Diagram of connecting solar panels to the battery. Solar batteries for home: application and connection diagrams

I decided to write a separate article for beginners about options for connecting solar panels. Many people don’t know how to properly connect solar panels into a circuit, what wire to use, where to install diodes, but you can expand on it longer if you write under the topic.

And so let's start with the connection option for 12 volt SB:

It is better to use wires from solar panels 2 kW/mm up to 100 Watt, 2.5 KW/mm up to 150 Watt, 3 kW/mm 200 Watt, etc.

For six solar panels of 4 A *6 = 24 A, the wire cross-section should be at least 6 sq/mm, the best option is 12 sq/mm.

The advantages of such a system: maximum current, cheaper design and not for other voltages, wide applicability of such a connection, many devices are designed for power supply of 12 Volts.

Cons: Expensive pure sine wave inverters.

Connecting 12 volt solar panels to obtain an output voltage for charging 24 volt batteries:

At the output, connecting 2 in series, we get an increased voltage; the current will be equal to the weakest of the two SBs.

It is better to use wires from solar panels 2 kW/mm up to 150 Watt, 2.5 KW/mm up to 250 Watt, 3 kW/mm 350 Watt, etc.

We select the wires to which we connect the solar panels based on the length of the wire From all solar panels to the controller.

For three pairs of solar panels of 4 A *3 = 12 A, the wire cross-section should be at least 4 sq/mm, the best option is 8 sq/mm.

Pros: Cheap inverters, cheaper wires to interface the power supply and controller. If you have an even number of SBs and identical batteries, then you can easily convert your 12 volt system to 24 volts.

Minus: you cannot connect different panels in pairs to avoid current drawdown! Panels designed specifically for this voltage are too bulky for normal charging of two batteries connected in series at 180 -200 A. Difficulties in correct connection.

Let's consider connecting 48 volt SB:

At the output, connecting 4 in series, we get an increased voltage; the current will be equal to the weakest SB.

It is better to use wires from solar panels 3 kW / mm up to 400 Watts

We select the wires to which we connect the solar panels based on the length of the wire From all solar panels to the controller.

For four solar panels of 4A *1 = 4A, the wire cross-section should be at least 3 sq/mm, the best option is 6 sq/mm.

Pros: well, I don’t know what advantages these systems have!, except for the thickness of the wires.

Cons: Expensive charge controller, expensive SB, expensive batteries. Difficulties in installation if you assemble the system alone, increased voltage control is required, additional. installation of protection systems.

Connecting solar panels often raises certain questions, especially when you need to connect several modules. It seems that this is a very complex process that requires specific knowledge. But in fact, the connection diagram is very simple, it is easy to implement and assemble a photo battery of the required power.

There are three options for connecting batteries to a common circuit. These are serial, parallel and mixed (series-parallel) connections.

In this case, the terminals of the same name of the two modules are connected to each other (“plus” with “plus”, “minus” with “minus”). Next, wires are output from the terminals of one of the photomodules, which are connected either to the charge controller or directly to the battery. Thus, you can combine any number of solar panels, the main thing is to connect only terminals of the same name to each other.

This circuit involves connecting the “plus” of the first module to the “minus” of the second, and the output of external wires from the “minus” of the first photomodule and the “plus” of the second. Here it also does not matter how many solar panels will be combined into one battery. The main thing is not to violate the principle. “Plus” of the first to the “minus” of the second, “plus” of the second to the “minus” of the third, “plus” of the third to the “minus” of the fourth, etc. Wires from unused terminals (“minus” of the first module and “plus” of the last) are output to the controller or battery.

A mixed connection scheme is often used. In this case, first you need to assemble two groups of parallel-connected modules (by combining terminals of the same name), and then connect them to each other in series as if they were single modules, not groups. The number of groups (as well as the number of batteries in them) can be any.

Why are different connections needed?

Different switching methods are necessary to obtain the desired output parameters. For example, if you need to provide a power of 160 W and a voltage of 12 V, but the power of one solar battery is only 80 W at the required 12 V, then this means that you need to connect 2 batteries in parallel. As a result, the system voltage will not change (12 V), and the total output power will become 160 W. If it is necessary to obtain an output voltage not of 12 V, but, say, 24 V, then in this case a series connection of two modules is used. The mixed circuit allows you to adjust both parameters simultaneously. Thus, using different types of switching, it is possible to assemble a solar power plant with characteristics that are optimally suitable for operation.

Connecting to the home energy system

As for the integration of the assembled solar battery into the energy system of a private home, there are several options. Thus, the most popular is a circuit using a charge controller, a battery inverter and batteries. The voltage from the heliofield is first directed to charge the battery and only after that is transferred to the load.

The load is usually divided into 2 categories: redundant (refrigerators, gas boilers, emergency lighting, etc.) and non-redundant (regular lighting, computer, etc.). The power consumption of redundant devices can be any, but the duration of their autonomous operation is determined by the capacity of the battery.

Thanks to the presence of a special battery inverter, it becomes possible to transfer electricity to the loads if the voltage on the battery exceeds a specified value. At the same time, consumers can be powered from solar energy even if there is voltage in the central power grid. Thus, the external energy consumption of the house is significantly reduced.

When the central network is disconnected, the inverter will power the redundant load from the battery. If the heliofield produces energy at this time, then the inverter uses it too. Excess solar energy not spent on the load will be used to charge the battery. This circuit is excellent for providing autonomous power supply; it also works in the absence of a central supply voltage. But at the same time, the non-redundant load will be powered only from the sun (using residual technology); redundant consumers are priority.

If you plan to use the heliofield only to reduce power consumption from the external network, then you can use a simpler and cheaper scheme. It is much more profitable during rare and short-term power outages. During the day, the heliofield supplies energy to consumers; if this is not enough, then electricity is taken from the external network. But when the centralized power is turned off, the inverter will turn off and solar energy will not be used. The redundant load will be powered by the battery.

Alternative energy is becoming more accessible. This article will give you a complete understanding of local solar energy, types of solar cells and panels, principles of building solar farms and economic feasibility.

Features of solar energy in mid-latitudes

For residents of mid-latitudes, alternative energy is very attractive. Even in northern latitudes, the average annual daily radiation dose is 2.3-2.6 kWh/m2. The closer to the south, the higher this figure. In Yakutsk, for example, the intensity of solar radiation is 2.96, and in Khabarovsk - 3.69 kWh/m2. Indicators in December range from 7% to 20% of the annual average, and double in June and July.

Here is an example of calculating the efficiency of solar panels for Arkhangelsk, a region with one of the lowest solar radiation intensity:

Q is the average annual amount of solar radiation in the region (2.29 kWh/m2);
To off - coefficient of deviation of the collector surface from the southern direction (average value: 1.05);
P nom - rated power of the solar panel;
Kpot - loss coefficient in electrical installations (0.85-0.98);
Q test is the radiation intensity at which the panel was tested (usually 1000 kWh/m2).

The last three parameters are indicated in the panels' passport. Thus, if KVAZAR panels with a rated power of 0.245 kW operate in the conditions of Arkhangelsk, and losses in the electrical installation do not exceed 7%, then one block of photocells will provide generation of about 550 Wh. Accordingly, for an object with a nominal consumption of 10 kWh, about 20 panels will be needed.

Economic feasibility

The payback period for solar panels is easy to calculate. Multiply the daily amount of energy produced per day by the number of days in a year and by the service life of the panels without reducing power - 30 years. The electrical installation discussed above is capable of generating on average from 52 to 100 kWh per day, depending on the length of daylight hours. The average value is about 64 kWh. Thus, in 30 years, the power plant should, in theory, generate 700 thousand kWh. With a single-rate tariff of 3.87 rubles. and the cost of one panel is about 15,000 rubles, the costs will pay off in 4-5 years. But the reality is more prosaic.

The fact is that December values of solar radiation are approximately an order of magnitude lower than the annual average. Therefore, for fully autonomous operation of a power plant in winter, 7-8 times more panels are required than in summer. This significantly increases the investment, but reduces the payback period. The prospect of introducing a “green tariff” looks quite encouraging, but even today it is possible to conclude an agreement for the supply of electricity to the network at a wholesale price that is three times lower than the retail tariff. And even this is enough to profitably sell 7-8 times the surplus of generated electricity in the summer.

Main types of solar panels

There are two main types of solar panels.

Solid silicon solar cells are considered first generation cells and are the most common: about 3/4 of the market. There are two types of them:

monocrystalline (black) have high efficiency (0.2-0.24) and low price;
polycrystalline (dark blue) are cheaper to produce, but less efficient (0.12-0.18), although their efficiency decreases less with diffused light.

Soft solar cells are called film cells and are made either from silicon deposition or by a multilayer composition. Silicon elements are cheaper to produce, but their efficiency is 2-3 times lower than crystalline ones. However, in diffused light (twilight, cloudy conditions) they are more effective than crystalline ones.

Some types of composite films have an efficiency of about 0.2 and cost much more than solid elements. Their use in solar power plants is very questionable: film panels are more susceptible to degradation over time. Their main area of application is mobile power plants with low energy consumption.

In addition to a block of photocells, hybrid panels also include a collector - a system of capillary tubes for heating water. Their advantage is not only in saving space and the possibility of hot water supply. Due to water cooling, photocells lose less performance when heated.

Table. Review of manufacturers

Model	SSI Solar LS-235	SOLBAT MCK-150	Canadian Solar CS5A-210M	Chinaland CHN300-72P
A country	Switzerland	Russia	Canada	China
Type	Polycrystal	Monocrystal	Monocrystal	Polycrystal
Power at 1000 kWh/m2, W	235	150	210	300
Number of elements	60	72	72	72
Voltage: no-load/load, V	36,9/29,8	18/12	45,5/37,9	36,7/43,6
Current: at load/short circuit, A	7,88/8,4	8,33/8,58	5,54/5,92	8,17/8,71
Weight, kg	19	12	15,3	24
Dimensions, mm	1650x1010x42	667x1467x38	1595x801x40	1950x990x45
price, rub.	13 900	10 000	14 500	18 150

Equipment for solar energy complex

The batteries generate a direct current of up to 40 V during operation. To use it for domestic purposes, a number of transformations are required. The following equipment is responsible for this:

Battery pack. Allows you to use the generated energy at night and during low-intensity hours. Gel batteries with a nominal voltage of 12, 24 or 48 V are used.
Charge controllers maintain the optimal battery cycle and transfer the required power to power consumers. The necessary equipment is selected according to the parameters of the batteries and accumulators.
The voltage inverter transforms direct current into alternating current and has a number of additional functions. Firstly, the inverter sets priority to the voltage source, and if there is insufficient power, it “mixes” power from another. Hybrid inverters also allow you to feed excess generated energy into the city grid.

1 - solar panels 12 V; 2 - solar panels 24 V; 3 - charge controller; 4 - battery 12 V; 5 - lighting 12 V; 6 - inverter; 7—smart home automation; 8 — battery block 24 V; 9 - emergency generator; 10 - main consumers 220 V

Household use

Solar panels can be used for absolutely any purpose: from compensation of received energy and powering individual lines to complete autonomy of the energy system, including heating and hot water supply. In the latter case, the large-scale use of energy-saving technologies - recuperators and heat pumps - plays an important role.

For mixed use of solar energy, inverters are used. In this case, power can be directed either to the operation of individual lines or systems, or partially compensate for the use of city electricity. A classic example of an efficient energy system is a heat pump powered by a small solar power plant with a bank of batteries.

1 - city network 220 V; 2 - solar panels 12 V; 3 - lighting 12 V; 4 - inverter; 5 - charge controller; 6 - main consumers 220 V; 7 - battery

Traditionally, panels are installed on the roofs of buildings, and in some architectural solutions they completely replace the roofing covering. In this case, the panels must be oriented to the south side so that the incidence of the rays on the plane is perpendicular.

Solar energy is a real find for obtaining cheap electricity. However, even one solar battery is quite expensive, and in order to organize an effective system you need a considerable number of them. Therefore, many people decide to assemble a solar battery with their own hands. To do this, you need to know how to solder a little, since all the elements of the system are assembled into tracks and then attached to the base.

The main and rather difficult task is to find and buy photoelectric converters. They are silicon wafers that convert solar energy into electricity. Photocells are divided into two types: monocrystalline and polycrystalline. The former are more efficient and have a high efficiency of 20-25%, while the latter are only up to 20%. Polycrystalline solar cells are bright blue and less expensive. And mono can be distinguished by its shape - it is not square, but octagonal, and their price is higher.

If soldering is not very good, then to connect a solar battery with your own hands, it is recommended to purchase ready-made solar cells with conductors. If you are sure that you can solder the elements yourself without damaging the converter, you can purchase a kit in which the conductors are included separately.

Growing crystals for solar cells yourself is a rather specific task, and it is almost impossible to do it at home. Therefore, it is better to buy ready-made photocells.

How to choose and where to purchase converters

It will be cheaper to purchase photocells on Chinese Internet sites, although, of course, they often sell defective factory parts. For a start, this is not bad, especially since their price is lower. And after you gain experience in assembling batteries, you can take higher quality parts from the factory.

Some sellers sell converters all en masse sealed in wax so that they are not damaged during transportation, because silicon wafers are fragile, like crystal. Cleaning them of wax is a very labor-intensive task. First you need to immerse them in hot water and after the wax has melted, very carefully separate them. Afterwards, you need to immerse each photocell in a soapy solution, and then in clean hot water. And so on until the wax leaves the plates completely. Then you need to lay them out to dry on a terry towel. In general, this is extra hassle, so it is better to buy plates without wax.

It is safe to purchase photocells for installing solar panels yourself on trusted Chinese sites Ebay and Alibaba. To purchase, you need to register and enter the desired query in the search bar. Several suggestions will be displayed on the screen.

You need to choose not only for the reasons that you liked this particular product - you must definitely pay attention to the reviews and ratings of the seller. If you don’t want to pay twice as much for an item due to paid shipping, you need to see if the selected item has a “free shipping” option. If not, this is not a suitable option, since it is too costly.

Money for the goods must be transferred immediately. They will be sent to the seller only after confirmation of receipt of the goods by the buyer. You can pay directly with a payment card or through intermediate services - it all depends on the degree of trust in such online trading resources. You can also return the product, but it is better to immediately purchase from a seller with a good reputation in order to avoid litigation regarding the return. The parcel can take a month or a month and a half - this is already at the mercy of the post office.

Soldering and assembly of panels

Do-it-yourself solar panel assembly can be divided into three stages:

Frame production;
Soldering of photoelectric converters;
Installing them into the frame and sealing them.

The frame can be made from wooden planks or welded from aluminum corners. One way or another, its dimensions, shape and choice of materials for manufacturing directly depend on how it will be mounted.

Required materials and tools

To assemble a solar battery you will need the following materials:

aluminum or steel corner with a section of 25x25;
bolts 5x10 mm – 8 pcs;
nuts 5 mm – 8 pcs;
glass or polycarbonate 5-6 mm;
glue – sealant Sylgard 184;
glue – sealant Ceresit CS 15;
polycrystalline converters;
flux marker (a mixture of rosin and alcohol);
silver tape for connecting to panels;
tire tape;
fine solder;
foam rubber - 3 cm, sawdust or shavings;
dense polyethylene film 10 microns.

Tools needed for assembly:

file;
hacksaw for metal with blade 18;
drill, 5 and 6 mm drills;
open-end wrenches;
soldering iron

Assembly steps

Assembly consists of several stages:

First you need to decide on the dimensions of the frame frame. They will depend on the dimensions of the panels themselves and their quantity. When solar panels are placed on the roof, the panels can completely cover the slope or occupy a small part of it - there are no specific rules, so what width and length the frame will be is chosen by the assembler himself.
It is necessary to install glass on top of the frame to protect the photocells from destruction. It can be secured with a thin layer of silicone sealant, but it is better not to use epoxy resin for these purposes, since it will be extremely difficult to remove the glass in case of need for repair work without damaging the panels.
When connecting solar panels to the network, it is better to choose a mixed scheme, as it is optimal. The assembled panels are placed into a previously prepared frame. At this stage, it is important not to confuse the back of the panel with the front.
To protect the back of the battery during assembly, you can make a foam mat and wrap it in plastic wrap. Sawdust or shavings are also suitable, but the main thing is that their particles do not remain on the elements.
After this, you need to remove the air bubbles that form between the photocells and the glass, since their presence will interfere with the efficient operation of the battery. To do this, you need to place a load on the panel and a hard sheet of plywood on the soft mat. Thus, the photocells become jammed and must be left like this for half a day. Then the weight is removed, and the plywood and mat are removed. It is too early to install the battery after this; the sealant needs to fully set.
The last stage is the manufacture of the back wall of the battery from chipboard or fiberboard with a backing - this will prevent deformation of the panels.

Possible installation locations

There are several different options available for installation location:

If you decide to install solar panels on the roof, then its slope should be no more than 40 degrees. This option involves using profiles as a supporting structure for a solar battery. If the roof slope is 30-40 degrees, you can install solar panels without a bracket.
To install a solar battery on a flat roof, you will have to make a frame with a special inclined stand, since the structure must be sloped towards the roof of the house.
Installing solar panels on the wall is quite rare. In this case, as in others, you will need a steel inclined frame, which will ensure that the battery is located at an angle.
If the area is characterized by heavy rainfall in winter, the installation can be placed on the ground. To do this, you will need to support it on a special rod.
The battery can be placed on the roof of a balcony or loggia, if it is the top floor of a private house or the apartment is on the top floor. If insolation allows, then you can install a solar panel on the outside of the balcony.

System connection diagrams

The solar panel connection diagram consists of several devices:

A solar panel, which will accumulate light and convert it into electricity.
Controller, which will monitor the charge level in the device. When the batteries are charged, this device automatically turns off charging, and when the charge level drops, the controller will work again.
Battery, which is needed to collect the generated energy.
Inverter– this device creates the required voltage for the network, receiving electricity from the battery and converting it to 220 V.

Fuses must be installed between all network participants in order to avoid short circuits and damage to one of the devices.

If you plan to use one solar panel, then everything is clear.

When installing two or more, first you need to choose one of the following schemes for connecting solar panels in a country house or apartment:

Parallel. This method of laying panels occurs by connecting terminals of the same name. The voltage does not change and remains at the same level.
Consistent. In such a circuit, the plus of one of the photocells is connected to the minus of the other. Making such a connection is quite simple, but the output will be 24 V.
Mixed. Such a system consists of several groups. Elements within a group are connected in parallel, and the outer panels of the groups are connected to each other in series.

The latest parallel-serial scheme for connecting solar panels is optimal in order to save on purchasing a controller, since such a scheme will not require a powerful device. In such a system, a balance is created between the high voltages that arise from a series connection and the high currents of a parallel circuit.

Installation of the structure

First of all, you need to decide on the installation location - either directly on the roof, or using a frame made of special trusses as a stand. How to attach a flexible solar panel to the roof? It needs to be bolted to the profiles, which will save space and have an aesthetically attractive appearance.

If you decide to install panels on trusses, then you must:

Buy farms. Since they are sold as corners, you will need to assemble them yourself.
Connect the frame elements with bolts.
Decide on the installation location of the panels.
The solar panel is attached to the farm using a bolted connection. This should be done carefully so that any weather conditions cannot affect the strength of the structure.
The last stage is connecting all participants to the network: battery, accumulator, controller and inverter.

How to avoid common mistakes

When assembling and installing, pay attention to the following nuances:

There is no need to assemble it on a frame with a back wall made of beams, since the wood can swell and the structure becomes deformed. In addition, the beam makes it very heavy.
You cannot use plexiglass as a cover, as it overheats and due to this, the contacts between the panels become unusable, and the system itself may depressurize.
Connecting terminals are not the best option for combining panels with each other, since in case of repair it will be impossible to separate them - it is better to use connectors specially designed for this.

The panels must be thoroughly cleaned of snow, dirt and dust, as this significantly reduces the absorption of solar energy by the device.
Lush crowns of tall trees that prevent sunlight from reaching the battery will have to be thinned out. If the house is located in the shade of other buildings, then installing solar panels is only advisable only polycrystalline ones, and then the efficiency will be reduced.
Before you start assembling the panels, you need to make a small calculation. First you need to analyze how many kilowatts you need to get from the system per day. One panel is capable of generating 0.12 kW, so it may be that with low consumption their installation will pay for itself in 50 years, so it is not advisable. Depending on the required average daily norm, the number of panels is selected.
When installing solar panels with your own hands, it is better to orient the panels to the south, since during sunny hours the maximum amount of solar energy comes from this side.

Video

Watch our video for detailed instructions on how to assemble a solar battery.

Connecting solar panels. Solar panel connection diagram.

Solar panels can provide electricity in conditions where there is no connection to the mains power supply.

In this article we will look at how to properly connect a solar panel to power household electrical appliances.

Which panel is better?

Polycrystal is definitely better, as it works more efficiently in cloudy weather and weak sunlight. Monocrystalline panels have a smaller area at the same power as a polycrystalline panel, so in cloudy weather monocrystalline panels work less efficiently.

The most commonly used are 12 volt panels, which are more convenient to adapt with 12 volt batteries. Typically, a 12V panel means 17V - 18V, this is necessary so that when the panel produces less energy in cloudy weather, it can compensate for the voltage drop.

When manufactured, solar panels already have connected Schottky diodes, which protect the solar cells from failure at the moment when the panel stops generating electricity and becomes itself a consumer of electricity from the battery. It is the diode that prevents the reverse flow of electric current.

Charge controller.

The battery charge controller controls the charging process and prevents the battery from overcharging and discharging.

The operating principle of the controller is as follows. When the panel generates electrical current, the battery is charged. When the voltage at the 12 V battery terminals reaches the limit value of 14 V, the controller turns off charging.

When the solar panel is not operating at night, the system runs on battery power. When the voltage at the battery terminals reaches the lower limit of 11V, the controller will disconnect it from the system, thereby preventing its complete discharge. You can connect 12V DC consumers to the controller through the appropriate terminals (indicated by a light bulb), for example, LEDs for room lighting.

Accumulator battery.

In the system, the battery acts as an electricity accumulator, which recharges the solar panel. To connect to the system, you can use any lead-acid batteries, as well as gel ones. In a residential area, it is better to use sealed batteries. Typically 12V car batteries are used.

Inverter.

An inverter is also a voltage converter, it is connected to the battery and receives a constant voltage at the input, usually 12V; at the output from the inverter we already receive an alternating voltage sine wave 50Hz, 220V, to which you can connect household appliances operating on a 220V AC network.

Cable.

When installing stationary solar panels, manufacturers recommend using a special cable to connect solar panels, which has increased insulation protection from ultraviolet rays. You can use a regular copper cable with additional corrugated protection. This only applies to the cable that goes from the panel to the controller; in all other areas, a regular copper cable is used.

Solar panel connection diagram.

All components must be connected in strict sequence.

First you need to connect the battery to the controller plus - plus, minus - minus using a copper cable. There is a battery icon drawn on the controller.

Then we connect the solar battery to the controller plus - plus, minus - minus. The controller also has a solar battery icon next to the corresponding connection contacts. If you need to install several panels, they are connected in parallel.

The next step is to connect the inverter to the battery plus - plus, minus - minus.

If the polarity is not observed when connecting, the controller may be damaged.

Solar battery operation diagram.

Solar panels are mounted in open, unshaded areas facing south, at an angle of 45° to the horizon. You can install the panel on an automatic rotator that gradually rotates towards the sun throughout the day.

The solar battery, when exposed to sunlight, generates voltage that is supplied to the controller. In turn, the controller charges the battery, which is connected to the inverter.

The inverter receives direct current, for example 12V, at the output of the inverter we receive alternating current 220V, consumers of electricity are connected to the output of the inverter - a laptop, TV, etc.

Even a small solar power plant can power household appliances such as a laptop, TV, phone chargers, lighting lamps, and other low-power household appliances.