The introduction of the net-billing system was supposed to reduce electricity bills in prosumer households. The mechanism is simple: the higher the electricity prices, the greater the savings generated by the PV installation. However, recent months have brought drops in the prices at which prosumers sell energy to the grid. A record low rate was recorded in May this year. What does this mean for producers of electricity from home installations? Is net-billing still a profitable solution? And what is the significance of energy storage in all this?
How does net billing work?
Net-billing is a cash settlement system for energy produced by PV installations and fed into the grid by prosumers. In practice, this means that any surplus electricity generated by a home photovoltaic installation and fed into the grid is converted into a monetary value in złoty. A specific value is transferred to the prosumer's virtual account. This is the so-called prosumer deposit. The prosumer can use these funds to pay for electricity drawn from the grid at a time of increased household demand for electricity.
The rates are determined based on average prices from the Day Ahead Market (RDN) operating within the Polish Power Exchange. Surplus energy is settled at the average price from the previous calendar month. This is the so-called monthly market price of energy (RCEm), which is published monthly by Polskie Sieci Elektroenergetyczne (PSE).
The higher the market price of energy, the higher the value of energy fed into the grid and thus the larger the prosumer deposit. Conclusion? High prices are beneficial for prosumers who settle in the net-billing system. Recently, however, there has been a record low rate for energy. Does this mean losses for prosumers?
Record low energy sales prices – what does this mean for prosumers?
On June 11, Polskie Sieci Elektroenergetyczne published RCEm for May. RCEm amounted to PLN 381.44 per MWh, which is the lowest value since the introduction of net-billing. Interestingly, the amount for May is even lower than the prices for March (PLN 509.72 per MWh) and April (PLN 506.6 per MWh; after correction PLN 505.44), which were the lowest rates so far. Therefore, a downward trend is visible.
Net-billing has stirred up a lot of emotions from the very beginning. According to the May rate, for every kilowatt-hour of energy fed into the network, the prosumer will receive 38 groszy. The low rate is the result of high electricity production caused by favorable weather conditions. An interesting situation occurred on June 11, when negative electricity prices were recorded on the Polish market for the first time in history. This situation will undoubtedly translate into a low energy price for prosumers in June. However, we have to wait until July for the final amount.
Does this mean that photovoltaics are no longer profitable? It doesn't have to be. A typical household pays PLN 785-1000/MWh for electricity. In the case of RCEm, prosumers are PLN 400-600 in the black in May. However, the solution is to strive to increase self-consumption of energy by storing it.
The solution is energy storage
Today, in uncertain and unstable times, households should strive for the highest possible self-consumption of generated electricity. Self-consumption refers to the use of energy produced by a home PV installation for one's own needs.
A typical 5 kWh PV installation uses about 20% of the energy produced. The rest is fed into the grid and billed according to accepted principles, e.g. net-billing. Increasing self-consumption increases energy independence. In addition, it significantly shortens the payback period for photovoltaic investments. But how to use more energy?
The solution is storage. An energy bank, or storage, is a special device that allows you to store the surplus energy produced. The device charges at the moment of the greatest energy yield from the panels. Installing a 5 kWh bank increases self-consumption by up to 55% (in the case of a 5 kW installation).
Surplus energy stored in the warehouse can be used at a time of reduced electricity production or increased demand. By investing in an energy bank, the prosumer becomes independent from market prices of electricity. What's more, the increase in self-consumption in households is beneficial for the entire energy sector. Energy storage is of great importance for improving energy security in Poland!
