The year 2022 in the photovoltaic industry is marked by energy storage. Storing electricity produced from the sun is not only a way to avoid the distributor’s commission, but also a safeguard in case of power cuts. What are the advantages of a photovoltaic system with backup power? What should I consider when choosing home energy storage? How much do photovoltaic energy storage units cost? Which energy storage unit should I choose? Check our guide and ranking of energy storage 2022. The huge popularity of photovoltaics in Poland clearly shows that Poles are looking for ways to protect their household budget. Rising electricity prices are forcing them to look for alternatives. This particularly affects entrepreneurs, who are not covered by the regulations of the Energy Regulatory Office and can expect high increases. According to the Energy Market Agency, at the end of 2021 the total photovoltaic capacity in Poland amounted to 7.6 GW. This is at the same time the largest share in total RES capacity.
In addition to photovoltaic systems in homes and businesses, energy storage facilities are becoming increasingly common. Why is it worth having them? One reason is to be able to store the surplus electricity produced for personal use. In the current net-metering system, unused energy is fed into the grid, where it is used by other households. However, the prosumer can take 80% or 70% (if the installation is larger than 10 kWp) of the energy at a later time. The grid thus acts as a virtual energy store, with a loss of 20% or 30%. In hybrid installations using batteries, these surpluses can be stored first. This avoids the distributor’s commission of several tens of percent.
However, this is only the beginning of the advantages of energy storage. An important issue, especially in the context of possible blackouts and power cuts due to windstorms, is the provision of emergency power. Photovoltaics combined with energy storage works very well in this role. A properly selected storage facility is able to power the entire house for at least a dozen or so hours. It is worth emphasising that photovoltaics alone will not fulfil this task, even during a sunny day.
The rationale for installing energy storage is also influenced by the state of the power grid in Poland. The energy infrastructure is outdated and the pace of its modernisation cannot keep up with the development of the RES sector. With a large number of micro-systems, at times of peak solar power production, local grid overloads can occur, resulting in inverters being disconnected. In order not to lose the possibility to continue the production of electricity during the peak hours, it is worth having storage on hand to receive this energy.
This will become even more important after 31 March 2022, when the new net-billing system comes into force. Surplus energy will not be stored, but resold at the market price. When there is a shortage of electricity, the prosumer will instead have to purchase electricity at the normal rate. Given that the purchase price of electricity will be up to three times higher than the selling price, self-consumption of energy will significantly increase the profitability of photovoltaics.
Energy storage for domestic photovoltaics is matched not only to the size of the photovoltaic system, but also to the energy requirements of the house. A heat pump, electric water heating systems, induction hob, air conditioning or a large number of electronic devices make it necessary to use larger batteries.
The way in which storage facilities are used also affects the type of energy storage chosen. Different types of batteries are used, e.g. iron, lead-acid or lithium-ion batteries such as those used in smartphones or laptops. However, lithium-iron-phosphate (LiFePO4) cells are best suited for use with photovoltaics, and are characterised by high durability, resistance to deep discharge (96%), no memory effect and a high number of cycles without loss of efficiency (even 6-10 thousand cycles).
Good quality home energy storage for photovoltaics must also have the necessary certificates and approvals. These certify the safety of use and the stability of parameters. Some of them include EN50549, NCRFG or 62109. To obtain them, the device must have electric shock and surge protection to guarantee trouble-free operation. How much does electricity storage cost? The cost of 1 kWh capacity is approximately PLN 2-4 thousand. The 10 kWh storage often chosen by private investors is an expense of around 20-40 thousand PLN. The better the components and the more modern the cells, the higher the price of the device. The models most often recommended by experts are those based on lithium-ion or lithium-iron-phosphate batteries, characterised by high efficiency. It is also worth remembering that the cost of investment can be reduced by government subsidies, such as Mój Prąd, Modernisation Fund or Agroenergia.
FoxESS is one of the world’s leading manufacturers of photovoltaic panels and inverters. In addition to classic energy storage units working with a hybrid inverter, FoxESS also offers AIO (All in One) units equipped with a FoxESS AC charger. This means that the storage can be combined with an existing photovoltaic system without replacing the inverter with a new one. Modern FoxESS AIO storage systems are designed to work with every brand of inverter available on the market. The charging and discharging efficiency is 97%, so energy losses are low. The high voltage charge controller allows up to 6 kW of continuous discharge and charge through the panels.
The Elite Series AIO storage units provide scaled power up to 5.8 kWh, while the Ultra Series units provide up to 11.6 kWh. High-voltage batteries from the HV2600 series allow storage to be expanded in a series system up to 20.8 kWh. Thanks to plug & play installation, fitting the modules is simple and cheap.
Energy storage units from German company Alpha ESS have a great reputation, and for a good reason. Founded in 2012, the company is now one of the leading manufacturers of energy storage devices. Every year, Alpha ESS stores up to 1 GWh of energy from renewable sources. The company also supports the energy transition in many countries, which is particularly important in Poland.
In the Alpha ESS range you will find state-of-the-art energy storage based on the best available cells, namely those made with lithium-iron-phosphate technology. LiFePO4 batteries are characterised by high safety in use, mainly due to lower risk of overheating. The manufacturer offers a 5-year warranty for the device and a 10-year guarantee of cell performance. The estimated service life of the energy storage is 20 years. Especially worth recommending is the SMILE series, equipped with an intelligent home energy management system. Alpha ESS photovoltaic batteries
If you are looking for a complete solution, with energy storage and inverter working together perfectly, a system from SolaX may be the best answer. The Chinese manufacturer’s units offer good value for money and provide emergency power in most cases. SolaX offers two types of batteries: the T30 with a capacity of 3 kWh and the T58 with a capacity of 5.8 kWh. The manufacturer quotes a nominal capacity, so before investing it is worth converting it into usable power, which is about 90% of the nominal capacity. A storage unit with a nominal capacity of 5.8 kWh can actually yield approx. 5.22 kWh – the remaining 10% is protection against over-discharge.
The manufacturer’s range includes SolaX Power X1 and X3 inverters, SolaX Slave Pack H 115500 and Solax Master Pack T-Bat H58 energy banks, as well as Solax AC Chargers X1 and X3. The company’s comprehensive service saves not only money, but also space in the utility room. The offer of the Chinese manufacturer is particularly beneficial when investing at once in a complete photovoltaic system with energy storage. In this way, you can save up to 35% of the costs (in relation to the expansion of photovoltaics with an energy bank).
BYD is one of the most recognisable companies in the battery industry. It produces not only home energy stores, but also batteries for smartphones, electric cars or buses. Huge experience and leading position cause that batteries for home energy banks BYD are relatively inexpensive. However, it is worth remembering that the company founded in 1995 produces only batteries, without accessories such as an inverter, AC charger or even a battery inverter. To get complete energy storage with control, you need to combine BYD batteries with compatible hardware. You can find compatible devices in the assortment of the following companies: Victron, GoodWe, Solis, Schneider, Selectronic, SMA and Studer. Given that battery life and safety are key factors, this combination is worth considering. Choosing the best components is no challenge for an experienced installation company.
In fifth place in the ranking was PylonTech energy storage. It is an experienced Shanghai-based company that has been offering energy storage solutions since 2009. However, the biggest breakthrough for the brand came in 2013, when the company committed to developing innovative applications for the global ESS market. On 30 December 2020, PylonTech raised 2 billion CNY on the stock market, as the first company in the energy bank industry. PylonTech’s storages work well with home photovoltaic systems, and their main advantages include ease of installation, excellent compatibility with inverters, and the ability to be installed outdoors.
PylonTech also manufactures storage units aimed at businesses, working with high voltages. The flagship storage series is based on the leading LiFePO4 technology, guaranteeing the longest life. The modular storage system allows for any configuration. It is worth noting that PylonTech is the first energy storage manufacturer to pass the most stringent certification standard in the world – 2Pfg 2511 and VDE-AR-E 2510-50. VDE and TUV Rheinland standards define the parameters for safety, durability, maintenance, energy management, operation and environmental protection, and are therefore the most comprehensive.
When planning to buy energy storage for your home photovoltaic system, bet on proven, safe solutions. With Solmix you will find ready-made photovoltaic kits, prepared by specialists. In addition to PV panels, inverters and energy storage, you will also find vehicle charging stations, mounting structures or safety devices that will allow you to enjoy your own electricity from the sun.