Over the past few decades, power grids across the world have become more unstable. This can be ascribed to three main elements:
- Rise in the number of natural catastrophes which has increased power instability levels and the related risk to business continuity
- Renewable energies have been added to grids, which have made it more complex to maintain stable energy provision; and
- Utility grids have been upgraded with significant infrastructure very few times.
Today, data centers, industrial sites, and commercial businesses rely mostly on their backup electricity generation platforms. They use a combination of generators and uninterruptible power supply (UPS) systems to obtain dependable backup power.
Generators provide long-term electricity backup lasting days. The UPS solutions can manage the situation for a few minutes until the generators become functional to support the vital load.
Data centers need to invest in a generator, and uninterruptible power supply technologies as electricity outages can impact operations. In data centers, any electricity disruption for over 20 milliseconds can make IT systems crash.
A power disruption of just 60 seconds can need a recovery time of even days to re-launch the IT applications and systems that got impacted. This can affect customer satisfaction and brand reputation and cost millions of dollars to organizations.
Factors to be considered for Electricity Backup
The uninterruptible power supply system is fundamental in data centers, and UPS batteries can be a weak link. Ideally, the UPS system needs to be designed to achieve a balance between capital expenses and the provision of uninterruptible power. It would help if you considered the subsequent factors in weighing the trade-off between availability and capital costs:
Delivering UPS electricity to Vital Loads
Modern data centers use uninterruptible power supply systems for their IT equipment. But their cooling systems only have generator power backup. Consequently, if there is a power outage, the cooling solutions will temporarily shut down till the generator power is activated. It could take some time for the cooling solutions to recycle, restart, and begin fsull cooling.
In low-density data centers (with an average of up to 5 kW a rack), the restart delay may not matter. Plenty of cool air space (for example, high bay ceilings) and low rack densities can offer a thermal cushion for a few minutes before the temperatures of IT components reach a stage where the solutions have to shut down due to thermal overload.
Today, most data centers use high-density racks such as blade server racks or hyper-converged racks with 10 to 20 kW each rack range. There is no thermal ride of a couple of minutes in these situations as these computing racks could face thermal overload in just seconds. Therefore, data centers need to back up their HVAC systems with a generator as well as an uninterruptible power supply solution.
Deciding Suitable UPS Battery Runtimes
In theory, you only require uninterruptible power supply battery runtime for about 10 to 20 seconds to manage the vital load until the generators start and support the load. However, the battery runtime could differ depending on the UPS-supported IT applications’ resiliency and the user’s risk tolerance.
Colocation and cloud data centers typically have 5 minutes of UPS battery runtime. The battery runtime is 10 to 15 minutes in the financial sector. Thus, the customer decides the amount of battery runtime. The more the runtime, the higher are the capital and annual maintenance costs.
UPS Battery Technology
For a long time, VRLA was the commonly used uninterruptible power supply battery technology. However, of late, lithium-ion batteries have become popular, and they have many advantages over conventional VRLA batteries. These batteries have a slightly higher CapEx, but they can reduce your total operation cost by a good 30% to 50%.
In addition, lithium-ion batteries can also reduce your risks compared to VRLA batteries. Their lifespan is about two to three times more than VRLA types. This means fewer battery refreshes are needed, which lowers the risk incurred in carrying out battery replacements.
A Word of Advice
Before making any decision about purchasing a UPS system, you must approach a licensed electrical professional to get advice on suitable electrical systems for your business needs. Doing so also ensures that you get recommendations for the best UPS products, guidance on selection, and help with installations.