RAPID development in solar energy technologies has made it an alternative to fossil-fuel power generation in many countries.
But Pakistan does not have to depend on borrowed ideas for generating bulk solar power at a high cost, when other economical options are available.
In a bid to overcome electricity loadshedding, the Punjab government has moved to tap possible energy resources for power generation on fast-track basis. An agreement was signed by it in July last year with a German firm to establish a 50-mw solar energy unit at Jalalpur Pirwala, Multan, apparently without conducting any project feasibility study. The first-ever solar farm costing $150 million, was to be installed within six months. But there is no physical progress achieved as yet.
Likewise, the government of Sindh has allowed an independent power producer (IPP) to construct a 50-mw solar power generation unit at Dhabeji and allotted 150-acres land to the investor at a nominal cost. The project, for which an agreement was signed by the sponsor with the same foreign company during the same period at a total cost of $125 million, was scheduled to generate power commercially by December 2011. So far, no construction activity has been undertaken at the site.
Both the projects are based on solar photovoltaic (PV) system and are proposed to be connected to the national grid. Seemingly, the projects are non-starters for a number of reasons. First, solar thermal electricity is the most expensive among other renewable energy resources.
In case of hydropower, and even wind energy, availability, reliability and affordability of power is comparatively much higher, since solar units usually attain the rated output only for about two hours a day around noon.
Also, capital cost is higher. Cost per mw for these solar projects works out to be $3 million, whereas hydropower costs $1.5 million and coal-fired $1 millon per mw, according to international markets.
Second, solar technology selected is not appropriate for on-grid application as its adoptability to the existing grid remains problematic, and in some cases, disruptive to the grid.
The power generation occurs only when sunlight is strong, weather not cloudy and supply to grid fluctuates broadly resulting in irregular, intermittent feed.
Third, the plant module, technology selected and foreign partner are apparently not suitable. The German company specialises in commercial and residential PV systems, having individual installations of maximum one megawatt only, and not having a utility-scale system.
There are no references for large-scale utility projects either in Germany or in export market. It has recently completed a 463-kW commercial project in the UK (equivalent to meet energy requirements of 125 homes on yearly basis).
Primarily, there are two solar systems for generation of electricity using solar energy – directly, using PV system, which is the most common, and indirectly, utilising concentrated solar power (CSP) system. By the end of year 2010, global installed capacity of solar PV power was about 40,000 mw. Germany alone ranked as the world leader in the field has installations of 17,370-mw cumulative capacity.
Normally, the maximum size of a solar electric system is of 20-mw capacity. The Sarnia Solar Project in Ontario, Canada has just become the largest PV solar power plant in the world with the recent quadrupling of its size from 20-mw to 80-mw capacity. The CSP technology is employed for large-scale power generation and has the ability to store energy as sunlight generating strong heat that, in turn, is used for power steam turbine.
The CSP technology, commercially developed in the late 1980s, is now proven and has an installed capacity of over 1,000 mw world over. There are four types of CSP plants: (i) parabolic trough, (ii) compact linear Fresnel reflectors, (iii) dish Stirling (parabolic) and (iv) solar power tower. International Energy Agency (IEA) forecasts that technology could be developed as a source of bulk power in peak and intermediate loads by 2020 and further, in base load, by 2030. Thus, within two decades the CSP technology might be able to compete with coal-fired power generation.
Currently, Mojave Desert of California has the world’s largest power plant, of 354-mw capacity, based on the CSP technology.
Now, Abu Dhabi plans to develop a 100-mw solar power plant adopting the CSP technology. Construction of the plant, which would cost $600 million, is scheduled next month.
Pakistan has abundant solar resources, while almost half of its population is devoid of electricity connectivity. There are about 40,000 villages with more than three million households that are without access to electricity and will remain so for long if allowed to depend on grid connection. Nevertheless, low-technology solar option offers long-term solution for electrification in these far-flung areas.
Based on PV, stand-alone solar systems are being used economically as a source of electric power for remote areas not connected with the grid. By the year 2010, a total of about 650 kW of PV have been installed for village electrification in Sindh and Balochistan. In addition, another 4,500 houses in Dalbandin (Balochistan) have recently been energised with solar power.
Moreover, stand-alone solar systems in the range of 600 watts to 5 kW have been installed in Sindh under the prime minister’s initiative.
Various NGOs have also electrified 485 houses in the FATA, about 2,000 houses in the AJK, and 12 solar panel systems of combined capacity of 3,600 watts in ten villages of Ziarat district (Balochistan). Other applications of solar energy in these areas are solar space heating, water heating, lighting, cooking, process heating, water pumping and telecommunication, etc.
The trend is being followed in urban areas. Besides street lights, a number of public and commercial buildings, including mosques, hospitals and parks, have been illuminated through solar energy. List covers the Quaid-e-Azam’s mausoleum and two systems of 180-kW each on grid solar system in Islamabad.
A number of solar thermal appliances such as solar cookers, solar water heaters and solar lights have been introduced in the country. Punjab also plans installation of tube-wells to be operated with solar energy at a cost of Rs1.36 billion.
Large-scale solar thermal power generation cannot play, and should not be allowed to play, a significant role in meeting power demands mainly for the reason that immense potential exists for hydropower and coal resources, which are abundant and cheap, and comparatively have many advantages for development under local conditions. This potential is required to be harnessed optimally and speedily. Simultaneously, solar PV system also needs to be developed further.
2011년 9월 12일 월요일
2011년 9월 11일 일요일
Sheffield solar power sees city top table for renewable energy installation
Sheffield solar power adoption since the introduction of feed-in tariffs has been so high that it is now the city with the highest rate of renewable energy installation per head. Photograph: Simon Burt/PA
Sheffield shines out as the soar-away winner of the solar stakes in the UK, with more solar power generation added in the city per household than in any other British city, according to a league table published on Monday.
Northern cities have been the unexpected winners from the boom in renewable energy that has followed the introduction of feed-in tariffs to pay for power generated by households, which are popular as they offer a guaranteed income stream as well as free electricity.
Nearly 2 megawatts of capacity have been added in Sheffield in the last 15 months, and Leeds comes second in the league table, with more than 1MW of capacity added. They are followed – though at quite a distance – by Bristol, Bradford and Birmingham, when renewable energy installations per person are counted.
London has added more renewable power than anywhere else, with more than 3.2 megawatts of capacity added in the 15 months since feed-in tariffs became available. But when assessed per head, it comes only sixth in the UK.Sheffield has benefitted from a strong push by the local council to encourage the take-up of renewable power, and in particular by plans to give people living in social housing access to the technology, said Colin McNaught, knowledge leader on renewable energy for AEA Group, which carried out the research on which the league table is based.
He said that the unexpected success of northern cities in installing new renewable power flew in the face of expectations that the south would benefit most from photovoltaic installations.
McNaught said the boom was likely to continue, both in terms of domestic solar power installations and in bigger renewable energy projects. He said that there had been a marked increase in applications for large-scale solar parks, since the government announced recently that only large scale installations begun before August would be eligible for the higher rate of feed-in tariff.
McNaught predicted that this would result in much more generating capacity being registered in the coming months, and he pointed to a new £100m fund to be offered by Barclays Bank to assist farmers to finance renewable energy projects.
Around the UK, in the first 15 months to 30 June 2011, more than 160MW of low carbon electricity generation has been applied for under the feed-in tariff scheme, with a total of 44,460 separate installations, according to data collated by the electricity regulator Ofgem and the Department of Energy and Climate Change. About three quarters of the installations are solar power, though in Scotland wind is predominant.
AEA, an energy and environmental consultancy, has calculated the rate of growth in capacity in microgeneration at about 400% since the feed-in tariff was launched in April 2010. Photovoltaic technology – solar panels – have been at the forefront, with an increase in generating capacity of about 900%, though part of this was owing to the pent-up demand as households delayed putting up panels until the feed-in tariffs came into force. Over the same period, wind generation and hydro electricity – some smaller installations of which also qualify for the enhanced feed-in tariffs - have also grown strongly.
2011년 9월 9일 금요일
Wind turbines harness MRI tech
GE Global Research
GE researchers are applying more than 30 years of experience developing superconducting magnets for MRI systems to design an advanced generator for large-scale wind power.
MRI systems are the tube-like contraptions that make images of damaged hearts, torn ligaments, brains, and other body tissues. Instead of X-rays, the images are made with superconducting magnets, which are electromagnets made from coils of superconducting wire.
GE has spent more than 30 years working on the magnets in MRI systems and now thinks they can apply what they've learned to make a more powerful and cost efficient wind turbine. The U.S. Department of Energy recently granted the company's research arm $3 million and two years to get cracking.
The goal is a wind turbine that is close to three times larger than the company's largest model, able to operate in the 10 to 15 megawatt range. One MW can power between 240 and 300 U. S. homes per year, according to the American Wind Energy Association. Most wind turbines in the market are in the 2-4 MW range.
GE's new turbine technology is a direct-drive system where the shaft of the rotor blade connects directly to a low-speed generator that uses permanent superconducting magnets to generate power.
Conventional generators produce magnetic fields made of copper coils, "which are resistive and lossy and produce a lot heat and hard to design with in a compact manner," Kiruba Haran, a manager in the electric machines lab at GE Global Research, explained to me Wednesday.
All direct-drive wind turbines on the market today overcome this problem by using magnets made from rare earth materials. One problem is most easily mined rare earths today are locked up in China.
Superconducting magnets are also more energy dense than rare earth permanent magnets "so the machine tends to be much lighter, more compact, and would enable you to scale up to a much higher megawatt rating in an easier manner," Haran said.
These new direct-drive systems are also considered more robust than traditional systems that connect the rotor shaft to a gearbox, which steps up relatively slow blade speeds of around 50 rotations per minute to the 1,000 rpm range needed by most generators to create electricity.
According to GE, gearboxes work well in turbines currently deployed, but they get too expensive when scaled up to the larger next generation wind platforms eyed by the government and industry mostly due to their heavy, clunky materials and maintenance costs.
The superconducting magnets reduce weight requirements since they are able to generate high magnetic fields without using as much heavy iron. "With the superconductor, we are trying to get the best of both worlds — bring the machine size down and have no gear box," Haran said.
Doing this, however, is a challenge. For one, superconducting magnets operate at temperatures approaching absolute zero. The DOE funding, Haran said, takes away some of the financial risk involved with translating MRI technology to a wind turbine.
"The applications are different," Keith Longtin, a wind technology expert at GE said in a news release, "but the basic technology is the same."
2011년 9월 8일 목요일
Solar Comes of Age: SolarCity to Double PV Systems on American Homes by 2016
A leading American solar company is set to begin the largest residential rooftop project ever undertaken, effectively doubling the number of solar systems currently on homes around the U.S.
Armed with funds from two major investment banks and a loan guarantee from the Department of Energy that will cover close to a third of the $1 billion project, SolarCity plans to install 160,000 solar photovoltaic systems on houses and other buildings on military bases around the country in the next five years.
As a “solar services” provider, SolarCity owns, operates and maintains the systems, and sells the electricity to the end-user. By working with investment banks to pool together often-complicated state and federal incentives, the company streamlines the process and simply offers the customer solar electricity — often at prices lower than current electric rates.
Given the relentless attack on green jobs and the DOE’s loan guarantee program in recent weeks, this story is particularly relevant.
SolarCity says it will try to employ American veterans and family members for the 750 people needed to complete the project, showing that green jobs do indeed exist. The company has seen extraordinary growth in recent years. After starting in 2006 with just two people, SolarCity has added over 600 employees since 2006. And this latest project will again double the staff.
The $344 million loan guarantee will leverage $1 billion from private investors Bank of America Merrill Lynch and USRG Renewable Finance. This comes after Google invested $280 million in a fund for SolarCity installations this past June.
With the bankruptcy of the solar company Solyndra last week, the Department of Energy loan guarantee program has been under major attack. What critics don’t mention is that the $535 million set aside for Solyndra is only two percent of all loan commitments to clean energy companies, and is dwarfed by the tens of billions of dollars leveraged by the program.
The DOE loan guarantee program is designed to fund “first-of-a kind” projects. As an ambitious 160,000-system undertaking, this project is exactly that. But it’s also a very safe bet. SolarCity is a company with a proven business model and a history of strong, sustainable growth.
You can bet that the critics who claim green jobs “don’t exist” or solar power “doesn’t work” will be ignoring this piece of news.
As a “solar services” provider, SolarCity owns, operates and maintains the systems, and sells the electricity to the end-user. By working with investment banks to pool together often-complicated state and federal incentives, the company streamlines the process and simply offers the customer solar electricity — often at prices lower than current electric rates.
Given the relentless attack on green jobs and the DOE’s loan guarantee program in recent weeks, this story is particularly relevant.
SolarCity says it will try to employ American veterans and family members for the 750 people needed to complete the project, showing that green jobs do indeed exist. The company has seen extraordinary growth in recent years. After starting in 2006 with just two people, SolarCity has added over 600 employees since 2006. And this latest project will again double the staff.
The $344 million loan guarantee will leverage $1 billion from private investors Bank of America Merrill Lynch and USRG Renewable Finance. This comes after Google invested $280 million in a fund for SolarCity installations this past June.
With the bankruptcy of the solar company Solyndra last week, the Department of Energy loan guarantee program has been under major attack. What critics don’t mention is that the $535 million set aside for Solyndra is only two percent of all loan commitments to clean energy companies, and is dwarfed by the tens of billions of dollars leveraged by the program.
The DOE loan guarantee program is designed to fund “first-of-a kind” projects. As an ambitious 160,000-system undertaking, this project is exactly that. But it’s also a very safe bet. SolarCity is a company with a proven business model and a history of strong, sustainable growth.
You can bet that the critics who claim green jobs “don’t exist” or solar power “doesn’t work” will be ignoring this piece of news.
2011년 9월 7일 수요일
2011년 9월 6일 화요일
Shining the light on solar energy
 "Photo: © NCSU Student Media 2011")
© NCSU Student Media 2011
Working at the NC Solar Center, Pennsylvania engireers Jeff Sloat from Summit Electric, and Matt Wilson, from Secco Inc, install solar panels as part of a national training course put on by SunPower Corporation April 14.
According to Lupo, passive solar energy pertains mostly to the construction of a building. Examples of this type of solar energy are seen throughout N.C. State's Solar House. It has amenities like natural lighting fixtures, which maximize outdoor lighting in the interior of a building.
The solar house also includes a large, south-facing sunspace—a two-story room with large windows to heat the house in the winter. The solar house also has thick, brick Trombe walls that help heat the bedrooms by providing solar heat. These walls store heat and slowly release it throughout the day. The basic concept of passive solar energy is using what is already there without having to convert it. These are very basic forms of solar energy, but take planning when building a structure.
Active solar energy is the more commonly recognized of the two, with its poster child: the solar panel. Yet, solar panels, while being well-known, are not well-understood.
According to Lupo, solar panels consist of two layers of silicon with a metal conductor in between. One of the layers is ingrained with atoms that have fewer electrons, usually boron atoms, the other with atoms that have more electrons, like phosphorous. When this system is exposed to sunlight, photons, the source of energy from the sun, force the electrons off of their atoms, which then travel between the two layers through the metal conductor, resulting in the production of electric current.
This current is then sent to the electric company via the grid, or the network that provides electricity from the electric company to the consumer. The electric company uses this energy to support the grid and pays whomever provides the energy. Thus, buildings that have solar panels do not necessarily run on solar energy, but they do provide this environmentally-friendly energy for the grid to use.
This raises the question of whether or not people who harness the sun's energy through solar panels are doing it for the economic reasons, or strictly for the environment.
"Most people go solar for environmental concerns, but there is an economic incentive," Lupo said. "[Solar is] not a quick payback, so you have to have interests in other areas like the environmental impact."
The initial cost of converting a small, residential structure is about $35,000, which Lupo rationalizes as being a reason for someone to have environmental concerns and economic interests. However, once someone decides to use solar panels, there are significant tax incentives. The state has a 35 percent tax incentive, and there is also a 30 percent federal tax incentive for the installation of a solar panel system. With these incentives, the cost to install solar panels could actually be cut in half, making the payback period significantly shorter.
With a rise in alternative energy use, people may wonder what direction solar energy is headed in the years to come. Although there is research going into futuristic products like PV ink, a solar panel technology in ink form, Lupo said these ink products will not be market ready for quite a while.
However, Lupo believes that significant improvements will be made in the efficiency of active solar energy products in the near future. This will also effectively shorten the payback period of going solar by increasing the output of current, according to Lupo.
Another issue is energy storage. As it is now, the energy company grid is acting as the storage space for solar energy producers; however, if an energy storage device is made and produced, this would be a new avenue for solar energy, allowing consumers to effectively store their own energy. Lupo said this can improve cutting costs.
"The more people who invest in it [solar], the cheaper it's going to be," Lupo said.
2011년 9월 1일 목요일
DOE approves loan for solar power plant
The Dept. of Energy has approved a partial guarantee on an $852 million loan to support the development of the Genesis Solar Project in California
U.S. Energy Secretary Steven Chu today announced that the Dept. of Energy finalized a partial guarantee for an $852 million loan to support the development of the Genesis Solar Project. The Genesis Solar Project is a 250 MW parabolic trough concentrating solar power (CSP) facility that will increase the nation’s currently installed CSP capacity by about 50%. NextEra Energy Resources, LLC, the project sponsor, estimates it will fund approximately 800 construction jobs and 47 operating jobs. The project is located on land managed by the Bureau of Land Management in Riverside County, California.
“This project creates jobs, avoids greenhouse gas emissions and helps strengthen our nation’s renewable energy future,” said Secretary Chu. “With the support of loan guarantees, we will enable the deployment of clean, renewable sources at scale, which will help bring down the cost of solar power in the years to come.”
The partial loan guarantee will support a utility-scale deployment of proven and scalable parabolic trough solar thermal technology that has been used commercially for more than two decades. The project is expected to produce enough electricity to power over 48,000 homes and avoid over 320,000 metric tons of carbon dioxide emissions annually. Power from the project will be sold to Pacific Gas and Electric Company. The lender-applicant, Credit Suisse AG, submitted the application under the Financial Institution Partnership Program (FIPP). Through FIPP financing, the Department of Energy guarantees up to 80% of the eligible costs of a loan provided to a renewable energy project by qualified financial institutions.
- Edited by Chris Vavra, Consulting-Specifying Engineer, http://www.csemag.com/
U.S. Energy Secretary Steven Chu today announced that the Dept. of Energy finalized a partial guarantee for an $852 million loan to support the development of the Genesis Solar Project. The Genesis Solar Project is a 250 MW parabolic trough concentrating solar power (CSP) facility that will increase the nation’s currently installed CSP capacity by about 50%. NextEra Energy Resources, LLC, the project sponsor, estimates it will fund approximately 800 construction jobs and 47 operating jobs. The project is located on land managed by the Bureau of Land Management in Riverside County, California.
“This project creates jobs, avoids greenhouse gas emissions and helps strengthen our nation’s renewable energy future,” said Secretary Chu. “With the support of loan guarantees, we will enable the deployment of clean, renewable sources at scale, which will help bring down the cost of solar power in the years to come.”
The partial loan guarantee will support a utility-scale deployment of proven and scalable parabolic trough solar thermal technology that has been used commercially for more than two decades. The project is expected to produce enough electricity to power over 48,000 homes and avoid over 320,000 metric tons of carbon dioxide emissions annually. Power from the project will be sold to Pacific Gas and Electric Company. The lender-applicant, Credit Suisse AG, submitted the application under the Financial Institution Partnership Program (FIPP). Through FIPP financing, the Department of Energy guarantees up to 80% of the eligible costs of a loan provided to a renewable energy project by qualified financial institutions.
- Edited by Chris Vavra, Consulting-Specifying Engineer, http://www.csemag.com/
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