Office energy efficiency: how to reduce real energy consumption?

We talk a lot about energy saving opportunities in the data center due to the thoughtful placement of equipment, optimal air conditioning and centralized power management. Today we will talk about how you can save energy in the office.

Unlike data centers, offices need electricity not only in technology, but also in people. Therefore, getting here PUE coefficient at the level of 1.5–2, as in modern data centers, will not work. People need heating, lighting, air conditioning, they use microwaves, ride on elevators and constantly include a coffee maker. IT equipment itself accounts for only 10–20% of energy consumption, and everything else is taken by the equipment necessary for a person.

This often creates problems, since in many cities of the Russian Federation less energy is produced than consumed. According to SO UES , in 2017 this situation developed in 49 regions of the Russian Federation, despite the commissioning of more than 25 gigawatts of capacity over the past 5 years. Large office centers in Moscow and other megacities often cannot provide a large supply of power for each tenant. Therefore, the optimization of energy consumption remains not only a way to save, but also a competitive advantage, a method of adaptation to modern conditions.

No need to warm (and cool) an empty office

According to statistics, the most expensive is air conditioning. In winter, offices require heating, and in summer, cooling. Therefore, air conditioners and heating appliances account for more than half of all energy costs. However, other equipment and lighting also make a considerable contribution to the monthly cost estimate, which, if desired, can be reduced by tens of percent.

Air conditioners and heaters can work constantly, but it makes no sense if there is nobody in the office, for example at night or on weekends. Using programmable thermostats, you can configure the on and off climatic equipment according to a schedule so that when the personnel arrive at work in the office there is a suitable temperature, but at the same time there are no extra costs at a time when people simply are not at work.

Window control helps save

Large windows, typical of modern offices, are the main causes of energy loss. In winter, heat leaves through them, and in summer - the air is heated, which then has to be cooled. Therefore, if energy efficiency is a priority, something needs to be done with windows. The most effective options include:

• The use of special films and glasses that retain heat (for the northern regions) and do not allow the sun to overheat the air (in the southern regions).
• Installation of roller shutters and shutters with automatic drive. You can program the closing and opening of windows according to the timer, as well as depending on the air temperature in the office and on the street.

You can use energy from IT equipment in winter

PCs and servers installed right in the work area not only create a lot of noise, but also heat the air. The power consumption of a modern computer is about 100-200 W, and if only 20 people work in the office, their equipment creates heat equivalent to an oil cooler of 2 kW.

As desktop virtualization is increasingly used today, you can place all the workloads in the server room, and give users access through energy-efficient thin clients. In addition to increasing the comfort of the office in the summer, such a move allows for additional heating in the winter. To do this, you need to think through a ventilation and recovery system (heat transfer) so that the air leaving the server room heats the office room.

Smart lighting

Lighting costs have become much lower with the advent of LED lamps. Intelligent light control further reduces costs.

Light control module with motion sensor

For example, switches with motion and light sensors allow you to turn on the light only when there are people in the room, and street light from the windows is not enough for comfortable work. Moreover, modern DALI lamps support intelligent dimming. Based on the readings of the sensors, the control system includes luminaires with the power that is necessary to obtain the optimal level of lighting. With this approach, in clear sunny weather, the office will not have the cost of artificial light at all, and towards evening the lamps will begin to shine brighter.

Power conditioning

Power surges and other disturbances are a common occurrence for our power networks. In order to protect sensitive equipment from them, active filters are used. Uninterruptible power supplies (UPS) ensure the operation of critical equipment during a power outage.

Power conditioning unit Delta PCS

An even greater effect can be achieved by installing power conditioning. For example, Delta PCS (Power Conditioning Systems) use batteries to compensate for peaks in power consumption, without creating an additional load on the mains. In addition, they help combat the problem of reactive power. Due to the uneven distribution of the load in the power grid (the elevator is turned on, someone in the office is making coffee, the cleaner is using a vacuum cleaner), part of the power becomes reactive, as a result of which the conductors and equipment are heated. The loss level in this case can be from several units to 50% of the net power. Reactive power increases dramatically with the number of electronic devices used in the building. In this case, PCS class solutions can reduce reactive power and significantly reduce power consumption.

Integrated Power Management

Maximum energy savings can be achieved by using an integrated monitoring and energy management system. For example, Delta enteliWEB solutions allow you to manage the engineering systems of a building or office through a web interface. You can connect to the control system air conditioners, heaters, lamps and lamps, as well as household appliances - generally any devices with standard interfaces. After that, you can control the energy consumption of the entire network, determine the load sources and control the drives and relays to provide maximum comfort and energy saving at the same time. Just such a solution was presented at COMPUTEX 2019. The Green Cinema (link to the last post) independently determines the presence and number of spectators in the hall, and also controls the lighting and curtain drives on the windows, changing the lighting before the show, during the session and after its completion.

Delta enteliWEB control system

When you need more energy

Often, power grids simply cannot provide the company with additional capacity or its cost is very high. Practice shows that to ensure peak load, you can use additional batteries and uninterruptible power supplies. The stored energy will be enough for a short increase in load. For example, the Battery Energy Storage systems shown at COMPUTEX 2019 were designed specifically for such tasks.

New Delta PV Inverters

However, no one cancels the "green" energy that can be obtained from the sun and wind. Modern highly efficient solar panels can serve as a source of several additional kilowatts, and the Delta PV inverter M70A inverter allows you to use the energy received from the sun, while the efficiency level is 98.7%. In addition, the inverter integrates with cloud-based electricity generation monitoring systems.