Schemes and methods of connecting solar panels: how to properly install a solar panel

An alternative energy source based on solar panels is an excellent option for organizing an independent power supply.It will provide high energy efficiency not only on hot days, but also in cloudy weather. It would be nice to have such a device at home, wouldn't it?

To do this, you just need to correctly select the technical components and carry out installation. Anyone can do this if they know the diagrams and methods of connecting solar panels. We will tell you how to build a productive system that converts “green energy” into electricity needed to power household equipment.

In addition, you will learn how to choose a place to install solar panels and how to combine them with a stationary electrical network. Useful tips and important recommendations will provide effective assistance to home craftsmen. To make it easier to understand, thematic photographs, diagrams and videos are provided.

Solar battery device

When planning to connect solar panels yourself, you need to have an idea of ​​what elements the system consists of.

Solar panels consist of a kit photovoltaic batteries, the main purpose of which is to convert solar energy into electrical energy. The current strength of the system depends on the intensity of the light: the brighter the radiation, the greater the current generated.

The main structural elements of the system are:

• Solar battery – converts sunlight into electrical energy.
• Battery – a chemical current source that accumulates generated electricity.
• Charge controller – monitors battery voltage.
• Inverter, which converts the direct electrical voltage of the battery into alternating 220V, which is necessary for the functioning of the lighting system and the operation of household appliances.
• Circuit breakers, installed between all elements of the system and protecting the system from short circuits.
• Set of MC4 standard connectors.

In addition to the main purpose of the controller - to monitor the battery voltage, the device turns off certain elements as necessary. If the indicator at the battery terminals during the daytime reaches 14 Volts, which indicates they are being overcharged, the controller interrupts charging.

In addition to the solar module, the device of such a power plant includes photoelectric converters - a controller and an inverter, as well as batteries connected to them

At night, when the battery voltage reaches an extremely low level of 11 Volts, the controller stops the operation of the power plant.

Where is the best place to install the panels?

The first thing you need to do before installing and connecting a solar battery is to decide on the location of the unit.

To install photovoltaic modules, it is convenient to use stationary structures made of metal profiles, or more modernized rotary analogues

Solar panels can be placed in almost any well-lit point:

• on the roof of a country cottage;
• on the balcony of an apartment building;
• in the area adjacent to the house.

The main thing is to provide the necessary conditions for obtaining maximum electricity generation. One of these is the orientation and angle of inclination relative to the horizon.So the light-absorbing surface of the unit should be directed to the south.

Ideally, the sun's rays should fall on it at 90°. To achieve this effect, it is necessary to select the optimal slope angle depending on the climatic conditions of the region. This indicator is different for each region.

To ensure maximum performance of solar panels, it is recommended to change the angle of the devices 2-4 times a year: April 18, August 24, October 7 and March 5

For example, in the Moscow region, the angle of inclination of the surface of solar panels for the summer months is 15-20°, and in the winter months it changes to 60-70°.

When placing solar panels in the area adjacent to the house, it is better to raise the panels above the soil surface by at least half a meter - in case a large amount of snow falls. This solution is also correct in the sense that it provides sufficient distance for air circulation.

It is worth remembering that even a small shadow has a detrimental effect on the electricity generation of the unit. Panels should be placed only in places that are not subject to even the slightest shading.

Some “craftsmen” install additional glass on top of the panels to protect the batteries, but even with visible transparency, the glass layer can reduce the efficiency of the panels by 30%

There are several ways to fix the panels:

• by activating the clamping clamps;
• by bolting through through holes located at the bottom of the frame.

The supporting structure must be made of corrosion-resistant materials. Regardless of the installation method, you cannot make changes to the panel design yourself or drill additional holes.

It is the homeowner's job to keep the panels clean. Collecting dust, snow and bird droppings on the screen will reduce the amount of electricity produced by the system by at least 10%.

Solar battery connection options

Solar panels are made up of several individual panels. To increase the system output parameters in the form of power, voltage and current, elements are connected to each other using the laws of physics.

Connecting several panels to each other can be done using one of three solar panel installation schemes:

• parallel;
• sequential;
• mixed.

A parallel circuit involves connecting terminals of the same name to each other, in which the elements have two common nodes for the convergence of conductors and their branching.

In a parallel circuit, “pluses” are connected to “pluses”, and “minuses” to “minuses”, as a result of which the output current increases, and the output voltage remains within 12 Volts

The maximum possible output current in a parallel circuit is directly proportional to number of connected elements. The principles for calculating quantities are given in our recommended article.

A series circuit involves connecting opposite poles: the “plus” of the first panel to the “minus” of the second. The remaining unused “plus” of the second panel and the “minus” of the first battery are connected to the controller located further along the circuit.

This type of connection creates conditions for the flow of electric current, in which the only path remains for the transfer of energy from the source to the consumer.

With a serial connection scheme, the output voltage increases and reaches 24 Volts, which is enough to power portable equipment, LED lamps and some electrical receivers

A series-parallel or mixed circuit is most often used when it is necessary to connect several groups of batteries. By using this circuit, both the voltage and current can be increased at the output.

With a series-parallel connection circuit, the output voltage reaches a level whose characteristics are most suitable for solving the bulk of household problems

This option is also beneficial in the sense that if one of the structural elements of the system fails, the other connecting circuits continue to function. This significantly increases the reliability of the entire system.

The principle of assembling a combined circuit is based on the fact that devices within each group are connected in parallel. And all groups are connected in one circuit in series.

By combining different types of connections, it is not difficult to assemble a battery with the required parameters. The main thing is that the number of connected elements must be such that the operating voltage supplied to the batteries, taking into account its drop in the charging circuit, exceeds the voltage of the batteries themselves. batteries, and the battery load current provided the required amount of charging current.

Solar power system assembly diagram

Connection of solar panels is carried out using built-in connecting wires with a cross-section of 4 mm². Single-core copper wires, the insulating braid of which is resistant to ultraviolet radiation, are best suited for this purpose.

If you use a wire whose insulation is not resistant to UV rays, it is recommended to lay it externally in a corrugated sleeve.

The end of each wire is connected to an MC4 connector by soldering or crimping, resulting in a sealed connection

Regardless of the chosen scheme, before connecting solar panels It is imperative to check the correctness of the electrical installation.

When connecting panels, it is not recommended to exceed the technical requirements for the permissible current and maximum voltage of other devices. It is important to adhere to the charge controller and inverter specifications specified by the manufacturer.

The standard assembly diagram for the simplest solar power plant is as follows.

The connection diagram of the panels to the battery, inverter and controller is simple in design, and therefore does not cause any particular difficulties in connection

To avoid breakage controller, when connecting system elements, it is important to follow the sequence.

Installation work is carried out in several stages:

1. The battery is connected to the controller using the appropriate connectors and remembering to observe the polarity.
2. A solar battery is connected to the controller through connectors, maintaining the same polarity.
3. A 12 V load is connected to the controller connectors.
4. If it is necessary to convert the electrical voltage from 12 to 220 V, then an inverter is included in the circuit.It is connected only to the battery and in no case directly to the controller.
5. Electrical appliances designed for a voltage of 220 V are connected to the free output of the inverter.

After making the connection, you need to check the polarity and measure the open circuit voltage of the panels. If the indicator differs from the passport value, the connection is not made correctly.

To connect the device to the system, there is no need to open the junction box - all connecting connectors are located within easy reach

At the final stage, the solar battery must be grounded. To minimize the likelihood of a short circuit, fuses are installed at the connection points between the battery, inverter and controller.

The energy of solar power plants will be used in powering low-power household appliances and in charging batteries of mobile equipment:

Those wishing to build a solar battery with their own hands will be helped by the information provided. in the next article.

Connecting multi-directional elements

When using a sequential solar panel installation scheme, in order not to reduce the efficiency of the devices, all panels of the common circuit should be placed at the same angle and on the same plane.

If the panels are located in different planes, this may lead to the fact that the closest or more illuminated one will work more powerfully than those located a little further away.

This means that the near panel will generate electricity, some of which will be released to heat the distant panels. And the reason lies in the fact that current flows along the path of least resistance. To minimize losses, it is better to use a separate controller for each panel.

The main requirements when using the controller are the power of the connected panels over 1 kW and the distance between the batteries at a sufficiently large distance

The issue can also be resolved by installing cut-off diodes. They are placed inside between the plates. Thanks to this, while delivering maximum power, the plates do not overheat.

The voltage drop in the connections, as well as the wires themselves, of the low-voltage part of the system is also important.

Table of discrepancy between the transmitted power and the wire cross-section, indicating in red the parameters at which there is a risk of strong fire heating

An example is the fact that for a meter piece of cable with a cross section of 4 mm² when a current of 80A (voltage 12 V) passes, the values ​​drop by 3.19%, which is 30.6 W. When twisting is activated, the voltage drop can vary from 0.1 to 0.3 V.

Combination of solar energy and stationary network

When planning to use electricity from the sun in parallel with an equipped centralized stationary network, the connection diagram is made slightly different. And the main reason for this decision is that the private consumer does not have the opportunity to “dump” the remaining energy.

And this can provoke voltage surges lasting up to one second.

When combining solar electricity with a stationary centralized network, they are guided by the same rule: the more sources are connected, the more complex the scheme becomes

According to the above diagram, the voltage from the heliofield is first directed towards the battery, and from there it is transmitted to the load.

When designing this installation option, it is worth taking two types of load into account:

• non-reservable – lights in the house, household appliances, etc.;
• reserved – emergency lighting, refrigerator, electric boiler.

Keep in mind: the larger the battery capacity, the longer the backup electrical appliances will work in autonomous mode.

When choosing this method of generating energy into the network, be prepared for the fact that you will have to apply for permission from local power grids.

Although inverters for solar panels produce voltage, the quality of which is sometimes higher than that in the centralized network; local power networks do not give the go-ahead for the electric meter to rotate in the opposite direction.

For this reason, according to the scheme, solar inverters stop working when the voltage in the network is lost. And the redundant load begins to be “powered” from the battery.

Conclusions and useful video on the topic

The authors of the video material, which is provided below, share their personal experience and analyze the nuances of installing solar panels.

Video #1. An example of assembly and installation of a factory-standard system:

Video #2. How to install panels correctly:

There is nothing complicated in the process of connecting several panels with other elements of the system. But for a novice master, the process can become difficult. Therefore, if you do not have experience in calculations and installation skills, you should contact a specialist who has the necessary knowledge.

Would you like to tell us how you assembled your own solar power plant for your dacha or country house? Perhaps you know the subtleties of the process that are not described in the article? Please write comments in the block below, ask questions, share your opinion and photos on the topic of the article.