Sunday, June 28, 2020

Gel Makes Solar Panels “Sweat” to Cool Themselves


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Last month I read something interesting in the news concerning solar panels and I decided to write a post about it in my blog. It is something new in solar power technology - gel-like material makes standard solar panels “sweet” to cool themselves. Liangbing Hu, a materials scientist at the University of Maryland, College Park says: “it’s a simple, elegant, and effective way to retrofit existing solar cell panels for an instant efficiency boost.”

Typical silicon solar panels convert approximately 20% of the sun’s light into electricity. Much of the rest turns into heat, which can warm the solar panels by as much as 40°C/104°F. As we know, the heating of the panels is one of the most serious problems - solar panels are much less efficient when overheated. In fact, with every degree of temperature above 25°C/77°F, the efficiency of the solar panel drops. 

In recent years, researchers have devised materials that can suck water vapor from the air and condense it into liquid water for drinking. Among them are researchers at the University of Texas who have created a new gel-like material. Initially, the gel was created to produce clean drinking water. It proves its effectiveness and has the potential to provide a clean, sustainable water source for millions.

The gel-like material is a mix of carbon nanotubes in polymers with a water-attracting calcium chloride salt. This substance absorbs water vapor at night when the air is cold, and humidity is high. Then it causes the water vapor to condense into droplets that the gel holds. When the heat rises during the day, the gel releases water vapor. If covered by clear plastic, the released vapor is trapped, condenses back into liquid water, and flows into a storage container.

Peng Wang, an environmental engineer at Hong Kong Polytechnic University, and his colleagues figure out another use for the condensed water: coolant for solar panels. So, the researchers applied a 1-centimeter thick sheet of the gel against the underside of a standard silicon solar panel. Their idea was that during the day, the gel would pull the heat from the solar panel. It initiates an evaporation process for the water it pulled out of the air the previous night, releasing it through the bottom of the gel layer. Thus the gel-like material can make solar panels “sweat" and cool - just like sweating cools the human body. The amount of gel needed per panel depends on its size and the temperature and humidity in your location. In a desert environment with 35% humidity, a 1-square-meter solar panel required 1 kilogram of gel to cool it. In a muggy area with 80% humidity, only 0.3 kg of the gel is needed per square meter solar panel.

The temperature of these solar panels can drop to 10°C/50°F, and the electricity output of the panels can increase by 15% to 19%. In the area of solar technology, this is considerable. “In a field where engineers struggle for every 0.1% boost in power conversion efficiency, even a 1% gain would be an economic boom,” says Jun Zhou, a materials scientist at Huazhong University of Science and Technology.

One disadvantage of this solution is that rain could dissolve the calcium chloride salt in the gel, sapping its water-attracting performance. Peng Wang acknowledged this as a possible problem, despite the hydrogel sitting beneath the solar panel, and being somewhat shielded from the rain. He said he and his colleagues were working on a second-generation gel that would not degrade, even when wet.

The team is also looking at another design option that could trap and re-condense water after it had evaporated from the gel - and potentially using the collected water to clean solar panels from the dust.

Currently, over 600 gigawatts of solar power exist worldwide, providing 3% of global electricity demand. This number may increase by about five times over the next decade.


Saturday, June 20, 2020

SmartFlower Solar Power System - an Alternative to Solar Panels


SmartFlower solar power system
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SmartFlower solar power system comes from Austria. It is an innovative and unique solar panel system that can be mount on the ground in your backyard. This high-tech “smart” solar power system is an alternative to rooftop mounted solar power systems.

When you install a conventional solar panel system you have some limitation like roof type and space availability while with the SmartFlower solar power system you only need to choose the place which has sufficient exposure to sunlight. Another advantage is that this portable solar panel system shaped like a flower, can follow the sun throughout the day and this is a far more efficient way of harnessing solar energy. The photovoltaic device does all of this autonomously through algorithm-based dual-axis tracking. Thus, SmartFlower can produce up to 40% more solar energy than a conventional solar panel system.

SmartFlower solar power system has a stunning design and some cool high-tech features. Its height is 16.4ft (5 meters), weighs around 650 kg, and it rotates throughout the day in the same way as sunflower petals do. The “smart” photovoltaic system occupies 194 square feet. It consists of 12 “petals” covered with solar cells, which open up every morning when the sun rises. The SmartFlower moves toward the sun at a 90-degree angle and produces approximately 2.5kW of electricity in peak sunlight conditions. When the sun goes down the petals close. 

The SmartFlower gathers information about weather conditions and takes it into account when decides whether it should be open or fold together for protection. In winds 29 mph+ the SmartFlower solar petals automatically move to a horizontal position. At 39 mph+, the solar petals will completely fold down. Also, the solar petals clean themselves through the anti-microbial brushes that are attached on the back of each petal.

The upgraded model of the SmartFlower is named SmartFlower +Plus. SmartFlower +Plus is the same as the main version but includes battery storage to store solar energy. The stored excess solar energy can cover cloudy days and peeks in consumption. SmartFlower +Plus can work on-grid and off-grid - completely independent from the grid. This model is available in two versions –one with a storage capacity of 4.6 kWh and the other with 13.8kWh storage capacity. In addition, there is another model of the SmartFlower that lets you charge electric cars. 

Besides tracking the sun and self-cleaning, other “smart” features are self-containing and self-cooling. The SmartFlower solar power system is an all-in-one complete solar energy system, with an inverter, battery storage, battery charger, monitor, and control box, all integrated into a single unit. SmartFlower solar system also has rear ventilation to keep the system up to 18°F cooler than it would be without it. That is good for solar cell efficiency, which means 5-10% more output on average.

The SmartFlower is available in eight colors (berry, ocean, amber, mermaid, pearl, lavender, jungle, and porcelain). It can be fast and easily installed (just plug and play). And by removing four bolts and one cable you can move SmartFlower anywhere you want.

According to the news, the Austrian manufacturer of the SmartFlower began bankruptcy proceedings in Germany in 2017. However, the U.S. division of SmartFlower operates independently from the original Austrian developer. So far, the SmartFlower has been installed at numerous U.S. backyards, in addition to organizations like the Detroit Zoo, Mary Baldwin University, and Virginia Wesleyan University. The United States division of SmartFlower is currently based in Boston, Massachusetts.

SmartFlower solar power system is a real alternative to solar panels. If you want to buy one of the models, you should know that before applying for all incentives and tax credits, the SmartFlower solar panel system ranges from $25,000 to $30,000. SmartFlower can generate between 4000 and 6500 kWh per year. The average home in the United States uses 10,400 kWh annually, so this will cover 40-60% of your energy bill.

You can visit the official SmartFlower website for more information.

Sources: & Internet