Top 7 energy-saving technologies in Russian retail

More than 50% of the store's costs are the costs of operation of refrigeration equipment. It is not surprising that technical solutions that reduce these costs are becoming increasingly relevant today - in conditions of serious market competition. Sergey Pleshanov, Technical director of Land, spoke in detail about the most effective energy saving technologies in the store, about what savings they allow to get, and how soon they pay off.

Recently, all major federal networks have introduced the TCO indicator (Total Cost of Ownership) into the procedure for choosing a supplier of refrigeration equipment. Thus, energy consumption and cold consumption become a key factor when choosing an equipment supplier. As part of this procedure, not only the price is compared, but also the energy consumption for the period of operation. This allows to adequately compare the capital costs of the buyer's company and clarify the forecast for the operating budget.

The modern level of automation development provides ample opportunities for energy saving. The figure below shows the main technologies that will give the maximum effect in reducing the energy consumption of the store, while they have a low payback period and can be recommended for widespread use in the technical specification of the customer's company. We will tell you in order how much the use of these technologies allows you to save and for how long the funds invested in them will pay off.

Структура затрат современного магазина
Cost structure of a modern store

Энергосберегающие технологии современного магазина
Energy-saving technology of a modern shop 

1. Energy-saving facade glazing

Installation of facade glazing on shelving showcases (slides) is currently the simplest and most effective way to reduce cold consumption and, in turn, energy consumption of equipment.

Two types of glazing installed on refrigeration equipment have found application in Russian retail:
hot-tempered glass with K-coating;
one- or two-chamber double-glazed windows.
The principle of operation is simple: with the standard design of a shelving showcase, about 80% of the load is created by warm air entering the showcase from the trading floor. In fact, refrigerated display cases are starting to work on the air conditioning of the trading floor. The installation of glazing allows you to reduce, and in some cases exclude the flow of air into the working volume of the showcase. The main advantage of glazing is the possibility of its installation in standard equipment, that is, not only at the stage of implementation of the object, but also during operation. When installing such glazing in commercial equipment, a significant effect of reducing the cost of electricity consumed is guaranteed.

The solution with the use of tempered glass is an easier way to reduce the cold consumption of equipment. A frame is installed in a standard showcase, in the perimeter of which glass is placed. The glasses themselves are not equipped with load-bearing structures and have a relatively light weight, due to which the glazing is almost imperceptible. Such a solution allows you to reduce the cold consumption of the showcase by 30-40%. The use of this technology does not exclude the ingress of air into the showcase, since the structure does not have a tight fit to the frame, and also the tempered glass is not an effective heat insulator.

Проект выполнен архитектурным отделом компании «Лэнд»
The project was carried out by the architectural department of the Land company

The double-glazed window solution was used mainly for low-temperature equipment and has recently found application on medium-temperature. Manufacturers of such glazing were forced to find a balance between the excessive weight of the product and the lightness of the design for the visual component. The design with a double-glazed window is similar to glazing made of tempered glass with the only difference that the double-glazed window insulates the working volume of the showcase as much as possible from the arrival of warm air flows from the outside of the retail space, since the double-glazed window fits snugly to the frame without gaps and is also an effective heat insulator itself.

The use of double-glazed windows for closing shelving showcases allows you to reduce cold consumption from 50 to 80%, which means that you can significantly reduce the power of the refrigeration unit, the condenser and the volume of mounting materials. That is why this technology can be called the most effective at the moment.

On an average supermarket format with 30 slides of 3.75 m, the installation of double-glazed windows leads to significant savings of 3,340,480 rubles, or 77% of the store's energy consumption, for 1 year of operation.

Таблица 1. Эксплуатационные затраты при установке стеклопакетов, энергопотребление постоянная величина
Таблица 1. Эксплуатационные затраты при установке стеклопакетов, энергопотребление постоянная величина

Let's estimate the impact of the cooling and energy consumption of the slide (heating elements, lighting, fans) on the total effect of saving operating costs.
Таблица 2. Влияние холодопотребления горки на эксплуатационные затраты
Table 2. The impact of the cold consumption of the slide on operating costs

As we can see from Table 2, the influence of energy consumption on the operating costs of refrigeration furniture is insignificant, the main influence, more than 94%, is the cold consumption of equipment. The payback period for the use of closures, based on a standard supermarket of 1000 sq. m, is:
  • tempered glass with K-coating - 0.5-1 year;
  • one- or two-chamber double-glazed window - comes instantly due to the reduction of CAPEX and ОРЕХ.
If we consider retrofitting slides with double-glazed windows in existing stores, the payback increases and ranges from 3 to 5 years, since the main equipment does not change.

2. Floating condensation pressure function

The floating condensation pressure function allows the electronic control system to automatically adjust the operating parameters of the system depending on the ambient temperature: the lower the ambient temperature, the less load on the compressors and the lower the energy consumption of the system.

Setting the floating condensation pressure function allows you to save up to 20% of the energy consumption of the refrigeration system. In ruble equivalent per 1000 sq. m . m the use of floating condensation for Moscow gives savings per year – 400 thousand rubles.

In fact, the payback of such a solution comes within one day, since to implement the basic function, it is necessary to install an outdoor air sensor and turn on the function in the controller.

3. Floating boiling pressure function (using the example of algorithms implemented in the control systems of refrigeration equipment manufactured by Danfoss)

The floating boiling pressure function is based on machine analysis of the condition of each display case or refrigerating chamber connected to a central refrigerating machine. Such an analysis is carried out automatically by a centralized management system. Based on the data obtained on the temperature inside the cooled volumes, the system changes the installation for compressors, increasing the boiling pressure if the air temperature in the showcases and chambers is at the required level. It is known that the operation of compressors with higher pressure is much more efficient in terms of electrical energy consumption.

The use of floating boiling pressure for Moscow gives savings per year – 100 thousand rubles. for a standard supermarket with an area of 1000 sq. m.

To implement the floating boiling pressure function, it is necessary to use a centralized control device (System Manager) from Danfoss. Many modern stores are equipped with a centralized management system, so we can talk about the lack of investments. If we consider the system as additional equipment, the payback period will not exceed 2 years.

Проект выполнен архитектурным отделом компании «Лэнд»
The project was carried out by the architectural department of the Land company

4. Smooth control of the performance of the lead compressor

The essence of this technology is the ability to adjust the performance of compressors as accurately as possible relative to the needs of consumers. During the operation of the central refrigeration unit, the load on the compressors is constantly changing, because there are a lot of consumers in the store, each working on their own volume. It is not possible to select compressors so that there is no excess power at a minimum load (for example, the operation of 5 showcases out of 60), since the number of compressors on the frame of the unit is usually limited to 4-5 pcs. A standard supermarket at the same time has about 60 different refrigerated volumes. Thus, at low load, stable operation of the compressors cannot be ensured, starting the compressor leads to its shutdown after a short time and re-switching on at full load. Such a mode of operation leads to excessive consumption of electrical energy.

The use of smooth control with the use of a frequency converter allows you to adjust the operation of compressors relative to load changes. With a minimum load, one compressor can operate at 50% of capacity, and, for example, with an average, one compressor can operate at 100%, and a leader compressor at 75%.

In addition, the use of a frequency converter allows you to boost the compressor motor over 50 Hz, which, in turn, increases the compressor performance at the same installed capacities.

At the moment, this technology allows you to save energy and ensure the desired performance of the refrigeration unit.

The payback period of the solution with frequency control of compressors is no more than 3 years.

5. Electronic temperature control valve (TСV)

The use of ETСV allows you to maintain the exact value of the overheating of the gas in the evaporator under any variable conditions. In comparison, for example, with a mechanical temperature control valve (TСV), the electronic ensures constant efficient operation of the evaporator by accurately filling it with a refrigerating agent, forcing the entire heat exchange area to work fully.

There are two types of ETСV:
  • pulse,
  • stepper.

The stepper ETСV is similar in principle to the mechanical one, that is, the diameter of the passage hole for supplying the refrigerating agent varies depending on the need, only a stepper motor is used to change the diameter.

The pulse ETСV is a simpler design. In this ETCV there is a throttle opening that closes and opens during operation. The supply of the refrigerating agent is regulated by the duration of the cycle. For example, "3 seconds closed, 3 seconds open" is regarded as 50% performance.

The use of ETCV at a standard facility will provide about 10-12% reduction in electricity consumption compared to mechanical, provided that the Danfoss controller is used with special ETCV control algorithms that allow optimal filling of the evaporator over the entire load range and in combination with the floating boiling pressure function discussed above.

The payback of the ETCV solution in comparison with the mechanical TСV, taking into account the possibility of switching off the lighting by the controller at night, does not exceed 3 years.
Проект выполнен архитектурным отделом компании «Лэнд»
The project was carried out by the architectural department of the Land company

6. Adaptive defrosting

A special electronic algorithm developed by Danfoss, called "Adaptive Defrost", allows the electronic control system to monitor the decrease in performance of each evaporator and make a decision on the need to turn on the defrosting mode.

The practical tests of the algorithm carried out by Land showed the following results:
ST trade furniture - a decrease of 31%. The average number of thawing cycles per day is 2.8 instead of 4.
NT trade furniture - a decrease of 46%. The average number of thawing cycles per day is 2.1 instead of 4. To implement this function, a pulse ETСV and a monitoring system are required.

On average, enabling this feature provides about 1% reduction in system power consumption and pays off instantly.

7. EC (electronically commutable) fans.

The production of cold is based on the heat exchange of air with a refrigerating agent, while at the standard facility there are a large number of fans that operate non-stop. Currently, energy-saving fans are widely used in refrigeration furniture. Installing fans with EC technology allows you to reduce energy consumption by more than three times. An effective solution can also be called the replacement of energy-intensive condenser fans with energy-efficient fans, because it is in this heat exchanger that the heat taken from the cooled product is utilized.

The payback period of EC fans on refrigeration furniture does not exceed 3 years.

Summing up, it should be noted that the use of energy-saving technologies (excluding closures) together allows to reduce the energy consumption of equipment in the order of 39%.

For the supermarket format with an area of 1000 sq. m. this allows you to save about 135 thousand kWh per year of electricity, or 871 thousand rubles for the conditions of Moscow, which allows you to direct the saved funds to the opening of new stores. It is important to note that in terms of setting up energy-saving functions, control is required at all stages: from installation and commissioning to acceptance for service and monitoring of operability during operation. At Land, we understand this well: the control is prescribed in the installation, service regulations and source documents from the facility, as well as the control is carried out remotely by the monitoring service on an ongoing basis.