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Sun 5 Aug 2007 10:36 AM

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Solar solution

The latest developments in the worldwide use of solar power for electrical and thermal energy.

The demand for electricity is dramatically increasing in many parts of the world. The estimated global growth of electricity consumption is 2.7% per year; in the Middle East, annual increases are expected to average about 3% until 2030.

As environmental issues squeeze the conventional development of electricity supply systems based on hydrocarbon fuels, alternative sources of energy are becoming mature enough to acquire high shares of the market. In recent years there have been important advancements in both the research and use of renewable energy. Solar energy is currently a US $11 billion (AED40 billion) worldwide market and interest in this sector is increasing in many areas of the world, especially those where sunshine is abundant, such as the Gulf region.

Methods to convert solar energy to electricity have been developing over many decades and the research of Lebanese inventor Hassan Kamel Al-Sabbah who died in New York in 1935 is proof of how old this dream is. Today things are starting to look much brighter for the solar power sector and the list of projects being undertaken throughout the world is growing.

Huge solar power plants are now being developed in Europe and the United States of America (USA). The European Commission (EC) foresees at least 1GWe implemented in Europe by the year 2010 and after this year, the World Bank (WB) predicts a cost reduction in the production of solar power to below 6 US cents/kWh, which is very promising for its future use.

The difference between projects supported by the EC and those supported by the WB is that the EC only sponsors pure solar plants, whereas the WB focuses on the integration of solar into combined-cycle plants in sunny, developing countries. In addition to governments and international development agencies, private investors and commercial lenders are slowly beginning to see the opportunities of solar power.

There are three major factors currently stimulating investments in solar power:

Rising fuel costs- with over 80% of today's energy produced from fossil fuels, high oil and gas prices are making renewable energy more competitive in the power market;

Environmental concerns- a byproduct of burning fossil fuels is carbon dioxide, perhaps the greatest contributor to global warming. Fears about this phenomenon have triggered public and political demands for renewable energy;

Engineering advances- in 1980 the cost of generating solar power with silicon cells was around US $30/W (AED110/W), today it averages $3-4/W. New technology currently being applied is expected to bring the cost down to below $1/W.

Solar technologies

Several different technologies are now available for the harnessing of solar power. The most developed of these are:

• Parabolic trough solar electric generating system (SEGS);

• Central receivers power plant;

• Solar pond power plant;

• Photovoltaic technology;

The first three of these come under the banner of solar thermal (ST) technology. In general, they use a collector to convert sunlight into heat energy. Photovoltaic (PV) technology turns sunlight directly into electricity by means of absorbent semiconductors. In both cases, solar energy has been confirmed as a reliable and proven technology for producing clean energy.
The deployment of ST has grown quickly in Asia and Europe and is currently the most widely used rewable energy technology in the Middle East, while the production of PVs has increased during the last decade in Japan as well as Europe. Japan is currently ahead of every other country in terms of annual MW capacity, while Germany is at number two. Moreover, the imposing of new regulations that will increase the uptake of these technologies should be noted. In Barcelona, Spain for example, all new and remodelled buildings must now incorporate ST technology.

From an economical point of view, solar thermal technology is far less expensive per delivered energy unit than PVs:

• ST requires five times less area per delivered energy unit than PV;

• ST technology costs four to six times less investment per watt than its PV equivalents;

• ST has an efficiency level that is almost double that of PV technology.

However, from an environmental perspective, PV technology produces ‘green energy', which is pollution-free in terms of CO2 emission as illustrated in the graph below. It is also worth noting that although solar ponds may seem financially attractive, these are predominantly only practical in agricultural areas as it requires a pool of water to absorb and store the energy.

In the USA, solar power is finally being seen as a solid opportunity for the production of energy. On 7 June 2007 a 64MW solar thermal power plant came online near Boulder City, Nevada. The new facility is one of the largest of its type to be built in the world and meets the energy demands of about 40,000 households.

The parabolic trough power plant comprises three main components: mirrors, receivers and turbine technology, with 19,300 receivers forming the heart of the system. The receivers convert energy from the sun into electricity by concentrating solar radiation from the parabolic mirrored trough reflectors, which increases the temperature of the thermo-oil heat transfer fluid flowing through the receivers to over 398°C. This heated fluid is then used to turn water into steam, which drives a turbine and in turn generates electricity. The Nevada installation is expected to open up new opportunities within the solar thermal industry throughout the world.

On the PV front, new technology is already making the difference for many investors. The vision is to turn every dead rooftop space into a small power plant using improved PV technology, which would provide tremendous opportunities for an increase in the uptake of PVs. Other companies are improving the pv silicon wafers by introducing thin-film cells that can be integrated into glass or other materials to use on building facades.

And while the pressure is mounting to provide timely electricity to the huge developments currently underway in countries throughout the Gulf, producing clean energy in those countries where the CO2 emission per capita is among the highest in the world is certainly a must. The abundant solar energy in the region has been going unused at least until recently. Various developments are now underway however that are changing this. It was recently announced that the first solar power plant in the region is scheduled to be operational in Abu Dhabi in 2009. This will have a capacity of 500MW.
This is an important move that must be replicated persistently. Standing atop a sea of oil should not defer plans to complement the energy sources in the region and now it is the right time to start.

Sunshine statesThe uptake in the use of solar technologies in the Gulf region has risen greatly over the past year, reports MEP Middle East.

In Abu Dhabi, plans are underway for the construction of a US $350 million (AED1.3 billion) 500MW solar power plant. The project is scheduled to be operational in 2009 and forms part of the Emirate's plan to move away from a reliance on hydrocarbon fuels.

In another venture, in February 2007 the Abu Dhabi Future Energy Company (ADFEC) signed an agreement with Massachusetts Institute of Technology to establish the Masdar Institute of Science and Technology. This is the centrepiece of the Governments's regional economic development program the Masdar Initiative, which is the driving force behind much of the adoption of solar technologies. The Masdar Institute will promote and develop new industries using renewable energy and resources. Developments already underway include pv and concentrating solar power projects and a world-scale polysilicon factory is being built to provide additional ventures such as the manufacture of PV cells.

In Dubai the Government has announced the development of a Renewable Energy Division, which will be responsible for renewable power generation, green buildings plus energy and water conservation. And developers throughout the region are also waking up to the benefits of solar power, with some major developments including solar thermal and pv panels.

Nakheel, for example, included solar panels in its Shoreline Apartments development on Dubai's Palm Jumeirah to produce domestic hot water. The firm is also examining the potential of solar power for air conditioning systems. Pacific Control Systems also made use of solar energy at its new Jebel Ali hq. Here, around 50kW of electricity is generated by rooftop PVs and a ST panels provide 90TR for the air conditioning system.

And as more products come onto the market and prices drop, the uptake is set to increase further throughout the entire region.

Wissam Yaacoub is a senior project engineer with MEP contractor Thermo.

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