Battery for solar cell: overview, types, characteristics

The use of solar energy is an alternative to irreplaceable energy sources. Modern technologies allow the use of solar panels for street lighting, heating and lighting of small houses. Today it is not uncommon for solar panels to give, which allow to provide electricity in the summer.

Solar panels

A device that is a large number of photoelectric converters connected in a single system, and there is a solar battery.

For a solar battery, it is important to have direct sunlight, the energy of which is converted into an electric current.

Batteries are installed in those areas where sunny days make up most of the year. However, the geographical breadth also affects the efficiency of solar batteries . After all the further from the pole, the more powerful the sun's rays. But even in the middle zone of Russia in winter solar panels reduce electricity consumption from common networks, and in summer it becomes possible even to sell its surplus.

Solar batteries are monocrystalline, polycrystalline and thin-film.

Directed in different directions crystals in polycrystalline batteries allow to reduce dependence on direct solar beams. Such batteries are today the most common, they are used to illuminate public buildings and private houses. Often, street lighting on a solar cell is of a polycrystalline type.

Solar panels for cottages

More recently, the main argument against the installation of solar panels in the country was their cost. Today, this production begins to produce domestic industry, its prices are lower, the choice is wider, and service maintenance is more affordable.

Modern technologies are quite capable of coping with lighting the site and ensuring the operation of household appliances. True, this requires a battery for the solar battery, and also a charge controller and an inverter that converts DC to AC.

Today you can buy a complete set of solar mini-power plants for a summer residence or a small house with autonomy of work within 24 hours. The power of such a power plant is 235 W with a battery capacity of 2.4 kWh.

Accumulators for solar batteries

Rechargeable batteries are an important part of the modern solar system equipment.

In bright sunny days, solar panels generate much more electrical energy than electric appliances, and at night, when lighting is particularly important, do not work at all. Hence, it is necessary to store and store electricity for its subsequent use.

A rechargeable battery for a solar battery and is designed for uniform and uninterrupted power supply.

Also, rechargeable batteries (AKB) cover peak loads, too large for photomodules, use stored energy in the dark, compensate for the difference in the generated and consumed energy in cloudy weather.

Ways of connecting the battery

Most often, one battery is not enough for a full-fledged solar power plant, and you have to use several same-type batteries. Experts believe that they should be from the same party.

Three ways to connect (switch) the battery are used to increase the overall capacity of the system.

With a parallel connection, all the batteries are stacked, and the total voltage is equal to the voltage in one device.

A serial connection, on the contrary, allows to sum all the voltages, and the capacity remains equal to the capacity of one battery in the circuit.

The most productive is a combined serial-parallel connection, in which both voltages and capacitances are summed.

True, with this connection, the batteries are subject to unbalance, that is, the total voltage will be constant, but for each individual battery its readings will change. This phenomenon leads to the fact that some of the batteries are not recharged, and some are charged above the norm, and the resource is produced prematurely.

Therefore, each solar system must include a solar charge controller and jumpers, which connect the midpoints for self-leveling of the voltage in the battery.

Features of storage batteries for solar systems

A rechargeable battery for a solar battery must satisfy a number of requirements. It must withstand a large number of charge / discharge cycles. At the same time, self-discharge should be minimal, and the value of the charging current is large, and the operating temperature range is wide.

Today, manufacturers are already producing special batteries, so-called solar batteries, which fully meet these requirements.

A set of solar cells with such devices and a charge controller allows you to accumulate energy and store it with maximum efficiency. A network inverter - convert it to connect household appliances and lighting.

Criterias of choice

Choose a battery for solar panels for the house you need several parameters.

The most important of these is capacity. Based on the required power consumption, the estimated capacitance value is calculated, increases by 35-50%, and already one or more devices for parallel connection are selected for it. The battery with sufficient capacity holds up to 4 days.

Duration of discharge and charging. Of the two devices with the same capacity rating, it is preferable that for which a shorter time interval is required for charging.

The capacity of a lead-acid battery depends on the weight of the lead in it, so the larger the battery mass, the higher its actual capacity. When choosing, pay attention to the weight and dimensions of the device.

Manufacturers set the range of operating temperatures and the frequency of maintenance for their products, and these indicators should also be taken into account.

The accompanying documents always indicate the period of use of the battery, the number of random cycles (the higher this index, other things being equal, the better) and the amount of self-discharge per month.

When calculating the parameters of the battery, it is necessary to take into account the energy losses during storage and conversion. The efficiency of modern devices for solar systems is about 85%.

Types of batteries for solar panels

Accustomed car batteries are not designed for a large number of cycles and are characterized by significant self-discharge. For heliostations, completely different devices are used.

1. AGM-accumulators, in the construction of which between the absorbing glass mats is in the bound state of the electrolyte. Such a device can be operated in any position, at a low price and a charge depth of about 80% can withstand up to 500 cycles and are characterized by a high level of charge.

The term of operation is not so great - 5 years, and the operating temperature range is limited to 15-25 ° С, but they are quickly charged - it takes less than 8 hours for a full recovery, can be transported in a charged state and operated in a room with insufficient ventilation.

AGM-batteries quickly fail because of overcharging, but the undercharging is transferred quite satisfactorily.

2. The gel battery for the solar battery can also work in any position. The gel-like gel electrolyte is retained in the pores of silica gel, which serves as a spacer for the plates. The indisputable advantage of this design - the electrodes do not crumble, because the entire free space is filled with gel, and therefore, the possibility of a short circuit is excluded. In addition, they can withstand full discharge and a significant number of cycles, about one and a half times more than similar AGM-batteries. But their price is much higher.

Despite the price, gel batteries are more economical, do not need maintenance, can be completely discharged without damage, a few days, energy losses in them are insignificant due to small self-discharge.

3. OPzS batteries, the so-called filling devices with liquid electrolyte, which do not require maintenance, are designed specifically for discharge by low currents. They withstand a very large number of deep cycles, they are used, as a rule, in powerful expensive solar systems, and they themselves are quite expensive.

Solar charge controller

Electronic devices are designed to control and adjust the level of charge on the battery. They protect the battery from complete discharge, and from excessive charging.

Charge controllers are very important elements of solar panels. They provide multi-stage battery charging, automatic shutdown when the battery is fully charged and with a minimum charge - loads, connecting photomodules when the battery needs to be charged, and reconnecting loads after charging.

The cheapest and most primitive type of On / Off controllers disconnect the solar panels from the battery when the voltage reaches the limit, preventing the batteries from fully charging and thereby reducing their life.

PWM controllers working on PWM (pulse width modulation) technology, economical and efficient in areas with high sun activity. They stop charging, allowing the battery to fully charge. Installed such devices in low-power, up to 2 kW, systems with a small-capacity battery.

MPRT-controllers control the maximum energy peaks. They are most effective in solar systems, but also much more expensive than other models.

Manufacturers of batteries for solar panels

In the Russian market there are not many manufacturers of this type of products.

CSB Battery Co., Ltd. (Taiwan) offers lead-acid batteries manufactured using AGM technology, with a service life of up to 10 years, rated at 12 V, from 26 to 100 Ah for a price of 2.6 to 8 , 2 thousand rubles.

Approximately the same batteries are produced by Shandong Sacred Sun Power Sources Co., Ltd (China).

HAZE Battery Company Ltd (Great Britain) supplies gel batteries with a service life of up to 12 years, working voltage 12 V, capacity from 15 to 230 A * h and a temperature range from -20 to +50 ° C at prices ranging from 7 to 28 thousand rubles .

SSKGroup (Russia-Belgium) produces reliable gel storage batteries for solar batteries with a flame arrestor with a service life of 15 years, capacity from 100 to 180 A * h at prices from 11 to 19 thousand rubles.

Manufacturers of solar panels

For a long time the main producers of solar batteries were Japan, Germany, the USA and China. Russian solar panels are assembled from materials produced in these countries. The most popular domestic solar batteries with an affordable price are made of polycrystalline silicon, produced in Germany and the United States.

Today Russian manufacturers not only produce solar modules, but also develop new ones, such as Kvant in Moscow.

Krasnodar company "Sunny Wind" produces not only modules, but also ready-made home solar stations. He designs ready-made solar energy systems and "SolarInTech" from Zelenograd.

In the domestic market, more equipment for solar systems, including ready-made standard projects. But with some engineering skills and perseverance, you can independently calculate the system for specific operating conditions and pick up the necessary equipment: solar panels, batteries, controllers of different manufacturers in a wide price range. Thus it is possible to save on some components, having collected them independently from improvised materials, for example, the controller.