What happens when a module fails in a 1-megawatt photovoltaic system, bringing down a 3-kilowatt string?
If the monitoring system tracks production for each of the two 500-kilowatt inverters, the loss of output will only represent 0.6 percent of a 500-kilowatt array’s capacity — virtually impossible to detect, especially when pyranometers commonly used in utility-scale PV plants measure solar irradiance with a +/- 2 percent uncertainty (or more). Even comparing the output of both inverters would hardly allow detection of the fault: inverters measure power output with a relatively high uncertainty (typically +/- 1 percent to +/- 5 percent).
Arguably, even multiple string failures could go unnoticed until the next inspection when maintenance technicians perform systematic string testing.
In order to quickly detect such failures and minimize the associated energy losses, some PV plants are equipped with string monitoring equipment. This consists of “smart combiners” collecting current (and sometimes voltage) for a string or a small group of strings, and sending this data to the monitoring system where some software analyzes the information and identifies low production string conditions.
String monitoring is a common practice in most European markets, along with string inverter designs for PV systems, which intrinsically provide the ability to monitor at the string level, since each inverter is a string or a small group of strings. In a recently published report about global PV monitoring markets, GTM Research and SoliChamba Consulting estimated that 100 percent of new utility-scale PV plants in Germany in 2012 were string-monitored, along with 95 percent of large commercial systems and 85 percent of small commercial ones (including plants with string inverters).
In other parts of the world like the U.S. and Japan, however, very few PV plants are string-monitored, even in the utility-scale segment. In those markets, the dominant perception is that string monitoring significantly increases the initial cost of the PV system without providing enough yield increase to justify such investment. No independent study has either proved or disproved this theory, and opinions may vary between EPC firms and project developers.
In order to better understand the logic behind this different approach, let’s examine the economics of a broken “3-kilowatt string”. Assuming that the average annual yield is 1,500 kWh/ kWp and the faulty string goes undetected for six months (until the next inspection), the lost production would amount to 2,250 kilowatt-hours. For a 2006-built German plant benefiting from the 40 euro cents feed-in tariff, this would represent a $1,200 loss. For a 1-megawatt system, the additional cost of string monitoring equipment ranges from $10,000 to $15,000, which is the equivalent of $500 to $750 annually over a twenty-year time span (excluding financing costs and installation, which is usually part of overall EPC budget). In these conditions, an average of one string failure per year would justify the investment. For a U.S. plant with a PPA (Power Purchase Agreement) price of 10 cents, however, the same production loss would only be worth $225, so it would take two to four annual string failures on the same 1-megawatt array to justify the investment. This simple calculation goes a long way toward explaining the gap in string monitoring adoption rates between Germany and the U.S.
In the past few years, a new DC array monitoring practice emerged in America, referred to as “zone monitoring” or “sub-array monitoring.”
By collecting sub-array data from the master combiner, zone monitoring provides an intermediate level of granularity for issue detection and diagnostics, at a much lower upfront cost than string monitoring ($3,500 to $5,000 for a 1-megawatt plant). With this approach, the ability to detect subtle issues is more limited, and the guilty string cannot be specifically identified — it is only possible to single out the sub-array that is underperforming because of it. In the case of our previous example, if each 500-kilowatt master combiner includes 15 sub-arrays (for a 33-kilowatt individual capacity), the loss of a 3-kilowatt string represents a 10 percent reduction of the affected sub-array’s capacity — an easily detectable anomaly. GTM Research and SoliChamba Consulting estimate the adoption of DC monitoring in the U.S. in 2012 at 65% in the utility-scale segment, 25% in the large commercial segment, and 15% in small commercial. Most of it is believed to be zone monitoring.
As often in the solar world, the ultimate decision to adopt a technology lies in the hands of the investors and their technical advisors. In Europe, these firms often mandate string monitoring for large-scale plants, and will consider a PV system less valuable if it does not include such monitoring capability. In the U.S., few solar investors have a strong opinion on this topic, and independent engineering firms that validate the production estimates used in financial calculations do not consider any difference in output whether a plant is a monitored at the inverter, sub-array or string level. In such circumstances, project developers and EPC firms are unlikely to invest in string monitoring technology.
Over time, as more data becomes available about module and string failure rates, we can expect the choice of monitoring approach to become less cultural and more financial.
Unleashing Delhi solar potential is an in-depth analysis of the potential for Roof Top in Delhi. Since Delhi is facing a potential electricity crisis. Demand of the Electricity is expected to reach an all-time high of 6000MW this summer. With the crippling power supply situation there is an urgent need to rethink electricity and supply in the city.
Within the last decade Delhi electricity demand rose by an average of 6% every year. From 20 BU in 2002 the demand will reach over 33BU by 2017 a 65% growth. As a capital and second richest state in the country Delhi is in a very good position to take the lead in transitioning to a decentralised,sustainable energy paradigm. For this capital has started a campaign “switch on the sun” campaign. In the coming days the campaign seeks to bring distribution companies, government decision makers, regulatory bodies & electricity consumers all together.
In coordination with RWA’s we have individual colonies like sukdev vihar , Delhi Pledge their commitment for Roof Top solar.Delhi can be 2GW solar city by 2020,the total land are on which Delhi is built could support 123GW therefor 2GW will require only 6% of the city land. The First Step toward positioning solar Roof top solar energy as a solution is to understand its potential in the city.
KOLKATA, India, Aug. 22 — The U.S. Energy Information Administration lists India as the world’s fourth-largest energy consumer. The Indo-Asian News Service reported on Wednesday that the country’s shortage of domestic energy supplies has heightened its interest in renewable energy.
India currently has 211 Giga-Watts of installed electricity capacity; most is generated by coal-powered plants. Coal remains India’s primary source of energy and the country has the world’s fifth-largest coal reserves. Because of insufficient fuel supply, India suffers from a severe shortage of electricity generation, leading to rolling blackouts, which is having a negative impact on the country’s exports. In 2011, India was the 10th-largest economy in the world, as measured by nominal gross domestic product. The U.S. Government’s Energy Information Administration projects India and China to account for the biggest share of Asian energy demand growth through 2035. While India’s primary energy consumption more than doubled between 1990 and 2011, according to the International Energy Agency, India’s per-capita energy consumption remains lower than that of developed countries.
Searching for energy alternatives, West Bengali capital Kolkata may soon get India’s first floating solar power station by the end of next year. The facility has been proposed by Indian solar expert S.P. Gon Chaudhuri.
“Each station would require around 3,000 square feet of space to generate 20 kilowatts of power,” Gon Chaudhuri said. “There are many water bodies that could be used for this. Such floating solar stations would generate more energy as research has shown that if the panels stay cooler, they generate more energy, up by 16 percent.” The project is scheduled to be installed in a pond in Victoria Memorial in the city of Kolkata in India. The floating solar platform is being funded by the Ministry of New and Renewable Energy, and is said to be the first of its kind in India. Reservoirs and dams of hydroelectric power stations are also attractive spots for the floating solar power generator. “This would not only help conserve water for the dry seasons when power generation goes down because of lack of water but would also help us generate extra power – solar and hydro from a single station,”
India’s Ministry of New and Renewable Energy, which has underwritten the research, expects the project to be implemented by 2014. Current cumulative solar installations in India stand at 1,761 megawatts. In 2012 India installed 980 megawatts of solar power installations, with about 557 megawatts installed thus far in 2013.
Many Indian analysts subsequently commented that, as India’s solar market is still in its infancy, starting a trade war could become costly when New Delhi’s prime concern should be to encourage new technologies, competition and free markets. Solar power has the immense capacity to bring in stability to the fluctuating electricity tariffs in India, as it is cheaper than thermal and domestic coal. States have realized that solar sector is positive as most solar radiation in the worst parts of India is better than in the best parts of Europe. Solar is a serious area to work for large scale projects in India.
Solar Energy has a great potential to end the power sufferings, it provides clean energy, removes all the disadvantages provided by the fossil fuels and the added advantage is it creates well paying jobs.
Many studies have proved that solar and renewable energy creates 10 times more jobs than provided by fossil fuel industry.
University of California (UC) report concludes we can expect 86,370 new energy jobs in the U.S. by 2020 if we continue with our current energy mix. But if 20 percent of our energy were to come from renewable sources, then 188,000 to 240,850 jobs could be created, depending on the proportion of wind, solar and biomass energy. The American Council for an Energy-Efficient Economy estimates that 1.1 million jobs could be created in the next 10 years through investments in energy efficiency technology.
Solar offers high paying manufacturing and installation jobs as well as jobs for highly skilled people such as engineers and managers, often in areas of the country struggling with higher unemployment.
Author of the UC report Daniel Kammen, head of UC Berkeley’s Renewable and Appropriate Energy Laboratory says, “Investing in clean energy technologies would both reduce our trade deficit and reestablish the U.S. as a leader in energy technology, the largest global industry today.”
Scope for a ‘green’ career in India
One of the major developments in the Indian solar sector is the JNNSM initiative, which basically aims at generating 20 GW of solar power by year 2020.
In a growing industry like solar power generation, opportunities will also naturally be on the rise.
“As per official statistics, in order to fulfil the 20,000MW installed capacity targets under the Jawaharlal Nehru National Solar Mission, the Indian solar energy industry will need an estimated 300,000 people by 2022 across all domains, profiles and levels,” says Singh. Commenting on the scope for a career in this field, Nayak shares, “The scope is unlimited since PV offers a unique opportunity to solve the 21st century’s energy and environment related problems simultaneously.” He adds, “There are enough opportunities in production and project execution of solar projects as massive plans are being laid by every state.”
At least 20 resident welfare offices in the New Delhi district will soon be powered by the sun. A proposal has been approved for a pilot project under which porta cabins provided by the government to RWAs for office use will have rooftop solar panels. The initial planned solar capacity is 20 kW and is expected to be increased as more areas will be brought under the ambit of the project.
A list of 20 locations has been identified but a final list will be prepared once feasibility of each location is confirmed. “The project will be funded entirely under the ‘My Delhi, I Care’ scheme of Delhi government.
RWAs had been given porta cabins but many of them were finding it hard to function without provision for power. Some have taken up independent connections but are finding it hard to pay bills. The government then stepped in with the proposal for roof-top solar panels. This is the only district in the city with such a provision,” said Nila Mohanan, deputy commissioner, New Delhi. The project will be set up by discom Tata Power Delhi Distribution Limited (TPDDL). Its CEO and executive director Praveer Sinha said that it would be implemented within the next two to four months.
“Each porta cabin will have a 1 kW capacity system which takes the total project up to 20 kW. Each unit will be able to run at least a fan, a tube light and a television with this much supply. If the project is successful, it will be expanded to cover more areas. The power generated through the panels will be free for the users as they will be stand alone arrangements. Each system will cost roughly Rs 1.5 lakh,” said Sinha.
Sources said that a total of Rs 1 crore has been allocated for the project though the initial expenditure would be about Rs 30 lakh. “The remaining amount will be kept aside for the expansion of this project. Roughly 50-odd locations can be covered under this system eventually,” said sources.
Meanwhile, even though Delhi’s renewable power obligation has been identified, sources said that it would take another two to three years at least for it to be implemented by the discoms.
(Source: Times Of India)
The importance of Government and Bank support in the field of Solar for the local players has been shown by Chinese Banks for their manufacturers. With the sharp decline in the prices of solar modules worldwide, the world has already seen the downgrading or in some cases even shutdowns of various big manufacturing companies of Europe and US. The result of such a downfall as people call it is because the Chinese manufacturers have come up so fast with the cheap technology of solar modules.
Chinese Solar industry that is termed to be the biggest industry and believed to be among the most profitable is finally seeing the reality which they were not realising until now. But even in scare of such market there has been a lot of support from the Chinese banks to bail them out from such severity of high debts. As said by Wayne in an article “China’s top 10 listed solar companies, though saddled with a combined debt put at $17.5 billion by investment bank Maxim Group, have emerged relatively unscathed from market woes that have driven foreign peers to the wall.”
As compared to Chinese scenario many European companies crunched to the downfall in the market as they were unable to raise the capital against the debt they had. Q-cells which are one of the largest solar cell makers in the world filed for bankruptcy in April as it was unable to clear a debt of $725 million. Even the biggest Chinese companies are also running into losses with the prices of modules going way below than expected. It was the period of 2009 till 2011 in which the solar companies took much of the debt during the downturn of market. Banks also supported such companies with debt as these companies helped to generate employment as also provided a huge boost to China’s economic growth, there banks took the responsibility of providing such companies with debts.
To make sure that these investments don’t go to waste, instead of asking the companies to clear the debt local banks rolled over mature loans each year according to Chinese solar companies and analysts. World’s largest supplier of solar panels Suntech Power Holdings has also huge debt to their name and though they are hopeful to clear it still analysts and shareholders are working out alternative ways with the banks to form an agreement to clear the debt. Even though to repay the debt companies are lowering prices but to remain in the market they will need additional capital which will be very difficult to get with current market scenario.
Apart from these there are many other big solar manufacturers who have huge debts which they are due to pay this year and if the banks decide to recall the capital instead of saving their investments it will be very difficult for companies to compete in the market. So unless there comes a big boom in the solar market all of a sudden companies are going to face real difficulties in the near future.
(Source: Wall Street Journal)
ADS Projects & Systems Pvt. Ltd, India, has been approved by MNRE as a Channel Partner for Off-Grid and Decentralised Solar Applications.
From the time when the government introduced a solar energy policy (2011-16) solar sector is on developing ride in Karnataka.
According to a report Renewable Energy prepared by PwC, which was released at the conference on ‘Sustainable Energy Through Renewables’, organised by Confederation of Indian Industry (CII), here on Wednesday, Karnataka is the only state to have supported solar projects under the REC (Renewable Energy Certificate) mechanism. Close to 950 Mw of project proposals have been submitted to Karnataka Renewable Energy Development Ltd (KREDL), which are under different stages of implementation like preparation of DPR.
Marvellous progress has been made by Karnataka in solar sector. Already it is having 14 MW installed capacity, and over 1.2 GW in the pipeline under various schemes. The 14MW installation is done under Arunodaya programme by Karnataka Power Corporation Ltd. Of these 3 Mwp each are in Kolar, Belgaum and Raichur and a 5 Mwp in Mandya district in Karnataka. Based on report submitted to CERC in 2010, the energy produced by the 3 MWp in Belgaum was around 3.9 million units.
In a recent bid the government has allotted projects for 80 MW (60 MW for solar PV and 20 Mw for solar thermal) at tariffs between Rs 7.94 to Rs 8.50 per unit for solar PV and between Rs 10.94 and Rs 11.32 per unit for solar thermal projects.
Karnataka is having one of the highest potentials for renewable energy among all states in India. Renewable sources are contributing to around 24% of the state’s installed capacity. If minor changes are done in the policy framework, Karnataka may come in the top 3 states in terms of annual wind capacity additions. Investors are attracted by the large untapped wind potential and above average wind.
Estimated renewable energy potential is 28 GW. As per the report a total of 17,278 MW, has been allotted from wind, small hydro, co-generation and biomass sectors which is nearly 60 per cent of the full potential. Of this, 2,016 MW is from wind, 88.5 MW from biomass, 948.7 MW from bagasse co-generation, 646 MW small hydro and 14 Mw of solar power have been explored. Most of the sites are far from grid. There is therefore a need to develop a robust and reliable transmission system for extracting the renewable potential. This will definitely help develop Karnataka as a leader.
(Source: Business Standard)
Dairy owners used to worry on the unscheduled load shedding during summer or if not that then from bad power quality of electricity supply. They then used do to run diesel generator or use labour for milking their cows and buffaloes at their farms giving them high bills.
On the USP of elimination of noise and cost saving a milking machines operated on solar power is launched. It will now be reducing the electricity bills and labour costs.
“It will be useful for small and medium dairy owners. It is priced at Rs 70,000 and is eligible for subsidy from Karnataka Milk Federation. The quantity of the subsidy varies from one milk producers’ association to the other in the state since each of them has its own norms and rules. A dairy farmer who buys this battery-operated milking machine is eligible for subsidy between Rs25,000 to Rs40,000,’’ said BG Santosh, Sales Manager, Siddon Biotech a Bangalore based company providing solutions in the field of animal nutrition care.
The viability of it comes for them more who uses diesel generator . Other advantages of it is that It is an easy to go machine as it is a trolley-mounted and it has a provision of auxiliary supply from electricity. The machine was brought in limelight during the AgriTech India 2012 in Bangalore.
(Source: DNA India)
A US-based agency, Schanti Partners, New York will be developing 50MW project worth Rs 580 crore for a solar energy project in Kaimur district of Bihar. Initially, a 10MW unit would be setup. They have received approval letter from Bihar State Investment Promotion Board, no-objection letter from Bihar Renewable Energy Development Agency (BREDA),and the proposal is submitted to Bihar State Electricity Board (BSEB).
Intention is to have a 12.5Rs/unit PPA of 25 years with BSEB.
A fully-owned subsidiary of Schanti Partners LLC ‘Sparkle Solar Bihar I’ will be executing the project. The project will be developed in a phase of 10 MW in 5 phases. The equipment would be sourced from Sol Focus Inc. , a US solar equipment manufacturer. An official marking the importance of project said “With the setting up of this solar energy plant, Bihar will emerge as a leader in solar energy development among eastern states of India”.
The project will use the most recent version of photovoltaic technology called Concentrating Photovoltaic (CPV) system; it is the PV technology with an optical system that focuses sunlight over a large area onto each cell.
The agency would not be taking help from Bihar industrial land bank. As per the proposal, the land would be leased for 30 years term directly from the owners, in lieu of annual lease payments to them.
The financing for the project has already been secured, with a letter of intent(LOI) from the Export-Import Bank of the US. The letter of intent provides for approximately $30 million in financial support with factors depending on extent of US-made solar power equipment.
Kaimur district has robust electricity infrastructure for power evacuation, with grid connectivity and nearby electrical substations. Power lines of 33kV and 132kV and electrical substations are already in place in the district.
Allocation of 175MW of grid-connected solar power projects was granted last year by Bihar Solar Policy.
(Source: India Times)