Hydroelectric Solar Wind Geothermal Marine (Wave and Tidal)

Prof. R. Shanthini Jan 26, 2013

- Hydroelectric Hydroelectric

- Solar Solar

- Wind

- Geothermal

- Marine (Wave and Tidal)

- Biofuels (Biomass, Bioethanol and Biodiesel)

RE technology options:RE technology options:


Major Reference:Major Reference:

Solar energy: Trends and enabling technologies (by V. Devabhaktuni, M. Alam, S.S.S.R. Depuru, R.C. Green II, D. Nims, C. Near) Renewable and Sustainable Energy Reviews, Vol. 19 (2013): 555–564


The earth receives a huge amount of energy in the form of solar radiation.

On average, it is 1,700 kWh/m2/year (= 194 W/m2)

The total amount received on the planet’s surface is equal to approximately 10,000 times the global energy consumption.

Average annual global solar energyAverage annual global solar energy


Average annual global solar energyAverage annual global solar energy

Source: NASA 2008

Clear sky insolation, incident, horizontal surface (kWh/m2/day)

7.5

7

6

5

4

3


is a technology by which sunlight is used to directly warm water or air without involving electricity.

Major solar energy conversion technologies:Major solar energy conversion technologies:

Solar Thermal (Solar T):

are arrays of cells containing a semiconductor material that converts solar radiation into direct current (DC) electricity.

Solar Photovoltaics (Solar PVs):

is a technology by which sunlight is focused by mirrors or reflective lenses to heat a fluid in a collector at high temperature.

Concentrated Solar Power (CSP):


is a technology by which sunlight is used to directly warm water or air without involving electricity.


Solar Thermal (Solar T):


Solar heating capacity was 185 GWh-thermal in 2011.

Solar Thermal: Solar Thermal: Solar water heaters


- Passive solar water heaters- Active solar water heaters

Solar Thermal: Solar Thermal: Solar water heaters


Solar Thermal: Solar Thermal: Passive solar water heater

- It consists of an absorption mechanism.- The absorption mechanism is typically some type of copper tubing (in various configurations) that are painted with a coating to improve efficiency. - Water (or air) is sent through the absorption piping system where it is heated.


Solar Thermal: Solar Thermal: Passive solar water heater


It consists of the following:

- an absorption mechanism

- a transfer mechanism

- a storage tank

Solar Thermal: Solar Thermal: Active solar water heater


Solar collector

To taps

Tank

Cold water feedPump

Controller

Boiler





Solar Thermal: Solar Thermal: solar water heaters

Flat plate solar collection system

Evacuated tube solar collection system



is a technology by which sunlight is focused by mirrors or reflective lenses to heat a fluid in a collector at high temperature.

Concentrated Solar Power (CSP):


Concentrated Solar Power (CSP):Concentrated Solar Power (CSP):

In CSP systems, sunlight is focused by reflective lenses to heat a fluid in a collector to high temperatures.

I. Purohit, P. Purohit / Energy Policy 38 (2010) 3015–3029

Prof. R. Shanthini Jan 26, 2013 http://www.greenrhinoenergy.com/solar/technologies/cst_technologies.php

CSP for electricity generation: CSP for electricity generation: Parabolic trough

Prof. R. Shanthini Jan 26, 2013 Source: http://en.wikipedia.org/wiki/Parabolic_trough

A solar parabolic trough is constructed as a long parabolic mirror (usually coated silver or polished aluminum) with a Dewar tube running its length at the focal point.

Sunlight is reflected by the mirror and concentrated on the Dewar tube.

The fluid (eg. Oil) running through the Dewar tube is therefore heated up.



The trough is usually aligned on a north-south axis, and rotated to track the sun as it moves across the sky each day.



Steam Turbine

Steam Generator

ElectricGenerator

Condenser

Cooling Tower

Thermal oil is circulated in a closed loop

Solar Troughs

Source: http://www.solarpanelsplus.com/parabolic-trough-collectors/

Solar energy trapped by solar troughs heats the thermal oil.

Oil circulating in a closed loop heats high volumes of water to generate steam at high temperatures (up to 400oC).

Steam turbine generates electricity (at about 30% conversion efficiency).



- 354 MW installed capacity - power 232,500 homes- have a total of 936,384 mirrors - cover more than 1,600 acres (6.5 km2) - lined up, the parabolic mirrors would extend over 370 km.- 3000 broken mirrors (mostly by wind) per year are replaced

Source: http://en.wikipedia.org/wiki/Solar_Energy_Generating_Systems

Solar Energy Generating Systems (SEGS) consists of nine solar power plants (built between 1984 and 1990) in California's Mojave Desert, where insolation is among the best available in the US.


http://upload.wikimedia.org/wikipedia/commons/4/40/Solarplant-050406-05.jpg


http://www.abengoasolar.com/corp/web/en/technologies/concentrated_solar_power/power_tower/index.html

CSP for electricity generation: CSP for electricity generation: Solar tower




- There is a central tower receiver surrounded by a field of mirrors (called heliostats)

- The mirrors (tracking the angle of the sun) concentrate the solar radiation onto a central heat absorber situated in the tower.

- The temperature of the fluid in the absorber on the tower can reach up to 500oC to 1000oC.

- The fluid is used to heat water and run the steam turbine that produces electricity.

http://www.greenrhinoenergy.com/solar/technologies/cst_technologies.php





Solucar PS10 (in Spain) is a commercial solar thermal power tower-based plant

http://en.wikipedia.org/wiki/Solar_power_tower



- Solar tower is 115 m high, 40-story tower where a solar receiver and a steam turbine are located

- 624 movable mirrors (called heliostats) with 120 m2 surface area each

- four years to build

- cost 35 million Euros

- 11 MW installed capacity

Facts on Solucar PS10:

http://en.wikipedia.org/wiki/PS10_solar_power_tower



If heat received could also be stored in a thermal storage media, the parabolic-trough and central tower CSP plants can reduce the effects of solar intermittency by producing electricity at night.

http://www.greenrhinoenergy.com/solar/technologies/cst_technologies.php

Storage media used are: - pressurized steam- concrete- molten sodium nitrate - molten potassium nitrate- purified graphite

CSP for electricity generation:CSP for electricity generation:

Documents

Hydroelectric Solar Wind Geothermal Marine (Wave and Tidal)