The most popular type of photovoltaic installation in Poland is the on-grid system. Although this solution significantly increases the production of electricity from renewable sources, it does not solve the problem of low self-consumption of electricity. The remedy for this situation is hybrid installations, which combine the advantages of on-grid and off-grid photovoltaics. What exactly are hybrid installations? And why is it worth investing in them?
What is a hybrid photovoltaic installation?
A hybrid PV installation is a combination of a photovoltaic system with an energy storage. The generation of electricity from sunlight takes place in the same way as in a classic PV installation. The key difference, however, is the use of a bank to store surplus electricity.
Traditionally, in an on-grid installation, excess energy is transferred to the power grid. At the time of increased demand, the prosumer can withdraw energy from the grid. Meanwhile, in a hybrid system, excess energy is stored for later use.
It should be noted, however, that although the term "island system" suggests the ability to function independently of the grid (off-grid), not all hybrid installations are adapted to this. In practice, the presence of an energy bank is important, which allows the storage of excess energy and its use when needed, which is a key feature of hybrid systems.
Choosing a hybrid installation does not mean completely disconnecting from the grid, as in the case of an off-grid system. When the bank is full, the surplus energy is directed to the grid. After using up all the electricity stored in the bank, the prosumer can draw electricity from the energy distributor.
Increasing self-consumption of electricity – an important aspect in times of crisis
Polish energy policy assumes a reduction in the use of conventional energy sources in favor of renewable sources. According to the plan, the level of RES in the entire energy sector is to reach 23% by 2030. The most popular in Poland is photovoltaics, which in 2022 accounted for as much as 53.8% of the total installed capacity of RES. Today, in the era of a deepening energy crisis, rising electricity prices and the unstable situation of power grids, increasing self-consumption of energy is of key importance.
Self-consumption, or the use of produced energy for one's own needs by a home photovoltaic installation, depends on many factors. For example, for a household with an annual energy demand of 4000 kWh, a typical 5 kW PV installation allows self-consumption of around 20%. This means that only 20% of the energy produced is directly used, with the rest going to the power grid.
The use of a hybrid installation, i.e. one that combines PV panels with an energy storage, allows for a significant increase in the self-consumption rate. For a household consuming 4000kWh of energy per year, adding a 5kWh energy bank allows for an increase in self-consumption to about 55%. With a 7.5kWh storage, this rate increases to about 61%, and in the case of a 10kWh bank, self-consumption reaches a level of about 65-66%.
Therefore, appropriate selection of the energy storage capacity allows for optimisation of the consumption of the produced energy, which translates into greater savings and energy efficiency.
The hybrid installation guarantees continuity of power supply
In recent years, we have seen that the weather likes to surprise. Violent storms, strong winds and other severe weather conditions regularly lead to long power outages that significantly impede normal functioning. There are many more reasons for power grid failures that result in power outages.
In the case of a traditional photovoltaic installation with an on-grid inverter, a grid failure usually results in the inverter being switched off. This is due to the specifics of the operation of such an inverter, which synchronizes the current produced by the photovoltaic panels with the grid current. When there is no current in the grid, the inverter is unable to perform this synchronization, which leads to its switching off. This cuts off the power supply to the household. Although one of the consequences of this is to protect the employees of the power grid from potential electric shock from prosumer installations, the key reason is the principle of operation of the on-grid inverter.
While some hybrid photovoltaic systems can safely disconnect the internal PV system in the event of a grid failure, turning it into a home-based, self-sufficient power plant, this is not a feature of all hybrid systems. In fact, about 70% of hybrids available on the market do not operate this way and, like on-grid systems, switch off when there is no electricity in the grid. In the case of these systems, the main role of the hybrid system is to increase self-consumption of energy, not to provide uninterrupted access to electricity during a grid failure.
A hybrid photovoltaic installation ensures energy security in the event of a grid failure. The stored energy can power basic household appliances in the event of a failure. Even a small storage is enough to maintain the continuity of operation of a refrigerator, heating or router, and thus provide energy comfort to household members.
Hybrid installation pays off – examples
The government has been supporting the development of prosumer energy for years. The result is numerous subsidy programs that are intended to make it easier for Poles to achieve various goals related to improving energy efficiency. These include programs such as "Clean Air", which focuses on the thermal modernization of residential buildings, or "Mój Prąd", which is aimed at promoting and financing photovoltaic installations and energy storage.
Funding - how much can you gain?
The most popular is undoubtedly the “Mój Prąd” project. The fourth edition of the program has recently ended, but another one has been announced immediately. Mój Prąd 5.0 started in the second half of April. Subsidies for the purchase of photovoltaics and additional elements remain at the same level. Those who decide on a hybrid system can count on the greatest benefits. The subsidy for the energy bank can amount to up to PLN 16,000.
The cost of a classic 5 kW photovoltaic installation is approximately PLN 30,000 gross. The customer can count on a PLN 6,000 subsidy under the Mój Prąd program (data from 4 editions) and from PLN 2.9 to PLN 8.6 thousand of thermal modernization relief. Ultimately, he will pay PLN 15.4-21.1 thousand.
For a 5 kWh hybrid installation equipped with a Miellec LV-5 energy bank and an inverter, Deye will pay around PLN 49,000 gross. Under Mój Prąd, it will receive up to PLN 24,400 in subsidies, including:
- PLN 14.4 thousand in subsidies to the energy bank,
- PLN 3,000 subsidy for the inverter,
- PLN 7,000 subsidy for PV installation.
The thermal modernization relief will amount to PLN 2.9-8.8 thousand. The final cost for the customer is PLN 15.6-21.5 thousand, which is almost the same as in the case of classic photovoltaics without a power bank and hybrid inverter. Self-consumption of energy will increase to approx. 55%. Additional benefits include grid stability and energy security. There is no doubt that choosing a hybrid installation pays off much more.
The advantages of the hybrid installation kit also include benefits for installers. The retail price of a classic 5 kW installation is approximately PLN 28,000 net. The cost of such an installation is approximately PLN 22,000. The installer earns approximately PLN 6,000 on this.
Adding a power bank and hybrid inverter to the installation increases the costs of the entire set to about PLN 45,000 and the costs of implementation to PLN 37,000. At the same time, it is associated with a profit for the installer of PLN 8,000. If the installer decides to increase the price of the set to PLN 49,000 net, he will earn about PLN 12,000, which is twice as much as in the case of a classic PV installation. The conclusion is obvious.
Is it worth investing in hybrid energy storage?
In our opinion, absolutely! These types of installations provide a number of benefits that make them an attractive solution for both households and businesses. First of all, hybrid energy storage allows for increased self-consumption of energy, which translates into greater savings on electricity bills. They also provide energy security, guaranteeing access to electricity even during a grid failure.
What's more, the use of such a system is supported by numerous subsidy programs, which reduces the cost of the investment. Additionally, hybrid installations are beneficial to the environment, which is of great importance in the era of growing ecological awareness. Therefore, investing in hybrid energy storage is a cost-effective and sustainable solution that allows for the full use of the potential of solar energy.
