Photovoltaics has settled in Poland for good. More and more Poles are seeing the benefits of investing in this innovative technology. According to preliminary estimates by Solar Power Europe, 4.9 GW of installations will be connected to the grid in 2022 alone. However, generating electricity from free solar energy is not everything. The challenge faced by today's prosumers is to increase self-consumption of acquired energy. Currently, self-consumption is only 20-25%. How to increase it? And why is it so important?
What exactly is meant by self-consumption?
Self-consumption is nothing more than the consumption of electricity for one's own needs without sending it to the grid. In other words, self-consumption of electricity determines how much electricity generated by a given photovoltaic installation was used to cover the current needs of the household.
In principle, a PV installation produces electricity but has no capacity to store it. What is obtained must be used immediately. Surplus energy is directed to the power grid.
Auto consumption in a typical household – how much is it?
Self-consumption from photovoltaics in a typical household oscillates around 20-25%. There are many reasons for low self-consumption. The problem primarily results from the fact that during the time when the PV installation produces the most energy (around noon), the house remains empty - the residents are at work, school, etc. The peaks of energy consumption in the household, on the other hand, occur in the morning hours (6:00-9:00) and afternoon and evening hours (15:00-21:00). As a result, only a small part of the electricity produced is used on an ongoing basis. The rest goes to the grid. The problem of low self-consumption is particularly visible in the summer, when - due to large and intense sunlight - the PV installation is able to produce the most energy.
Read also: Energy storage - the key to energy independence
On the importance of high self-consumption of energy
Low self-consumption of electricity means real losses for the investor. The installation of a PV system is supposed to provide the prosumer with savings on electricity bills. Unfortunately, low current consumption is associated with the need to draw paid energy from the grid.
What's more, low self-consumption in Polish households increases energy transmission to the grid, which can cause voltage problems. What does this mean for the typical prosumer? More frequent grid failures, which deprive the household of power for many hours.
The less is wasted, the more can be gained! Increasing self-consumption allows to limit losses of generated surpluses, increases energy independence and reduces the operating costs of the building. What is more, higher individual self-consumption supports the functioning of the entire power system.
How to increase self-consumption of energy?
In an ideal world, the average household would have 100% self-consumption of energy. Unfortunately, we don't live in an ideal world. Achieving 50% is already a big success. How to do it?
The simplest way is to rationally plan the work of energy-consuming household appliances, i.e. adjust the working hours of devices to the periods of the highest production of electricity by photovoltaic panels. Instead of turning on the washing machine or dishwasher after dark, it is worth doing it at noon. A useful solution in modern household appliances is the option of delayed start-up.
You can increase your self-consumption of electricity by investing in a heat pump for heating the building and heating utility water. In this way, you can save on heating and increase your contribution to protecting the natural environment - the pump, unlike gas furnaces or coal boilers, is an ecological solution.
Photovoltaic electricity can power air conditioning – especially in the summer, when energy production is at its highest. In this way, not only does self-consumption increase, but thermal comfort is also ensured on hot summer days.
Energy storage – the best way to increase self-consumption
Storage is of great importance for increasing self-consumption of energy. Storage can be defined as postponing the consumption of electricity generated by photovoltaic modules by storing it in a special energy bank.
The energy bank is a special photovoltaic battery that charges during periods of the highest energy yield from the panels. Surplus electricity is transferred to the grid even when it is only slightly filled.
How does an energy storage affect auto consumption? According to statistics, adding a 5 kWh bank to a typical 5 kWh home photovoltaic installation increases auto consumption to about 55% in a household with annual consumption of 4,000 kWh. Investing in an energy bank increases energy independence and translates into real savings.
A photovoltaic installation with an energy bank connected to the grid is called a hybrid. Interestingly, thanks to government support programs, investing in such a solution seems more profitable than installing a classic photovoltaic installation. An example is the Mój Prąd program. In the fourth edition, it was possible to receive as much as PLN 16,000 in funding for the energy storage alone. According to initial reports, in the next, fifth edition of the project, the level of subsidies is to remain the same. What does this mean?
Hybrid photovoltaic installation - even greater financial benefits
For a classic 5 kW photovoltaic installation, you have to pay an average of PLN 30,000 gross. A prosumer can count on a PLN 6,000 subsidy under the Mój Prąd program. Additionally, they can get a refund of PLN 2.9-8.8 thousand as a thermal modernization relief. The final cost of classic photovoltaics is PLN 15.4-21.1 thousand.
The sample retail price of a hybrid set consisting of 5 kW photovoltaics, a Miellec LV-5 energy bank and a Deye hybrid inverter is PLN 49,000 gross. The subsidy in the Mój Prąd program increases to PLN 24.4 thousand. A prosumer can count on approximately PLN 14.4 thousand in subsidies for the energy bank, PLN 3 thousand in subsidies for the inverter and PLN 7 thousand in subsidies for the PV installation. The thermal modernization relief amounts to PLN 2.9-8.8 thousand. The final cost for the investor is PLN 15.6-21.5 thousand, which is almost the same as in the case of a classic photovoltaic installation. Autoconsumption increases by 55% compared to regular photovoltaics. The conclusion is simple: investing in a hybrid set pays off more.
Every prosumer should strive for the highest possible self-consumption of electricity generated by a home photovoltaic installation. The best solution is to buy a power bank, which allows you to store the generated electricity with a view to its later use. Although the initial costs of such an undertaking may be terrifying, it is undoubtedly worth it! In this way, you can gain energy security, which is of great importance today, in unstable and uncertain times.
