Solar panels for a private house and apartment. Solar energy in an apartment building

It is not worth talking about the advisability of using solar panels for a country house in the absence of a central power supply. Such systems are completely cost-effective and highly economical when compared to fossil fuel generators. But what about the apartment? How feasible are solar panels for apartment buildings or single apartments? What are the features of the installation and operation of such systems, we will try to analyze in this article.

Features of installation and operation of solar power plants in apartment buildings

In recent years, it has become extremely fashionable to build "Eco Houses", including multi-storey complexes with low energy consumption, energy-efficient lighting with LED lamps or geothermal heating. Awakened people's interest in solar energy as a renewable and endless source of electrical energy. Solar power plants have become so common in the suburbs of megacities and in the news media that there is probably not a single person left who has not even heard about this technology. But the use of new technology in high-rise, multi-apartment complexes is sometimes fraught with many limitations:

• the space available for installing a solar array is generally too small in relation to the energy consumption per square meter of building area;
• shading from adjacent buildings;
• high initial cost of equipment,

All this makes it impossible to introduce solar systems into existing infrastructure. After all, it is sometimes impossible to justify to each resident of an apartment building the cost of introducing a novelty. Therefore, in practice, "solar houses" are designed long before they are built, selecting locations and infrastructure that best meets the requirements of energy supply systems. At the design stage, engineers will think through all the nuances, minimizing the future energy costs of residents. Or solar panels are installed in homes for general needs, such as:

• illumination of entrances and nearby territories;
• power supply of the security and communication system;
• uninterrupted power supply of electricians of boiler rooms and other public systems.

Justifying such systems is much easier, and the cost of their initial installation is usually lower and pays off faster, bringing benefits to every tenant.

The third option for the use of photovoltaic cells in apartment buildings is individual backup power supply systems installed by residents of individual apartments for their own needs. As a rule, the problems faced by apartment owners dreaming of solar power plants are of the widest range:

• the impossibility of installing the system on the roof of the building due to the failure of the management company;
• lack of windows and, accordingly, adjacent walls (sometimes balconies) oriented to the south;
• shading from trees and nearby buildings, and as a result, limited space for placing an array of solar panels;
• prohibition of management companies on the installation of extraneous equipment on the facade of the house;
• other restrictions on the installation of other components of the equipment.

But, despite the long list of limitations, resourceful high-rise residents still install backup systems that succinctly fit into the design of high-rise buildings.

Non-standard design of a balcony or a mini-power station in an apartment?

The south-facing balcony and radio engineering education of the owner of this apartment predetermined the future of its residents. Now they are not afraid of temporary blackouts or power outages. And the bills for light will flicker in smaller numbers. Indeed, on the balcony of this apartment, instead of the usual PVC panels, there are solar panels.

Four monocrystalline solar panels fit perfectly into the frame of an ordinary balcony, replacing its non-functional elements. Oriented almost strictly to the south, they are not shaded by nearby houses, and produce almost the maximum possible energy. At the same time, the batteries do not violate the overall design of the building, without being conspicuous and succinctly coexisting with other elements of the house.

In summer, such a system generates 1.0 -1.5 kWh per day and can provide energy for a small refrigerator or energy-saving apartment lighting. In winter, when the insolation drops to a large extent, the system will perform the function of an uninterrupted power supply when the mains electricity is turned off.

In the event that you want to save money on electricity or live in a territory that is difficult to access for a power line, we offer to look at and buy sets of high-quality solar panels at an affordable cost for your home on the website of the Solar Batteries online store in Moscow. Experienced and friendly managers will answer all questions. You will make the right decision by knowing exactly what type you need (polycrystalline, thin-film or monocrystalline module). We will deliver the goods without additional payment, in a short time.

Science is advancing, more and more efficient variations of these systems are being created, the price is being optimized, and the ability to convert light is increasing. If in the past only fairly rich people or large corporations could order them, at the moment the cost of a set of solar 5 kW solar power plants for a home is publicly available.

This variation is most beneficial for residents of rural private houses. There will be no difficulties if you decide to sit at the computer or watch TV after exhausting work on the garden plot, you just need to place, ordering from us at a nice price, a set of solar panels for your home or cottage.

The advantages of such complexes-power plants include:

• Reliability and durability. With careful use, the normal service life is up to 30 to 25 years.
• Highly economical in use. Requires almost no maintenance. Cleaning of light-sensitive surfaces is organized only once a year.
• harmless to nature. Liquid fuel is not used.
• Quiet operation.
• Easy to install and transport. Mounted on the roof from the most illuminated side.

People are looking for other sources of electrical energy and are improving methods that allow it to be extracted from new sources. Buying 5 kW solar panels for a private house or summer cottage at a popular price is a reasonable and prudent decision.

The devices quite effectively solve their problem - they provide owners with free electricity. One set can give such an amount of electricity that it will more than cover all basic needs. In warm summers, you can do without connecting to external networks. The cost of a kit for a summer house or a private house of solar batteries-power plants is pleasant and, if you often use electrical appliances, it will quickly pay off.

One of the reasons why you need to cooperate with us: our price (cost) of a set of solar batteries for a private house is one of the most economical. If you are looking for new opportunities, cheaper and safer power supplies for your household appliances, then we recommend buying a set of solar power plants at an economical price for a private home. Warmth, safety, cost savings are our motto: life is more carefree, life is more comfortable!

Recently, renewable energy has become more and more popular among them, solar energy should be highlighted. It is good because it is inexhaustible. The amount of heat given off by the sun is great. Today, when new technologies are constantly developing, this natural gift is worth taking advantage of. But to collect and accumulate such energy, it will be necessary to install solar panels for the apartment.

Installation location

In order for solar panels to work with the greatest efficiency, it is necessary to take into account the features of their location. For example, if the battery is placed in a shaded area, it will not be able to generate enough power to operate normally. As a result of improper installation, the design may fail completely after a while, not having time to justify the cost of the purchase.

Solar panels for the apartment should be directed towards the sun. It is important to carry out the installation so that the flow of sunlight falls on the solar cells of the battery for most of the day. If the house is located in the northern hemisphere, then the front surface of the device should be oriented to the south. If you are in the southern hemisphere, you must install the batteries so that they face north. The slope is also quite an important aspect and depends on the geographical location. As experts advise, the angle of inclination should be equal to the latitude in which it is located.

If the house is not located on the equator, then the angle correction must be carried out depending on the time of year. It is important to provide access to the batteries. The invention is unpretentious, but dirt and dust can cover its front surface over time, in winter the battery can be covered with snow. If this happens, then the accumulation of energy will decrease. In order to solve the problem, the base of the structure must be cleaned regularly. It is important to remember that a layer of snow on the surface of the battery can stop power generation, so you need to monitor the condition of this part of the panels.

Installation steps

You can install solar panels for an apartment yourself. It is important to decide where they will be located; special farms or the roof of a house can become a place. If you stop at the last option, then you have to install the profiles and fix the panels to the bolts. It is recommended to use fasteners for this, the diameter of which varies from 6 to 8 mm.

If you install solar panels for an apartment on profiles, this will fix them in a stationary state and save space on the balcony. When installation is carried out on land farms, you should first purchase them. They are usually aluminum profiles, corners or iron elements supplied in a collapsible form.

Work methodology

To carry out work, in addition to fasteners, you will need keys, the size of which depends on the parameters of the bolts. In order to install solar panels in an apartment, you need to assemble farms, and then choose a place, guided by the tips given above. The place of installation can be the roof. The design is fixed on it in the allotted place, and then the panels are installed.

At the final stage, it is important to make sure that the batteries do not move even with strong gusts of wind. Once the above steps have been completed, you can proceed to connect the batteries to the panels. The first of them will be connected to controllers or inverters.

Mounting Features

If you decide to install solar panels for an apartment in an apartment building, you should study the installation nuances. Whatever type of installation you choose, you need to monitor the angle of inclination. It is important to note that the batteries, if installed incorrectly, may be shaded by each other. If you install the elements on the same plane, then with the help of farms you can form several levels. It is important to consider the distance to avoid shading.

In order to use the available space more efficiently, battery layout techniques should be combined. For example, batteries installed on the roof can be supplemented by ground systems. It is important to remember that after installing solar panels, it will not be possible to refuse the services of local power networks, because the houses have energy-intensive devices such as TVs, irons, electric heaters, for which the charge of the modules will not be enough. Therefore, before installing solar panels in an apartment, you need to consider whether the event will be cost-effective. After carrying out all the calculations, it is necessary to purchase the main parts of the system, namely:

• solar panels;
• accumulators;
• inverters;
• controller.

As practice shows, the main problem when installing batteries and accumulators is choosing the right place. Solar panels should be exposed to sunlight for most of the day, there are very few such places in the apartment, so the choice is small. To do this, you can use the walls closest to the balcony and balcony glazing. This is true if roof mounting is not possible.

Most often recently, batteries are installed on the glass of the balcony, but this negatively affects the natural lighting in the apartment. Some consumers find positive aspects in this output, which are associated with a delay in ultraviolet radiation. Fastening in this case can be carried out in a balcony frame or on glass.

A set of solar panels for an apartment can be installed using this technology only if the balcony is on the sunny side, otherwise the installation does not make sense. The next important point will be to find a place for the location of the accumulating elements. When purchasing an average set for an apartment, you must acquire batteries in an amount of 20 to 30 pieces. For an apartment in a panel house, this area is quite large. It will be difficult to place such a number of batteries.

You can solve the issue by placing the elements in the upper part of the balcony ceiling. However, this place is rarely used. To do this, a shelf is usually built on which all the batteries are located, which in this case will not be visible, in addition, they will not interfere. It is important to remember the mass of the elements, the weight of each can vary from 15 to 20 kg, so the shelf must be reliable.

What is important to remember

It is necessary to pay special attention to the insulation of the shelf. This is due to the fact that in cold weather, the capacity of batteries may decrease if they are not protected from frost. In order for the batteries not to work in vain, they need to be insulated with high quality. If the installation of alternative sources is not done correctly, then you will only face unnecessary costs. Therefore, you should reconsider your opinion regarding some electrical appliances.

Before installing batteries, experts recommend abandoning powerful consumers, replacing them with less energy-intensive ones. For example, a laptop or computer will perfectly replace plasma panels. They are not as energy intensive and save kilowatts. A prerequisite will be the use of energy-saving light bulbs, but LED lighting devices are an ideal option.

Conclusion

Solar panels for an apartment on the balcony can be installed independently. For this, a loggia is best suited, since in its space you can place shelves in the ceiling area. Additionally, they should be insulated with thin heat-insulating materials.

Ecology

Hi Geektimes. This article is a continuation of the previous part, about the travel charger "". The idea of ​​using a solar battery to charge various gadgets seemed to me very promising, but of course, 21W as a universal charger is not enough - I want to be able to charge not only in sunny weather, but for this you need a power reserve. Therefore, full-fledged solar panels were bought and experiments with them began.

What came of it, details under the cut.

Iron

1. Solar panel

There are different options here, but on the balcony the main limitation is the availability of free space. To understand the order of prices, a 50W battery costs about 5000 rubles and looks like this:

Panel dimensions in mm - 540x620x30, weight 4kg.

Balconies are different in size, based on the dimensions of the panels, it is quite possible to place 2 or 4 pieces without any problems, it will not fit anymore. For the test, 2 panels of 50W were purchased. Such a battery gives about 18V under load or 24V without it, which means that when using 2 batteries, you need to count on a total voltage of up to 50V (for example, many dc-dc converters normally operate up to 30V). You can connect the batteries in parallel, but then the losses due to the length of the wires will be slightly higher.

2. Controller

There are 2 options here:

- Solar panels + controller + battery

This is a classic design: the controller charges the battery when there is sun, the user uses this energy when he needs it.

This system has several advantages:

Energy can be used at any time, and not only when it is light,
- the ability to connect an inverter and get 220V output,
- as a bonus, a backup source in the house in case of a power outage.

There is only one drawback: the use of a high-capacity battery fundamentally kills the environmental friendliness of the idea of ​​\u200b\u200bthis event. The number of charge / discharge cycles of batteries is limited, they do not like overdischarging, besides, both batteries and controllers are quite expensive. The price of the controller ranges from 1000 rubles for the cheapest PWM version, to 10000-20000 rubles for the more expensive (and efficient) version with MPPT support (you can read what MPPT is). The price of the battery is from 5000 rubles for a regular 40-50Ah gel battery, some use LiFePo4 batteries, they are of course more expensive.

- Grid-tie inverter

This technology is the most promising at the moment.

The bottom line is that the converter converts and gives energy directly to the home electrical network. At the same time, the energy consumed from the general network decreases, the house electric meter records lower readings.

Ideally, if the solar panels provide enough energy for all consumers, the value on the electricity meter will not increase at all. And if the consumption of an apartment / house is less than the production of solar panels, then the meter will record the "export" of energy, which should be taken into account by the electricity supplier. In Russia, however, such a scheme does not yet work - moreover, most of the old electricity meters consider energy "modulo", i.e. You will also have to pay for the energy supplied. It seems that in 2017, microgeneration issues were promised to be resolved at the legal level. But by the way, for the panels on the balcony, all this is only of theoretical interest - their production is too small.

The price of a grid-tie inverter is from $100, depending on the power. Separately, it is worth noting microinverters - they are placed directly on the battery, and they immediately give out the mains voltage, however, the recommended power of the panels is at least 200W. The inverter is mounted directly on the back wall of the solar panel, this allows you to connect them like this:

But for a balcony, of course, this is irrelevant.

Testing

First of all, it was interesting to find out what real power can be obtained from solar panels. For this, an ADS1115 ADC board for Raspberry Pi was bought for $ 15:

It is easy to use, the input voltage is divided by a divider and fed to an analog input, we have digital values ​​​​at the output. Sources for working with the ADC are available. I also bought an ACS712 current sensor, a voltage sensor was made from a bunch of resistors (only one rating was found at home). As a load, a conventional 100W light bulb was installed. Of course, it did not burn from 48 volts (the bulb is designed for 220V), but only barely glowed. The resistance of the spiral is 42 Ohms, which allows you to roughly estimate the power by voltage (although the resistance of an incandescent lamp is non-linear, but for a rough estimate it will do).

The first test version looked like this:

Technofetishists don't watch!

The source code was completed so that the data and the current time were saved in CSV, and a web server was launched on the Raspberry Pi to download files over the local network.

The results for a typical clear day with partly cloudy look like this:

It can be seen that the voltage peak occurs in the early morning, which is a consequence of improper installation of the panels - ideally, they should not stand vertically.

And this is how the “failure” looks like on the day when the clouds came up and it started to rain:

Given the voltage of 44V and the resistance of the lamp filament of 42 Ohm, we can roughly estimate (we ignore the non-linearity of the lamp resistance) that, at best, the resulting power is P = U * U / R = 46W. Alas, the efficiency of a 100-watt panel when installed vertically is not very good - the sun's rays do not fall on the panel at a right angle. In the worst case (cloudy, rainy), the power drops even to 10W. In winter and summer, the total energy received will also differ.

The experience with the return of energy directly to the network turned out to be unsuccessful: a 500-watt inverter from 45 watts simply did not work. In principle, this was expected, so the inverter was left for the future until moving to a place with a larger balcony.

As a result, given the decision to abandon buffer batteries, the only working option was to use dc-dc converters directly: for example, such a converter can charge any USB devices, it already has a USB connector at its output:

There are models a little more expensive, they have a higher maximum current and a larger number of USB connectors:

There is also an idea to find a dc-dc-converter for charging a laptop, their choice on eBay is very large.

Conclusion

This system is experimental in nature, but in general we can say that it works. As you can see from the graph, from about 7 am to 5 pm, the power output by the panels is more than 30W, which, in principle, is not so bad. In very cloudy weather, the results are of course worse.

Of course, there is no question of economic feasibility - when generating 40 W * h for 7 hours, 2 kW * h will be generated per week. Everyone can estimate the payback in the prices of their region on their own. Of course, the question is not in price, but in gaining experience, which is always interesting.

But where to put the energy, the question is still open. Using 40W to charge USB devices is overkill. There are 300W grid tie inverters on eBay with an operating voltage of 10.5-28V, but there are few reviews on them, and I don’t want to spend $ 100 on a test. If a suitable solution is not found, we can assume that one 50-watt panel is optimal for a balcony - it can charge various gadgets, redundancy in this case is minimal.

At least now all home digital devices (phones, tablets) have been transferred to "green energy" without much hassle. There is an idea to still consider using a buffer LiFePo4 battery - but the question of choosing both a battery and a controller is still open.

In addition: as suggested in the comments, you can use a lead battery, such as a car battery. Yes, it's really cheap and works, with a 100 watt panel a controller like this will suffice, costing only $10-20 on eBay.

Add your price to the database

Comment

Nowadays, almost everyone can collect and get their own independent solar power source(scientifically they are called photovoltaic panels).

Expensive equipment over time is compensated by the opportunity to receive free electricity. It is important that solar panels are an environmentally friendly source of energy.

In recent years, prices for photovoltaic panels have fallen dozens of times and they continue to decline, which indicates great prospects for their use.

In its classical form, such a source of electricity will consist of the following parts: directly, a solar battery (DC generator), a battery with a charge control device and an inverter that converts direct current into alternating current.

Solar batteries consist of a set solar cells (photovoltaic converters) that directly convert solar energy into electrical energy. Most solar cells are made from silicon, which is quite expensive. This fact will determine the high cost of electrical energy, which is obtained by using solar panels.

The most important technical parameter of a solar battery, which has a major impact on the efficiency of the entire installation, is its net power. It is determined by voltage and output current. These parameters depend on the intensity of sunlight falling on the battery.

Where is it appropriate to put it?

Installing solar panels in apartment buildings and connecting them to the apartment electrical network, of course, is not practical.

• Firstly, you are unlikely to be allowed to do this by the supervisory authorities for the operation of urban electrical networks.
• Secondly, the rather expensive panel and complex control scheme, as well as the inconvenience of installation work in an apartment building, will make your innovation in the field of storing and producing electrical energy economically unfeasible.

But in a private house, cottage or country house, especially if they are located more than 1.5 km from centralized power lines, it is very advisable. The purchase and installation of solar panels, as well as the minimum cost of their maintenance, will pay off in 5-10 years. Also, when deciding whether to install solar panels, you need to determine the average intensity of sunlight for your area (solar insolation coefficient). If you live in sunny areas, then the solar battery will work almost all year round, and therefore pay off faster. For areas and areas with insufficient light flux, it may not be advisable to install panels at all, especially if the industrial network provides electrical energy without interruption.

Price

Solar panels as an additional source of electricity for a private house or cottage have recently become very popular. Despite their still relatively high cost ( one panel with a power of 100-200 W will cost $ 100-150), their installation in many cases can be quite justified.

In 2016, solar panels fell in price in rubles by an average of 30%

Calculation of the cost of a solar power plant for a private house

The most universal solution for providing a private house or cottage with electricity is solar-powered power plants (solar power plants). Typically, such a system consists of the following components:

• solar panels (provide the conversion of light into electricity);
• battery charge controller (correct battery charge mode);
• rechargeable batteries (accumulation of electricity during the day and return in the evening and at night);
• inverter (DC voltage conversion to ~220 V, 50 Hz).

To calculate the cost of the necessary equipment, let us consider in more detail the approximate energy consumption options with different levels of generated power and connected load.

1. Complete autonomous system with a monthly consumption of 270 kWh/month

For example, we can take the most common household appliances: a boiler, a refrigerator, a TV and several energy-saving lamps. A simple calculation of the power of these electrical appliances and the average time of their operation from an autonomous network shows an approximate result of energy consumption during the day - 8-9 kWh with an average daily power of 0.35 - 0.40 kW. The average monthly result will be about 270 kWh.

To achieve these power outputs, the following components must be included in our system:

• 13 solar monocrystalline panels 180 Wt ($200 x 13);
• 13 solar panel mounts ($25 x 13);
• 10 batteries 12 V, 200 Ah ($ 130 x 10);
• inverter 48 or 120 V, 2 kW ($ 300).

Total: $4,500.

To calculate the cost of the components, average market prices were used, which gives a quite adequate idea of ​​the level of financial costs. At the same time, it is important to take into account that if the life of solar panels can be from 20 years or more with only a slight decrease in their efficiency, then the battery life, on average, is about 10 years.

1. Autonomous system with a monthly consumption of 700 kWh / month

This option differs from the previous one in increased energy consumption, which may be necessary for a large family or in the case when the comfort of the inhabitants of the house is put in the first place and only then - saving electricity. For an example of calculating the power consumption, let's take the following electrical appliances: a boiler, a refrigerator, 7 energy-saving lamps, 2 TVs, street lighting and a pump. Approximate energy consumption during the day in this case will already be 20-23 kWh with an average daily power of up to 1 kW. With such indicators, the average monthly result will be about 700 kW / h.

An approximate calculation of the cost of components:

• 33 monocrystalline solar panels 180 Wt ($200 x 33 = $6,600);
• 33 solar panel mounts ($25 x 33 = $825);
• 20 batteries 12 V, 200 Ah ($ 130 x 20 = $ 2600);
• inverter 48 or 120 V, 3 kW ($500).

Total: $10,525.

1. Redundant system with a monthly consumption of 150 kWh

This version of the system is designed to operate during short-term power outages from the main power grid, although it can also be used as a seasonal source of electricity, for example, in a country house for basic needs. As an example, to calculate energy costs, you can take into account the load from the refrigerator, a pair of energy-saving lamps, a TV and a pump.

With average energy costs up to 5 kWh / day, the simplest system is sufficient, which includes the following components:

• 7 monocrystalline solar panels 180 Wt ($200 x 7 = $1,400);
• 7 solar panel mounts ($25 x 7 = $175)
• 2 batteries 12 V, 200 Ah ($ 130 x 2 = $ 260);
• inverter 48 or 120 V, 0.5 kW ($ 100);
• automatic transfer cabinet ($270).

Total: $2,205.

1. Two 120W modules, 20 amp MPPT controller, 2 x 100 Ah gel batteries, 1300 W inverter with pure sine wave signal.

Provides electricity to a small country house in the summer without electric heating. The inverter instantly turns on the backup power circuit when the main power is turned off. The maximum power consumption is 1.3 kilowatts.

Development of the system in the summer (April-August): 1.1-1.25 kW per hour/day in the Leningrad region.

Overall dimensions of the 120 W model: 1170 x 670 x 40 mm. Weight of each battery: about 35 kg.

Solar panels, price: 48 200 rubles. Installation cost from 12 thousand rubles.

1. One 60 W solar panel, 10 amp MPPT controller, 60Ah battery, 600W inverter with modified sine wave.

Allows you to provide electricity to the needs of a temporary home or a small house: lighting, phone charge, laptop, TV, etc. The maximum power consumption is 600 watts.

Overall dimensions of the 60 W option: 830 x 670 x 40 mm.

About 3700 rubles. Installation is possible with your own hands.

Benefits of Solar Residential Buildings

• The energy of the sun is infinite (at least for the next 5 billion years, give or take),
• provides clean energy,
• without greenhouse gas emissions, and it can save people money on their electricity bills.

But there are factors to consider when deciding on solar power – and cost is just one of them. In this article, we'll look at six of the most important questions to consider when you're thinking about investing in a solar panel installation. Using photovoltaic power is a very green solution and a potentially beneficial move, but it's not quite as easy as getting your power from a regular grid.

The first factor is one you may not have thought about:

1. Service

Turning your home on solar energy requires more maintenance than using a conventional old power grid. But not much.

Solar panels have no moving parts. They are part of a complete stationary system. So once they're installed, there aren't many reasons why things can go wrong. Pretty much the only thing a homeowner has to do is keep the panels clean. This is an important task, because too much snow, dust and bird droppings on the panels can reduce the amount of sunlight. The accumulation of dust on the screen can reduce the amount of electricity produced by the system by as much as 7 percent.

This type of maintenance does not need to be done once a week, however. It is enough to water the panels with a hose from one to four times a year. To do this, you do not need to climb onto the roof. The hose with the nozzle from the ground works great. If there is construction in your area, it is necessary to clean the panels more frequently to avoid additional buildup dust buildup.

In addition, check from time to time that all parts are in working order. In addition, it is necessary to replace the batteries, but this is once a decade.

1. Neighborhood

The location of your home has a big impact on your solar energy efficiency. This is an obvious problem: If your electrical output depends on sunlight, things like shadows from tall trees and high shadows from buildings will be a problem.

This is an even bigger problem than some people realize. Different types of panels react differently to shadows. While polycrystalline panels can significantly reduce power output, any part of the shading of a monocrystalline panel will stop power generation completely.

So, to build a solar home, you need to make sure that there is no shade on the panel over the roof area during the sunny hours of the day (generally from 10 am to 2 pm) and preferably during all sunny hours. The more hours the panels are exposed to full sunlight, the more efficient the power generation will be.

Achieving the greatest efficiency may mean pruning or completely removing the trees in your area. If your home is surrounded by tall buildings that block the sun from the roof, this is a big problem.

1. Insolation

Sunlight obviously plays a key role when it comes to solar energy and not all regions are created equal in this respect. It is important to know how much sunlight reaches the ground in the area where your potential solar home is located.

What we're talking about here is called insolation, a measure of how much solar radiation hits the earth in a given area in a given period of time. This is usually measured in kWh/m2/day and it will tell you how much sunlight will be available for your solar panels to turn into electricity. The higher the insolation value in your area, the more electricity each of your panels will be able to generate. The high insolation value means you can get more power from smaller panels. The low insolation value means you could end up spending more to achieve the same power output.

So you should build your solar home in the southwest, not the northwest? Not at all. It just means that you will probably need more panels to achieve the same power output.

1. Coverage

Contrary to what most people think, the size of a solar power plant has nothing to do with the size of a house.

Instead, only two parameters should be taken into account:

• insolation, which we have just discussed,
• how much power do you need.

To get a very rough estimate of how big a system you need, look at your electricity bill and find out how much kWh you use per day.

The average home uses about 900 kWh per month, or about 30 kWh per day. Multiply this by 0.25. We get 7.5, so we need 7.5kW of the system.

A typical solar panel produces up to 120 watts, or 0.12 kW per day. To provide 7.5-kW, you need about 62 panels. One panel can be approximately 142 by 64 centimeters, so a 62-panel would take up approximately 65 square meters.

You should also take into account insolation and how many hours of peak sunlight you get per day, and also make adjustments if you use batteries with panels. Therefore, it is best to turn to the pros.

1. Expenses

In 1956, solar panels cost about $300 per watt. Only the very rich could afford a 7.5 kW system.

Of course, you can partially provide the house with solar energy. If you want to invest $2,000 in solar panels, you can supplement the electricity from the grid with a 1.5kW solar system. Although in the west they already practice renting solar panels. There are no upfront payments. Homeowners pay a monthly rent to use the panels, and the rental company owns and maintains them.

1. Disposal

The service life of solar panels is 40-50 years, the controller and inverter 15-20 years, batteries, depending on the type and nature of use, 4-10 years.
Although the issue of recycling solar panels remains open, only 30% of all manufacturers take them back for recycling.
Nevertheless, the demand for used solar panels is growing every year. Since the extraction of rare metals is becoming more and more expensive, the recycling of panels will lead to their reuse.

In addition: there is a secondary market for photo and wind power installations, where already used equipment can be further used.

In countries with economies in transition, used solar modules can be used. Thanks to more intense solar radiation, these modules can generate more electricity.