biomass energy is converted into sources of fuel through thermal and chemical processes. Even biochemical processes are used for conversion of biomass energy to tangible sources of fuel. Here is a quick glance of some biomass energy resources and the processes for producing bio-fuel, along with the costs incurred in utilization of biomass energy.

Process
In thermochemical processes, decaying plant matter is heated, which emits many gases (like methane) leaving behind the residue in liquid or solid state. These gases can be processed and utilized with useful fuels like alcohol. The methane emitted from plants can also be used by biomass gas turbines to produce electricity. Another alternative is to utilize the biomass energy in fuel cells which can effectively convert hydrogen rich fuels into electricity and water with less pollution. Meanwhile, biochemical processes also help in making biomass energy. Yeasts and enzymes break down carbohydrates through fermentation. This is how biomass liquids are converted to alcohol which is a combustible fuel. Similarly, grain alcohol (ethanol) can be mixed with gasoline to produce a biomass fuel - gasohol. When biomass decomposes, it emits methane and carbon dioxide, of which methane is again a source of combustible fuel. Many biochemical processes are used today to extract the biomass energy, which can be further used for generating electricity. Even soybean oil can be converted to biomass fuel (diesel fuel) through chemical processes. For instance, cooking oil which is wasted in restaurants, can be used to produce biodiesel through chemical processes.

Costs Incurred
Concerning electricity, biomass energy cost per kwh (Kilo watt hour) is about 5-10 cents which approximately amounts to USD 1500 - USD 1800 per Kwp (Kilo watt peak). However, the cost of electricity generated from biomass energy differs as it is also dependent on certain factors as listed below:

• Kind of the biofuel used
• Method adopted to generate biomass energy from biofuel
• Size of the plant for generating biomass energy
• System design of the plant

In Pacific Northwest and Oregon, biomass energy cost is about 5.2-6.7 cents pre kwh. This is comparatively costlier than the electricity generated from natural gas, which is only 2.8 cents per kwh. There is a reason for the costly side of biomass energy. To generate electricity from biomass, a massive amount of biomass is required to generate biofuel. Availability of biomass fuel sources is not consistent as reliance on the forest and agricultural residual sources is quite uncertain.

Costs involved in generating electric power from anaerobic digestion of animal manure is about 3.7-5.4 cents per kwh. To serve such options, there are large farm site manure digester machineries. However the cost of a farm site manure digester is factored by various conditions such as the site location and the number of animals it can house. A plug flow digester equipment can help in processing manure of about 500 cows. Costs incurred in this investment for production of biomass range between USD 230,000 - USD 260,000. The heat generated from digester gases is used in generation of electricity and the residual liquid and fiber digester residues serve the purpose of fertilization for soil effectively. The cost of biomass energy can be recovered from the energy cost savings. Producing biomass energy from ethanol is quite an extensively used method.

About 85% of ethanol in United States is produced from corn feedstock. The estimated cost for producing ethanol is about USD 1.10 - USD 1.43 per gallon. Ethanol is mixed with gasoline to make a blended biofuel - gasohol (10% ethanol and 90% gasoline). Nowadays, biodiesel is also becoming a popular choice for fuel. The only hurdle faced in commercial biodiesel production is the costs incurred in producing the source of fuel. Approximately 75% of the cost of producing biodiesel is accountable for procuring the vegetable oil seeds, extracting oil from them, storing them and transporting them. For example, the cost of producing biodiesel in Idaho is about USD 2.56 per gallon of rapeseed methyl ester. However, a blended fuel of biodiesel which contains about 80% of petroleum diesel can considerably reduce production cost to USD 1.10 per gallon. Instead of using vegetable seeds, low cost organic oil feedstock (like waste food processing tallow) can be used. This will aid in bringing down the costs incurred in production of biodiesel.

Today biomass fuel constitutes about 11% of electricity generation in United States. On a global level, biomass fuel meets about 14% of world's energy requirements. One of the important biomass energy advantages is the re-usability of fuel resources without polluting the environment. Biomass energy costs are definitely high, but with economical alternatives cropping up, the biomass energy utilization is bound to become an indispensable sources of fuel.