Photovoltaic has been very popular lately. Who only has the conditions and the money, installs panels to have his own cheap electricity. There are many programs in place to financially support these private investments. So, is photovoltaics a panacea to the energy crisis and climate change? Turns out not necessarily.
To make photovoltaics an alternative and widely available source of energy, gigantic expenditures are necessary – for example on the modernization of energy networks, and this – at least for now – is not planned. It was pointed out by councilor Bronisław Szafarczyk in his question to the city mayor, although the appropriate addressee of such comments should not be the local government of Bielsko, which cannot do much about it – in fact , only limit (at least for a while) subsidies to city residents allocated for the purchase and installation of photovoltaic panels in the premises of Bielsko-Biała. Yet, it doesn’t look like it, and the actions of the city authorities are going in the opposite direction – towards more and more signs!
– I was approached by residents of Hałcnów, reporting the problem of operation and efficiency of their renewable energy installations. According to the information provided to me, these devices do not work with adequate power and the problem occurs mainly in the event of good sunlight – explains Councilor Szafarczyk and underlines that neither the producer of the panels nor the energy engineers feel responsible for the situation.
What’s the problem ? Let’s try to explain in a simple and accessible way (may the experts forgive us these simplifications, especially those who pointed out the problem to us). The process of generating electricity in private buildings is based on a simple principle: panels generate electricity from solar energy, which is used for household needs, and its surplus is discharged into the electricity grid. . The producer, i.e. the prosumer, buys (obtains) electricity from the electrical grid at a time when his panels are not “producing” – he is an element (a very small cog) of the national energy system at large. It should be mentioned here that the electricity produced by it, the surplus of which goes to the grid, is not transferred to distant recipients, but supplied (sold) by the energy sector to buildings supplied by the same transformer substation to which the prosumer is connected. Thus the proverbial Kowalski, who installed photovoltaic panels on the roof of his house, can only supply the buildings of his neighbors with the surplus energy he produces.
When there are not too many such facilities in a given area (connected to the power grid) – no problem. It is worse when there are many photovoltaic panels in the area and there is no surplus to collect (because everyone has enough electricity). This is most likely the case in Hałcnów. The worst situation is on sunny days in the morning, when the panels are working at full power and household energy demand is negligible at that time. The huge surplus of electricity transferred to the power grid from domestic photovoltaic installations can lead to an increase in voltage in the transmission network, which does not serve it and even poses a serious threat to transformers. As a result, the protection against grid overloads cuts the capture of electricity from the photovoltaic panels, which leads to their shutdown. Such frequent extinguishings are not good for the panels, and their installation in an area “saturated” with such installations jeopardizes the whole project.
How do I get out? There are two solutions, both very expensive. The first is a complete modernization of the entire transmission network, including the replacement of transformers, so that it can cope with the described overvoltages and overloads. However, this is a monstrous undertaking, and nationwide, so don’t expect it to happen anytime soon. The second possibility is the construction of so-called energy reservoirs (kind of batteries), in which excess electricity can be accumulated and stored until it is needed. They must be installed by both energy companies and owners of buildings using photovoltaic panels. The problem is that such installations “storing” electricity in private homes are still rare.
Experts say that in areas with high panel saturation (and there are more and more such areas), it makes no sense to install more panels without installing home energy storage. . The problem is that these are very expensive devices, and their purchase (unlike slabs) is not subsidized – at least for now. Meanwhile, more and more photovoltaic panels on the roofs…