How not to make a mistake in the capacity of the installation and not overpay?
The editors of “Solara” interviewed Russian companies and shares the results.
Almost without exception, the specialists interviewed say that it is important to decide on the tasks that need to be solved: reduce costs, increase reliability, provide a reserve, for example, for an electric boiler or a server, or make a completely autonomous solution.
Important: first of all, you need to raise all payments for the last months and calculate how much electricity you have consumed, and preferably during daylight hours.
If the calculation of kilowatt-hours is difficult, then to talk with the company you contacted, you need to take with you information about your monthly expenses for electrical energy. This will be quite enough to approximately estimate the capacity of the future solar power plant. Dmitry Loktionov, CEO of Seton, explained this approach: “The most cost-effective and correct situation would be when all the electricity generated from solar panels is consumed in the house.
thereby reducing consumption from the external network.” For a private house with low activity during the day, experts recommend a solar power plant, the power of which is no more than 30% of the calculated one, and for an office or production, the recommended power will be up to 80% of the calculated one. Nikolay Druga, Technical Director of Soya Energeia, agrees with him and additionally proposes to divide all household appliances and appliances in the house into two key groups.
those that are backed up in case of a network failure and those that are not backed up (which automatically turn off in the event of a network failure). In addition, Mr. Druga proposes to foresee the possible appearance of prospective consumers in the house (household appliances, appliances, replacement of lighting in the future). He also suggests refraining from copying the technical parameters of “neighboring” objects and approaching his own individually.
Pavel Size, technical director of Smart Systems 21, commenting on the issue of calculating the capacity of a solar power plant, noted that in the case of a ban on the return of excess solar electricity to the grid, it is important that the output from the array of solar panels at any given time does not exceed the volume of own consumption. The leading manager of Havel Retail, Evgeni Zitcovich, proposes to calculate the capacity of a solar power plant in such a way that the total average daily output is at the level of 50% of the current average consumption. And this is in a scenario that excludes the issuance of excess solar electricity to the grid.
Another important issue that we asked experts to comment on is the advisability of buying batteries and integrating them into the solar system. Dmitry Loktionov gave as an example two cases in which the choice should be made in favor of autonomy: if there are frequent power outages or if the cost of electricity is above 20-25 rubles per kWh. Nikolai Dirge believes that it is necessary to install drives when the degree of network failure is significant or high.
Or the installation of a battery is a fundamental decision of the customer. At the same time, he continues, the capacity of the batteries should be reasonably minimal to solve the tasks in specific conditions. Evgeni Zitcovich shares the same opinion, noting that batteries are selected based on the need to reserve critical consumers (equipment in the house, the operation of which is very important for the household) for the required time (it is desirable to represent the average duration of a power outage).
According to Pavel Size, it is also important to take into account the need to power the load from batteries in the dark. At the same time, in the case of using an autonomous system during normal network operation, for a quick payback, it is important that most of the loads in the house are turned on during daylight hours. At the same time, in the event of a surplus, the functionality of most modern hybrid inverters allows you to programmatically prohibit the transfer of surpluses to the network and send them to charge the battery.
Pavel Size concludes that in most regions of Russia, network systems in the private sector are not widely used, since the main load consumption occurs in the morning and evening hours. Grid inverters, in his opinion, for the most part still remain the lot of the commercial sector and industry, as well as the southern energy-deficient regions of Russia with high tariffs and the widespread use of “garage” house workshops (microbusiness).
By the way, in the case of hybrid systems operating both offline and in parallel with the network, it is of great importance how specialists connect the power plant. To avoid the release of surpluses into the network when the equipment is working in the house, it is important to draw up a detailed list of equipment that needs to be supplied with electricity and orient specialists in the operating modes of this equipment even at the stage of selecting kits.
There are cases when a 1000 W system is installed on the house, there is a battery, while in the summer months a large amount of surplus goes to the network, while some of the equipment in the house continues to take electricity from the central network. If the decision is made in favor of a hybrid power plant, then it is better to order the installation and connection of such a system from companies with experience in working with autonomous and combined power plants.
Pavel Size notes that in order to maximize energy consumption by the household, the problem can be solved in various ways – from the use of a charge / ballast load controller in the simplest case and through the use of WATT Router devices with more advanced functionality. For example, with the help of WATT Router it is possible to almost completely limit the transfer of excess energy generated by the solar power plant to the external network.