Solar-Powered Backpack

A solar-powered backpack is one of the recent environment-friendly solar innovations which become more and more popular. It allows the hiker or traveler the opportunity to keep their electronic devices charged anywhere they go using solar energy. 

We live at the age when we are constantly connected to one device or another such as smartphones, MP3 players, tablets, laptops, so the importance of having a source of power with us has never been greater. Here comes a solar-powered backpack. It can harness enough solar energy to keep us connected with the world and it is ideal for people who like to take hiking trips or go camping.

The solar-powered backpack has a small solar panel attached to its outer surface so we can capture the sun’s rays. The interior space includes a storage battery and other components. The solar panel is lightweight, waterproof and can produce up to 10 watts of power. 

Other components of the solar-powered backpack include a flexible mono-crystalline or thin-film solar panels, charge controller, a variety of cell phone adapters and a USB plug for your MP3 player.

With the solar-powered backpack, you can also power a GPS, a travel lamp, a digital camera, a palm pilot, and other rechargeable electronic devices.

The solar-powered backpack has a lithium-ion battery pack inside to store this energy. NASA and the US Army have used copper indium gallium diselenide (CIGS) solar cells for its unbreakable strength and flexibility.

A solar-powered backpack known as REPPS (Rucksack Enhanced Portable Power System), was first used by the US army for communication equipment in 2010 in Afghanistan. The US Air Force had previously used solar panels on shipping containers, developed by Lockheed Martin. And the Marines developed suitcase units of foldable solar panels which can also be carried as a backpack.

A solar-powered backpack can also be used for international aid, disaster relief, and humanitarian relief efforts where power from the utility grid is not available. (read this article)

Several companies are manufacturing solar backpacks and they range in price from $75 to $500.

How to Harvest Solar Energy on Cloudy Days

Image credit: SunModo

Talking about solar energy without sunlight, it is interesting to see how solar energy can be harvest on cloudy days. 

Even on cloudy days, there’s still solar energy send down to earth from the sun. And although solar panels don’t produce as much electricity as they do on sunny days, they have been shown to produce 25% of what they produce on a sunny day, or 10% when it’s very cloudy. The exact amount will vary depending on the density of the clouds, and may also vary by the type of solar panel - some kinds of panels are better at receiving diffuse light. SunPower solar cells, for example, have been designed to capture a broader range of the solar spectrum. By capturing more red and blue wavelengths, their solar panels can generate more electricity even when it’s overcast.

We may assume that solar panels thrive in hot, sunny weather, but too much heat can also reduce solar panel output 10-15%. The very hot climate isn't the best condition for them. Most solar panels' power outputs start to degrade if the temperature of the panel goes over about 25°C. 

Solar power can work well in areas known for cloudy, cold weather. For example, New York, San Francisco, Milwaukee, Boston, and Seattle. These cites often have bad weather, from blizzards to rain and fog. However, each of these cities tops the list of those that see major savings due to solar power installations. And rain helps to keep the panels operating efficiently by washing away any dust, pollen, and dirt. Clean panels turn out the most electricity.

San Francisco is well known for its foggy days with cool weather but rooftop solar power systems in San Francisco do function well. The amount of direct sunlight is reduced by fog and clouds, but as already was said, solar panels function better at cooler temperatures, so the electricity output in San Francisco is still significant. Using a home solar power system there can save approximately $1,500 per year on utility bills.

Germany is the fourth-largest PV market in the world that's famous for its lack of sunlight. Germany accounts for about 25 percent of the world's solar power output and achieved its strongest growth in half a decade during 2018, according to a recent Greentech Media article. 

Going solar is about saving on your energy costs as well as helping our planet and the weather can’t be an obstacle.

And if we choose to rely on solar panels for our home electricity use, we can also use a solar battery system to save money by storing free energy for use when it’s cloudy or for night use. Solar batteries have been around for a while, but up until recently, the costs were very high, the equipment was bulky and they were difficult to use. Except for people who lived off the grid, they weren’t so good investment. But that has changed in recent years. The price of solar batteries has dropped and in many cases, they are now an excellent investment for homeowners in cloudy regions who want to reduce their electricity bills.

Sources: Cleantechnika & Powerhome

                     

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.

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.

Solarpro’s Yankovo PV Power Plant Put into Operation

On 24 August the first stage of the photovoltaic plant of Solarpro in the village of Yankovo, northeastern Bulgaria, has been officially put into operation. The first phase of the project "North-East 1" features installed capacity of 338kWp . The plant had been successfully acceded to the power grid of E. ON and delivers electricity to the electricity distribution company. The project is scheduled to reach full capacity by the end of the year. The whole plant "North-East 1" has nominal power of 2404kWp will be the largest photovoltaic park in the country.

Solarpro, 80% owned by Bulgarian miner Kaolin, has launched production of photovoltaic (thin-film amorphous-silicon PV module) solar panels at its factory in Silistra, on the Danube. At the end of March the first panels of the first production line of the photovoltaic plant in Silistra were produced.

The "North-East 1" PV power plant is constructed with 8064 thin-film photovoltaic panels, manufactured by Solarpro, in its Silistra-based factory. It is the only company in Bulgaria, which concludes the entire PV module manufacturing – power plant integration chain. The components of the power plant are mainly made in Bulgaria, and all subcontractors are local companies.

Solarpro is the first and only manufacturer of solar panels in Bulgaria. Solarpro is the biggest solar panels manufacturer on the Balkans, with planned capacity of 18 MW annually, organized in three production lines, one of which currently operational. The company came into being in end-2007 in line with a strategy of its owner to bolster energy efficiency and reduce dependence on fossil fuels.

Sources: solarpro.bg & alfafinance.bg

World's Leading Photovoltaic Companies

Sharp Solar is the world's largest photovoltaic module and cell manufacturer, with an overall capacity of 600 megawatts. It manufactures in Japan, in the UK - near Wrexham, and recently opened a large manufacturing facility in Memphis. Sharp Solar produces both single and multi-crystalline solar cells which are used for many applications. Sharp began its development of solar cells in 1959, with mass production first beginning in 1963. In 1980, it was one of the first companies to introduce calculators powered by solar cells.

Established in 1999, Q-Cells is the world's second largest cell manufacturer, based in Thalheim, Germany (Q-Cells AG was the single largest producer of solar cells in 2007 according to industry data). Its core business is the development, production and marketing of high-quality (mono- and multi-) crystalline silicon photovoltaic cells.

Based in Wuxi, China, Suntech Power is the world's third largest producer of photovoltaics in 2007. Suntech Power manufactures solar cells and modules and it is a global leader in solar energy as measured by both its production output and the capacity of its solar cells and modules.

Headquartered in Kyoto, Japan, the Kyocera Corporation is a pioneer in the solar energy market and began to develop solar cells in 1975. Today Kyocera is one of the world’s leading manufacturers of solar cells and modules, with a highly controlled mastery of all the production steps from wafer and cell fabrication to module assembly.

The Phoenix, Ariz.-based First Solar is a leader in the development and manufacture of high quality thin film solar modules. They manufacture photovoltaic solar modules developing advanced, thin film semiconductor deposition and high volume manufacturing processes, based on Cadmium Telluride (CdTe).

Motech is the largest manufacturer of photovoltaic cells in Taiwan. For over 25 years, Motech Industries, Inc. (Motech) has been creating high quality products, from testing and measuring instruments to solar cells. Motech has now become one of the top 10 producers of solar cells and the 6th largest crystalline solar cell manufacturer in the world (2007).

SolarWorld is headquartered in Bonn, Germany, and purchased Shell Solar's crystalline silicon activities in 2006. SolarWorld is one of the three largest solar energy groups in the world. The SolarWorld Group of companies is involved in every step of the solar value chain from raw silicon to turn-key solar power systems and is active in growing solar markets around the world.

Japanese company Sanyo Electric has been manufacturing solar cells and panels since 1970s. In 1992, Sanyo Electric started the practical application of installing the first PV generation systems on individual houses in Japan. SANYO HIT (Heterojunction with Intrinsic Thin layer) solar panels are a leader in cell and module efficiency with models up to 16.2 Watts per sq. foot (17.4% module efficiency). On July 29, 2008 the company announced, that it achieved a cell conversion efficiency of 22.3% at the research level.

China-based Yingli Green Energy is one of the world's leading vertically integrated PV product manufacturers. Yingli Green Energy sells PV modules under its own brand name, Yingli Solar, to PV distributors located in various markets around the world, including Germany, Spain, China and the United States.

SunPower Corporation is a Silicon Valley based solar company, and is one of the largest in existence.The company designs and manufactures high-efficiency silicon solar cells and solar panels based on an all-back-contact "All-Black" design. They install them through their subsidiary PowerLight. Their Nellis Solar Power Plant is currently the largest PV installation in North America

Schott Solar Germany is among the world's leading fully integrated manufacturers of PV wafers, cells and modules. The company has more than 40 years of experience and offers reliable PV solar electricity modules for almost any kind of application. Schott Solar is also one of the leading companies in thin film technologies.

Renewable Energy Corporation (REC) is based in Norway, and was established in 1996. Over a relatively short period, REC has become the world's largest producer of poly silicon and wafers for PV applications. The company has seven production plants in three different countries and customers all over the world.

Mitsubishi Electric is one of the world’s largest manufacturers and providers of solar power technology, including PV cells, modules and inverters. The company’s eco-friendly photovoltaic systems are used throughout the world to bring clean, reliable energy to residences, business, power generation plants, schools, and factories.

BP has been involved in solar power since 1973 and its subsidiary, BP Solar, is now a major worldwide manufacturer and installer of PV solar cells, with production facilities in the United States, Spain, India and Australia. Headquarters for BP Solar are located in Frederick - a city in west-central Maryland, United States.

Isofoton is a Spanish company, the biggest solar panel manufacturer in Europe. The company designs and manufactures high-efficiency mono crystalline silicon cells (also the most expensive), and it is currently the largest mono crystalline producer worldwide.

Nanosolar was started in 2002 and is headquartered in Palo Alto, California. Nanosolar is a maker of thin-film solar panels and is a global leader in solar power innovation. Nanosolar Powersheet, a very thin film solar panel has won the Popular Science Innovation of the Year award. The company manufactures Powersheet by printing a solar absorbing “ink” onto a thin rolled metal sheet in a low-cost, fast, continuous process. The company has manufacturing operations in Silicon Valley, California, and the Berlin capital region, Germany.

Solar PV Power in Cold Climate

Many people interested in generating solar PV power for their household power needs are also interested to know how PV solar panels operate at colder temperatures or in cloudy conditions. Actually, PV solar panels work better at colder temperatures - some of the best efficiencies ever recorded were at the South Pole! This is because the solar cells in the panels are electronic devices that generate electricity depending on the amount of sunlight they receive, not heat. In cold climates, PV panels will generate less energy in the winter than in the summer, but this is due to the shorter days and less sunlight, not the colder temperatures.

Photo credit: altenergy.blog-city.com

PV solar panels continue to work even in cloudy conditions, although they do produce less electricity. On days with cloud cover or windblown snow, the PV panels' output power is reduced significantly. With sun angles approaching the highest limits and visibility being high, the PV panels reach their rated output power.

Many countries in the northwestern region of Europe, including Denmark and the rest of Scandinavia, make extensive use of solar power. Germany is the world's leading installer of photovoltaic (PV) solar cells, although its climate is mostly temperate. Japan is also a major installer of solar PV panels, and their climate is temperate.

An example of integrating PV technology in the daily life are solar powered parking meters which are fairly common in Germany and the Netherlands. The electricity which runs them is supplied by small solar panels on top of the parking meters, right there in the streets.

Canada is another cold-weather country where PV technology is quickly gaining ground. PV cells have been used in Canada over the last 20 years or more for many applications. Photovoltaic modules were used as standalone units, mainly as off-grid distributed electricity generation to power remote homes, telecommunications equipment, oil and pipeline monitoring stations and navigational applications. Over the last few years PV technology has also started to be introduced into urban areas, incorporated into the roofs and facades of homes, offices and factories. And the largest solar PV energy park in North America will be located on approximately 300 acres of land in the Township of Stone Mills, Lennox & Addington County, Ontario. The 19-megawatt project, known as First Light, is being built by SkyPower Corp and SunEdison Canada. The construction is anticipated to be completed by the end of 2009 and local communities will benefit from clean renewable energy sufficient to power more than 2,000 homes annually.

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.