the blog of TECNOPOLIS.EU

an italian forum about Science & Technology (english version coming soon)

Wednesday, June 07, 2006

The Power of Sun

The major obstacle for spreading solar energy is the low conversion efficiency into electrical power (at the present 10-15%). This together with high energetics cost to build solar systems makes Solar Energy an option with low EROEI and high costs pro KWh.

But the sector is booming for R&D and the convinience of solar power will probably increase in the next 5 years. The target is an increase in efficiency up to 30/40% and EROEI about 10:1

I report here some interesting and promising projects around the world:

- Concentrated Solar Power (CSP) Plants -
"CSP plants use different kinds of mirror configurations to convert the sun's energy into high-temperature heat. The heat energy is then used to generate electricity in a steam generator" -USA Department of Energy
three types of CSP technologies are currently being developed:

CSP 1- Trough Systems - the most successful and cost-effective CSP system design at present.
Take a look at the SEGS system a 330 MW thermal CSP plant based in California:

CSP 2 -dish/engine systems,

CSP3 - power towers/heliostat - array of flat, moveable mirrors to focus the sun's rays upon a collector tower. Energy trasnferred via Liquid Sodium (metal with a high heat capacity, allowing that energy to be stored and drawn off throughout the evening).
A 100 MW Solar Power Tower in South Africa:

- CSP units for direct conversion into electricity (without steam generation)
They concetrate solar energy reflecting it on a small PV cell. The most advanced version used 2 PV cells (one with silicium , one with InGaP) adsorbing diacroic separated radiatiation from the mirror improving efficiency (each PV cell is optimazed for a given spectrum of the source radiation). This project is carried on from Univ. of Ferrara / Physics Dep. and SGS-Future
[ - this source is in Italian]

[Pictures: 1.cristinevadai (USA), 2 ips-solar (USA),3 monsterdesign (korea), 4 sgs-future(Italy)]

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