Thursday, June 26, 2008

Mandatory solar panels in German town of Marburg


Solar Panelsin German town Marburg

The central German town of Marburg is the first in German to make solar panels mandatory for almost all rooftops of private and commercial buildings. The controversial new law requires a solar panel for every new building and every old building that is being renovated. The historical buildings such as the Marburg Castle, Marburg's City Hall, and the Elisabeth Church will be exempt from the requirement.

The solar law was approved by the town's council on June 20, and will take effect Oct. 1. According to the law, a 1 square meter (10 square feet) panel must be installed for every 20 square meters (200 square feet) of surface area. Installing the panels could cost homeowners up to €5,000 ($7,800). The cost would be paid off through savings in energy bills over a 15-year period, the town's mayor, Franz Kahle, said. Those violating the law will face fines starting at €1,000 ($1,500).

The town is home to Marburg University and has about 80,000 residents. Most of the residents support the decision made by the Social Democrats and Greens, but the opposition leaders say that to force people to equip their homes with solar panels equates to a "green dictatorship," and that "nobody dares to say anything."

"Sometimes you must force the hand of consumers for their own good", says the specialist in solar Vajen Klaus, a professor at the University of Kasel.

Sunday, June 22, 2008

Solar Photovoltaic (PV) Panels


Solar Photovoltaic Panels
Solar photovoltaic (PV) technology uses the sunlight to produce electricity. PV cell is the smallest element in the PV system. A PV cell is made up of two thin layers of semi-conducting material (usually silicon), treated with small amounts of substances giving the cell the means to produce electricity when exposed to sunlight.

The basic PV or solar cell typically produces only a small amount of power. To produce more power, solar cells can be connected in series to make a PV module (a.k.a. PV panel, solar electric panel). Solar cells or more photovoltaic modules form a PV array. The amount of power solar panels produce is determined by the quality of the solar panel, solar cells and technology used in making the solar panel.

Conventional PV solar panels made from silicon wafers (monocrystalline silicon) convert about 17 to 20 percent of sunlight into usable electricity. The latest solar panels that utilize the new cell can convert into electricity 22 percent of the sunlight they collect. Polycrystalline panels efficiency typically range from 15% to 17%.

Typically, PV panels are mounted on a roof or are integrated in the roof so they act as both a part of the roof or shingles, and a solar panel at the same time. PV can also be incorporated as building facades and canopies. Integrated PV systems are usually installed during construction of the building. The amount of power that a PV panel will deliver is proportional to the amount of sunlight that falls upon it. Ideally PV panels are best placed so that they face south (±450). Photovoltaic panels, however, suffer from decreased power output when they heat up, so high temperatures decrease their efficiency.

When the PV panel is tied to a power grid, the DC (direct current) is converted to alternating current (AC) at grid rating by an inverter. Grid connect PV systems are often integrated into buildings. If you generate more power than you consume, the meter spins backward, as that surplus electricity flows back into the grid for others to use. By returning surplus electricity to the grid, no battery is needed. Some power companies will compensate surplus at a rate that is different than the cost of consumption.

A basic off-grid PV system consists of a solar panel, which generates DC power, a battery bank that stores the DC power, and an inverter (if AC power is required). Modern PV systems are also equipped with some kind of electronic charge controller. The main job of the charge controller is to prevent the battery from being overcharged and also from deep discharging of the battery. The charge controller also protects the solar panels from electrical damage.

The working life of a solar panel is approximately 20 to 25 years and once purchased they continue to produce electrical power for many years. Virtually, they require little or no maintenance, but dust or grime on the front of solar panels will substantially reduce the output, so they should be cleaned periodically.

Sunday, June 15, 2008

Applications of Photovoltaic PV Power Today


Solar garden lights
PV power, definitely, is not just the energy of the future. Thousands of PV systems are used in the world today for a variety of applications because they can be easily adapted to suit any requirement - large or small. Virtually any power need can be met with photovoltaics, although some are more cost - effective than others.

PV cells have been used for many years in our daily lives to power small applications such as watches and pocket calculators. Today there are available numerous small, medium and large-scale PV applications for residential and industrial purposes. This includes PV power plants, stand-alone PV arrays, building-integrated PV systems, PV solar lighting applications, PV water pumps, solar powered cell phone chargers, and other solar accessories for our homes and businesses. In general, though, PV is not used to generate electricity for space heating, hot water, electric cook stoves or ovens, or other applications with high power needs.

Lighting is one common use for PV systems. Cost-effective applications of lighting powered by photovoltaics include garden lights, lighting for recreational areas, street lights, etc. Remote monitoring, telecommunications equipment, highway construction signs, and navigational warning signals are also excellent applications for PV.

PV systems are an economical option for remote residences and rural areas. In most remote places, it is impossible to connect to the electrical grid and in many such locations, photovoltaic technology is the least-cost option for meeting remote energy needs.

PV systems are used effectively worldwide to pump water for plants, livestock, or humans. Since the need for water is greatest on hot sunny days, PV is a perfect fit for pumping applications. Water can be pumped into a storage tank during daylight hours, then distributed by gravity whenever it is needed. In the developing world, entire village water supplies are powered by photovoltaics.

PV systems offer a number of unique benefits that have led to their rapid growth in popularity in recent years. This growth was particularly impressive in countries such as Japan, Germany and the US.

Thursday, June 12, 2008

Dream Big: Solar Future


Future solar aircraft?
Solar energy has captured the human imagination and the news like the previous one about building solar-powered speedboat shows that high quality solar technology exists here and now. The story sounds somewhat distant from the everyday life of the average person since only a few very rich people can afford such a pricey water vehicle. However, I think that all news concerning solar energy are important and they worth to be published not just out of curiosity. Solar-powered aircrafts, solar-powered boats, solar-powered cars, or solar-powered houses - maybe all this still sounds unrealistic, or utopic, or futuristic for many people. But I believe that one day (not so far in the future!), it could be an real and affordable option for all of us. Or at least... we can dream!

Tuesday, June 10, 2008

First Solar-Powered Speedboat


The world’s first solar-powered speedboat Czeers
Credit: Czeers
Recently was announced that two Dutch researchers at the Technical University of Delft - Nils Beers and David Czap managed to develop the world's first solar-powered speedboat Czeers MK1. (a combination of their last names makes Czeers, pronounced "Cheers").

The speedboat was made from 100% black carbon fiber and covered with 150 square feet (14 square meters) of solar cells. The solar vehicle can approximately reach a top speed of 30 knots (about 35 miles / hour or 55.5 km/ph). The solar powered motor allows the boat to operate quite gentle.

The whole décor is luxurious: the boat has a LCD touch-screen control system and a fine leather interior. The approximate price is seven hundred thousand euro, or about $1.1 million.

Sources: FoxNews & Uberreview

Thursday, June 5, 2008

The Flight of Solar-Powered Aircraft Helios


Here is a video showing compilation of test flights of the solar-powered, remotely piloted NASA's Helios aircraft.

Helios set out from Kauai in the Hawaiian Islands before 9:00 AM on Monday, August 13, 2001. Just over seven hours later, it reached 96,500 feet. Flying at about 25 miles an hour, the mission lasted nearly 17 hours, landing at 1:43 a.m. August 14, 2001

This was the first time a non-rocket powered aircraft has maintained flight this far above the earth. At this altitude above ground the sky is almost black, stars shine in the daytime, and the horizon looks curved.

Helios was an ultralight flying wing built by AeroVironment Inc, as a part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. Covered with solar cells, Helios' impressive 247 foot wide wing exceeds the wing span and even overall length of a Boeing 747 jet airliner.

Helios had about 62,000 solar cells across the wing. The solar cells collect energy from the Sun and convert it to electricity, which runs the 14 small motors. The motors turn the 14 propellers, which are specially designed to pull the aircraft aloft even in the very thin air that's 18 miles high.

Helios was intended as a technology demonstrator, but in the extremely thin air 100,000 feet above Earth's surface, the flight of Helios also approached conditions for winged flight in the atmosphere of Mars, since the atmosphere at that height above earth replicates the atmosphere near the Martian surface.

Sunday, June 1, 2008

More Key Steps in Photovoltaic History


Airplane Icare
The world’s most advanced solar-powered
airplane Icare
Credit: University of Stuttgart, Germany
In 1955, the first solar-powered automobile was publicly demonstrated in Chicago. It was a 15-inch Sunmobile built by William G. Cobb of the General Motors Corporation. Light energy falling on 12 selenium photoelectric cells created electric current to power a tiny electric motor. The solar automobile was one of 253 free exhibits of the General Motors Powerama, Chicago, Illinois.

In 1976 NASA’s Lewis Research Center starts the installation of 83 PV power systems on every continent except Australia.

In 1978 was installed the world's first village PV system at Papago Indian Reservation, Schuchuli, Arizona.

In 1980 ARCO Solar is the first company to produce more than 1 MW of PV modules in one year.

In 1981 Paul MacCready builds the first PV-powered aircraft known as the Solar Challenger, which flies from France to England across the English Channel. The aircraft had over 16,000 solar cells mounted on its wings, which produced 3,000 watts of power.

Volkswagen began testing PV arrays mounted on the roofs of vehicles in 1982.

In 1982 a Danish-born Australian eco adventurer Hans Tholstrup drives the first solar-powered car - the Quiet Achiever - almost 2,800 miles between Sydney and Perth in 20 days. The vehicle had photovoltaic system of 1 kW and the average speed was 23 km/h. Tholstrup is the founder of the World Solar Challenge in Australia, considered the world championship of solar car racing.

In 1984, a 1 megawatt photovoltaic electricity plant began to operate in Sacramento, California.

ARCO Solar introduced a G-4000, the first commercial thin film photovoltaic module in 1986.

The world’s most advanced solar-powered airplane, the Icare, flew over Germany in 1996. The wings and tail surfaces of the Icare are covered by 3,000super-efficient solar cells, with a total area of 21 m2.

The 11th tallest skyscraper in New York City, built in the 1990s - the Condé Nast Building, officially 4 Times Square - includes building integrated photovoltaic (BIPV) panels on the 37th through the 43rd floors on the south and west-facing facades to produce a portion of the building’s power.

In 1999 Germany launches a 100,000 solar roofs scheme to promote the on-site generation of clean electricity.

On August 13, 2001 after long research and trial, the solar powered wing aircraft Helios set an unofficial world record by a winged aircraft of flying at a sustained altitude above 96,000 feet (29,250 m) for 40 minutes. Helios is a remotely operated (by two controllers using computers on the ground), solar powered aircraft developed by NASA and AeroVironment Inc.

In 2002 Japan installed 25,000 solar rooftops.