helpful

2. ABSTRACT
A major focus of the current energy debate is how to meet the future
demand for electricity while reducing the nation’s dependency on
imported oil.
Conversion in buildings and industry, and conversion of utility central
station capacity to alternate fuels will play a major role in reducing oil
use in these sectors.
Industrial and commercial sector ultimately will have to seek
alternative sources of energy.
Benefits of co-generation are much higher like fuel efficiency and
lower environmental load compared with other levels.

3. INTRODUCTION
We have one of the most promising commercially available
technologies is Co-Generation.
Co-Generation is the simultaneous generation of heat and
power, both of which are used.
Co-Generation is also known as ‘combined heat and
power(CHP)’ and ‘Total Energy’.
Traditionally steam and electricity have been produced
separately; steam at industrial plants and electricity by utilities.

4. DEFINITION OF CO-GENERATION:
The principal behind co-generation is simple.
 In Conventional power generation, on average is only 35%
electricity is used and remaining 65% of the energy is released
as waste heat.
More recent combined cycle generation can improve this to
55%,excluding losses for the transmission and distribution of
electricity.
 co-generation reduces loss in industry by using the for
industry.
In conventional power generation further losses of around 5-
10% & co-generation offers energy saving range between 15-

5. Electrical efficiency=electrical output (kw)
fuel input kw
Thermal efficiency=thermal output (kw)
fuel input kw
Overall efficiency=useful thermal electrical output (kw)
fuel input kw
CO-GENERATION VERSUS CONVENTIONAL GENERATION:

6. Efficiency Comparison between Conventional system
and co-generation
Conventional system:
100
200
POWER PLANT
BOILER
FUEL ELECTRICITY
36
FUEL HEAT
100 80
η = 36 + 80
Total efficiency:
= 0.58

7. ELECTRICITY
Fuel Co-generation 30 Total Efficiency:
HEAT
System η = 30 + 55 = 0.85
100
100
55
CO-GENERATION SYSTEM:

8. BENEFITS OF CO-GENERATION SYSTEM
Improved efficiency of fuel energy use:
 The production of both electricity and thermal energy from a cogeneration system
leads to energy use efficiencies of 80 to 85%
 A typical cogeneration system can convert 30 to 35% of energy in the fuel to
electricity with another 50 to 55% produces as steam or hot water.
Reduced emission of pollutants and Greenhouse Gases:
 Improving the over all efficiency of fuel energy also leads to
reduced emission of pollutants and greenhouse gases into atmosphere.
 The cogeneration system supplies both electricity and thermal energy, in
place of purchasing electricity from the grid and firing natural gas in a
separate boiler to the generator thermal energy for plant use .

9. Development of Competition within the Electricity supply
Industry:
 Cogeneration plants are usually small plants sized to either the user’s
electricity demand or thermal demand.
 Often they are operated by small independent power producer
rather than the utilities controlling the transmission grid.
Low cost of coal:
 Locally available coal is typically the lowest cost fuel, within site
power plants producing the lowest fuel costs.
 Coal-fired Power plants located at the mine site benefit from low fuel
costs and decreasing cost per kWh with increasing size of power
plant.

10. Applications of co-generation :
Co-generation may be implemented in four main sectors:
1.Public power system
2.Industrial sector
3.Commercial-building sector
4.Agricultural sector
Data for each of these sectors are presented in detail below.
1) Public Power System:
 Power generation plants may be converted into co-generation
stations in order to cover heat needs of cities or settlements,
industries, water desalination plants, greenhouses, fisheries etc.
located in their region.
 Ensuring proper distance and dispersion of heat consumers
around the plant is essential for the feasibility of the overall
installation.

11. 2)Industrial Sector
 In the industrial sector, many processes require heat and
power at the same time. Depending upon the temperature required
the following classification applies:
a) Low temperature processes (below 100°C) e.g. drying of agricultural
products, heating or cooling of areas, utility hot water.
b) Medium temperature processes (100-300°C) e.g. processes in paper
industry, in spinning mills, in sugar industry, in some chemical
industries etc. Typically, these processes require heat in the form of
steam.
c) High temperature processes (300-700°C) e.g. in some chemical
industries.

12. 3)Commercial- Building Sector
This sector includes hotels, hospitals, shopping malls, schools, office
buildings, residences etc. Co-generation covers power and heating
needs of the buildings .
The commercial- building sector may be divided in three main sub-
sectors:
 a) hospitals and hotels;
 b) multi-apartment complexes; and
 c) Office buildings.
4)Agricultural Sector
Co-generation is not widely spread in the agricultural sector; however,
its implementation may lead to fuel savings and positive financial
effect on rural communities

13. Impacts of Co-generation:
 Through co-generation systems, efficiencies may be boosted to
70-80%. In contrast, power generation plants have an average
efficiency of 31%, while combined-cycle plants new with gas turbines
may achieve efficiencies of 40-50% ( as shown in Figure ) .
 The inefficiency of our power generation infrastructure is due
to poor industry performance but to the lack of policies necessary to
extensively implement co-generation.

14. FIG:Cogeneration plant efficiency compared with conventional power plants

15. Fuel Consumption Effects:
 All co-generation systems save fuel because they exhibit
higher efficiencies compared to separate power and heat
generation.
 For example, using a co-generation system with steam
turbines, fuel consumption is reduced by 15% , whereas using a
co-generation system with diesel engine, fuel consumption is
reduced by 25%.
 The co-generation systems to be installed and the fuels they
operate on should be selected in accordance with the national energy.

16. Environmental Effects:
 When many small and widely dispersed co-generation units
replace large central plants with high stacks, then the following are
necessary:
– Elastic seating and sound insulation of the system
– Construction of a stack higher than the adjacent buildings and
– Installation of systems for collecting and removing solid and liquid
residuals.

17. Future scope:
 In an attempt to create the conditions in which the energy sectors
would be able to contribute as much as possible to a financial
development and prosperity of the nations, protecting the
environment at the same time, they put the following common
objectives:
1. Diversity, efficiency and flexibility in the energy sector, these being
the basic conditions for a long term energy safety.
2. Capability for a timely and flexible response in case of emergency
energy needs.
3. Environmentally accepted (viable) disposal and usage of energy.
4. Encouragement and development of more environmentally
acceptable energy sources.
5. Improvement of energy efficiency, contributing to environmental
protection and energy safety in a more efficient manner.