It's time to talk about how effective solar energy is in the Moscow region. For a whole year I collected statistics on solar energy production from two 100-watt solar panels installed on the roof of a country house and connected to the network using a grid inverter. I already wrote about this a year ago. And now it's time to take stock.
Now you will learn something that solar panel sellers will never tell you.
Exactly a year ago, in October 2015, as an experiment, I decided to join the ranks of the “greens” who are saving our planet from premature death, and purchased solar panels with a maximum power of 200 watts and a grid inverter designed for a maximum of 300 (500) watts of generated power . In the photo you can see the structure of the polycrystalline 200 watt panel, but a couple of days after purchase it became clear that in a single configuration it was too low voltage, not enough for the correct operation of my grid inverter.
Therefore, I had to change it to two 100-watt monocrystalline panels. In theory they should be a little more efficient, but in reality they are just more expensive. These are high quality panels from the Russian brand Sunways. I paid 14,800 rubles for two panels.
The second cost item is a Chinese-made grid inverter. The manufacturer did not identify itself in any way, but the device was made with high quality, and an opening showed that the internal components are designed for a power of up to 500 watts (instead of 300 written on the case). Such a grid costs only 5,000 rubles. The grid is an ingenious device. On the one hand, + and - from the solar panels are connected to it, and on the other hand, it is connected to absolutely any electrical outlet in your home using a regular electrical plug. During operation, the grid adapts to the frequency in the network and begins to “pump” alternating current (converted from direct current) into your 220 volt home network.
The grid operates only when there is voltage in the network and cannot be considered as a backup power source. This is its only drawback. And a huge advantage of a grid inverter is that you basically don’t need batteries. After all, batteries are the weakest link in alternative energy. If the same solar panel is guaranteed to work for more than 25 years (that is, after 25 years it will lose approximately 20% of its performance), then the service life of an ordinary lead-acid battery under similar conditions will be 3-4 years. Gel and AGM batteries will last longer, up to 10 years, but they also cost 5 times more than conventional batteries.
Since I have mains electricity, I don't need any batteries. If you make the system autonomous, then you need to add another 15-20 thousand rubles to the budget for the battery and the controller for it.
Now, as for electricity generation. All energy generated by solar panels enters the network in real time. If there are consumers of this energy in the house, then all of it will be used up, and the meter at the entrance to the house will not “spin”. If the instantaneous generation of electricity exceeds that currently consumed, then all the energy will be transferred back to the network. That is, the counter will “spin” in the opposite direction. But there are nuances here.
Firstly, many modern electronic meters count the current passing through them without taking into account its direction (that is, you will pay for the electricity sent back to the network). And secondly, Russian legislation does not allow private individuals to sell electricity. This is allowed in Europe and that is why every second house there is covered with solar panels, which, combined with high network tariffs, allows you to really save money.
What to do in Russia? Do not install solar panels that can produce more energy than the current daily energy consumption in the house. It is for this reason that I have only two panels with a total power of 200 watts, which, taking into account inverter losses, can supply approximately 160-170 watts to the network. And my house consistently consumes about 130-150 watts per hour around the clock. That is, all the energy generated by solar panels will be guaranteed to be consumed inside the house.
To control the energy produced and consumed, I use Smappee. I already wrote about him last year. It has two current transformers, which allow you to keep track of both the network electricity and the electricity generated by solar panels.
Let's start with theory and move on to practice.
There are many solar power plant calculators on the Internet, so you can take a look at what it is. From my initial data, according to the calculator, it follows that the average annual electricity production of my solar panels will be 0.66 kWh/day, A total output for the year - 239.9 kWh.
This data is for ideal weather conditions and does not take into account losses for converting direct current to alternating current (you are not going to convert your household's power supply to direct voltage?). In reality, the resulting figure can be safely divided by two.
Let’s compare with actual production data for the year:
2015 - 5.84 kWh
October - 2.96 kWh (from October 10)
November - 1.5 kWh
December - 1.38 kWh
2016 - 111.7 kWh
January - 0.75 kWh
February - 5.28 kWh
March - 8.61 kWh
April - 14 kWh
May - 19.74 kWh
June - 19.4 kWh
July - 17.1 kWh
August - 17.53 kWh
September - 7.52 kWh
October - 1.81 kWh (until October 10)
Total: 117.5 kWh
Here is a graph of electricity generation and consumption in a country house over the last 6 months (April-October 2016). It was during April-August that the lion's share (more than 70%) of electrical energy was generated by solar panels. During the remaining months of the year, production was impossible mainly due to cloudiness and snow. Well, don’t forget that the efficiency of the grid for converting direct current into alternating current is approximately 60-65%.
Solar panels are installed in almost ideal conditions. The direction is strictly south, there are no tall buildings nearby that cast a shadow, the installation angle relative to the horizon is exactly 45 degrees. This angle will give the maximum average annual electricity production. Of course, it was possible to buy a rotary mechanism with an electric drive and a sun tracking function, but this would increase the budget of the entire installation by almost 2 times, thereby pushing back its payback period to infinity.
I have no questions about generating solar energy on sunny days. It fully corresponds to the calculated ones. And even a decrease in production in winter, when the sun does not rise high above the horizon, would not be so critical if not for... cloudiness. Cloudiness is the main enemy of photovoltaics. Here is the hourly output for two days: October 5 and 6, 2016. On October 5 the sun was shining, and on October 6 the sky was covered with lead clouds. Sun, oh! Where are you hiding?
In winter there is another small problem - snow. There is only one way to solve this: install the panels almost vertically. Or manually clear them of snow every day. But snow is nonsense, the main thing is that the sun is shining. Even if it’s low above the horizon.
So, let's calculate the costs:
Grid inverter (300-500 watts) - 5,000 rubles
Monocrystalline solar panel (Grade A - highest quality) 2 pcs, 100 watts each - 14,800 rubles
Wires for connecting solar panels (cross section 6 mm2) - 700 rubles
Total: 20,500 rubles.
Over the past reporting period, 117.5 kWh were generated, at the current daily tariff (5.53 rubles/kWh) this will be 650 rubles.
If we assume that the cost of network tariffs will not change (in fact, they change upward 2 times a year), then I will be able to return my investments in alternative energy only after 32 years!
And if you add batteries, then this whole system will never pay for itself. Therefore, solar energy in the presence of grid electricity can be beneficial only in one case - when our electricity costs the same as in Europe. If 1 kWh of network electricity costs more than 25 rubles, then solar panels will be very profitable.
In the meantime, it is profitable to use solar panels only where there is no network electricity, and its implementation is too expensive. Let's assume that you have his country house, located 3-5 km from the nearest electric line. Moreover, it is high-voltage (that is, you will need to install a transformer), and you have no neighbors (no one to share the costs with). That is, you will have to pay approximately 500,000 rubles to connect to the network, and after that you will also have to pay network tariffs. In this case, it will be more profitable for you to buy solar panels, a controller and batteries for this amount - after all, after putting the system into operation, you will no longer need to pay any more.
In the meantime, it is worth considering photovoltaics exclusively as a hobby.
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.
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:
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.
High solar activity in the region is definitely one of the main criteria for.
However, no less important for the productivity of using the potential power of solar rays is the quality of the equipment - the very thing that is responsible for converting the energy of the rays into electricity.
In order for solar panels to work as long and efficiently as possible, you should take their choice seriously. Let us note the main points that you should pay attention to when choosing solar energy converters.
Mark Astafiev, member of the photovoltaic systems installation team:
“The photovoltaic market is filled with inexpensive Chinese modules - but this does not always mean low quality. Subsidies introduced by the Chinese government allow manufacturers to reduce prices.
In order not to take risks, you should choose products from large, well-known companies - as a rule, they use high-quality equipment for the production process. For example, JA Solar and Yingli Solar are engaged in the manufacture of both silicon elements and the modules themselves.
If defects are identified after a few years, you can easily exchange the defective product, since serious companies take warranty obligations responsibly.
As for the durability of solar panels, which, for example, are installed on the roof of a private house, they will last about 40 years. Usually the inverter, controller and other components of the system fail, but the modules themselves remain operational for a long time.
If you purchase from an online store, you can check the stability of the parameters of the purchased items.
Sergey Bondarenko, tester at a solar module factory:
“The power and other parameters of the efficiency of solar panels, their performance in real, and not close to ideal, conditions are revealed during testing. Such tests are carried out both in production and by independent laboratories.
It is difficult for the average consumer to check the quality of soldering and protective film, the presence of protective diodes, the degree of sealing, and find out the detailed characteristics of the elements. All this can be found in the description and conclusion prepared by specialists in the field of solar engineering.
Most solar cells produced today are made of silicon.
- monocrystalline;
- polycrystalline;
- amorphous.
The debate about which one is better continues. However, it can be unmistakably stated that low-quality monocrystalline ones are inferior in performance and durability to polycrystalline ones.
The opposite statement is also true: low-quality polycrystalline elements perform worse than those with a monocrystalline structure. As for the efficiency, solar cells made of monocrystalline silicon have the highest, but the difference is in tenths of a percent.
Everything solar powered includes several important parts.
- panels with elements that convert photon energy;
- batteries with charge controller;
- inverter.
The characteristics of each part are important to the job. Equipping the panels with connectors and cables for installation will eliminate the need to spend extra money on purchases. Although, it is worth noting that even reliable manufacturers of high-quality photovoltaic cells do not always supply a complete set.”
Anton Vasiliev, solar engineer, has been supporting projects for organizing the production of solar panels over the past few years:
“Modules that are attractive for their power and price can be supplied with a non-standard voltage.
A module with a standard rated voltage of 24 V will cost more than a 20 V module. But such equipment will also require a more expensive MPPT controller, so it will not be possible to reduce the cost of the system.
Also, when purchasing, you need to pay attention to the quality of fasteners.
The efficiency of solar cells directly affects the footprint.
And batteries for the roof of the house, that is, there are no size restrictions; it is much more important to evaluate the overall efficiency of the entire system.”