Subject:- Renewable Energy Sources

Topic:- Wind Energy

Difficulty:- High

• Individual / Family type biogas plants cannot be installed by poor farmer since they cannot beat the high cost through they are highly subsidized department of non-conventional energy sources.
• The large quantities of cow drug & other organic wastes in rural areas can be used to produce significant amount of biogas in an organised way. Such biogas plant in rural areas are called community biogas plants or sometimes also called as biogas farming.
• The development of these biogas plants is an answer to the rising prices of crude Oil or in village where there is no availability of electricity.
• community biogas plants could also emerge as an alternative to fossil fuels whose availability is depleting as years passby. It will also play an important role in the rural economy.
• Another major point which favours the installation of community biogas plants as compared to individual plants is its lower cost/m3 of gas generation, cost of supervisory staff & other maintenance cost.
• The biogas so generated can be used for heating, generation of lower in an engine/ generator to right up the village, pumping of waste, running of mills etc.
• Biogas can produce approximately $1.5 kWh/m^3$ of gas. The gas has C.V. of $20000 kJ/m^3$ approximately.
• Shortage of gas can be met by alternative routes which may be gasification using biomass such word, waste of crops, vegetables using biomass etc which are readily available in village.
• Another advantages of biogas production is to reduce emissions with reduction in wastes.
• Material which can be used for biogas plants could be animal waste like cattle dump, urine goat & poultry droppings, piggery wastes etc.
• It can also be human wastes, agricultural wastes & wastes of aquatic origin like water hyacinth, Water weeds, algae etc.

Advantages of community biogas plants over individual biogas plants.

• a) Reduction in capital & maintenance cost .
• b) Reduction in land area. The land needed is inversely proportional to square of the capital of gas produced.
• c) Reduces emission, smoke & flies etc.
• d) It produces compost as by- product.
• While designing community biogas plants, it must be ensured that it is reliable. It requires proper planning & management of the system.

It needs the following for its reliable operation:-

• 1) Adequate supply of feed stock to keep the plant operative. Dung supply is erratic due to climatic instability.
• 2) Use of two or more small plants instead of single big plant.
• 3) A back up source for fuel & power. We may have gasification plant for production of gas by biomass, PV solar cells, wind power etc.
• 4) Size depends on availability / collection of feed material.
• 5) Too large plant lead to underfeeding & evefual failure of plant to produce gas.
• 6) Location of biogas plant. In winters the capacity of plant is reduced.
• 7) Limit community plant to about 50 families instead for the whole village for better reliability.