Modern man spends quite a lot of his summer time outside the city in the country. When going out into nature, he, like his family members, experience a completely natural desire as an addition to clean air to enjoy all the benefits of civilization, which are largely tied to the electrical network as a source energy.
A large number of summer cottages are located on inconvenient lands, those in places where the state of electrical networks leaves much to be desired. In this situation, the owner in most cases is faced with the problem of choosing an energy source for the electrical network.
There are two main approaches:
- connect to the existing power grid and endure frequent blackouts, poor quality of electricity supplied and rising tariffs:
- create an autonomous network on the site using a gasoline generator as a source.
Next, we will consider the financial pros and cons of the second approach, which is free from the shortcomings of power supply from the external network.
Comparison of electricity costs
The cost of wiring in the house and on the site can be ignored in further reasoning, since it is the same in both options. Under these assumptions, the cost of electricity from the generator is determined by the price of fuel and depreciation costs. Modern generators to generate one kW of electricity consume about 0.5 liters of gasoline.
A variety of gas generators are on sale that can be used as autonomous sources. An example is shown in Figure 1. The retail price of such a unit is approximately 5-6 thousand rubles per kW, and the normal duration of its operation is 10 years. Thus, for a 5-7 kW source, depreciation costs do not exceed approximately 10% of the fuel cost.
The given estimate shows that at the prevailing gasoline prices, the cost of electricity from an autonomous source is 2 - 4 times higher than the cost of electricity from the grid.
These calculations did not take into account the natural increase in electricity tariffs. This factor will change the difference in prices, but not significantly: gasoline, as the main component of the cost of electricity, will also grow in price, and the growth rates are likely to differ little from those for tariffs for power supply.
What else is advisable to introduce into an autonomous power grid
It is known that gasoline consumption is weakly dependent on the power of electrical loads. This feature allows you to significantly reduce the required amount of fuel due to the use of an intermediate storage. Its functions are taken over by the uninterruptible power supply UPS, Figure 2,
- the power of which must be at least commensurate with the power of the generator;
- and which is completed with a rechargeable battery or a block of such batteries with a capacity of about 100 - 120 A * h.
During the day, the gasoline unit operates in the maximum efficiency mode, supplies powerful consumers such as a washing machine and a water heater, and also charges the UPS battery. The charge stored in the battery is consumed at night. The duration of the petrol generator activation is determined by the battery capacity and the power of the “night” loads. It turns off at night, which additionally contributes to the silence in the house.
Adding a solar panel to the system
In some cases, the autonomous system being created can be supplemented with a solar battery, Figure 3. Its main drawback is at least a double increase in capital costs. Pros:
- the possibility of reducing the consumption of gasoline for the generator at least two to three times during the summer months;
- environmental friendliness and noiselessness.
The solar power plant itself assumes the presence of a buffer battery, which makes it possible to refuse to purchase a UPS.
Conclusion
The above considerations show that with the current level of technology and prevailing prices, the cost of electricity generated by an autonomous system will be higher than that obtained from the electricity supply network organizations. At the same time, the cost gap will remain in the foreseeable future.
Nevertheless, with the unsatisfactory quality and reliability of the functioning of the general electrical network, that very often found in practice, it is strongly recommended to consider the possibility of creating an autonomous systems. Its presence will not only create guaranteed comfort in the house, but also protect smart household appliances from failure. equipment with increased requirements for the quality and continuity of the supply voltage.