Solar-Powered School in Copenhagen

This is one more interesting news that represent another effort to be developed colored solar panels.

The International School in Copenhagen is using custom-built colorful solar panels as a featured architectural element. Each panel is individually angled and the result is really cool impression. The materials that were used in the new building are entirely natural. Thus the school made both an aesthetic and sustainable decision.

The campus of the cosy school is covered by 12,000 solar tiles making it the largest solar facade in the world. On sunny days the solar panels generate electricity that is contribute to the grid and to the school itself.

The solar panels are spanning over an area of 65,100ft2 and provide it with 300 MWh of electricity per year, meeting over half of the school's energy needs. One of the key vision of the school is to educate thair students of a sustainable world.

The unique building stands out because the panels are a distinctive sea green, the same of Copenhagen’s symbol - Andersen’ mermaid, which welcomes tourist in the Danish capital. Although no pigments were used to make them, the color comes from a process of light interference developed over more than a decade in the labs of the Ecole Polytechnique Federale in Lausanne (EPFL).

Based on a new technology developed in Switzerland the process that produced color of these panels is a similar to the effect seen in soap bubbles.

The researchers developed special filters, which they applied to the glass panels in nanometric layers. This filter determines which wavelengths of light will be reflected as visible color. The rest of the sunlight is absorbed by the solar panel and converted into energy.

“The iris effect creates a colorful rainbow on a very thin layer. We used the same principle and adapted for glass,  said Jean-Louis Scartezzini, the head of the Solar Energy and Building Physics lab at EPFL.

The school building won the 2017 Iconic Award - an international award program for architecture and urban planning professionals in the architecture category.

Green Colored Solar Panels

Highly rated models of solar panels are now running in excess of 20-percent efficiency at turning sunlight into electricity. But they are bulky and still aren't very pretty. In addition, traditional solar panels take up a lot of room.

Fortunately, solar technology is changing continuously. Earlier this year Tesla began selling solar shingles that can generate power for the home and still look like ordinary shingles. Other solar panel developers have made solar windows, skylights, patio covers, carports, and roads to generate electricity. And now researchers in the Netherlands say they have developed a process for making conventional bluish-black solar panels bright green. Probably the same technology might also make it possible to create panels in other colors, and even in white which would be a really big step in the solar industry. 

Researchers from AMOLF, the University of Amsterdam (UvA) and the Energy research Centre of the Netherlands (ECN) have developed a method for imprinting existing solar panels with crystalline silicon nanocylinders. The nanocylinders are about 100 nanometres wide and exhibit electromagnetic resonance that scatters a particular wavelength of light. They produce the green color by scattering green frequencies of light back while letting other frequencies of light pass through. They are laid down on the solar cells via a process the researchers likened to rubber stamping. The panels have a green appearance from most angles and they are only about 10 percent less efficient than conventional panels.

The method used for the colored solar panels is called soft-imprint lithography. “In principle, this technique is easily scalable for fabrication technology,” AMOLF scientific group leader and senior author Albert Polman said.

Such colored solar panels would afford a level of versatility - for example, red panels could be used on rooftops, white ones on walls, and the green ones could blend in with nature. Thus would encourage the reliance on solar energy and integration of solar technology into every part of our daily lives.

“You have to combine different nanoparticles, and if they get very close to each other they can interact and that will affect the color,” said Polman.

These aren't the first colored solar panels. But the ones already on the market use dyes and reflective coatings that give them their color, greatly reduce efficiency and they are about 45 percent less efficient than ordinary solar panels at generating electricity.

The new design was published online on August 15, 2017, in Applied Physics Letters.

Power Your Home with Solar Roof Tiles

Today the main way for homes to harness solar power is still through bulky rigid panels added to the rooftop or mounted on the ground. But inte recent years there are some innovations within the solar PV industry such as solar roof tiles. Solar roof tiles refer to Building Integrated Photovoltaics (BIPV) systems. They blend in better and help deliver clean, green solar power, without the need to sacrifice the aesthetic look and beauty of your home.

Solar roof tiles are made with built-in photovoltaic cells and the color of the solar tiles range from blue to violet to gray and blends well with most colors. Solar roof tiles are connected to each other via MC or other suitable connector type used inphotovoltaics and they work like conventional solar panels. One tile produces about 60 - 180 watts of electricity, and an entire roof could definitely power your entire house. A real hot sunny day could even mean profit for you, excess energy can be sold at a nearby company.

Solar roof tiles are more expensive than solar panels but in terms of the advantages it gives to a local user, it should outweigh the cons. Also, the government offers considerate breaks in taxes for homes that use solar power electricity.

Some of the companies currently producing solar roof tiles are General Electric, PowerLight, Sharp Electronics, and SunPower Corp.

Solé Power Tile, created by SRS Energy, is the industry’s first building-integrated photovoltaic product designed specifically for curved-roof systems and in my next post I'm going to write about it.

Thin-film Photovoltaic (PV) Cells

In some of my previous posts I have mentioned thin-film photovoltaic cells and in this article I'll give a brief overview of them.

Solar panels based on the photovoltaic effect have been used for more than thirty years and have traditionally been built using wafers of crystalline silicon, which requires expensive processing and results in ridged, heavy and fragile solar panels.

Crystalline silicon PV cells are still the mainstream products in the PV cell market because they have high conversion efficiencies. However, their output is increasingly being bogged down by shortage of raw material, high production cost and difficulty of processing. These factors have given rise to rapid development of second generation PV technology known as thin-film PV technology.

Thin-film solar cells are generated by coating a substrate (glass, thin flexible metal or plastic substrate) with layers of conductive and semi-conductive materials of a few micrometers in thickness. The individual layers of material are deposited by various processes.

The key materials for the thin-film solar cells are semiconductor elements such as amorphous silicon (a-Si, still silicon, but in a different form), cadmium telluride (CdTe) and copper indium (gallium) diselenide (CIS or CIGS).

Amorphous silicon (a-Si) was the first thin-film material to be commercialized, although, the PV cells built from amorphous silicon are invariably less efficient than crystalline PV. These PV cells have low efficiency and limited lifetime (approximately 10-15 years). Initially, a-Si was mostly used in consumer items such as calculators. Amorphous silicon is the most widely used for the creation of thin-film solar panels. It has a sun energy conversion rate as high as 9%.

Cadmium telluride (CdTe) is a highly useful material in the making of solar cells. Cadmium telluride PV (CdTe PV) is the first and only thin-film photovoltaic technology to surpass crystalline silicon PV in the marketplace in terms of lower system price for a significant portion of the PV market – large (multi-kW) systems.

CdTe PV cells structure includes a very thin layer of cadmium sulfide that allows most sunlight to pass through to the CdTe layer. These characteristics provide the potential for high-efficiency modules with low-cost manufacturing processes. CdTe cell efficiencies are over 16% in the laboratory; commercial module efficiencies are likely to be in the 9% range in the first manufacturing plants.

Copper indium gallium diselenide (CIGS) cells create more electricity from the same amount of sunlight than does other thin-film PV and therefore has a higher "conversion efficiency". Besides that, CIGS conversion efficiency is very stable over time, meaning its performance continues unabated for many years.

CIGS cells use extremely thin layers of semiconductor material applied to a low-cost backing such as glass, flexible metallic foils, high-temperature polymers or stainless steel sheets. They are of interest for space applications and the portable electronics market because of their light weight. CIGS cells are also suitable in special architectural uses, such as photovoltaic roof shingles, windows, siding and others. CIGS thin-film solar cell recently reached 19.9 percent efficiency, setting a new world record for this type of cell.

Thin-film PV technology has attracted a lot of interest in the recent years. The main reason for this interest is that thin-film PV cells are less expensive than other PV systems. Rather than being manufactured laboriously piece by piece, thin-film can be mass-produced in cheap rolls like packaging - in any colour. Thin-film PV cells also can harvest as much energy from the sun with far less semiconductor material. They can be made with flexible substrates which allow them to be used in more locations than silicon cells, such as clothing and sails. A number of applications are being pursued using thin-film PV technologies, including roof-top applications (such as rooftop shingles, roof tiles), building-integrated photovoltaics (BIPV), the glazing for skylights or atria, and utility-scale applications.

Thin-film PV cells represent the most promising technology for providing more affordable solar cells for residential and other uses in the future. According to NanoMarkets, the thin-film photovoltaics (TFPV) market will produce 26GW by 2015, generating over $20 billion in revenues.

Silicon-Based Solar Cells for Flexible and Transparent Solar Applications

Scientists at the University of Illinois at Urbana-Champaign have developed new high-efficient silicon-based solar cells that are flexible enough to be incorporated on a curved surface or fabric, and transparent enough to be used to tint windows on buildings or cars.

The finding, reported in the journal Nature Materials, offers a new way to process conventional silicon by slicing the brittle wafers into ultra-thin layers and carefully transfers them onto a flexible surface.

"We can make it thin enough that we can put it on plastic to make a rollable system. You can make it gray in the form of a film that could be added to architectural glass. It opens up spaces on the fronts of buildings as opportunities for solar energy.” said John Rogers of the University of Illinois at Urbana-Champaign, who led the research.

Many international companies are making thin-film solar cells, but they are usually less efficient at converting solar energy into electricity than conventional cells.

Rogers' team uses a special etching method to slice very thin solar chips off the surface of single crystal silicon wafers which are highly efficient but, in their current form, rigid and fragile. The sliced chips are 10 to 100 times thinner than a normal silicon wafer, and the size can be adapted to the application. Once sliced, the bits of silicon chips are picked up by a special device and deposited on the target surface "like a rubber stamp".

“These silicon solar cells become like a solid ink pad for that rubber stamp. The surface of the wafers after we’ve done this slicing become almost like an inking pad,” said Rogers. “We just print them down onto a target surface." "The final step is to electrically connect these cells to get power out of them," he said.

Adding flexibility to the material would make the cells far easier to transport. Rogers envisions the material being “rolled up like a carpet and thrown on the truck.”

The technology has been licensed to a startup company called Semprius in Durham, North Carolina.

Sources: Reuters & Energy Efficiency News

China - a World Leader in the Solar Water Heating Market

A roof-mounted solar water heater
Photo credit: www.bcsea.org

China is by far the world's largest producer and consumer of solar water heaters. A basic models of solar water heaters in China are very cheap, starting at around 1,500 yuan (US$190). By 2006, the cumulative installed area of water heating collectors in China hit 100 million square meters, and that is roughly 80 percent of the global solar thermal capacity installed worldwide. But this number corresponds only to 78 sqm of collector surface installed for every 1000 inhabitants, which implies a large margin of market potential. So, although China is the biggest solar thermal producer and market in the world, per capita installations of solar hot water systems are still quite low compared to countries like Israel, Greece, Cyprus, Germany and many others.

More than 30 million Chinese households now have one solar water heater installed, and the popularity is due to the efficient evacuated tubes which allow the heaters to function even under cloudy or smog-choked skies and at temperatures well below freezing. The evacuated tube technology was initially developed by Qing Hua University in Beijing in the early eighties, with pilot manufacturing in 1985.

A report from the China's top planning authority predicted that by 2010, the coverage of solar water heating systems in operation in China will reach 150 million square meters. It is also estimated, that by utilizing solar energy, China can save more than 50 million tons of coal in 2010.

"Green Olympics" - Beijing 2008

Beijing National Stadium - 'Bird's Nest'
Photo credit: Guo Lei/Xinhua

The 2008 Summer Olympics in China are in their apogee and they are drawing a lot of attention. Taking into account a massive global audience, the Beijing Olympic organizers are hoping to focus our attention to climate changes and popularize the idea of using eco-friendly technologies. The "Green Olympics" may help change peoples attitudes and set standards for future building projects in China and around the world.

The Olympic organizers are trying to make the Olympic Games environmentally friendly and Beijing a model city for using green technologies, zero net emissions and sustainable architecture. As a part of these efforts, more than a quarter of the energy used at Olympic venues is coming from renewable sources.

Beijing's Olympic Village is a great example of sustainable community development. All seven main Olympic stadiums are equipped with solar generators capable of outputting 480 kilowatts of energy at any given moment. The entire hot-water supply for the Olympic Village will be powered by solar energy. Photovoltaic panels are incorporated on the stadium walls and roofs for most of the outdoor lighting. Also, the main stadiums will receive power from Beijing's first wind farm.

Beijing National Stadium - 'Bird's Nest' includes a rainwater collection arrangement, a natural ventilation system and its upper surface is clad with Ethylene Tetrafluoroethylene (ETFE) roof panels, that let in natural light. The stadium is referred to as the ‘Bird’s Nest’ because of its saddle-shaped steel roof and interwoven façade

The spectacular-looking structure called "Water Cube" looks like a building made of bubble-wrap. It is officially known as the National Aquatics Center and is completely surrounded with ETFE pillows. It is expected to cut energy use by 30 percent and has been built so that after the Olympic Games to be converted easily to a shopping area and leisure center.

The idea for the Beijing's "Green Olympics" makes perfect sense because China sees its energy costs rising and energy sources dwindling, as well as significant damage to the environment. And the so-called "Green Olympics", although will not solve China's environmental issues, they could point the way to a more sustainable future, according to officials and experts.

China is already a world leader in many renewable energy technologies, but so far many of the green technologies have been for export only, because they are too expensive for the country to use itself. China, for example, led the world in manufacturing and utilisation of solar water heaters and energy efficient light bulbs. It is also on the way to becoming the world leader in wind turbine manufacturing and installation.

Solar Energy from Saharan Sun Could Power Europe

Solar thermal parabolic trough power plant;Source: Solar Millennium, TREC

According to an article published recently in the UK’s Guardian newspaper, EU scientists are working on an ambitious plan to harvest the sun in the Sahara desert in Africa to provide electricity for Europe. Europe needs a lot of electricity, but gets little sun. Vast solar power farms in the Sahara desert could provide clean electricity for the whole of Europe.

The EU scientists are calling for the creation of a series of huge solar farms - producing electricity either through photovoltaic cells, or by concentrating the sun's heat to boil water and drive turbines - as part of a plan to share Europe's renewable energy resources across the continent.

Speaking at the Euroscience Open Forum in Barcelona (ESOF), Arnulf Jaeger-Waldau of the European commission's Institute for Energy, explained how electricity produced in solar farms in Africa, each generating around 50-200 megawatts of power, could be fed thousands of miles to European countries by using high-voltage direct current (DC) transmission lines instead of the conventional alternating current (AC) lines. Energy losses on DC lines are far lower than AC ones where transmission of energy over long distances is uneconomic.

Depending on the size of the grid, building the necessary high-voltage lines across Europe could cost up to €1-billion a year every year till 2050, but Jaeger-Walden pointed out that the figure was small when compared to a recent prediction by the International Energy Agency that the world needs to invest more than $45-trillion in energy systems over the next 30 years.

Doug Parr, Greenpeace UK's chief scientist, welcomed the proposals: "Assuming it's cost-effective, a large-scale renewable energy grid is just the kind of innovation we need if we're going to beat climate change."

The idea for developing a major innovative super-grid based on renewable energy is already gaining political support in Europe, with both the UK Prime Minster Gordon Brown and and the President of France Nicolas Sarkozy, recently backing the north African solar plan.

The scientists say that harnessing solar energy from the Sahara would be especially effective, because the sunlight in that area is much more intense: solar photovoltaic panels in northern Africa could generate up to three times the electricity compared with similar panels in northern Europe. And it would require the capture of just 0.3%of the light falling on the Sahara and Middle East deserts to meet all of Europe's energy needs.

Source: http://www.guardian.co.uk/environment/2008/jul/22/solarpower.windpower?gusrc=rss&feed=environment

Note: An earlier article in Spiegel Online from April 30, describes the project and also how it will benefit Africa because it is important that such an ambitious development is sustainable and beneficial to both continents. Read more: "Is Desert Solar Power the Solution to Europe's Energy Crisis?"

For the original plan visit: http://www.desertec.org/concept.html

Rotating Skyscraper Powered by Wind and Sun in Dubai

The Italian architect David Fisher said he is ready to start construction on a  futuristic rotating skyscraper in Dubai that will be "the world's first building in motion". The modern "Dynamic Tower" construction, which would be energy self sufficient and cost about 700 million dollars to build, will represent an 80-storey tower with revolving floors that give it an ever-shifting shape. 

The spinning floors, hung like rings around an immobile central column, would offer residents a constantly changing view of the city's skyline and the Persian Gulf. Each floor will rotate independently at different speeds. It will take between one and three hours for the floors to make a complete rotation.

Rotating floors are just one of several futuristic features in the building. Using wind and solar power, it will generate more electricity than it uses. Horizontally mounted giant wind turbines fitted between each rotating floor will generate enough energy to power the tower and nearby buildings. 20% of each roof will be exposed to the sun and photovoltaic cells placed on the roof of each rotating floor will produce solar energy. For the interior of the luxury apartments will be used only natural and recyclable materials, including stone, marble, glass and wood.

The dwellings will be assembled in a factory outside Bari in southern Italy, equipped with plumbing and electricity systems, kitchens, bathrooms and ceilings. They will arrive also painted, decorated and, in some cases, with walls hung with artwork. An apartment will cost between $3.7 million to $36 million dollars. Lifts will allow penthouse residents to park their cars right at their apartments.

The plan was revealed by Mr Fisher in a press conference at the Plaza Hotel in New York on June 24. "Today's life is dynamic, so the space we are living in should be dynamic as well," he said. "Buildings will follow rhythms of nature. They will change direction and shape from spring to summer, from sunrise to sunset, and adjust themselves to the weather. In other words, buildings will be alive."

Construction of the rotating skyscraper is scheduled to be completed by 2010.

Update 2020: The project has not been completed yet.

Solar Photovoltaic (PV) 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.

Applications of Photovoltaic PV Power Today

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.

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