Lanco Infratech Ltd. (LANCI), India’s second-biggest non-state power generator, is seeking private- equity investors to help expand its solar capacity fivefold as a coal shortage roils its thermal business and payment defaults by state utilities widen the group’s losses.

Lanco needs funds to meet a plan of adding 500 megawatts annually in three years, with 350 megawatts to be built for customers and the rest coming from its own plants, V. Saibaba, chief executive officer of the New Delhi-based company’s Lanco Solar unit said in a telephone interview. Government policies to promote alternative energy sources will make the investment attractive, he said.

“The political intent in India is very strong,” Saibaba said, speaking from his office in Gurgaon near New Delhi. “Constraints like coal availability and fuel import bills will ensure India will have to focus on renewable energy.”

Lanco is joining Tata Power Co. (TPWR), India’s biggest non-state utility, which said Feb. 5 that it is scouting for investors and planning to sell shares at its solar unit as India extends grants to cut solar project costs and ease curbs on equipment imports. A plan announced last year by the Lanco group to raise $750 million selling stake in its conventional power unit to private-equity funds has stalled amid losses that have surged nine times in the first three quarters of the financial year.

Losses Widen

Shares of the New Delhi-based company have slumped 86 percent from a record reached on Dec. 28, 2007 to 11.2 rupees. The slide in the value has eroded the wealth of Chairman L. Madhusudhan Rao, who was a billionaire as late as January last year, according to data compiled by Bloomberg. The shares fell 1.3 percent at 11:39 a.m. in Mumbai.

“Lanco hasn’t done well when it comes to the power business,” which suffers from fuel supply problems, said Gaurav Oza, Mumbai-based analyst at GEPL Capital Pvt. “They seem to have done much worse in managing utilities as compared to their earlier success in construction.”

Lanco reported an annual loss of 1.1 billion rupees ($21 million) for the group in the year ended March 31, its first since its shares started trading in November 2006. The combined loss in the three quarters ended Dec. 31 climbed to 9.9 billion rupees, according to data compiled by Bloomberg.

State-owned regional electricity distributors, often forced to sell energy below costs, are unable to pay producers as the difference between the cost of supply and average tariff has widened. The utilities had debt of 1.9 trillion rupees as of March 2011, government estimates show, even as lenders tightened credit. That has resulted in poor cash flows for Lanco.

Debt Outstanding

The company has 35 billion rupees of receivables, Rohit Sanghvi, an analyst with Prime Broking Co. in Mumbai, wrote in a Feb. 15 report. The outstanding amount is more than Lanco’s market value. Total debt stood at 95.7 billion rupees, of which the solar unit accounted for 5.5 billion rupees.

Lanco may be counting on interest in solar projects as the government targets to build 9,000 megawatts of grid-connected solar plants by 2017, more than eight times its current capacity. Solar-power producers are assured payments through letters of credit and escrow mechanisms set up by state governments, according to Saibaba.

With costs for alternative energy projects coming down, the tariff for solar and thermally produced electricity may reach parity in about three years, Saibaba said.

Interest Costs

Better potential realization is also helping lenders offer cheaper credit for solar producers, said Satnam Singh, chairman of Power Finance Corp. (POWF), India’s biggest state lender to electricity utilities.

“We cut lending rates for renewables this month because we see better returns in the near future,” Singh said in an interview. Of the 23.7 billion rupees sanctioned by Power Finance to renewable companies in the year ending March 31, 15.8 billion rupees was to Lanco Solar, he said.

Solar companies have to pay interest rates as high as 13.5 percent to 14 percent in India, Saibaba said. The weighted average cost of debt for NTPC Ltd. (NTPC), the nation’s biggest power producer, was 8.6 percent according to data compiled by Bloomberg.

India’s policy draft released in December said the government would for the first time fund the solar industry with direct grants covering as much as 40 percent of the upfront cost of building projects. That model has previously been used to build roads, ports, railways and fossil-fuel power plants in India.

Slow to Fund

Private lenders have been slow to fund solar because of a lack of confidence in the technology, according to the draft. Solar companies in India sell power to state utilities which in turn cannot recover their costs from customers who buy power at lower rates.

Lanco will add 90 megawatts of solar capacity by the end of the fiscal year ending March, including a delayed 75-megawatt photovoltaic project for the local state-owned utility in the western Maharashtra state that it won in May 2011, he said.

Another 100 megawatts of capacity being built using solar- thermal technology in northern Rajasthan state has been delayed by a year, Saibaba said. The project, awarded under the first phase of India’s solar auctions in 2010, had to be reengineered to make allowances for differences in radiation levels and delays in getting heat-transfer fluid from U.S. suppliers, he said.

‘Still Grasping’

Lanco Solar is completing a manufacturing plant that will be able to produce 1,800 tons of polysilicon, 100 megawatts of ingots and wafers and 75 megawatts of modules a year, Saibaba said. The company expects to increase that capacity to 250 megawatts of modules annually in three years, he said. The total cost of this plant is 13.4 billion rupees of which 70 percent has been funded by loans, he said.

Private investors may look at the government’s commitment to support alternative energy sources before pledging any funds, said Mahesh Patil, who manages $2.5 billion in equity as co- chief investment officer at Birla Sun Life Asset Management Co. in Mumbai.

“Investors the world over are still in the process of grasping the business dynamics of solar-power developers,” Patil said. “Secondary markets, at least in India, aren’t yet ready to support share sales by renewable-energy companies.”

Did you know that today’s photovoltaic cells are based on a lucky finding by Alexandre Becquerel way back in 1839? He placed an electrode in a conductive solution, and when it was hit by sunlight a current was generated. The first solar cell, however, wasn’t produced until 1883, Charles Fritts produced a 1%-efficiency (!) selenium-on-gold photovoltaic panel.

The photovoltaic effect was then followed by the discovery of the photoelectric effect, which Albert Einstein would publish a paper about in 1904. A flurry of photoelectric advances followed, until eventually, in 1954, AT&T Bell Laboratories created the first modern silicon solar cell. Bell Labs also produced the solar cells used in early space satellites like the Vanguard 1. Soyuz 1, in 1967, would also use solar cells, and would become the first manned spacecraft to do so.

Between the 1950s and 70s, solar power fell out of grace. Producing solar cells was still prohibitively expensive ($250 per watt), and their efficiency still hadn’t broken past the 10% mark. As the semiconductor industry flourished, however, and as the size of silicon boulesand the integrated circuit market boomed, the cost of solar panels plummeted. By 1973, solar panels had reached 15% efficiency, and could be produced for around $10 per watt.

Today, the solar power industry is very healthy indeed. The price per watt is down to around $3 and at-home installations (and government subsidies!) are becoming increasingly common — and just take a look at the number of photovoltaic power stations that opened in 2010! Indeed, you have to look no further than President Obama himself to see how popular solar power is becoming: in 2010, he ordered the installation of solar panels and a solar hot water heater at the White House. Now it’s just a matter of when solar power will overtake coal in terms of cost and efficiency, which could occur in the next few years.

For more information on the history of solar technology, check out the infographic below, or read more about the history of solar power on Wikipedia.

Infographic by SunRun – Home Solar Leasing Made Easy

Introduction

A light-emitting diode (LED) is a semiconductor light source.Introduced as a practical electronic component in 1962,early LEDs emitted low-intensity red light, but modern versions are available across the visible, ultraviolet, and infrared wavelengths, with very high brightness.

The process by which LEDs emit light is called electroluminescence. The color of the light is determined by the energy gap of the semiconductor.

LEDs present many advantages over incandescent light sources including lower energy consumption, longer lifetime, improved physical robustness, smaller size, and faster switching.

Light-emitting diodes are used in applications as diverse as aviation lighting, automotive lighting, advertising, general lighting, and traffic signals. LEDs have allowed new text, video displays, and sensors to be developed, while their high switching rates are also useful in advanced communications technology. Infrared LEDs are also used in the remote control units of many commercial products including televisions, DVD players, and other domestic appliances.

Science behind LED

The LED consists of a chip of semiconducting material doped with impurities to create a p-n junction. As in other diodes, current flows easily from the p-side, or anode, to the n-side, or cathode.

The wavelength of the light emitted, and thus its color depends on the band gap energy of the materials forming the p-n junction.

LED development began with infrared and red devices made with gallium arsenide. Advances in materials science have enabled making devices with ever-shorter wavelengths, emitting light in a variety of colors.

LEDs are usually built on an n-type substrate, with an electrode attached to the p-type layer deposited on its surface. P-type substrates, while less common, occur as well.

Most materials used for LED production have very high refractive indices. This means that much light will be reflected back into the material at the material/air surface interface. Thus, light extraction in LEDs is an important aspect of LED production, subject to much research and development.

Lifetime and failure

Solid-state devices such as LEDs are subject to very limited wear and tear if operated at low currents and at low temperatures. Typical lifetimes quoted are 25,000 to 100,000 hours, but heat and current settings can extend or shorten this time significantly.

Like other lighting devices, LED performance is temperature dependent. Most manufacturers' published ratings of LEDs are for an operating temperature of 25 °C. LEDs used outdoors, such as traffic signals or in-pavement signal lights, and that are utilized in climates where the temperature within the luminaire gets very hot, could result in low signal intensities or even failure.

Types of LEDs

The main types of LEDs are miniature, high power devices and custom designs such as alphanumeric or multi-color.

Miniature

These are mostly single-die LEDs used as indicators, and they come in various sizes from 2 mm to 8 mm, through-hole and surface mount packages.

Mid-range

Medium-power LEDs are often through-hole-mounted and used when an output of a few lumen is needed. These LEDs are most commonly used in light panels, emergency lighting, and automotive tail-lights. Due to the larger amount of metal in the LED, they are able to handle higher currents (around 100 mA).

High-power

High-power LEDs (HPLED) can be driven at currents from hundreds of mA to more than an ampere, compared with the tens of mA for other LEDs. Some can emit over a thousand lumens.Since overheating is destructive, the HPLEDs must be mounted on a heat sink to allow for heat dissipation.

Advantages of LEDs

Efficiency: LEDs emit more light per watt than incandescent light bulbs.Their efficiency is not affected by shape and size, unlike fluorescent light bulbs or tubes.

Diversity of Colors: LEDs can emit light of an intended color without using any color filters as traditional lighting methods need. This is more efficient and can lower initial costs.

Size: LEDs can be very small (smaller than 2 mm2) and are easily populated onto printed circuit boards.

Quick On/Off time: LEDs light up very quickly. A typical red indicator LED will achieve full brightness in under a microsecond.LEDs used in communications devices can have even faster response times.

Frequent On-Off Cycling: LEDs are ideal for uses subject to frequent on-off cycling, unlike fluorescent lamps that fail faster when cycled often.

Dimming: LEDs can very easily be dimmed either by pulse-width modulation or lowering the forward current.

Cool Light: In contrast to most light sources, LEDs radiate very little heat in the form of IR that can cause damage to sensitive objects or fabrics. Wasted energy is dispersed as heat through the base of the LED.

Slow Failure: LEDs mostly fail by dimming over time, rather than the abrupt failure of incandescent bulbs.

Lifetime: LEDs can have a relatively long useful life. One report estimates 35,000 to 50,000 hours of useful life, though time to complete failure may be longer.Compare these to CFLsthat are rated at about 10,000 to 15,000 hours, and incandescent light bulbs at 1,000 to 2,000 hours.

Shock resistance: LEDs, being solid-state components, are difficult to damage with external shock, unlike fluorescent and incandescent bulbs, which are fragile.

Focus: The solid package of the LED can be designed to focus its light. Incandescent and fluorescent sources often require an external reflector to collect light and direct it in a usable manner.

Disadvantages

High initial price: LEDs are currently more expensive, price per lumen, on an initial capital cost basis, than most conventional lighting technologies.

Temperature dependence: LED performance largely depends on the ambient temperature of the operating environment. Over-driving an LED in high ambient temperatures may result in overheating the LED package, eventually leading to device failure. An adequate heat sink is needed to maintain long life.

Voltage sensitivity: LEDs must be supplied with the voltage above the threshold and a current below the rating. This can involve series resistors or current-regulated power supplies.

Light quality: Most cool-white LEDs have spectra that differ significantly from a black body radiator like the sun or an incandescent light. The spike at 460 nm and dip at 500 nm can cause the color of objects to be perceived differently under cool-white LED illumination than sunlight or incandescent sources, due to metamerism,red surfaces being rendered particularly badly by typical phosphor-based cool-white LEDs.

Droop: The efficiency of LEDs tends to decrease as the current increases.

Applications

In general, all the LED products can be divided into two major parts, the public lighting and indoor lighting. LED uses fall into four major categories:

• Visual signals where light goes more or less directly from the source to the human eye, to convey a message or meaning.
• Illumination where light is reflected from objects to give visual response of these objects.
• Measuring and interacting with processes involving no human vision.
• Indicators and signs
• Red and green traffic signals
• The low energy consumption, low maintenance and small size of modern LEDs has led to uses as status indicators and displays on a variety of equipment and installations.
• One-color light is well suited for traffic lights and signals, exit signs, emergency vehicle lighting, ships' navigation lights or lanterns
• Because of their long life and fast switching times, LEDs have been used in brake lights for cars' high-mounted brake lights, trucks, and buses, and in turn signals for some time, but many vehicles now use LEDs for their rear light clusters.
• Due to the relative cheapness of low output LEDs, they are also used in many temporary uses such as glowsticks, throwies, and the photonic textile Lumalive.

Lighting

LED streetlights 

With the development of high-efficiency and high-power LEDs, it has become possible to use LEDs in lighting and illumination. Replacement light bulbs have been made, as well as dedicated fixtures and LED lamps.

• LEDs are used as street lights and in other architectural lighting where color changing is used. The mechanical robustness and long lifetime is used in automotive lighting on cars, motorcycles, and bicycle lights.
• LED street lights are employed on poles and in parking garages.
• LEDs are used in aviation lighting. Airbus has used LED lighting in their Airbus A320 Enhanced since 2007, and Boeing plans its use in the 787. LEDs are also being used now in airport and heliport lighting and also as runway lights, runway centerline lights, taxiway centerline and edge lights, guidance signs, and obstruction lighting.
• LEDs are also suitable for backlighting for LCD televisions and lightweight laptop displays and light source for DLP projectors.
• LEDs are used increasingly in aquarium lights. In particular for reef aquariums, LED lights provide an efficient light source with less heat output to help maintain optimal aquarium temperatures.
• The lack of IR or heat radiation makes LEDs ideal for stage lights, as well as medical lighting where IR-radiation can be harmful.
• LEDs are small, durable and need little power, so they are used in hand held devices such as flashlights.
• LEDs are used for infrared illumination in night vision uses including security cameras.
• LEDs are now used commonly in all market areas from commercial to home use: standard lighting, AV, stage, theatrical, architectural, and public installations, and wherever artificial light is used.

Smart Lighting

Light can be used to transmit broadband data, which is already implemented in IrDA standards using infrared LEDs. Because LEDs can cycle on and off millions of times per second, they can be wireless transmitters and access points for data transport.Lasers can also be modulated in this manner.

Sustainable Lighting

Efficient lighting that consumes less power and lasts long is needed for sustainable architecture. LEDs fit the bill perfectly.

Other applications

• As the light from LEDs can be modulated quickly they are used extensively in optical fiber and Free Space Optics communications - remote controls, such as for TVs, VCRs, and LED Computers.
• In many sensor systems rely on light as the signal source, LEDs are often ideal as a light source due to the requirements of the sensors. LEDs are used as movement sensors, for example in optical computer mice.
• Plant growers are interested in LEDs because they are more energy-efficient, emit less heat (can damage plants close to hot lamps), and can provide the optimum light frequency for plant growth and bloom periods compared to currently used grow lights.
• LEDs have also been used as a medium-quality voltage reference in electronic circuits.