TechBlog3: Why are PV efficiencies so low?

After a bit of a delay, we bring forth the third technical blog for you to learn the science behind solar power. This blog talks about PV solar modules efficiencies and addresses why nature limits them to such low numbers and how scientists are trying to overcome these limitations.   It would probably not have escaped your notice that the efficiencies of the solar PV modules are quite low. You usually see transformers and inverters, other electrical equipments used in solar plants have efficiencies above 95%. And yet, the PV panels have efficiencies < 20%.The most commonly used PV technology, crystalline-Si, has best commercial efficiencies 16-19%. The emerging thin film technologies give at best 12% (CdTe thinfilms). So, almost 80-90% of the energy in the sunlight is not being utilized by the solar cells. Why? And where is this wasted energy going? Read further to find answers to these questions.   Efficiencies are limited by the very nature of energy conversion in solar cells. What does a solar cell do? …

Every house in every village of India will be provided electricity by 2017: PM

Source: Newstrackindia.com The Prime Minister, Dr. Manmohan Singh, on Wednesday said that his government would initiate measures to ensure that every house in every village of India would be provided with electricity in the next five years i.e. 2017. Addressing the nation on the occasion of the country’s 65th Independence Day from the ramparts of the historic 17th century-built Red Fort, Dr. Singh said: “When the UPA Government came to power in 2004, we had promised that we would provide electricity to all villages. To fulfill this promise, we launched the Rajiv Gandhi Rural Electrification Scheme. More than one lakh new villages have been provided with electricity connections under this scheme and now almost all the villages in the country have been electrified.” “Our next target is to provide electricity to each and every household in our country in the next 5 years and to also improve the supply of electricity,” he added. India currently suffers from a major shortage of electricity generation capacity, even though it is the world’s fourth largestenergy consumer after United …

Energy Efficiency as Important for Branding as for Bottom Line, Deloitte Says

Source: Environmentalleader Improving energy efficiency at America’s businesses is as important to brand building as it is to growing the bottom line, according to a new Deloitte report. The study, reSources 2012, shows that while 85 percent of companies claim that electricity cost reductions are essential to staying financially competitive, almost as high a proportion – 81 percent – believe they are critical to brand building.  In fact, more than three-quarters of the organizations surveyed say they are actively promoting their energy efficiency efforts to their customers. Deloitte says that there is now a clear consensus in corporate America that energy efficiency is an important competitive advantage and that senior business leaders are beginning to see it as as a strategic business driver. Survey respondents say they have achieved close to 60 percent of their targeted energy reduction levels.  However, much of this progress is the result of initiatives that are easy to implement, such as installing more efficient light bulbs. As companies move away from the “low hanging fruit” and on …

A New Point System Lets You Measure The Sustainability Impact Of Anything

Source: Fastcoexist There are any number of problems facing the world right now, and a limited amount of resources and time to handle them. Sometimes, you have to think about triage. But the scope of the problems can make that hard. What’s more important: creating clean energy or managing water scarcity. Those two issues are measured differently, making it hard for non-experts to compare them analytically. Energy Points is a new startup on a mission to quantify sustainability. Instead of using different ways of conceptualizing consumption (say, of water, electricity, waste, transportation and the like) the company smooths out diverse units and translates them into one common denominator: the amount of energy it takes to generate one gallon of gasoline. The result is that companies (and eventually individuals) can conduct one-to-one comparison of any sustainability project or resource consumption, regardless of the native unit of measure (kWh, gallons, BTUs, CO2 abated). All of these units of measurement are now expressed in energy per gallon, the same way miles per gallon represents …

Cost-effective solar power module could also serve as an eco-friendly furnace

Source: Gizmag Borrowing technology from sophisticated telescope mirrors as well as high-efficiency solar cells used for space exploration, a group of students and researchers at the University of Arizona is putting the final touches on a novel power plant that promises to generate renewable energy twice as efficiently as standard solar panel technology with highly competitive costs and a very small environmental impact. Curved mirrors in solar power plants usually concentrate the sun’s rays along a water pipe, heating the water into steam that is then fed to power-generating turbines. But rather than distributing the power over the area of a water pipe, researchers at the University of Arizona are working on focusing as much as possible of the sun’s captured energy onto a precise point in space. The target is a small glass ball that is only five inches in diameter. The ball contains a specially coated lens that redirects the light to an array of 36 small, high-efficiency solar cells, which were originally developed for space applications, that …

BEE plans risk guarantee fund for energy efficiency projects

Source: Mydigitalfc The Bureau of Energy Efficiency (BEE) plans to set up a partial risk guarantee fund (PRGF) to enhance financing options for energy efficiency projects. PRGF would provide commercial banks with up to 50 per cent of risk coverage against loans issued for such projects. BEE is also looking to set up a venture capital fund for the same. BEE has initiated the process and has requested proposals to shortlist a project approval unit for it, a senior official of the agency said. Under the programme, participating financial institutions would take guarantee of up to Rs 3 crore per project from the PRGF before disbursement of loans. In case of default, the fund will cover the first loss, subject to maximum of 10 per cent of the total guaranteed amount and cover the remaining default amount on pari-passu basis up to the maximum guaranteed amount, he added. BEE was created with a mission to assist in developing policies and strategies to enhance the overall energy efficiency of the country. …

Bigger Is Better for Wind Turbines

Source: Cleantechnica Scientists have concluded in a new study that, the larger the wind turbine, the greener the electricity it produces. The report appears in the American Chemical Society journal Environmental Science & Technology. Marloes Caduff and colleagues concluded that wind power is an increasingly popular source of electricity, providing almost 2 percent of global electricity worldwide, a figure that is expected to reach 10 percent by 2020. The size of turbines is also increasing One study recently showed that the average size of commercial turbines has grown 10-fold in the last 30 years, from diameters of 50 feet back in 1980 to nearly 500 feet today. Unsurprisingly, super-giant turbines approaching 1,000 feet in diameter are on the horizon, which pushed the authors into wanting to determine whether larger was better. Their study showed that bigger turbines do in fact produce greener electricity, for two primary reasons: Manufacturers now have the knowledge, experience, and the technology to build big wind turbines with great efficiency, minimizing the need for research and development. …

Have we reached a tipping point for solar powered buildings?

Source: Rejournals Due to advances in technology and improved manufacturing, the cost of solar technology, specifically solar photovoltaic panels, has declined dramatically over the last few years.  Coupled with available funding from federal, state and local utility company incentives, many industry experts believe we will see a growth in solar power for industrial buildings in the years ahead. Could we be nearing the tipping point between the initial cost and long-term utility savings for different types of solar systems for buildings?  The answer is found by investigating the return on investment that solar systems can provide.  In all cases, the return on investment depends on material and installation costs, current utility rates, future utility rates, overall consumption, tax depreciation, and incentives.  Historically, the time period required for solar power savings to offset initial material and installation costs could range anywhere from 10 to 20 years.  Today, with the proper incentives, solar installations are proven to pay for themselves in six years or less.  With this reduced payback timeframe, many owners …

Solving the World’s Water Problems through Technology

Source: Environmental Leader As I read report after report about the daunting water infrastructure and scarcity challenges we all face, I am heartened by the promise of technological innovation. Everywhere I look in the water world, I see talented, dedicated people developing smart, new solutions to some of our most intractable problems. Some of the solutions involve creating more energy efficient treatment technologies, while others find better ways to collect data and harness it for more efficient operations. For example, I recently attended a Water Environment Council (WEC) dinner in Washington, D.C., awarding IBM the 2012 Gold Medal for advancing environmental sustainability both internally and with customers. As I listened to IBM’s Chairman Sam Palmisano’s remarks in accepting the award, I heard quite a bit about how IBM is helping cities deal more efficiently with water challenges. What Companies Are Making the Biggest Splash? Along with GE, Intel, American Water and many other organizations, IBM is a member of the Water Innovations Alliance (WIA). WIA is an industry association focused …

Energy Revolution Brewing in Bihar

Source: sierraclub.typepad.com Something’s brewing in Bihar. After decades of being India’s most notoriously ‘backward’ state, the Chief Minister Nitish Kumar has tempered corruption, built roads and spurred development. Given the impressive achievements of his previous term, it’s no surprise he rode to overwhelming victory in recent elections. What is surprising is that his campaign platform consisted of more or less a single promise – to deliver electricity access to the 82% of the over 100 million inhabitants of Bihar who lack it. With little fossil fuel reserves to speak of, Bihar will need to write a blueprint for a clean energy revolution to deliver on that promise. As Shaibal Gupta, Secretary, of the Asian Development Research Institute puts it, Bihar now requires an infusion of energy to further ‘lubricate’ the wheels of development. That’s putting it lightly. Bihar faces a 30% peak power deficit (highest in the country) due to its paltry 546 megawatts of installed capacity – about the size of one average coal plant. Worse, Bihar loses roughly 38% of …

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