2. Photo-Voltaic Cell
It is based on the photovoltaic effect.
The photovoltaic effect means the generation of
a potential difference at the junction of two
different materials in response to visible or other
radiation.
a Photo-Voltaic with a 10cm2 surface area, a
light with 10W of power falls. The maximum
electric power that this cell can produce would
be 3W.
8. Parabolic Trough Systems
The sun's energy is concentrated by parabolically curved, trough-shaped
reflectors onto a receiver pipe running along the inside of the curved
surface. This energy heats oil flowing through the pipe, and the heat
energy is then used to generate electricity in a conventional steam
generator.
A collector field comprises many troughs in parallel rows aligned on a
north-south axis. This configuration enables the single-axis troughs to
track the sun from east to west during the day to ensure that the sun is
continuously focused on the receiver pipes. Individual trough systems
currently can generate about 80 megawatts of electricity.
Range in size from 14 to 80 MW and represent
A total of 354 MW of installed around the world.
A heat transfer fluid (HTF) is used as a heat
exchangers to drive a steam turbine system.
9.
10.
11.
12. Power Tower Systems
A power tower converts sunshine into clean electricity for the world’s
electricity grids. The technology utilizes many large, sun-tracking mirrors
(heliostats) to focus sunlight on a receiver at the top of a tower. A heat
transfer fluid heated in the receiver is used to generate steam, which, in
turn, is used in a conventional turbine-generator to produce electricity.
Early power towers (such as the Solar One plant) utilized steam as the
heat transfer fluid; current US designs (including Solar Two, pictured)
utilize molten nitrate salt because of its superior heat transfer and
energy storage capabilities. Current European designs use air as heat
transfer medium because of its high temperature and its good
handability
Salt Water (Brine) is heated to 565ºC
Ability to generate 10 MW
16. Ocean Thermal Energy Conversion
Here we use the temperature difference between the hot
surface of the ocean and the cooler, deeper layers beneath
to drive a heat engine.
The average range to get a temperature gradient of about
20ºC-35ºC is as 500–1000m or 1000–3000ft.
Ammonia is used as a heat exchange fluid as it has a boiling
point of -33.5ºC
A 10-MW closed cycle OTEC pilot system is operational
at Hawaii. This system is being designed to expand to 100MW commercial systems in the near future.
There are two other plaans of 2 and 7MW capacity in
Hanian and Japan
19. Tidal energy
Tides are caused by the gravitational pull of the
moon and sun, and the rotation of the earth.
Ocean Currents are always flowing in a particular
direction 24x7.
St. Lawrence River's kinetic energy and turn it
into electricity. This project is for 15 megawatts,
23. Advantages
No fuel cost
No Pollution
Completely renewable
Very flexible regarding location of plant
Disadvantages
Efficiency is less
No output during Night or Cloudy weather
Plant implementation cost very high
24. Cost per 1MW
Solar PV Cells – Rs.1,438/kW
Trough System – Rs.7,182/kW
Solar Tower – Rs.4,380/kW
OTEC - ??
Tidal - ??