Moscow, May 25. /TASS/. At the Northern Arctic Federal University Kirill Romanov studied how wind-solar hybrid systems work. The student was absorbed in the topic and decided to make another electric plant - a mobile plant, which uses energy of the Sun.

The post-graduate has been working on a mobile solar farm, which could work in the Arctic. According to Kirill, the project seems attractive for companies, which lay communication cables, which sent expeditions to the Far North, and for even national parks.

When frost is an advantage

Kirill studied industrial power supplies, when the university installed a hybrid wind-solar farm to see how renewable energy sources could be used in Arkhangelsk.

"My friend and I were to study how it works so that further on the farm could be integrated into the building’s energy system," Kirill said. "I got absorbed in the project."

The university had studied alternative energy before Kirill began the project, though the focus was on energy of the wind. As soon as a small solar farm was installed on the building, everyone could see how effective it was.

"Our conclusion was that in Arkhangelsk solar panels are more effective than they are supposed to be. In the working mode, temperature of silicon photo elements in the panels goes up, thus boosting the efficiency. Since the average temperature in past winter was about minus 15 degrees, the elements were cooled naturally, and consequently the photo elements demonstrated their potential even in low insolation. We saw that the panels could work effectively, that they have potential a good potential to work in the Arkhangelsk Region even in winter."

Thus, it is the colder the better for solar batteries. However, in freezing air snow may stick to their surfaces, so they should have hydrophobic coating. This coating is also important for wind power generators.

Use of solar energy usually applies to southern regions, but during the polar summer it may be used even in the Far North, when the Sun stays in the sky between May and September. On Russia’s northernmost archipelago - Franz Josef Land - the amount of solar energy within one day is comparable with that in Moscow in mid-summer.

The Russian Arctic National Park began using solar farms back in 2013. The first experience was very modest - on Cape Zhelaniye (Novaya Zemlya) they managed to use energy from solar panels to boil a kettle.

Anyway, the experiment was successful, and now the solar farm produces electricity in summer on the Zhelaniye Cape, in Tikhaya Bay, on the Hooker Island and on the Alexandra Land. Thus, the park saves about 1,000 liters of diesel per every location within one season, and, what is very important, keeps the environment clean.

"We shall continue to use the solar energy in the park," its Director Alexander Kirilov said. "We have bought panels for the Heiss Island. And the Zhelaniye Cape remains our test area for alternative energy sources. Now we watch how wind generations work."

At the same time, he said, modern mobile solar farms are complicated to use, and, if the energy output is high, they are huge in size. They require high professionals to manage all the controllers and inventors. If a farm is not big, its energy may be sufficient only to charge a cell.

Catching the Sun

Kirill has been working under a grant for young scientists, aged between 18 and 30. In the end, he should produce a farm, ready to be manufactured. The winner will receive 500,000 rubles ($7,000) to finalize the project. Kirill has been working to improve the prototype.

He suggests two solutions. The first is to use mirrors, or rather mirror concentrators to catch most sunlight. The mirrors should adjust automatically as soon as a panel receives little light.

"If the air temperature is plus 20 degrees and they remain exposed, the photo elements will fail due to overheating. But closer to the evening, when the photo element’s temperature returns to nominal levels, the mirror concentrators will begin working," Kirill said.

The mirror concentrators should learn to fold in strong wind. Another task is to find material suitable for the mirrors. Concentrators in the first prototype were unreliable and heavy, and now the young scientist is picking from thin flexible materials, which could stand strong winds.

"I want to have a thin film with ideal reflection and without distortions," he said.

Following the light source

The biggest challenge is to have the solar farm move after the Sun - both vertically and horizontally, like Arctic poppies do. Their yellow buds look like little solar batteries.

This task has many aspects. For example, the system must not freeze down, and thus it must be clear what deicing liquids could be used. Such aspects are the most complicated tasks in the project, Kirill said.

Another important objective is to make the farm easy-to-transport and easy-to-manage, which current models usually lack, the national park’s director said.

The young scientist wants his farm to fit a car trailer or a box, which a helicopter, plane or ship could deliver.

"It should be a Plug and Play device. Just press the button and the microcomputer identifies the geolocation, searches for the Sun and adjusts the tracker for effective work of the solar batteries," Kirill said.

Artificial Sun

This year, spring in Arkhangelsk is rather overcast, and Kirill has made an artificial Sun in the lab to experiment with mirrors and panels.

"The batteries’ main absorption spectrum is the visible radiation, closer to infrared," he said. "The solar panel practically does not react to daylight lamps, it reacts much more to just a match than to an led lamp. I’ve been studying microcrystalline and polycrystalline solar panels. A well-known myth claims polycrystalline panels on overcast days work better than mono-crystal panels. I want to see how they differ in freezing temperatures."

The young scientist has made an interesting discovery. Panels with some transparent lining between photo elements. Rays pass through it and, reflecting from the snow, fall on the back surface, which also has solar cells. For the Arctic, where there is a lot of snow, this option of bifacial solar cells may be highly effective. Mirrors, by the way, could play the role of the snow.

Kirill names the target consumers. Those are scientific expeditions to hard-to-reach areas, like to the Arctic Circle, or to mountains; or towns for shift workers in the Arctic. They could use a hybrid: a solar battery and a diesel generator. Other consumers could be travelers and fishers.

"Besides, I thought about the cultural heritage objects," Kirill said. "At national parks or museums, with old buildings, where it is important to keep the ecology safe. Quite often, using diesel generators is out of question there, but anyway they need to have light at souvenir shops or in old houses, which tourists come to see." 

The scientist hopes the work on mirror concentrators will finish by late May, and before the New Year he will present the prototype of a mobile solar station.