2.  Definition  Centralized System  Fuel cells  Photovoltaic  Wind Turbines  Islanding  Advantages  Disadvantages

3. Distributed Generation (or DG)refers to small-scale(typically1KW-50MW)electric power generators that produce electricity at a site close to customers or that are tied to an electric distribution system

4.  Currently, developing countries generate most of their electricity in large centralized facilities, such as fossil fuel(coal, gas powered) nuclear or hydropower plants  plants are built according to a number of economic, health & safety, logistical, environmental, geographical and geological factors.  usually transmit electricity long distances and can affect to the environment.

7.  Efficient Clean fossil-Fuels Technologies 1.micro-turbines, 2.Fuel Cells  Environmental Friendly Renewable Energy Technologies 1.Biomass 2.Solar/Photovoltaic Array 3.Small Wind Turbines 4.Hydro Turbines

8.  21st Century -likely to be the century of the fuel cell, and as a result fuel cells will revolutionize the way to currently generate electric power offering the prospect of supplying the world with clean, efficient, sustainable electrical energy because they use hydrogen as a fuel.  A fuel cell is defined as an electrical cell, which unlike other storage devices can be continuously fed with a fuel in order that the electrical power can be maintained.  The fuel cells convert hydrogen or hydrogen- containing fuels, directly into electrical energy, heat, and water through the electrochemical reaction of hydrogen and oxygen.

9.  FC is a device used to generate electric power and provide thermal energy from chemical energy through electrochemical processes.  Acts like a battery supplying electric energy as long as its fuels are continued to supply.  Unlike batteries, FC does not need to be charged for the consumed materials during the electrochemical processing as these materials are continuously supplied.  FC is a well-known technology from the early 1960s when they were used in the Modulated States Space Program and many automobile industry companies. Later in 1997, the US Dept of Energy testedgasoline fuel for FC to study its availability for generating electric power.  FC capacities vary from kW to MW for portable and stationary units.

10. The fuel cell plant consists of three main parts: a)reformer-convert the fuel into the hydrogen depending on the demand of the load current,, b)stack c)power conditioning unit (PCU) Auxiliary Systems : (i)Fuel Processor Controller - hydrogen gas, (ii)Air Compressor to provide pressurized oxygen flow through the cathode (iii) Valve to control the hydrogen flow through the anode, (iv) Humidifier to add moisture to the hydrogen and oxygen gases, (v)Water Cooling System to remove heat from the stack.

11.  Quite  Low Emissions  High Efficiency  High cost  limited field test experience,  low temperature waste heat may limit cogeneration potential

12.  Solar PV :-  most versatile renewable technology with varied applications.  Consturction:  basic unit of PV is a cell may be round or square in shape, made of doped silicon crystal.  Cells are connected to form a module or panel and modules are connected to form an array to generate the required power.

14. Advantages of PV System  Work well for remote locations  Require very little maintenance  Environmentally friendly (No emissions) Disadvantages of PV System  low output power  Local weather patterns and sun conditions directly affect the potential of PV system.  Some locations with poor solar intensity/climates lacking reliable sun exposure will not be able to use solar power.  Regions with high cost of land will also not be able to use solar power.

15. Construction:  WT is not a new form it has been used for decades.  consists of a rotor, turbine blades, generator, drive or coupling device, shaft, and the nacelle (the turbine head) that contains the gearbox and the generator drive.  Modern WT can provide clean electricity as individuals or as wind farms.

16.  wind rotates the windmill- like blades, which in turn rotate their attached shaft.  shaft operates a pump or a generator that produces electricity.  The energy characteristics of larger wind turbine farms are closer to the centralized energy sources.  Small WT(working as modules) can be combined with PV and battery systems to serve area of 25–100kW.

17.  Low cost energy  No harmful emissions  Minimal land use  No fuel required  Variable power output due to the fluctuation in wind speed  Location limited  Bird mortality

18.  Islanding is the situation in which a distribution system becomes electrically isolated from the remainder of the power system, yet continues to be energized by DG connected to it, known as micro-grid.  Current practice is that almost all utilities require DG to be disconnected from the grid as soon as possible in case of islanding.  Islanding can be intentional or non intentional.

19. Advantages OF DG Flexibility : - DG resources can be located at numerous locations within a utility's service area. This aspect of DG equipment provides a utility tremendous flexibility to match generation resources to system needs. Improved Reliability :- DG facilities can improve grid reliability by placing additional generation capacity closer to the load, thereby minimizing impacts from transmission and distribution (T&D) system disturbances, and reducing peak-period congestion on the local grid. Improved Security : - The utility can be served by a local delivery point. This significantly decreases the chances of interrupted service from imported electricity supplies due to natural disasters, supplier deficiencies or interruptions, or acts of terrorism. Infrastructure - Reduces the necessity to build new transmission and distribution lines or upgrade existing ones. Reduce transmission and distribution line losses

20.  no uniform national interconnection standards addressing safety, power quality and reliability for small distributed generation systems.  Interconnection may involve communication with several different organizations  The environmental regulations and permit process that have been developed for larger distributed generation projects make some DG projects uneconomical.

21. The promise of a future world dominated by rapid population growth and unparalleled energy demand presents many challenges to the global energy industry and indeed society as a whole. Increased electrification will be central to future world energy development. The distributed generation concept offers many advantages over established electricity generation infrastructures and will play a major role in the provision of world energy needs.

22.  K. Purchala, R. Belmans, L. Exarchakos, A.D. Hawkes,” Distributed generation and the grid integration issues”.  Murray J. Height,10.391J Sustainable Energy,Spring 2000.  Dr.Bidyadhar Subudhi, Distributed Generation:Concepts & Issues.