How can you determine the right backup power system size for your facility?

You need to understand what power requirements need back up power, does it need UPS back up as well. How long do you want the back up to last, all these answers will help determine the solution, UPS with generator and the required fuel capacity

This can be achieved by assessing the type of load, classifying the load, calculating the load profile of the system, equipment or facility and the length of time a backup UPS is required to power the load.

It’s very crucial that the load type of the power network is understood prior to selecting a backup power supply. A quick load list calculation could help to categorise the resistive, inductive, and capacitive loads of the system. With all this understood the estimated kVA of load could be documented and an emergency power supply that is 120% of the overall load kVA could be selected. In the case where not all of the power system loads are required during a main power failure, a load management system could be introduced to the power network. This load management system would introduce load shedding and as a result, the backup power supply kVA could be reduced as required.

Conduct load assessment based on requirements, select and design suitable energy resources fits facility needs, plan budget, procurement, purchase and develop maintenance plan.

Power backup totally depends on two factors. First set is the location, terrain and the history of the power outage. Second set is the facilities requirements, what all needs to be covered, is it the essential or up to 100% coverage. Depending on the identified requirements you can measure the peak load and conclude what power backup is required.

It appears that several concepts are mixed up. Just to highlight the key distinctions between black start and plant backup units: - A plant's backup or reserve is a power generating unit that is designed to fulfill the connected grid's maximum load demand. During normal operation, it is in reserve/backup mode. But in the event that one or more units were to fail for whatever reason, the backup unit would be able to supply the maximum load demand. There is a second strategy to select the backup unit's ratings such that they equal the largest unit in the plant. - Black start units are used to start the main power plant and supply just the essential loads, such as diesel gensets, UPS, etc

Simply the Backup power is the support which is provided instantaneously/immediately without any appreciable interruption, like UPS(Uninterruptible Power Supply) or generators. Depending upon the site requirements/configuration this back can be partial or full. Black starts are used to recover from a total/partial shutdowns, or could be for turning on and operating the entire facility for the first time like in Oil & Gas field. One very good example of this is hydropower plants where very little power is required to start the system, like opening the gates and excite the generator(s).

It’s important to consider fuel source and available during an outage. Also, consider what the objective is. Do you want to be able to operate indefinitely under any types of failure? The answer to this question will determine the reliability your power type should have.

Backup power duration alongwith the load requirements(total/partial power) are very important aspects, as this will decide the type of back up to be recommended/used for a particular facility/outlet. For partial requirements and limited durations UPS are very good but for more power generators are used.

What is typical to see in an administrative facility is a large UPS sized for a specific loading and a specific ATS-limited duration. The UPS installed only provides emergency power just beyond the time it takes to receive input from the automatic transfer switch (ATS) and Emergency Diesel Generator (EDG). What one should also consider when purchasing very large UPS unit are the batteries, their availability, and obsolescence (which could either depend on the material of construction or supplier). A special battery guaranteed for 10+!years is great, but the fact that it is special will impact maintenance and replacement costs, especially if the supplier(s) no longer exist or vendor no longer manufactures the battery.

Depending on the facility energy demand, the switching between back up and primary/main energy source can be automatic. This drastically reduces/eliminate potential losses due to power outages. The switching time is a function of type of operation/activities being performed in the facility. Another important thing to consider is availability and reliability of back up sources especially in areas where utility hardly fail. In such areas, an availability run schedule should designed to keep the back up source in top notch and ready to operate whenever needs be.