What Is a Commercial Power System?

When you look at the wires on a power pole, you may not realize what an incredible system it takes to get that electricity to your house or office.

Load forecasting helps to save costs, improve reliability and inform decisions for expansion and development.

A substation adjusts the high voltage of the transmission grid to a lower level for Commercial Power System distribution. Conductors then transfer the power to a utility meter or panel board in your home, garage or basement.

Power Distribution

In the broadest sense, power distribution refers to the lines and circuits that transmit electric energy from generating centers to many points of use. In its more specialized sense, it refers to the system of transformers that convert voltage from transmission lines into utilization voltages for use in homes and businesses.

One of the most critical components of any commercial power system is the electrical distribution system. This includes the main distribution board in a commercial building and sub-distribution boards in larger buildings. The design and layout of these boards is usually determined by the size and dimensions of a building, the length of the supply cables, and the types and ratings of the loads in each room or area.

Depending on the type of equipment and the loads, commercial building power systems typically utilize either single or three-phase power. Single-phase power uses two hot wires with a 120° phase difference. The power in each wire peaks at the same time during one cycle, and the voltage never drops to zero.

In large commercial buildings, the high voltage switchgear and distribution transformer may be located at the ground floor or basement. This is especially desirable in multi-storage big buildings with large appliances (such as lifts, air conditioning equipment and electric kitchens) requiring substantial power demand at the highest floors. This way, the high voltage can be brought as close as possible to these loads without compromising the safety of the power distribution system.

Power Generation

Power systems are networks that encompass power generation, transmission and use. They are typically centered around a generator and utilize AC power because it travels more efficiently over long distances than DC power. They also feature protective devices that keep circuitry safe from damage during failures. The quintessential protective device is the fuse which melts when current flows through it above a specific threshold, creating an arc across the fuse gap that interrupts the circuit. Fuses however have two significant drawbacks: they require frequent replacement and they cannot be reset once they function.

Power plants produce electricity by using coal, natural gas and other fuels. They usually produce three-phase power to minimize line loss. Once electricity leaves a generator it enters a power plant substation where large transformers convert the generator’s thousands of volts to high voltages for long-distance transmission on the electric grid.

Once electricity is on the grid it travels to commercial buildings through the power distribution system. Most large buildings receive alternating current (AC) because it reduces losses over longer distances. AC electricity can be delivered more effectively than direct current (DC) because it can be transmitted over much higher voltages.

In addition to providing clean power, commercial building generators provide backup power for critical facilities such as hospitals and industrial machinery. This backup power supply is often comprised of an inverter with battery backup. The inverter is designed to transfer from input power to battery power during a power outage, and the battery system is sized based on how much power the facility requires for an extended period of time.

Power Transmission

Most commercial power systems use three-phase AC power, the standard found in buildings, electric rail systems, ocean liners and submarines. Smaller systems may rely on single-phase power. The AC current in a single-phase system travels in one direction on each power wire, but the voltage peaks in different Commercial Power System places during a cycle. This allows the system to handle larger loads and provides for a more stable power stream.

In a residential system, the alternating current moves through a transformer that adjusts the high voltage for distribution to homes and businesses. Wires transfer the electricity from the transformer to a meter. From the meter it goes to a panel board that splits the high voltage into circuits for individual customers. The meter records the consumption of electricity and keeps track of peak demand, power factor and other energy information. Regulator banks along the distribution lines prevent over or undervoltage as the power flows to the consumers.

Loads can be affected by a variety of temporal issues including harmonic distortion, voltage sags, dips and swells, interruptions and voltage surge. These can lead to equipment malfunction, data corruption or a complete loss of power. Older electro-mechanical equipment could tolerate these problems but modern electronic equipment requires a stable power source to function correctly.

Most commercial systems require backup power capability that can support the critical load for a period of time in case the primary power source fails. This requires a power-flow study to determine the real and reactive power requirements of each load center and the system overall. A power-flow study also includes a calculation of the power losses in the system and if redundancy is appropriate.

Power Storage

Power storage is an advanced technology that allows electricity to be stored for use at a later time. It is used to perform tasks like peak shaving, load shifting and renewable energy integration. These are all ways to reduce commercial energy costs and increase energy security.

Energy storage can also improve the reliability of the grid by reducing outages. For instance, it can provide backup power during a blackout, and help ensure that the frequency of the alternating current remains stable. It can also be used to support the delivery of energy from variable sources, such as wind and solar, and from inflexible baseload resources.

Generally, energy storage systems are designed to be front-of-the-meter (FTM) or behind-the-meter (BTM). BTM systems are installed on the user’s premises and provide a way for them to reduce electricity costs by storing energy they produce with their solar panels or from the power grid at night and using it during peak demand times.

FTM energy storage systems are connected directly to the electricity distribution system and can be used to support national or regional demand side response programs, capacity markets with balancing functions or wholesale energy markets that allow businesses to trade energy for income. The flexibility and quick response time of these systems can create valuable revenue streams for commercial users who choose to participate.