The proposed project is part of a set of projects implemented by the Electricity Authority of Cyprus (EAC) and specifically the Basic Regulatory Activity of Transmission (B.R.D.M.) in order to upgrade Transmission Substations (S/S). Changes in the operation of the Electrical Network: Generally, the Electricity System produces, transmits and distributes electricity to consumers. Traditionally, electricity was produced in conventional power stations, transported en masse from the transmission system and ended up in urban consumption centers, in transmission substations. From there it was distributed to consumers through the Distribution System. This structure resulted in the energy flow being one-way and quite predictable. There was therefore no need, especially at the distribution level, for significant monitoring or for specialised remote measurement, surveillance, control and protection systems. With the development of dispersed energy sources, Renewable Energy Sources (RES), things have changed radically. The unpredictable and intermittent nature of RES, as well as the fact that they are mostly connected scattered in the Distribution Network and create reverse energy flows, has led to uncertainty in the operation of the electrical system and increased needs for monitoring and control. Increased need for green energy penetration in the Transmission and Distribution System: Due to national and European objectives and policies (e.g. European Union target "A climate-neutral EU by 2050" and the National Energy and Climate Plan (NECP) for 2030 implementation) there is an increased need to achieve maximization of green energy penetration in the EAC Transmission and Distribution System. Already, the penetration of RES has increased significantly in recent years and the rate of increase is increasing. This penetration poses significant challenges to the grids since their long-term conventional development and structure cannot support this increased penetration of green energy. Moreover, in many cases, the capacity of the grid is not sufficient when several RES production units are concentrated in an area.Changes in technologies: The electrification of energy continues drastically, due to the development of the technology, there is an increase in the replacement of technologies that use fossil fuels, such as motor vehicles and oil/gas burners with modern technologies such as electric vehicles and heat pumps. These technologies increase the need to increase the capacity of the System so that it can integrate the increasing demand for electricity and at the same time acquire flexibility so that its size and degree of use can be optimized, taking advantage of emerging technologies such as storage, and smart and bidirectional recharging of electric vehicles. Each transmission system includes voltage-reducing transformers to convert 132 kV or 66 kV high-voltage electrical power into an average voltage of 11 kV or 22 kV, which is fed into the distribution network to power the consumer load. In other words, technically transformers mediate between high and medium voltage. The photovoltaic parks are connected to the grid Medium voltage transmission and the flow of RES energy passes to the high voltage grid through the transformers. Therefore, the increase in the capacity of transformers enables to increase the penetration of RES in the EAC network. The upgrades that will be made through the proposed project in relation to the increase of the transformer capacity, are presented through the following table:It is clarified that the capacity in the table refers to the quantity of transformers and the power of each transformer (e.g. 3x40MVA).A/AT/Transmission SystemExisting Capacity (MVA)Future Capacity (MVA)1Strovolos3x31.53x402Orounta2x163x403Akoussos3x162x40It is clarified that the Laniteio Transmission System concerns a Primary Transmission System. Primary S/S are Medium Voltage S/S 22/11KV consisting only of switchgear and are connected directly to the Transmission S/S. The upgrade of the Primary S/S Laniteio concerns the upgrade of obsolete equipment with switches that will operate both at a voltage of 11kV and a voltage of 22kV to serve new loads in the Limassol shopping center by increasing the ability to connect RES to the EAC network.The proposed project is part of the objective of the NRMM for the upgrade of the Transmission S/S and concerns the upgrade of the S/S Strovolos, Orounta, Akoursos and Laniteio. It is clarified that the four substations mentioned above were grouped as one project based on the location and the contracts to be tendered. The grouping of projects is based on the following main criteria:Secure operation of the Transmission System: Projects for upgrading the infrastructure shall be planned and carried out on the condition that the uninterrupted supply of electricity to the consumers concerned is ensured. The timetable set by the TSOK for the implementation of each project.Breakdown by region: Th