Modern PV energy storage facilities – can a company be self-sufficient in its energy needs?

So far, the concept of energy self-sufficiency has most often been associated with a pro-environmental philosophy of life – a philosophy which is to reduce negative environmental impacts as far as possible and practical. The result of the ever-growing trend of zero waste was the race for getting energy from renewable sources. Over time, it turned out that the production of energy from RES can be truly cost-effective. For years, we have seen lots of companies in the market that are involved in the installation of solar panels. But will it work for the office building? Is it possible to implement these solutions in industrial facilities and achieve energy independence?

Yes and no. Why?

It is important to remember that the huge increase in demand for solar energy has resulted in the creation of hundreds of companies providing services in this sector. The competition in the RES market is so big that companies are fighting for customers in every possible way. Price has always been the most powerful tool. Paradoxically, it is this factor that has an impact on the low profitability of investments. Cheap panels are always of inferior quality. Solutions for the industry with the necessary technical certificates and approvals obtained under the particular climate zone conditions (weather effects, temperature differences between winter and summer) are more expensive than those for the systems installed on private houses. This is mainly related to the quality and durability of the components used. High-quality panels and systems ensure trouble-free use and come with 25 years of manufacturer’s warranty.

Read also Electrical power engineering in the face of the climate crisis

What is the price of a photovoltaic system?

A 300 kW PV system is about PLN 840 thousand net. With the current energy prices and increased efficiency of industrial panels, the system can provide a return on investment of 30%, so the whole investment will pay off within approx. 3.3 years. But is that enough? Is the installation of PV panels alone a solution that will make us energy-independent?

Unfortunately, not. Under the current regulations, we are not able to become completely energy-independent – we can only minimize power input from the operator. By setting up a PV system, we only resolve the issue of supplying energy to a given facility. First of all, we should ensure that the demand for media is reduced. This should be the starting point for our calculations.

The easiest, and at the same time most effective way is to replace lighting with the LED lamps. The current LEDs offered on the market are highly efficient, long-lived and characterized by low power consumption. The next step should be the implementation of smart lighting control systems and energy-efficient HVAC systems. That is where specialized companies can come with aid by conducting the energy audit of our building, carefully examining the power consumption at each location, and helping to select an energy management system that will significantly contribute to the cost savings. An example of such a system can be the lit parking lot with a loading ramp where, due to the use of infrared sensors, lamps light up only when a truck drives in, and when there is no activity, they enter the standby mode and emit only a soft glow to allow moving freely around the area. Similar systems can be used in shop floors with automated production lines, which only switch on the lighting when the operator appears.

Once the power consumption issue is resolved, it is useful to reduce heat losses to a minimum by sealing the building where necessary, and then reduce heating costs, e.g. by using solar panels or good quality heat radiators. In the latter case, due to high energy consumption, the use of PV panels as a power source is recommended.

The last but most important step that will relieve us in terms of energy is the creation of a photovoltaic plant with an energy storage facility that will operate even in the event of a power failure. Paradoxically, PV systems have systems in place that shut down their operation when the grid is out of power. This is because of the safety and high costs of the necessary equipment such as energy storage facilities and DC/AC inverters. Here too, it is not worth saving. Despite the fact that power supply stations and storage facilities cost even tens of thousands of Polish zloty per piece, this may prove to be a small price compared to the need to stop production, which almost always results in serious losses.

What are photovoltaic energy storage facilities?

Energy storage facilities for photovoltaics are batteries with lithium-iron-phosphate cells having high energy density and low self-discharge values. Energy storage facilities allow for, as the name implies, the storage of electricity produced by a PV system. The system does not allow the energy produced to be sent to the grid – this only takes place when there is a shortage of electricity. Modern PV energy storage facilities also serve as a UPS. Since 1st April 2022, the Net-Billing system has been in place that allows for selling surplus energy to the operator without the possibility of storing energy in the grid – the only way to store electricity will be stationary storage facilities.

What does the price of an energy storage facility for photovoltaics depend on?

What is the price of an energy storage facility? It depends. The key factors influencing the price of these devices are the capacity, size, types of cells used and the types of energy management systems used in the plant.

For a three-phase energy storage facility with a capacity of 40 kWh, continuous power of 22 kW and peak power of up to 44 kW, the cost of PLN 200 thousand net must be assumed. For the sake of comparison, the energy storage facility with similar parameters, but with a capacity of 5 kWh, is about PLN 15 thousand net. As you can see in this example, there is no pre-set price for energy storage facilities. The value of the plant is strictly dependent on the investor’s requirements.

It is worth adding that the government is announcing subsidies to the energy storage facilities under the “My Current 2022” program.

How to connect a PV energy storage facilities?

In order to connect the existing PV system to the energy storage facility, in the first step the aforementioned energy audit should be carried out to understand the energy demand and the efficiency of the system. Then, you should select the appropriate components necessary to connect the energy storage facility to the PV system. These include inverters, cables, charge regulator to protect the energy storage facility from overcharging, and app software for energy management.

Electrical energy storage facilities can be mounted to walls to save space inside the building.

In conclusion, the development of technology now allows achieving partial energy neutrality through the use of a photovoltaic plant with an energy storage facility. As it is just the beginning of the “energy revolution”, the solutions available on the market are not cheap, but reduce the costs of running a business in a measurable way. An investment in RES should be treated as a long-term investment. Of course, the end-to-end solutions are not versatile and will not work for everyone. However, it is worth to conduct an energy audit in your company and consider whether you can implement some of the solutions we offer to generate savings. When building new facilities, we recommend that you consider electrical energy storage facilities, i.e. smart energy management systems and power supply from alternative power supply sources, already in the design phase – so that the investment you make in the very beginning will start paying off for itself from the first day.

Author: Elżbieta Grosiak – Ignasiak