Power supply using solar panels: an overview of panels in the domestic market

Recommendation points

• Types of solar panels
• Silicon solar cells
• Film solar cells
• Comparative table of Russian, Taiwanese and Chinese solar panels

The article will help determine the need to purchase autonomous power supply sources, widely covers the topic of autonomous power supply using solar panels, the advantages and disadvantages of this energy source.

Solar panels are becoming more and more popular due to their increasing availability both financially and against the background of the expansion of the range in retail chains. Many articles have been written that provide feasibility studies for the introduction of solar power plants (the so-called solar energy generation systems). True, their payback period reaches several years..

A large segment of consumers is switching to autonomous power supply not so much because of the desire to save money, but because of the provision of power supply in areas where there are power outages or there is none at all.

The generation of solar energy is widely used for summer cottages. They are characterized by low power consumption and seasonal operation of solar panels. More rare cases – full electrification of the house with alternative sources. But the construction of solar energy generation systems for different operating conditions is fundamentally the same. So, we will consider this issue in detail and in order..

Types of solar panels

Another man in the street is unaware that the number of varieties of solar panels is already approaching ten. In order to somehow structure the whole variety of light detectors in consciousness, we will divide them into 2 classes:

• silicon
• film

Silicon solar cells

Monocrystalline and polycrystalline panels are widely represented on the market. Also included in this group are amorphous silicon panels and hybrid solar cells. As the name of the class implies, these light detectors are made from silicon and silicon hydrogen. The proliferation of silicon-based solar modules is due to their high specific energy efficiency, but the rather complicated manufacturing process makes them expensive..

Monocrystalline solar panels Are black squares with beveled corners. At the moment, such panels have the highest efficiency – up to 22%. All photosensitive cells of a monocrystalline panel are oriented in the same direction, on the one hand, this explains the relatively high efficiency, on the other hand, the panel should always be facing the sun to obtain maximum energy efficiency. In diffused light, for example, in cloudy weather, at sunrise and sunset, the electrical parameters of power generation are not at all impressive.

Another type of solar panels: polycrystalline – have a lower efficiency compared to single crystals (about 12–18%), but due to the multidirectionality of silicon crystals in the panel, better energy efficiency is achieved in diffused light. Polycrystalline panels can be recognized by the regular square shape of the dark blue plates with a frosty pattern.

Amorphous Silicon Panels (or, as they are called, a-Si) – the lowest performing in the line of silicon solar receivers. Their efficiency is at around 5-6%. But their use can be justified. And that’s why:

• firstly, the degree of light absorption of these panels is 20 times higher than that of other silicon competitors;
• secondly, the chaotic orientation of the photosensitive cells increases the efficiency of a-Si in cloudy weather.

Hybrid luminous flux converters Is a combination of amorphous silicon with microcrystals. Such panels are similar in properties to polycrystalline elements, with the only proviso that their performance in diffused light is much higher. Also, in addition to the ultraviolet spectrum, hybrid panels can convert infrared radiation into electricity..

Film solar cells

A fairly new development in the field of solar light detectors. I must say that at the moment it is difficult to find film modules on the Russian market, due to their high cost. Therefore, we restrict ourselves to enumerating their types.

Film elements include elements based on cadmium telluride (CdTe), copper-indium diselenide (CIS), copper-indium-gallium diselenide (CIGS), and polymer ones. Polymer panels are the most promising direction in the development of film technologies, since manufacturers promise their low cost, although the efficiency is only 6%.

Before delving into the description of solar panels, a few words about its parameters. The figure below shows the current-voltage characteristic of the solar panel (in red) and the power curve (in blue). The graph shows the points that are found in the technical characteristics of solar panels.

So, the short-circuit current is the current that occurs when the solar battery circuit is closed (the battery voltage is zero). The open circuit voltage, on the other hand, is an open circuit parameter (the current is zero). These two modes are not operational. Nominal operating conditions are indicated by a yellow dot at the intersection of the dotted lines. At this point, the maximum operating current and voltage. The most efficient use of a solar cell is at this operating point..

On the Russian market there are mostly mono- and polycrystalline panels in a large assortment. As you might expect, most of them are made in China. But this is not surprising: China is a leader in the production and sale of solar energy generation systems. In addition, there are German (Calixo, SCHOTT) and Japanese (SHARP) solar panels on the market..

The Russian “manufacturers” of solar panels are firms that mostly sell Chinese products, passing them off as their own. The segment of manufacturers engaged in the assembly of panels from Chinese components is also widely developed. But not everything is so hopeless. Russia can also “boast” of its producers of solar panels. The Hevel plant is located in Novocheboksarsk, which specializes in the production of thin-film hybrid panels. In Krasnodar, at the Saturn plant, solar cells based on gallium arsenide are manufactured; the products are mainly oriented towards the space industry. Two factories that are most focused on the production of household modules are located in Zelenograd (Telecom-STV) and Ryazan (Ryazan Metal Ceramic Devices Plant, RZMKP).

The range of Ryazan solar panels is limited to two main types:

• RZMP-130-T – has an output voltage of 15.9-17.5 V, a power range of 105-145 W;
• RZMP-220-Т – has an output voltage of 27.7-29.1 V, a power range of 200-240 W.

Telecom-STV offers a much larger number of articles of its products: mono- and polycrystalline modules, monocrystalline modules with increased efficiency, flexible and specialized solar batteries. The output voltage of the modules is adapted for both low-voltage systems (17-18.5 V) and high-voltage (34-38 V). Moreover, the price of these solar panels is one and a half times lower than the Ryazan ones. For example, the Ryazan RZMP-130-T with a power of 120 W will cost the buyer 16,100 rubles, and the Zelenograd TSM-120A with a power of 123 W can be purchased for 9,658 rubles. At the same time, the weight and dimensions of Zelenograd panels are less than Ryazan ones. The only thing that speaks in favor of the Ryazan solar panels is detailed information about the product..

Separately, let us say a few words about the Hevel plant in Novocheboksarsk. The only plant in Russia that has begun to produce panels based on amorphous silicon interspersed with microcrystals using micromorphic technology. Considering that in a significant part of Russia there is a large percentage of cloudy days a year, Hevel panels have great potential in the fight for the market with mono- and polycrystals. There are no Hevel panels in the retail sale yet, but judging by the wholesale prices, the consumer will have to pay about 10,000 rubles for a 125-watt panel. Hevel’s direct competitor is the thin-film hybrid panels of the Taiwanese manufacturer Green Energy Technology. Taiwanese panels can already be purchased for 7,000 rubles.

Comparative table of Russian, Taiwanese and Chinese solar panels

Manufacturer	Name	Production technology	Peak voltage, V	Peak current, A	Peak power, W	Dimensions, mm	Estimated price on the Russian market, rub.
Telecom-STV, Zelenograd	TSM-100A	polycrystal	17	5.6	96	1050x665x43	8429
RZMP, Ryazan	RZMP-130-T	polycrystal	15.9	6.65	105	1490x670x36	14600
“Hevel”, Novocheboksarsk	HEVEL P7	micromorphic	56.6	2.21	125	1300x1100x24	10000
Green Energy Technology, Taiwan	GET-115AT2	amorphous silicon	93.9	1.22	115	1300x1100x20 *	7000
Chinaland Solar Energy, China	CNH100-36M	single crystal	19.3	5.18	one hundred	1200x540x30	6350

* – without aluminum frame

Ultimately, it is up to the consumer to decide which panels to choose. As a recommendation, I would like to note that polycrystalline models of solar panels can be recommended for autonomous power supply at home. Yes, monocrystalline panels are more efficient, but do not forget that this is rather arbitrary..

The maximum power of monocrystalline elements will be achieved only on a sunny day using systems for rotating photosensitive elements. Therefore, these panels are more suitable for residents of the southern strip of Russia, where the number of sunny days is maximum. In the rest of the regions, when designing autonomous power supply systems, it makes sense to turn your attention to relatively new panels produced using micromorphic technology, which are capable of converting not only solar ultraviolet light into electricity, but also infrared radiation. This advantage of them can more than cover the lack of low efficiency..

Finally, I note that I personally gave preference to a polycrystalline panel, since it is intended for temporary power supply of a country house in the summer. It follows that the planned load is small, the daylight hours are long and sunny. Therefore, a polycrystalline solar battery in my case is the most optimal.