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Sofia plans to provide free of charge small solar systems up to 4 kW to be installed on the roofs of single-family residential buildings. However, only a small group of households will be able to benefit from this - only those who have replaced their wood and coal stoves with air conditioners (air-to-air heat pumps) under previous municipal programmes, Capital reports.
For this purpose, a tender has been launched seeking a contractor to supply a total of 220 photovoltaic systems. The budget is BGN 4.3 million excluding VAT, or about BGN 20,000 for one 4 kW system with batteries. At first glance, the price seems market, but if you compare single projects, as is already offered by a number of companies. In this case, however, we are talking about a large-scale scheme with 220 individual solar systems, which should bring the price down.
The call will be launched once a contractor has been selected under the procedure. The deadline for submitting bids is short - until 23 November, according to the website of the Agency for Electronic Public Procurement.
It is planned that only single-family buildings will be eligible to apply, which means that the measure will benefit those living in houses that predominate in districts such as Dragalevtsi, Boyana, Simenovo, and Krustova Vada, as well as in towns and villages within the municipality, such as Bankya, Novi Iskar, Bistritsa, etc. There is a certain logic in this, since, on the one hand, the power limit of up to 4 kW is just enough for a household, and on the other hand, in the case of cooperatives, the management of such sites becomes much more complicated.
The Municipal Council decision authorizing the procurement of the new solar systems shows that the other conditions for the applicants are:
The order shall include the supply, installation of 4 kW systems on the roofs, with supplementary energy from the grid, and batteries and devices to prevent the return of electricity to the grid. This makes 6 to 8 panels per household - and such decentralisation reduces the chance of large power surpluses. The funding is under the new European Environment Programme (2021-2027), and the tender with the conditions thus set is actually being launched at the end of the term of Mayor Yordanka Fandakova administration (27 October), but will be completed by the next mayor. Projected, a contractor could be selected in the spring of 2024 if there are no appeals. In this scenario, the call for applications could be released in the summer at the latest.
The municipality is looking for a contractor to design the installation of the PV system, deliver it, instruct the recipients and then take care of the warranty service. The system insurance and annual technical inspections are also included. The estimated total quantity for the supply, installation and commissioning of PV systems for self-consumption is 220 units, but more projects will be possible if bidders offer lower prices.
There are two requirements for applicants: to have a total turnover of at least 25% of the estimated value (BGN 4.3 million) for the last three financial years, and to have completed at least one delivery with a similar subject for the same period.
There are already completed studies on the solar potential in Sofia that confirm the efficiency of energy production from solar and photovoltaic installations. The municipality falls within an area where 1,100-1,200 kWh of annual electricity production is achievable with photovoltaic technologies from 1 KW nominal installed capacity, says a study by the Photovoltaic Geographic Information System (PVGIS). In comparison, the global sum of solar radiation on a unit surface positioned at an optimum angle is between 1500 - 1600 kWh per year.
Dust is also a problem in Sofia in particular, reducing the efficiency of the panels, in some cases by up to 30%.
Source: Capital
