Types of connection points to external power grids. Classification of voltage classes

класс напряжения

In the description of Ready to build land plots , our specialists always indicate the connection point parameters of the future industrial SPS to external power grids.


The most rational voltage class, from the point of view of minimum losses and capital investments, is determined at the stage of long-term planning of the electrical grid operating modes. In case of the land prepared by EDS-Development for the construction of industrial SPSs, it was selected taking into account the already existing substations in the immediate vicinity with the corresponding voltage class. This allows to carry out the connection without costly reconstructions.


Let’s consider the basic concepts and classification of electrical grids for different voltage classes.

классы напряжения электросетей

According to the voltage level, all voltage classes are conventionally divided into the following groups:

Ultra high voltage class - from 1000 kV.

Extra high voltage class - from 330 kV to 750 kV.

High voltage class - from 110 kV to 220 kV.

Medium voltage class - from 1 kV to 35 kV.

Low voltage class - up to 1 kV.

Voltage class is the voltage value that is used in electrical grids to transmit electrical energy to consumers. Depending on the classification of electrical grids, the voltage class also changes.


The need to introduce such a concept was due to an increase in the efficiency of distribution of electrical energy and a decrease in losses during its transmission. At low voltage, the transmission of electrical power will have large losses due to the high values of the flowing current.


Thus, it is advisable to transmit large powers at high voltage.


Energy companies are upgrading their electrical grids by raising the voltage class. Why? This reduces costs and losses during the transportation of electrical energy directly to the consumer.

Classification of electrical grids for voltage classes depending on the scope of application and purpose:

General service grids - used in household, agricultural and small industrial format.


Technological facilities grids - serve utility facilities and large industrial enterprises.


Self-contained power supply grids - used for mobile or remote facilities, such as ships or spacecraft.

Contact grids - transmit electrical energy to vehicles, for example, trams or locomotives.

классификация электросетей

Classification of electrical grids for voltage classes according to the scale characteristics and dimensions of the grid:

Backbone grids - link consumption centers with separate regions:

Voltage - extra high and high.

High power flow.


Regional grids - powered by backbone grids and focused on serving large consumers - cities or regions.

Voltage – high and medium.

High power flow.


Area grids - receive electrical energy from regional grids, usually do not have their own power sources, are focused on serving small and medium consumers.

Voltage – medium and low.

Light power flow.

Internal grids - distribute electrical energy to small spaces, such as a city. Internal grids can have a redundant (own) power supply.

Voltage – low.

Light power flow.


Electrical wiring - supplies power to individual buildings, workshops or premises.

Voltage – low (domestic).

Low power flow.

Classification of electrical grids for voltage classes by type of current:

Three-phase AC grids - current is transmitted through three wires with an alternating current phase shift in each of them by 120 degrees relative to the others. Each wire in it is considered a phase with a certain voltage, which acts as the 4th conductor.


One-phase AC grids - current is transmitted through two wires due to domestic electrical wiring from a substation or distribution board.

DC grids - for some self-contained power supply grids and a number of special extra-high voltage grids.

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An ambitious project - land for 100 MW SPS. Examples of large projects implementation in Ukraine

инвестиции в крупные проекты сэс

In November 2019, EDS-Development signed a Memorandum of cooperation and partnership with the Mezhivska village council (Dnipropetrovsk oblast). The purpose was the implementation of business projects (construction of industrial solar power stations) on the territory of Mezhivska OTH (amalgamated territorial community), tax deductions from which will be used to improve the socio-economic situation in the region.

One of the projects under the agreement is a land pot with an area of 185 ha, which our company is preparing for the construction of a large industrial solar power station with a capacity of 100 MW.

Large-scale projects are being successfully implemented in Ukraine. In 2019, for example, 200 MW Nikopolskaya SPS and 240 MW Pokrovskaya SPS (the second largest in Europe) were commissioned.

Let's take a closer look at these projects:

Large SPSs in UkraineNikopolskaya SPS 200 MWPokrovskaya SPS 240 MW
Investment amount216 000 000 euros (135 million euros of which were invested by CMEC + 81 million euros from DTEK)193 000 000 euros
InvestorUkrainian Solar Farm-1 (DTEK), Chinese China Machinery Engineering Corporation (CMEC)Solar Farm LLC - 3 (DTEK)
ContractorChinese China Machinery Engineering Corporation (CMEC). Construction period: April 2018 - March 2019 - 11 months.16 Ukrainian enterprises received orders for EUR 48,000,000. Construction period: April 2019 - October 2019 - 7 months.
Generation/tariff/income290,000,000 kWh per year, tariff 15.03 euros per MWh, income - 43,587,000 euros per year. Payback - 5 years.400,000,000 kWh per year, tariff 15.03 euros per MWh, income - 60,120,000 euros per year. Payback - 3 years.
инвестиции в крупные проекты сэс

In addition to the conclusion that large projects are being successfully implemented in Ukraine, we can make some simple calculations for our 100 MW project right now:

  • Investment amount

    82,000,000 euros is the amount of investment required for a 100 MW project.

  • Investors

    Most likely, it is necessary to attract foreign investors, the amount of necessary investments is large.

  •  Contractors

    You can safely involve Ukrainian companies as an EPC contractor (general contractor), or for partial tasks. As we saw on the example of Pokrovskaya SPS, Ukrainian companies out-did their Chinese colleagues:

    240 MW in 7 months and 193,000,000 euros (Ukrainian contractors)


    200 MW in 11 months and 216,000,000 euros (Chinese contractors)

    Nice to see such results!

  • Generation/tariff/income

    Generation on average is 145 000 000 kWh per year for our 100 MW facility;

    The project will participate in the Auction, the projected tariff rates are from 8 to 10 euros per MWh;

    Annual income for 100 MW SPS will amount to 11 600 000 euros per year (with an 8 euros’ tariff);

    Payback is 7 years.

девелопмент земельных участков

Description of the Ready to build land plot, ready for construction of a SPS by EDS-Development

Location - Ukraine, Dnipropetrovsk oblast, Mezhivskyi district, Mezhova urban-type village.

Status - Rent for 49 years. Realization through the sale of corporate rights.

Area – 185 ha

The cost of the plot - 2 500 000 euros without TU (technical conditions).

The cost of TU (technical conditions) - 6 000 000 euros.

Designated purpose - 14.01

Cadastral number - 1222687700:01:002:0466; 1222687700:02:002:0715; 1222687700:02:002:0711

TU (technical conditions) - 100 MW


  • Feasibility study.
  • Draft technical conditions.
  • Detailed territory plan.
  • PV layout.
  • Developed topographic and geodetic survey.
  • Land management project.

Infrastructure - Connection point: overhead line, 110 kV voltage class.

проект сэс 100 МВт

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Land plots for 1 MW SPS - an example of successful project implementation

СЭС на 1 МВт

The land plots base of EDS-Development, ready for construction of SPS, presents 12 facilities for solar power stations with a capacity of 1 MW. Definition into a separate group is connected with the peculiarities of the legislation on the application of different rates of the “green” tariff to industrial power stations of different capacities.

* SPP built from January 1, 2020 with a capacity of up to 1 MW are not required to participate in auctions and can issue a “green” tariff, receiving 0.113 Euro per kWh guaranteed by the state.

Let's consider step-by-step implementation of the project using the example of the realized 1 MW solar power station.

Let's break down the project into stages for understanding (note: the diagram reflects sequential realization, processes can go in parallel) and the timing of their realization:

  1. Preliminary analysis - 10 months.
  2. Development – the process took 11-12 months.
  3. Construction – 5 months.
  4. Legalization of a "green" tariff, start of generation - 2 months.
этапы реализации сэс на 1 МВт

The breakdown into stages allows us to see how much time takes development and preparation for the construction. 

A further step-by-step example of project implementation assumes that the land for the construction has a full package of documents and the Ready to build status.

Thus, we save 9-14 months and quickly start the construction.

Step 1 (1st and 2nd stages have already been completed):

Land plot selection from the EDS-Development database.

To date (May 2020) in the range are plots in the Dnipropetrovsk oblast, options for cooperation in all oblasts of Ukraine are possible.

проект сэс 1 МВт

Step 2:


Construction of solar power station:


The implementation of this stage takes on average 5 months.

Project details for our facility:


  • 3094 JA Solar photovoltaic modules 380 W each;
  • 13 SMA string inverters with a capacity of 75 kW each;
  • packaged transformer substation KTP-1000/10/0.4 kV was built for the transmission of alternating current to the grid;
  • connection to the distribution company grids is made using a 0.4 kV cable line;
  • the facility is equipped with monitoring, video surveillance, burglar alarm and lighting systems.
СЕС на 1 МВт

EDS-Development land plots are sold as a standalone product. You can build in-house or hire contractors who provide such services.

We certainly recommend EDS-Engineering LLC as a contractor.

They are currently offering a lucrative turnkey offer for 1MW projects.


Step 3:


Legalization of a “green” tariff and all necessary paperwork to start generating and selling electricity.

For the SPS, which we have chosen as an example, this stage took 2 months.

The calculation of a 1 MW SPS payback can be seen on the example. Figures may vary depending on the installed photovoltaic panels, number of sunny days per year, etc. тощо.

термін окупності сонячної станції на 1 МВт

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