One of the benefits of owning your own home is the ability to modify it. Including sources of alternative energy. Solar panels for a private home are currently the best way to provide yourself with environmentally friendly electricity.
Where to begin
Calculation of electricity costs. To determine the required power of a solar panel system, you need to calculate how much electricity you use. Much in this matter depends on whether a private house is used constantly or only as a summer house in certain seasons of the year. To calculate, take electricity payment receipts for the year and determine the total number of kilowatts spent during this period, then divide by 12 (the number of months) - you will get the average monthly electricity consumption.
Calculation of average monthly electricity consumption
As experience and reviews from real consumers show, in central Russia the result must be multiplied by a factor of 16 to obtain the required battery power in Watts.
Let's look at an example. In a year you spent 1625 kW, divide this figure by 12 months and multiply by a factor of 16 - it turns out 2166 watts. Those. a solar panel system will provide such a house if its power is at least 2200 Watt/hour
Where to mount?
Roof. Mounting solar panels on the roof is an obvious, but not always the best solution for a private home. A south-facing roof slope does provide the best results from permanent solar panel mounting methods, but the options don't stop there.
With this fastening, the roof slope should be to the SOUTH
Walls. If the wall “looks” south, it is perfect for placing solar panels on it. Observe whether shadows from trees, outbuildings, fences, or other objects fall on the wall. Do not place solar panels in these areas.
It is also advisable to use the south wall
You should not place panels on the east or west walls. Thus, during the most intense period of daylight, you will only receive oblique rays on your panels, which significantly reduces the efficiency of the system
Free placement. The most effective option for placing solar panels, but requires free space in the yard. When solar panels are freely placed in a private house, they can be mounted on hinges and thus directing their surface to the sun at 90°.
This arrangement of batteries allows you to get maximum power from them
What's included in the system
Solar panels. We wrote about how to collect them in (opens in a new window). You can buy a ready-made set of solar panels for your home, but to save money, you can purchase polycrystalline solar cells and assemble solar panels for your home with your own hands.
Inverter. Solar panels produce direct current close to 12 or 24 volts (depending on the connection), the inverter converts it into alternating current 220 V and 50 Hz, from which all household appliances can be powered.
Battery. Even their system. Solar energy is not produced constantly. During peak hours there may be an excess of it, and with the onset of dusk its production stops altogether. Batteries accumulate electricity during daylight hours and release it in the evening/night. How to choose a battery for a solar power plant is written in (opens in a new window).
Controller. Provides a full charge to the battery and protects it from overcharging and boiling. We wrote about which controller to choose in (opens in a new window).
Are solar panels beneficial for a private home?
In Western countries, the fashion for solar energy is dictated more by concern for the environment than by the search for economic benefits. Our realities are somewhat different.
At current prices for supplied electricity, a solar panel system assembled with your own hands for one private home and a family of 4 people will fully pay for itself in 4-5 years. At the same time, the service life of photocells is 20-25 years, but the batteries will have to be changed after 5-7 years, depending on the quality of the batteries.
So far, nowhere in the world (and Russia is no exception) has there been a reduction in prices for supplied electricity, so over the life of the photocells in the solar panel, the system will have time to pay for itself at least 4-5 times.
Video. How to calculate the required number of solar panels for your home
The video clearly shows the procedure for calculating the area of solar panels for a private home. Useful for those who want to take into account all the costs of building an autonomous solar power supply system already at the planning stage.
Most owners of solar panels use them only in the summer, which is quite logical. However, in some situations, additional energy is needed all year round. This means that photo panels must generate electricity both in the off-season and in winter. This raises the question of whether the solar battery will work effectively enough in winter and whether it will be able to cope with the assigned task.
Essentially, yes, it can. After all, in winter (on clear days) the sun shines just as brightly, and cloudy photo panels capture reflected (scattered) sunlight. Although the overall performance of solar panels will still decrease. The decline in productivity is the first problem that awaits those who want to use solar energy all year round. The second problem is snow accumulation (also causing a decrease in energy production).
Performance drop
According to practical data, the production of solar panels during the reduction of daylight hours in winter drops by an average of 1.5-2 times. Therefore, the battery power reserve for year-round power supply to the house must be calculated with an appropriate excess. Or you should stock up on an additional source of energy (for example, a wind, diesel or gasoline generator).
In addition, winter performance also depends on the installation angle of the photo panels. This is explained by the difference in the seasonal position of the sun relative to the horizon. In winter, the optimal angle of inclination of solar panels should be equal to the latitude of the installation site, increased by 10-15°.
But, speaking about the winter decrease in productivity, it is worth remembering that photo panels reflect not only direct, but also diffused sunlight. In other words, light reflected from snow that has fallen around the panel. Therefore, small snowdrifts around the battery can be very useful. But the formation of such snowdrifts is directly related to another winter problem - snow sticking to the work surface.
Snow accumulation
Cleaning the working surface from adhering snow is a mandatory condition for winter operation. Otherwise, the autonomous power supply from the sun will simply stop. Of course, in more southern latitudes, where there is very little snow in winter, this problem does not play such a role as in the northern regions. In the territory, for example, of central Russia, this cannot be avoided.
Winter snow removal can be passive or active. Passive consists of a pre-thought-out method of installing panels vertically either on the wall of a building or on a separate frame-rack. It is advisable that the space is well blown by the wind, then snow will not accumulate on the surface at all. The active method involves cleaning the surface of the batteries using a regular mop with long lint.
Features of working “under the snow”
Despite the fact that snow in winter creates a certain problem, it also greatly facilitates the use of solar panels. The fact is that when photo panels work, actively charging the batteries of the power system, they get quite hot. In summer, cooling the batteries is a major challenge, since overheating them can destroy the entire network. In winter, snow accumulating around the batteries creates a certain cooling effect. It also cools batteries and snow melting on the work surface. Thus, in small quantities it plays not a negative, but a positive role in the winter operation of photo panels.
Another benefit of surrounding snow is its high reflectivity. This is especially important for polycrystalline batteries, which excellently capture reflected and scattered light, thereby increasing their performance.
With constantly rising prices for electricity, you inevitably begin to think about using natural sources for power supply. One of these possibilities is solar panels for your home or garden. If desired, they can fully provide all the needs of even a large house.
Design of a solar power supply system
Converting the sun's energy into electricity - this idea kept scientists awake for a long time. With the discovery of the properties of semiconductors, this became possible. Solar cells use silicon crystals. When sunlight hits them, a directed movement of electrons is formed in them, which is called an electric current. When connecting a sufficient number of such crystals, we obtain quite decent currents: one panel with an area of a little more than a meter (1.3-1.4 m2 with a sufficient level of illumination can produce up to 270 W (voltage 24 V).
Since the illumination changes depending on the weather and time of day, it is not possible to directly connect devices to solar panels. We need a whole system. In addition to solar panels, you need:
- Battery. During daylight hours, under the influence of sunlight, solar panels generate electric current for the home or cottage. It is not always used in full; its excess accumulates in the battery. The accumulated energy is consumed in inclement weather.
- Controller. Not a mandatory part, but desirable (if you have enough funds). Monitors the battery's charge level to prevent it from over-discharging or exceeding its maximum charge level. Both of these conditions are detrimental to the battery, so having a controller extends the life of the battery. The controller also ensures optimal operation of solar panels.
- DC to AC converter (inverter). Not all devices are designed for direct current. Many operate on alternating voltage of 220 volts. The converter makes it possible to obtain a voltage of 220-230 V.
Solar panels for the home are only part of the system
By installing solar panels for your home or cottage, you can become completely independent from the official supplier. But for this you need to have a large number of batteries, a certain number of batteries. A kit that produces 1.5 kW per day costs about $1000. This is enough to meet the needs of a summer house or part of the electrical equipment in the house. A set of solar panels for producing 4 kW per day costs about $2,200, for 9 kW per day - $6,200. Since solar panels for home are a modular system, you can buy an installation that will provide part of the needs, gradually increasing its productivity.
Types of solar panels
With rising energy prices, the idea of using solar energy to generate electricity is becoming increasingly popular. Moreover, with the development of technology, solar converters are becoming more efficient and, at the same time, cheaper. So, if you wish, you can meet your needs by installing solar panels. But they come in different types. Let's figure it out.
The solar battery itself is a number of photocells located in a common housing, protected by a transparent front panel. For household use, solar cells are produced based on silicon, since it is relatively inexpensive, and elements based on it have a good efficiency (about 20-24%). Monocrystalline, polycrystalline and thin-film (flexible) solar cells are made based on silicon crystals. A certain number of these photocells are electrically connected to each other (series and/or parallel) and connected to terminals located on the housing.
Photocells are installed in a closed housing. The solar battery housing is made of anodized aluminum. It is lightweight and non-corrosive. The front panel is made of durable glass, which must withstand snow and wind loads. In addition, it must have certain optical properties - have maximum transparency in order to transmit as many rays as possible. In general, a significant amount of energy is lost due to reflection, so the requirements for the quality of glass are high and it is also coated with an anti-reflective compound.
Types of photocells for solar panels
Solar panels for the home are made from three types of silicon cells;
If you have a pitched roof and the facade faces south or east, there is no point in thinking too much about the space occupied. Polycrystalline modules may well suit this. For the same amount of energy produced, they cost slightly less.
How to choose the right solar panel system for your home
There are common misconceptions that make you spend extra money on overly expensive equipment. Below are recommendations on how to properly build a power supply system from solar panels and not spend extra money.
What to buy
Not all components of a solar power plant are vital for operation. Some parts can be done without. They serve to increase reliability, but without them the system is operational. The first thing to remember is to purchase solar panels at the end of winter, beginning of spring. Firstly, the weather at this time is excellent, there are many sunny days, the snow reflects the sun, increasing the overall illumination. Secondly, discounts are traditionally announced at this time. The following are the tips:
If you use only these tips, and connect only equipment that runs on constant voltage, a solar panel system for your home will cost a much more modest amount than the cheapest kit. But that is not all. You can leave some of the equipment “for later” or do without it altogether.
What can you do without?
The cost of a set of solar panels for 1 kW per day is more than a thousand dollars. Considerable investment. You will inevitably wonder whether it is worth it and what the payback period will be. At current rates, you will have to wait for more than one year until you get your money back. But costs can be reduced. Not at the expense of quality, but due to a slight decrease in the operating comfort of the system and due to a reasonable approach to the selection of its components.
So, if the budget is limited, you can get by with several solar panels and batteries, the capacity of which is 20-25% higher than the maximum charge of solar panels. To monitor the condition, buy a car clock that also measures voltage. This will save you from having to measure the battery charge several times a day. Instead, you will need to look at your watch from time to time. That's all for the start. In the future, you can purchase additional solar panels for your home and increase the number of batteries. If desired, you can buy an inverter.
Determining the size and number of photocells
Good 12-volt solar panels should have 36 cells, and 24-volt solar panels should have 72 solar cells. This amount is optimal. With fewer photocells you will never get the stated current. And this is the best option.
You should not buy dual solar panels - 72 and 144 elements, respectively. Firstly, they are very large, which is inconvenient for transportation. Secondly, at abnormally low temperatures, which we periodically experience, they are the first to fail. The fact is that the laminating film greatly decreases in size in cold weather. On large panels, due to high tension, it peels off or even breaks. Transparency is lost and productivity drops catastrophically. The panel is being repaired.
Second factor. On larger panels the thickness of the body and glass should be greater. After all, windage and snow loads increase. But this is not always done, as the price increases significantly. If you see a double panel, and the price for it is lower than for two “regular” ones, it’s better to look for something else.
Once again, the best choice is a 12-volt home solar panel consisting of 36 solar cells. This is the best option, proven by practice.
Technical specifications: what to look for
Certified solar panels always indicate operating current and voltage, as well as open-circuit voltage and short-circuit current. It is worth considering that all parameters are usually indicated for a temperature of +25°C. On a sunny day on the roof, the battery heats up to temperatures significantly higher than this figure. This explains the presence of higher operating voltage.
Also pay attention to the open circuit voltage. In normal batteries it is about 22 V. And everything would be fine, but if you carry out work on the equipment without disconnecting the solar panels, the no-load voltage will damage the inverter or other connected equipment that is not designed for such a voltage. Therefore, during any work - switching wires, connecting/disconnecting batteries, etc. etc. - the first thing you should do is disconnect the solar panels (remove the terminals). Having gone through the diagram, you connect them last. This procedure will save you a lot of nerves (and money).
Case and glass
Solar panels for home have an aluminum body. This metal does not corrode and has sufficient strength and is light in weight. A normal body must be assembled from a profile containing at least two stiffeners. In addition, the glass must be inserted into a special groove, and not fixed on top. All these are signs of normal quality.
When choosing a solar battery, pay attention to glass. In normal batteries it is not smooth, but textured. It is rough to the touch; if you rub it with your nails, you can hear a rustling sound. In addition, it must have a high-quality coating that minimizes glare. This means that nothing should be reflected in it. If reflections of surrounding objects are visible at any angle, it is better to find another panel.
Selecting the cable cross-section and the fineness of the electrical connection
Solar panels for your home must be connected using a single-core copper cable. The cable cross-section depends on the distance between the module and the battery:
- distance less than 10 meters:
- 1.5 mm2 per 100 W solar battery;
- for two batteries - 2.5 mm2;
- three batteries - 4.0 mm2;
- distance more than 10 meters:
- to connect one panel we take 2.5 mm2;
- two - 4.0 mm2;
- three - 6.0 mm2.
You can take a larger cross section, but not smaller (there will be large losses, but we don’t need it). When purchasing wires, pay attention to the actual cross-section, since today the declared dimensions very often do not correspond to the actual ones. To check, you will have to measure the diameter and calculate the cross-section (you can read how to do this).
When assembling the system, you can draw the positives of solar panels using a multi-core cable of a suitable cross-section, and use one thick cable for the negative. Before connecting to the batteries, we pass all the “pluses” through diodes or diode assemblies with a common cathode. This prevents the battery from shorting out (which could cause a fire) if the wires between the batteries and the battery are shorted or broken.
Diodes use types SBL2040CT, PBYR040CT. If these are not found, you can remove them from old power supplies of personal computers. There are usually SBL3040 or similar ones. It is advisable to pass through diodes. Don’t forget that they get very hot, so you need to mount them on a radiator (you can use just one).
The system also requires a fuse box. One for each consumer. We connect the entire load through this block. Firstly, the system is safer. Secondly, if problems arise, it is easier to determine its source (by a blown fuse).
The low efficiency of solar panels is one of the main disadvantages of modern solar systems. Today, one square meter of photocell is capable of generating about 15-20% of the power of radiation incident on it.
Such generation requires the installation of large batteries for full power supply. Moreover, in order to achieve the required output voltage, they are connected to each other in series or parallel. Their area can reach several square meters.
The efficiency of solar panels depends on a number of reasons:
- photocell material;
- solar flux density;
- season;
- temperature;
- and etc.
Let's talk more about each factor.
Photocell material
They are divided into three types, depending on the method of formation of the silicon atom:
- polycrystalline;
- monocrystalline;
- amorphous silicon panels.
Polycrystalline panels are made of pure silicon and have a relatively high efficiency of 14-17%.
Monocrystalline panels are less efficient at converting solar energy. Their efficiency is about 10-12%. But the low energy consumption for the manufacture of such converters makes them more affordable.
Amorphous silicon (or thin film) panels are simple and inexpensive to produce and, as a result, affordable. However, their effectiveness is significantly lower than that of the previous two types - 5-6%. In addition, elements of thin-film silicon converters lose their properties over time.
Thin film batteries are also made with particles of copper, indium, gallium and selenium. This slightly increases their performance.
Work in any weather
Graph of power depending on weather conditions This indicator depends on the geographical location of the panel: the closer to the equator, the higher the density of solar radiation.
In winter, the performance of photocells can decrease from 2 to 8 times. This is explained, first of all, by the accumulation of snow on them and the reduction in the duration and number of sunny days.
Important to remember: in winter, monitor the tilt of the panels because the sun is lower than usual.
Conditions for effective work
In order for the battery to work efficiently, you need to consider several nuances:
- the angle of the battery towards the sun;
- temperature;
- lack of shadow.
The angle between the working surface of the converter and the sun's rays should be close to right. In this case, the efficiency of photocells, all other things being equal, will be maximum. To increase efficiency, they are additionally equipped with a sun tracking system, which changes the inclination relative to the position of the luminary. But this does not happen often due to the high cost of the equipment.
During operation, many batteries heat up, which has a bad effect on the quality of conversion of solar energy into electrical energy. To avoid losses, it is necessary to leave space between the device and the supporting surface. This will allow air to flow freely and cool the converters.
It is important to know: it is necessary to wipe the panels 2-3 times a year, cleaning them from dust and thereby increasing the penetration of the sun's rays.
The efficiency of photocells directly depends on the amount of sunlight falling on them. And it is very important to provide for the complete absence of shadows falling on the work surface. Otherwise, the efficiency of the entire system may suffer. As a rule, batteries are installed on the south side.
There are batteries with 40% efficiency, see the following video about them:
We welcome everyone who would like to spend a couple of minutes getting interesting information!
So, we have once again replenished the warehouse with completely new products. The number of new products is not so great, but what a number!
We are proud to present to you a line of the most efficient and impressive solar panels on the Russian market - the Eclipse line from the Seraphim plant, which is included in the rating of the most reliable manufacturers (Bloomberg assigned Seraphim Solar TIER1 status back in 2015).
Two models of Seraphim solar panels are available for order:
- Monocrystalline panel Eclipse SRP-320-E01B
- Polycrystalline panel Eclipse SRP-290-E11B
The first model is made in the size of a standard monocrystalline 270 W module and at the same time produces 320 environmentally friendly watts. The second model corresponds to the size of a 250 W polycrystalline module, but the efficiency of this panel is 290 Watts - higher than that of a classic monocrystalline battery of the same size. How did you achieve such efficiency? Very simple and difficult at the same time! There are no tricks or shenanigans: the cells in Eclipse solar panels are laid out in such a way that almost the entire panel area is occupied by silicon, and the efficiency of the entire battery becomes almost equal to the efficiency of the silicon cells that make it up. True, the cells in Seraphim Eclipse solar panels are also not entirely simple - they are made using a special technology and can actually be “glued” to each other, which reduces losses on internal connections and also increases the final power.
In fact, at the moment, the premium monocrystalline solar battery Seraphim SRP-320-E01B is the most efficient one available on the Russian market.
Also, another addition has been made to the shelf of solar battery models supplied by our company: an innovative “transparent” solar battery GP Solar GPDP-265W60 265 Watt power:
This model is a completely new line of solar panels. Made from two sheets of tempered glass, the thin and partially transparent (in our case 10%) solar panel is a definite trend in the world of solar energy. Anticipating and perhaps even anticipating the imminent rush of builders and architects, as well as ordinary users, we present you this new product. Transparent solar panels are suitable for those who are interested not just in the “utilitarian” component of a solar power plant, but also in realizing their creative, aesthetic needs. One or two years ago, translucent panels were just a curious novelty at specialized exhibitions, but having met with explosive interest from consumers around the world, Dual Glass products appeared in every self-respecting manufacturer. Futuristic design clearly hints at the need to use it in architectural elements - after all, being next to such a panel, the future becomes not only visible, but also tangible.
In addition to their standard purpose as an attribute of roofs and ground areas, such panels can be used as the main surface of a wall, fence, canopy, they can become an excellent alternative to window glass, or the heart of an architectural composition - we leave this question to your discretion. Note that the strength of these panels is sufficient for an adult to stand comfortably on their surface (bearing capacity is 5400 Pa).
Of course, frameless technology, which has previously proven itself well in Pramac and Hevel micromorphic modules, is by no means new, however, in comparison with analogues, these batteries are significantly more efficient. The power density of GPSolar GPDP-265W60 transparent solar cells is 16.11%, which is more than 2 times higher than micromorphic solar cells. This is an undeniable advantage when organizing a solar power plant on a limited roof or canopy area.
Among other things, a frameless solar panel with two layers of glass has a longer service life, since, unlike traditional solar panels with an aluminum frame, it is not affected by the difference between the temperature deformation of the aluminum frame and glass (which over the years leads to damage to the structure, especially in Russian conditions, where solar panels are subject to large temperature changes each year).
As for mounting frameless solar panels, there are no difficulties with this either. Our company has been supplying high-quality batteries for many years, which installers of this type of batteries throughout the country have long known about.