Recommendation points
The cost of electricity supplied by central networks is growing from year to year, while its quality is not getting better. Power outages continue to occur in rural areas. And today we will consider options for autonomous power supply of a country house.
If within the city limits the problem of providing one’s living space with electricity arises only periodically, then with a country house everything is much more complicated – often utilities are damaged as a result of natural phenomena and the actions of hunters for non-ferrous metal. You can, of course, return to the decisions of the beginning of the last century, namely kerosene lamps and torches, in the end, go to bed at sunset, but we are already accustomed to the benefits of civilization, inextricably linked with electricity. Consider the issue of energy independence of a country cottage from unreliable central communications.
How to supply energy to your home
Owning a house in a rural area, at a considerable distance from industrial centers, is attractive from a position of silence, clean air, surrounded by natural nature. However, there are situations when household appliances in such a house refuse to work due to a lower or excessively high voltage in the electrical network than the nominal (220 V) – and the drops can exceed 10% established by GOST 13109-97.
The problem with a lack of voltage lies in the considerable length of wired communications through which electric current flows to the houses – the farther from the TP (transformer substation) the cottage is, the more voltage drops due to the resistance of the wires. During the day, the voltage in rural areas changes in relation to the nominal due to insufficient power of the TP and power grids – it is lower during the day, since at this time there are most consumers of electricity, at night it rises sharply, since at this time the consumption is minimal.
Power surges can cause the failure of household appliances – in other words, it burns out. Modern household appliances, especially European ones, are designed for 10% voltage drops in the power grid, but no more, and in rural areas 20-30% surges are quite possible.
It is possible to compensate for drops in the power grid with the help of stabilizers, but in the event of a critical voltage drop (more than 45%), even the best of them will not help. Devices are required that can provide power for household appliances in the absence of electricity from central networks. Their choice is determined by the purposes for which the equipment will be used – backup power supply, additional or main.
Equipment for the backup power supply is activated automatically or manually by its owner when the power supply from the central network is cut off or in case of a critical voltage drop in it – it is able to maintain the operation of household appliances for a limited time, until the power supply resumes.
Additional (mixed) power supply is necessary in cases where the existing voltage in the network is insufficient, and households intend to use energy-intensive household appliances.
In the event that a cottage cannot be connected to central networks, as well as with a constantly low quality of power supply, equipment for autonomous power supply is needed, which acts as the main supplier of electricity.
To simplify the task assigned to the backup and additional power supply equipment, it will be convenient to divide household appliances in the house into three groups:
- The first will contain electrical appliances, the uninterrupted operation of which is not required and you can get by with the main source of power supply. These include underfloor heating systems or wall-mounted infrared panels, electric saunas, groups of lamps designed for different lighting scenarios, etc..
- The second group includes household appliances that provide comfortable living conditions for households – basic lighting, air conditioners, kitchen appliances, televisions, audio equipment. Household appliances from this group need a backup power supply.
- Electrical appliances enrolled in the third group are of vital importance – emergency lighting, security and fire alarm systems, electronic locks, heating boilers controlled by automatic equipment, borehole pumps, etc. additional or reserve sources without fail.
The grouping of household electricity consumers will allow you to correctly select the capacity of equipment that generates electricity, assess the actual needs and not overpay for an unnecessarily powerful, or purchase an obviously weak model.
Any equipment for autonomous power supply is not capable of producing electricity from nothing – it requires initial resources, which are divided into renewable and non-renewable. We investigate the types of devices that generate electricity, depending on the resources consumed.
Non-renewable energy sources
Autonomous power supply of a house using equipment that consumes oil products or natural gas and generates electricity is most popular among owners of suburban real estate due to its wide popularity. However, only gasoline or diesel generators are popular, less is known about the rest..
Gasoline power generators.Small in size and weight, they are cheaper than diesel ones. But they are not able to supply electricity uninterruptedly – their duration of operation is no more than 6 hours in a row (motor resource is about 4 months), that is, gasoline generators are designed for periodic operation and are suitable in cases where the supply of electricity from the main supplier is interrupted for a period of about 2 -5 hours and only from time to time. Such generators are only suitable as a backup source of electricity..
Diesel Generators.Massive, dimensional and not cheap, but their power and service life are much higher than that of gasoline models. Despite the significant cost, diesel generators are more profitable in operation than gasoline generators – cheap diesel fuel and uninterrupted operation for more than 2 years, that is, this electric generator is able to work day and night, subject to timely refueling. Diesel generators are suitable as backup, supplementary and primary electricity supplier.
Gas powered generators.Their weight, size and cost are close to those of gasoline units of the same power. They run on propane, butane and natural gas, but are more efficient on the first two types of gaseous fuels. Despite a period of continuous operation similar to gasoline generators – no more than 6 hours, gas generators of electricity have a longer service life, averaging about a year. As the main source of electricity, gas generators are suitable with a big reservation, but for a backup electricity supplier, it is quite.
Cogenerators or mini-CHP.If we compare them with the electric generators described above, they have two significant advantages: they are able to produce not only electrical, but also thermal energy; have a long working life with uninterrupted use, averaging 4 years. Depending on the model, the cogenerators run on diesel, gaseous and solid fuels. Having significant dimensions, weight and cost, mini-CHPs are not suitable for supplying energy to one house outside the city, since their electric power starts from 70 kW – thanks to one such installation, it is possible to completely solve the issue of year-round supply of electricity and heat to the village from several houses.
Uninterruptible power supplies on batteries. By and large, they do not belong to generating sets, since they are not able to independently generate electricity, only accumulate and give it to the consumer. The energy capacity of the UPS is determined by the capacity and the number of batteries in the complex, depending on this and the number of electricity consumers, the battery life of the UPS can range from several hours to several days. Service life of one set of UPS – 6-8 years on average.
Regarding generating sets, one point needs to be clarified – the given lifetime does not mean that after its production the electric generator will have to be disposed of and bought a new one, it is only necessary to carry out major repairs and, despite some loss of power, its operability will be restored. You should also follow the rules for the maintenance and operation of the generator..
Renewable energy sources
In the natural environment of our planet, there are constantly or periodically sources of energy, the production of which is not associated with human activities – wind, water flow in rivers, sun radiation.
Wind turbines.They are capable of converting wind energy into electricity, but at a rather high cost, the efficiency of wind generators does not exceed 30%. The service life of wind generators is about 20 years, the continuity of electricity generation depends on the intensity of the wind. It is possible to consider these installations as a full-fledged source of power supply only if they are equipped with a UPS, as well as a backup electric generator (gasoline, diesel) in case of calm.
Solar panels.They absorb energy from the sun and convert it into electrical energy. And if the winds blow at an inconsistent speed, then the sun’s rays illuminate the Earth during each daylight hours. The efficiency of solar panels is about 20%, their service life is 20 years. As in the case of wind turbines, solar installations must be equipped with a UPS. The need for a backup generator depends on the intensity of solar radiation in a given area – in areas with a sufficient number of sunny days, an additional generator will not be needed and can be used as the main source of electricity.
Mini-hydroelectric power station.The energy of water, in comparison with wind and solar, is much more stable – if the first two sources are unstable (night, calm), then water in streams and rivers flows at any time of the year. The cost of equipment for mini-hydroelectric power plants is higher than that of wind generators and solar panels, due to a more complex design, because a water power generator works in aggressive conditions. The efficiency of the mini-hydroelectric power plant is about 40-50%, the service life is over 50 years. The mini-hydroelectric power station is capable of uninterruptedly supplying electricity to several houses at once for a full year.
After reading the recommendation on dividing household appliances into groups according to the degree of importance, it remains only to find out how exactly to select the power of an electric generator for equipment from one or more groups. The simplest way is to sum up the rated power of household appliances, for example: microwave oven – 0.9 kW; mixer – 0.4 kW; electric kettle – 2 kW; washing machine – 2.2 kW; energy saving lamp – on average 0.02 kW; TV – 0.15 kW; satellite antenna – 0.03 kW, etc. If we add up the power of the listed household appliances, we get an energy consumption of 5.7 kW / h – does this mean that an electric generator with a capacity of at least 7.5 kW (with a 30% power reserve) is required ? Not at all, because this technique does not work all the time, that is, you should also take into account its approximate operating time, for example: washing machine – 3 hours a week; electric kettle – 10 minutes for each boiling water; microwave oven – 10 minutes to heat one portion of food; mixer – 10 minutes; energy-saving lamp – about 5 hours a day, etc. It turns out that to provide electricity to household appliances described as an example, a generator with a capacity of about 3 kW is enough, you just need not turn on the equipment at the same time, distribute the load arising on the generator over time.
The choice of one or another type of electric generator, especially one that operates from renewable energy sources, primarily depends on the availability of the initial fuel resources. For example, a gas generator requires a stable supply of liquefied natural gas, that is, cylinders or a gas tank tank are required, and for efficient energy supply using solar panels, a sufficient number of sunny days a year.
What are the available options for autonomous power supply in a country house? I’m interested in knowing the different methods that can be used to ensure a self-sustaining power source for a rural property. Are there renewable energy solutions like solar or wind power? Or are there other alternatives that can be considered? I would appreciate any insights or recommendations on the subject. Thank you!