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While many countries still back the wrong horse by supporting its growth with fossil fuels, some emerging countries bet on solar energy to build a sustainable economy just as well as a solution to energy deserts, especially in MENA and across the African continent.
Experts of alternative energy are calling Nigeria ‘the Saudi Arabia of renewable energy’. “Nigeria is the Saudi Arabia of renewable energy sources and, if properly utilized, Nigeria can realize its place in the world as a great power,” says economist and activist Jeremy Rifkin.
The rising African country has set a target of meeting 40 percent of its energy needs through renewable energy by 2020.
And in this effort, the country is relying on renewable solar power. With an average of 320 to 350 sunny days a year and vast tracks of deserts and farm land, Nigeria could easily generate 5,000 trillion KWh of solar energy, says Dr. Patrick Owelle, a Solar Energy Scholar and Research Fellow.
Expert predict that the country could install around 1,000 GW of solar generation — equivalent to 40 times the current peak power demand (about 25 GW) — using just 0.5 percent of its land.
Nigeria is not a single case in a world that is looking to reduce carbon footprint and foster alternative and renewable sources of power. And in the race, solar seems to be way ahead compared to other renewables.
However, in parts of the world where there is a rising demand for alternative power, as in Nigeria, there is also a debate about which solar technology would best suit a country or region.
While it is undeniable that solar energy is far more dependable than other forms of renewable energy, there is a rising debate whether to use concentrated solar power (CSP) or photovoltaic (PV) cells.
Dino Green, a Mechanical Engineer and a qualified accredited expert in certification of energy performance of buildings identifies the criteria that is generally debated while choosing the solar power technology to be used.
“Energy markets consider three main factors in deciding on power sources – cost of energy, ancillary services and power dispatch-ability on demand,” Greene says.
Experts say that a time is coming where there probably would be no competition between the two technologies and they may work together to increase solar energy penetration into the power industry.
The primary advantage of CSP technology is its ability to store solar energy. Silvio Marcacci Silvio, Principal at Marcacci Communications, a full-service clean energy and climate policy public relations company based in Oakland, CA, even defines CSP technology as “the technology that will save humanity”. “CSP could meet up to 7% of the world’s projected electricity needs in 2030, and 25% by 2050”, says Silvio.
Given all the strong arguments in favor CSP, the technology is criticized for taking up a large area to install it traditionally uses static parabolic mirrors to concentrate solar energy and then passing that down the line through a system of heated water. This heated water runs a turbine that produces electricity.
However with the advent of the Compact Linear Fresnel Reflector or CLFR technology, CSP can shed off the criticism of taking up space. French firm Sun CNIM is the pioneer in LFR technology for solar power generation and has successfully set up and operated a pilot project in France. The company says that the technology has moved beyond the pilot stage and Sun CNIM is now ready to commercialize the technology for large solar power projects.
Moreover, “Sun CNIM’s Fresnel technology and direct steam generation avoid the use of hazardous fluid such as thermal oils, making them the ‘cleanest’ technologies currently available,” says Sun CNIM in a statement.
Linear Fresnel is a line-focusing technology consisting of reflectors that track the sun in one axis and focus the beam radiation onto fluid-carrying receiver tubes.
IRENA’s 2012 CSP report (*) draws out the advantages of LFR technology over trough technology. The report states that main advantages of Fresnel CSP systems compared to troughs are that Linear Fresnel Collectors (LFCs) can use cheaper flat glass mirrors, which are a standard mass-produced commodity, and that they require less steel and concrete – as the metal support structure is lighter – which simplifies the assembly process and leads to cost reductions.
“According to the status of development in 2012, the parabolic trough seems to be at the end of its evolution because of the temperature limitations, complicated manufacturing and toxicity of the HTF. Therefore, I would prefer the Fresnel technology and the solar tower technology. Both use nearly flat mirrors which enable a higher share of local production”, says Dr.-Eng. Hani El Nokraschy, Co-Founder and Vice Chairman of the Supervisory Board of Desertec Foundation.
According to the French firm Sun CNIM, LFR is easily integrated into the grid and can be operated on isolated sites. “The technology is flexible where the component modules can be installed in accordance with capacity requirements and can be act as a hybrid to other alternative power sources like biomass, fossil fuel or methanization plants, etc,” says Sun CNIM communiqué.
Fresnel may give an additional advantage because of shadowing the ground. This enables planting under the mirror roof protecting the plants from the burning sunrays and thus saving irrigation water”, Dr. Nokraschy says.
Another advantage of the LFR technology is the reduced optical losses and less mirror-glass breakage since the wind loads on LFCs are smaller according to the French innovation technology firm Sun CNIM.
Moreover, the mirror surface per receiver is higher in the LFC than in parabolic trough collector, which is important given that the receiver is the most expensive component in both technologies.
“Until recently, linear Fresnel plants were mainly pilot projects. But with remarkable advancements, the technology is quickly gaining operational parity with the parabolic trough, and the world’s largest Fresnel power plant has already started operation in Spain,” says Heba Hashem, a technology expert based in UAE.
With the debate over choice of technology for solar energy nearly over, researchers and businesses are now concentrating on ways and means to develop technologies that can better the storage of solar power. This is considered to be the next big step in solar power attaining maturity.
(*) http://www.irena.org/documentdownloads/publications/re_technologies_cost_analysis-csp.pdf