How to provide the house with electricity. Autonomous power supply systems

Provide electricity to your home  there are two ways: to connect to a common power supply system or create your own autonomous system for the production and distribution of electricity.

You can also choose the third option - to create a mixed system, when the connection to the common system is duplicated by offline sources.

Why you need an autonomous system

It would seem,  meaning in the autonomous power supply system is only one - this is when there is no power line near the house, and pulling your own line is too expensive. However, many homeowners create their own power supply system even if they are already connected to the common system.

What is the meaning of this autonomy?

• Regardless.  Its system will protect against power outages on various occasions. Autonomous system is also not immune from accidents and other troubles, but if you create duplicate devices, then the security against accidents will reach a maximum.
• In economy.  Electricity supplied by a single system is expensive. Creating an autonomous system is also not cheap, but many homeowners believe that it pays off very quickly, and just as quickly becomes a matter not just cheap, but also profitable.
• In mobility.  An autonomous system built on several power sources allows you to quickly react to the situation, remaining in the light in any situation.

Autonomous energy sources

Where does electricity come from?  You can get electricity from the stove. However, if you take into account the factor of time and effort, you can seriously consider only those sources that can work on their own. For this reason, the most popular are the following ways to provide the house with electricity.

1. Internal combustion engine with liquid fuel.  Such generators are available in a variety of options, but it is not advisable to use them as a permanent source of electricity in an apartment building. The reason is:

• high cost of fuel;
• noise of the generator;
• presence of exhaust gases;
• the need to allocate a separate room or a shelter for the generator.

2. Solar panels, they are also generators.  This is what does not require attention and fuel. The only thing they need is intense light, and since nature supplies these fuels not regularly, they also have powerful batteries. In the presence of the latter in a climate with a lot of sunny days to provide a house with electricity is quite possible.

The payback of solar generators is high, as some models can work without problems for thirty years.

3. Wind turbines.  These installations are no less popular than solar panels. However, they are even more dependent on the vagaries of the weather, so you can not rely on this source of energy anywhere.

4. MiniHPP.  They need a watercourse with a small difference in altitude to ensure the effect of falling water. In the place of such a drop, a small turbine is installed, and electricity will flow into your house constantly, and most importantly - free of charge. Under mini HPP, you can use a natural stream or a river, or you can dig a small channel that passes through your site.

However, such a hydroelectric station will only work in the warm season, then it will have to switch to other sources.

What to choose?

It is difficult to give a universal answer.  The choice, of course, is made on the basis of opportunities and conditions. If your house is located where there is a lot of sun and wind, then there is nothing to think about - install solar and wind generators. They will duplicate each other. If the weather does not spoil you either, you will have to buy generators for liquid fuels or look for other options.

How much is?

Based on modest needs  average house - 15.0 kW at a time, you need to purchase:

• solar generators - 250,000 rubles;
• wind generators - about 300 000 rubles;
• mini HPPs - from 150,000 to 600,000 rubles.
• generators for liquid fuels - 30 000 - 50 000 rub.

Cheapness of the latter  The source of energy is illusory, since it must be multiplied by the cost of fuel.

The conclusion suggests itself - if you want to do cheap and reliable, make a combined system of different energy sources.

Without electricity, modern man is like without air, and it does not matter whether he is in a city apartment with an abundance of technology, or in nature. Interruptions with electricity in the country or the complete absence of it forces you to look. The last mankind has not come up with so much yet: the engines for liquid fuels, solar batteries, wind generators and batteries, this if you do not take into account more exotic and sophisticated solutions. All existing methods have shortcomings, but if the dacha or plot is without, and construction work and simple household tasks are necessary, then you will have to choose one, or better two (to secure) the most suitable option of the autonomous.

What to consider when choosing an autonomous source of electricity?

Many parts of the country, no matter how surprisingly it sounded, have not yet been connected to the general electricity supply system. Others suffer from constant power outages. If there are no electricity grids in the region, and it's time to start building a house, what can we do: wait for the site to be connected to the network or to look for alternative solutions? What if the electricity is turned off in the evenings, and sometimes in the daytime, and often in general is unpredictable? Contemplation of the starry sky and - this, of course, is romantic, but without a refrigerator, a light bulb, a pump and other benefits of civilization in the country is already difficult.

Sooner or later everyone tries to find a way to connect electricity to the site. A universal formula for choosing its best source does not exist, since consider a lot of factors:

• the size of a country house, the regularity of his visit, the usual and the maximum number of people staying in it;
• number of devices that consume energy. It's one thing if it's a pair of light bulbs, an outlet and a kettle. It is much more difficult to solve the issue of power supply for a holiday home if many powerful electrical appliances operate in it, starting from several TV sets and a refrigerator, ending with water heaters and pumps;
• features of the region. In windy regions, an expensive, at first glance, windmill will be the most economical and quickly recouped source of electricity, and in the Moscow region, for example, the wind will no longer be such an advantageous source of energy;
• power supply. If the electricity grid in the region is not at all, and their construction is hardly expected, experts recommend using two sources of autonomous power supply. This advice can be ignored, if you rarely appear in the country.

Naturally, before choosing the type and power of an autonomous source of electricity, it is necessary to carefully calculate the amount of energy consumed. The number of electrical appliances and the characteristics of energy consumers are taken into account. The total capacity is obtained by adding the needs of all and equipment. To get the value it's better to throw 15-30% to make sure and not be afraid to turn on the new device. It should be remembered that to ensure maximum durability of work it is better that the generator functions at 80% of its capacity.

№1. Generator for dachas: gasoline, diesel, gas

The simplest and most popular way to solve the electricity problem on the land is to use fuel generator. In fact, it is a miniature power station that operates completely autonomously and converts the energy of fuel combustion into electrical energy. As fuel, gasoline and diesel are used, more rarely gas. To produce 1 kWh of energy, an average of 0.25 to 0.5 liters of fuel is required.

Using generators home electricity is easiest to organize: bought, hooked up and can use, just do not forget to add fuel in time. This is the main advantage. The main disadvantage is the need to constantly buy fuel, and if the house is large and there are many electrical appliances in it, the costs will be appreciable. In addition, the generator itself also costs money, and the higher its capacity, the higher the price. But if you compare it with a windmill or a solar panel, then the generator, of course, will be cheaper.

When the generator is a backup source of energy, it is important that it not only be included in time on time, but also be disconnected in a timely manner, so that no collision of two opposing streams of charged electrons occurs. To avoid troubles, the algorithm for switching the generator on has been developed for a long time. If there is no central power supply network, then it is recommended to use two generators: one - the main one, the second - the backup one and is put into operation when the fuel ends in the first one. The simultaneous operation of the two generators significantly increases the life of each.

On what fuel the generator will operate, its power, durability, noisiness, and also operation costs depend.

Diesel generator for summer residence

Diesel power generators are best suitable for permanent work. A long time of continuous operation is provided by the presence of a water cooling system. Among his other advantages:

Among the minuses:

Petrol generator for summer residence

Gasoline generator is better suited in those cases, when the plot is used from time to time. It can also work as a backup power sourcewhen the site is connected to a common network. In a small country house with a minimum set of electrical appliances, the gasoline generator proves itself best. The power of gasoline generators is usually not higher than 7-9 kW (but you can find models for 15 and even 20 kW), and they can not work for longer than 8 hours continuously - they get very hot.

Benefits:

Minuses:

• low efficiency;
• high cost of gasoline.

The noise level of the diesel and gasoline generator depends on the type of housing and the speed at which the generator operates: a device with 1500 rpm will give a much lower noise than the equivalent in capacity, but from 3000 rpm, but also will be more expensive .

Gas generator for summer residence

Gas generators allow you to get the cheapest energy, while The efficiency of their work is the highest, and the noise is minimal. The power can reach 24 kW, the generator can operate around the clock, and gas will be cheaper than gasoline and diesel. That's only until such devices are widely used, because they cost a lot, are difficult to operate and require connection to a gas pipeline, which is not everywhere. Nevertheless, some summer residents connect such generators to gas cylinders.

№2. Solar cells for cottages

The main disadvantage of fuel generators is the need to constantly buy fuel for them. This shortage is deprived generators, who use free energy, available to all. It is the energy of the sun and the wind. To get electricity, they also use geothermal energy, as well as water energy, but these options are unlikely to be suitable for supplying power to the suburban area.

If it's very simple, then principle of operation of solar panels  consists in knocking out electrons from the semiconductors located in the photocell by light photons, and the directed flow of electrons, as known from the school course of physics, is electricity. To ensure the generation of electricity from sunlight, its accumulation and further use for domestic purposes you need a whole set of equipment:

All elements are better to take in the kit - it will be much easier.

The prices for solar batteries strongly depend on their type, size, power and the name of the manufacturer. Of course, everyone wants for their money to achieve maximum productivity and energy independence, so you need to carefully study the nuances of weather in the region, what type of solar cells is best suited for a specific location:

Whichever version you choose, solar panels are always weight of advantages:

• the opportunity to get a full-fledged source of electricity, and the energy of the sun goes free. In developed countries, surpluses of such energy homeowners are sold to energy companies. On the domestic space, the first steps have already been taken in this direction, although the phenomenon is far from being massive;
• absence of monthly payments for electricity;
• long service life;
• environmental friendliness.

Minuses, of course, are present. First, the inability to use solar energy as a full-fledged source of electricity in regions with a lot of cloudy days a year. Snow can also become a hindrance, so it will have to be constantly cleaned. In addition, places for the entire set of home solar power plant will need a lot: it's the batteries and equipment for them. As for the cost, it is initially high, but in the end it pays off completely.

When choosing solar panels, pay attention to:

• power. Depends on the needs of a particular house and features of the region;
• battery life time directly affects the duration of the period during which it will be possible to receive electricity in inclement weather;
• class of operability. It is better to take batteries of class A;
• manufacturer name. The products of such companies as Sunpower, Sanyo, Jinko Solar are not bad.

Calculation of required power  - this occupation is a painstaking and knowledgeable mass of precise parameters. To estimate, what approximately batteries are necessary and to be guided by the price, it is possible to spend simple, but very much approximate calculation:

To obtain accurate calculations it is necessary explore weather diaries in the region  For the number of cloudy and sunny days in recent years in a particular month. Only after this it will be possible to judge the battery parameter and payback. In most cases, even a large stock does not make it possible to use solar energy as a full-fledged source of electricity in the winter, so you need a backup power supply from a gasoline generator.

No. 3. Wind generator for summer residence

Another free source of electricity - the wind, but, like the sun's rays, it is characterized by inconstancy. Main advantages, as well as with photocells, is the lack of the need for constant fuel purchase and environmental friendliness of the energy received. Minuses: the high cost of construction, the need to put not only the wind generator itself, but also additional equipment (inverter and batteries with controllers).

Today there are two type of windmills:

The main question that faces those who decided to install a windmill - it's not even his type, but power. Answering the question, it is worth take into account the generated, accumulated and consumed energy. Therefore, it is important to calculate how much energy is consumed, for example, per day, what is the average and peak load. Take into account the average wind speed, the number of days when the wind speed is above 5 m / s (most favorable), and the maximum duration of windless weather.

In practice, it turns out that weak winds of 2-3 m / s give insufficient energy. Therefore, experienced summer residents are advised to stock up high-capacity batteries to accumulate energy received on wind days, and use it in a period of calm and weak winds.

№4. Inverter batteries for cottages

Rechargeable batteries can be used to store energy from a variety of generators, but sometimes used as an independent source of energy. Naturally, consider this option as a way to constantly feed the site with electricity is not worth it, but here in quality reserve it will go. If suddenly the light switches off, the fuel for the generator is over or there will be no sunny days, then the minimum required set of electrical appliances can be powered.

The inverter battery is connected to the general electrical system of the house, it is charged from the central power supply network, and when there are interruptions with electricity, it gives up energy itself.

Battery parameters are selected depending on the needs, taking into account how much energy is consumed by electrical appliances in the house and for what period electricity may be cut off. For example, if you need a battery that will give 3 kW of electricity, and considering the conversion losses in the inverter (10%) this is 3.3 kW, at a voltage of 12 V, you need a battery of 275 A * h or 2 to 150 A h. When choosing a battery, consider the number of charge / discharge cycles (the more, the better), give preference to the models with the maximum service life and do not use car batteries, in spite of the fact that in all respects they seem to be suitable - for their safe operation they need specific conditions.

Finally

To obtain energy, mini-HPPs are also equipped, but this requires access to a water source, so this method has not found distribution. If a country house is used all year round, it is better to invest money in a wind generator or solar panels (though that is more profitable), and insure yourself with a fuel generator. If the dacha is used occasionally, then you can do with only the generator, and if electricity on the site is still there, but just serve it on schedule or with interruptions, then the option is a battery or a gasoline generator.

If your house does not have access to a power line, then it is not necessary to spend money on connecting to centralized power networks, there is another option - an autonomous system. This method is undoubtedly associated with significant costs, however, you will be completely independent of the networks, and the received electricity will not damage the environment.

When autonomous power supply systems are profitable

Laying new power lines requires significant costs, and if you also need to install a substation, the amount of connection will increase at times. And this money will go to purchase equipment that will not become your property, but will belong to local energy networks. Thus, an autonomous system can cost less (when accounting for electricity payments) than a connection to a power line.

It is worth noting and the fact that the autonomous system will be your property, with proper care it will last a very long time, and you, regularly checking its condition, protect yourself from sudden outages.

If you live in a region with suitable climatic conditions, the cost of energy generated by an autonomous system can be lower than when connected to a centralized network.

Such a method of generating electricity is absolutely safe for the environment, so it is always "beneficial" for nature. Care for the environment can and should be shown in all available ways.

Types of autonomous power supply systems

There are different types of electric power sources: a gasoline or diesel fuel (GTG) generator, a wind power plant, a photovoltaic (solar) battery, a small hydro power plant.

It is advisable to have not one, but two sources of energy, in which case you will be fully insured against outages. As a rule, ZhTG is used as an additional source. The need for it may not arise, usually this source is idle, however, it can come in handy at any time.

The second necessary element is a rechargeable battery. Without it, an autonomous system can not exist, since the renewable resource is unstable. Electricity accumulates in the battery, and you always have access to electricity. Even for systems where the source is a generator, you need a rechargeable battery that allows you to disconnect it for a while, and use electricity continuously.

Another important part of the autonomous power supply system is an inverter that converts DC to AC. Necessity is caused by high losses in DC wires. In addition, most devices require an alternating current of 220 V, which you can get from the inverter.

Be sure to purchase a battery charge controller, it is a separate, and sometimes built-in inverter. The task of the controller, monitor the battery status and prevent full discharge and recharging.

The cost of an autonomous power supply system also includes all necessary equipment: cables, automata, shields, grounding system, switches, etc. More details about the prices for autonomous water supply systems  you can read on the websites of specialized companies that are engaged in the design and installation of such systems.

What you need to pay attention to

First of all, you need to take care of the voltage, the higher the energy efficiency, the lower the costs in the long run. So, for example, LED lamps consume 10 times less energy than incandescent lamps. It's not just about saving the energy itself, but about saving on the system. Less power of an energy source is a significant reduction in the cost of an autonomous system. In addition, you will need a smaller battery, which will also affect the estimate.

Before choosing an automatic power supply system, it is necessary to conduct economic calculations. Even if the main goal of this installation is not in economic benefit, but, for example, in environmental safety, calculations are necessary. Without them you will not be able to present not only the total amount, but also the final cost of each kilowatt of the energy received.

For economic calculations, information is needed about natural opportunities or obstacles. For example, wind power plants located in the Moscow Region will produce only 10-15% of their nominal capacity, this energy source for this region will be an irrational choice. Solar panels are also suitable only for some regions of Russia, where the number of sunny days is much higher, otherwise the profitability of the autonomous system is reduced.

You also need to familiarize yourself with all technical and legal literature, consult with specialists in these fields. Only then can you decide to install an autonomous system with the selected energy source.

Do not forget that it is necessary to take care of this installation. When connecting to a power line, all costs for replacing obsolete equipment, as well as maintenance, become the responsibility of local power grids, and in the case of an autonomous power supply system, it is your responsibility. The simplest systems of care are systems powered by photovoltaic batteries. You need to draw up a maintenance plan and follow it. Remember that the more you care about an autonomous power supply system, the longer it will serve you, the more money you can save.

Another tip, which is suitable for home owners who already have a connection to the network - do not turn off. You will pay only for the electricity that is consumed by you, and its quantity will be reduced to a minimum. The existing connection is your backup power source, which will be needed only if the main one does not work. In addition, some networks take surplus energy generated by autonomous systems. So you can not only save money, but also make money.

The rapid growth of electricity prices forces dacha residents to look for an alternative to centralized AC supplies.

In the same place where the prospect of electrification is pushed back for many years or the costs of connecting to external networks are too great, stand-alone installations come to the fore.

Weakly understanding the intricacies of energy supply, not everyone is able to analyze what kind of independent power supply of a country house is economically profitable. We will try to help in this matter and consider three possible options for power supply: a gasoline generator, a battery converter and a solar battery.

The main selection criteria for a battery converter and a solar battery are: the cost of equipment, the period of its operation until it is written off, and how the resulting factor is the price of 1 kW of electric power produced during this time.

For a gasoline generator, the calculation will be different. Here in the foreground is the consumption and the price of fuel. Using these parameters and taking into account the cost of the generator itself, we get the price of 1 kilowatt hour of "gasoline" electricity.

Inverter gasoline generator

To date, this unit is most often used for backup power supply of country houses. The reason for such popularity is the generator's affordable price and ease of use. No installation and adjustment. He poured gasoline, pressed the button and got the light.

However, any comfort has its price, and it is very high in a gasoline generator. Let's calculate how much one kilowatt hour of electricity is supplied by this device.

For calculation, we take a single-phase generator HERZ IG2200E (Germany) with a power of 2 kW.

• Costs for the purchase - 21000 rub.
• The resource of the generator is 4000 hours.

The cost of a kilowatt is calculated as follows:

At a load of 2000 W, the gasoline consumption of AI-92 according to the generator's passport is 1.4 liters per hour (the cost of fuel is assumed equal to 36 rubles). We get the price of 1 kW * h = 36х1,4 / 2 = 25,2 rubles.

The cost of the generator is divided by its motor resource and we get: 21,000 rubles / 4,000 hours = 5.25 rubles.

As a result, the cost of 1kW * h = 25.2 + 5.25 = 30.45 rubles.

The price of 1 kilowatt hour of grid electricity for the Moscow region in the first half of 2016 is 5.03 rubles. We see that it turned out to be six times more expensive for a gasoline generator.

Conclusions:

• To use a gasoline generator for long-term power supply at home is unprofitable.
• The use of the generator (with the exception of installations with auto start) requires the presence of a person - to start, add fuel and monitor work.

The use of a gasoline generator at a dacha is economically justified only as an emergency or backup power source. In the absence of external power grids, it is better to operate it for a short time (4-5 hours a day).

Today, many manufacturers produce universal plants that operate both from gasoline and from balloon gas. Since the cost of liquefied gas is almost two times less than that of gasoline, it is more economical to receive electricity from this type of fuel.

Battery inverter

The principle of operation of this unit is cyclic charging of powerful batteries and their subsequent slow discharge into the power supply network of the house. In this case, in a special device-inverter, the battery current is converted from a constant current with a voltage of 12-24 V to a variable 220 V.

Such autonomous sources of power supply need to be charged from the apartment network in the city, and at the dacha to use electricity, which is a stock battery.

Home craftsmen should know that a standard starter battery from a car for such a converter will not work. It creates a powerful current in a short time. Here you need a small current, which feeds the network for several hours. Therefore, the inverter converter works with special maintenance-free batteries, which are 3-4 times more expensive than car batteries of the same capacity.

High cost in this case, it justifies itself. The lifetime of such batteries is 8-9 years, while automobile batteries do not serve more than three.

The price of a complete set of a battery converter consisting of an inverter and two batteries of 200 Ah each is about 110,000 rubles.

The required capacity of batteries for its operation is determined by the following formula:

Battery capacity (Ah) = Power consumption (W) x Discharge time (h) x Efficiency (0.7) * 1.2 (safety factor) / Battery voltage (V)

It turns out that to provide current for household appliances with a total capacity of 1500 watts for 5 hours, we will need batteries with a capacity of 1500x5x0.7x1.2 / 12 = 446 Ah. This is almost as much as is offered to the buyer in a bundle for 110,000 rubles.

For 8 years of battery life, it will take 21,600 Kilowatt hours of electricity to charge it at an "urban" price of 5.03 rubles.

The cost of one autonomous kilowatt in this case we define as follows:

• The cost of electricity for charging batteries (for 8 years of operation) is 21 600 x 5.03 rubles. = 108,648 rubles.
• The cost of equipment is 110,000 rubles.

In total, we received 218,648 rubles. The price of one kilowatt is 218 648/21 600 = 10.12 rubles. As we see, the battery converter provides electricity 3 times cheaper than the gasoline generator (10.12 versus 30.45 rubles.) And 1.7 times cheaper than the gas generating unit.

Solar battery

For the considered technologies of autonomous power supply of a country house, external support (gasoline and electricity) is needed. The solar battery is advantageous in that it takes energy directly on the spot. She does not need refueling and recharging of batteries. It does not poison the air with exhaust gases and does not create noise.

The warranty period of operation of modern solar panels is 25 years. This is quite enough for a full payback of costs and reducing the cost of a kilowatt hour.

Let us consider in more detail what solar autonomous electricity can give to a holiday home and how profitable its use is.

The cost of solar panels can not be called low. So for a single-crystal heliopanel, which produces 150 watts of electricity per hour, you will have to pay from 11,000 rubles.

In practical terms, the use of solar energy should not talk about one battery, but a complete photovoltaic station. It consists of 4 solar panels, two powerful batteries with a capacity of 200 Ah each, a voltage inverter (converts a DC 12 volts into an AC 220 volts) and a controller.

For one sunny day such a system produces 2.5 kWh of electricity. This is enough to power a small holiday home. Taking into account the overcast days, we will assume that the average energy output is 1.5 kW / h per day.

With an average cost of a "solar" set of 130 thousand rubles, he will work for at least 25 years. Batteries do not live that much, so for this time we will have to change them 2 times. The cost of batteries is 30,000 rubles. Expenses for the entire period of operation of the solar power plant will be: 130,000 + (30,000x2 = 60,000) = 190,000 rubles.

For 25 years, the station will generate 1.5 kWh * 365 days * 25 years = 13688 kWh. Dividing the cost of expenses for a solar station by the total amount of electricity received, we get 13.9 rubles per kilowatt. This is 2.75 times more expensive than the network tariff, but it guarantees the user full energy independence.

If we take into account the fact that solar technologies do not stand still, we will soon get more capacious and cheap batteries, as well as batteries with increased efficiency and lifetime.

Summing up our mini-research, we will present estimates to the options considered. So, the greatest cost of autonomous electricity is obtained from a gasoline generator (6 times more expensive than a network). In the second place are just two installations: a gas generator and a solar station.

Formally, the palm of the championship will have to be given to the battery converter, since it has the lowest energy price (10.12 rubles). However, it can be argued by a solar battery. It is completely autonomous and does not pollute the air with harmful emissions.