In Asahikawa, Hokkaido that, by Japanese standards is cold – sometimes up to -41 ° C. In addition, there is snowing periodically and because of this long leg Solar energy has never stepped on land thence …
But … the global restructuring of energy in this country in the end had no choice, and, lo and behold, local experts managed to partially pay the harsh climate to their advantage.
It would seem, given the geography of this country would do well to build up solar panels Ryukyu – places a lot more southern, snowless and receive a half times more solar energy per year than most northern Japanese island. But, as we have already mentioned, in Japan no one is looking for easy ways , because, actually, they are not.
Reflected from the snow, the rays still carry enough energy to 6-10% increase in power generation solar panels. Be in Hokkaido in winter as sunny as in the south of the Russian Far East, the effect could be even greater. (Here and below photo Nikkei BP.)
To curb the “snow factor” Hokkaido Energy decided early solar panels tilted abruptly by 40 °, which, on the one hand, reduces the production of energy in the summer, and with another – increases in winter, when it is most needed. And most importantly – it allows you to simply slide off the snow, without the need to seal the seams with silicone sealant between the panels.
But small gelioES “Asahikawa Hokuto” 1.25 MW, launched in November 2013, went further and tried to draw the enemy of snow solar energy in another. To do this, first for a large power such were used bilateral photocells, which, instead of an opaque plastic underlay is located on the back side transparent layer, whereby the sunlight reflected from the snow pack surrounding partially it is not used on the front and rear side.
At the same total thickness of the silicon layer is no need to increase, and that allows the manufacturer to the photocells, the Japanese company PVG Solutions , bullying is not higher than normal prices.
What is the effectiveness of such a decision? Usually serial monolayer silicon solar cells provide efficiency of about 15-16%. A double-sided solar panels shown in this winter 18% – during the period when the surface beneath them was covered with snow, and 16-17% in the snowless days when the amount of light reflected from the surface under the photocells fell. Although the numbers seem trifling, it is worth considering that the general power of solar energy around the world now substantially exceed 100 GW, and such optimization 6-10% in countries with boreal (where contrary to economic logic is introduced into the system the main part of solar panels) up sharply them out in the winter without the need for expensive multi-layer systems.
It is also important that such a two-sided form factor can be realized not only silicon but also for almost any other type of semiconductor materials: enough to make the rear battery cover transparent.
Despite the winter, solar panels installed at a height of 1.8 m, remain free of snow, even after many days of snowfall.
As experts say “Asahikawa Hokuto” The operating results of bilateral photocells induce them to think about the feasibility of applying some inexpensive white coating of relatively hydrophobic malopachkayuschegosya material that would provide higher efficiency solar cells not only in winter, but also throughout the year. After melting snow solar energy intend to conduct experiments on this subject, which can be a valuable experience for the solar industry almost any country with snow climate.