Securing data centre power

SECURING DATA CENTRE POWER

In Devon, a public swimming pool is being heated by an unusual source ─ a small, local data centre. Data centre use is ubiquitous, with virtually every business using its own, or someone else’s, data storage system. But power outages continue to pose a problem for these services, which, by the nature of their application, need to be available 24/7.

So how can we minimise the risks? Here, David Atkins, projects director at Cressall explains.

Data centres are physical facilities housing an organisation’s IT infrastructure, including its networked computers and data storage. These centres support many aspects of a business’s online applications and activities, whether it’s virtual desktops or enterprise databases. With the accelerating pace of digitalisation, the demand for data services is growing exponentially, with McKinsey and Company forecasting the demand for data centres in the US to grow ten per cent year-on-year until 2030. Similar growth has been forecasted in Europe and the Far and Middle East.

However even with the growth demand, data centres have an increasing problem ─ power outages. According to a 2022 report by the Uptime Institute, 20 per cent of organisations experienced at least one severe outage within the last three years. And more than half of those outages are costing businesses upwards of 100,000 GBP/Euros/USD in losses.

More than 40 per cent of outages that are classed as ‘significant’ in terms of their downtime and financial impact are related to power, with the single biggest cause of power incidents being uninterruptible power supply (UPS) failures. So why are outages such as a big problem with data centres, and what can we do to prevent them?

PREVENTING OUTAGES

Data centres are estimated to be responsible for around one per cent of the world’s total electricity usage. Devices and equipment run constantly to ensure an always-available service, consuming energy and generating a lot of heat, which in turn requires an advanced cooling system.

Combined with other common problems, such as machines reaching their end-of-life and equipment failures, means that the maintaining the infrastructure of a data centre is something that needs to be planned and supported. Making them more reliable doesn’t need to be complicated; with the right design, planning, and maintenance testing programs in place, data centres can maximise their efficiency and minimise potential downtime.

Ensuring sufficient infrastructure is in place right from installation helps to ensure that the facility has everything it needs to support its operations. Trying to squeeze in additional equipment at a later stage, though tempting, is only likely to increase the risk of potential problems caused by systems running at overcapacity or overheating the existing cooling systems in place.

It also doesn’t leave any servers free to reroute services to if another one fails, making contingency planning much more difficult. It’s important when making plans for potential failures that all potential problem areas are considered. For example, hot weather can put additional strain on cooling systems, so it’s recommended to leave some allowance for environmental factors.

Plans should also be made in case of blackouts. Data centres rely on the availability of a constant stream of electricity. In the case that this cannot be provided, there must be a working backup generator that can keep operations afloat.

THE IMPORTANCE OF TESTING

Implementing regular testing programs and inspecting all items of equipment is key in preventing outages and ensuring that all machines are operating correctly. But testing in these environments can be challenging. With many data centres designed to maximise equipment space, there may be limited room for maintenance workers to carry and move large testing equipment.

Furthermore, the testing must be carried out to a level that is representative of its working load. This is particularly relevant when it comes to backup generators, which may be called upon at any moment to provide power.

It may be difficult to find a tester that maintains its portability while being capable of handling the voltages present within data centres, but opting for a more compact solution like Cressall’s EV2 could be the answer.

Frequently implemented in electric vehicles to aid regenerative braking, the EV2 offers a high power-to-weight ratio of 9.3 kW/Kg. Its modular design also means that multiple units can be combined to cope with loads of up to 600 kW per cubicle making it ideal for these environments. The EV2 can also tap into the data centre’s existing liquid cooling system to dissipate the generated test power, meaning no further heat is lost into the air when testing, so putting no further strain on the existing air-cooling systems in place.

With demand for data centres only set to increase, improving their efficiencies and minimising downtime is high on the agenda for operators. And with the right design, planning and testing programs in place, the threat of outages no longer needs to cause alarm.

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The role of HVDC in energy transition

THE ROLE OF HVDC IN ENERGY TRANSITION

power transmission

With the rise of offshore windfarms and international grid links, effectively and efficiently transmitting electricity over long distances is more crucial than ever before.

Simone Bruckner, Managing Director of Cressall, explains the role of high voltage direct current (HVDC) and filter resistors in making long-distance energy transition possible.

The UK has four times more offshore windfarms in operation than in 2012, with the number set to rise significantly as the government looks to reach its goal of generating 50 gigawatts (GW) of offshore wind by 2030.

Along with this rise, international and intercontinental grid links have increased as the UK trades excess power with other countries, much of which is generated by renewable means. Trading the surplus not only saves energy, but also prevents Brits paying to turn off turbines when more energy is generated than the grid can take.

As the UK currently has 13.9GW offshore wind capacity compared to its 50GW goal, it is important that this output is used efficiently and energy loss is kept at a minimum. Although alternating current (AC) is standard in electrical power transmission, the current often concentrates near the conductor’s surface – known as the skin effect – which causes energy loss.

HOW HVDC HELPS

HVDC is a transmission system that uses direct current (DC) for the transfer of power over long distances. As remote offshore windfarms and the grid are often far apart, HVDC enables effective transmission due to its uniform current density throughout the line.

Additionally, HVDC supports the trading of excess power between unsynchronised AC distribution systems, which run at a set frequency and cannot be connected to those with a different frequency. As HVDC does not have a frequency, multiple circuits can be interconnected and converted to both system voltage and frequency levels of the system at point of use.

While HVDC is used for international grid links, it must be converted back to AC at the local grid level. However, converters create harmonic distortion, which in turn can cause lower efficiency, overheating and increased chance of equipment failure.

Therefore, harmonic filter resistors are a vital part of HVDC and SVC converter stations, helping to remove harmonics by dissipating them as heat. This ensures a safe and assured power supply for the UK and countries across the continent.

The UK’s rollout of offshore windfarms currently puts it among world leaders, and with the pipeline of projects close to 100GW, Britain could soon supply many countries with surplus energy. With the ever-increasing need for sustainable energy, HVDC ensures that countries across the world can safely and securely benefit from wind power.

Why are wind turbines being switched off?

WHY ARE WIND TURBINES BEING SWITCHED OFF?

POWER TRANSMISSION IS JUST AS IMPORTANT AS GENERATION

UK windfarms hit an all-time high in wind power last year, generating more than 80 thousand gigawatt hours (GWh) and enough power for over 22 million homes. Yet, reports also came out of wind turbines being switched off due to overcapacity — at the expense of customers.

Despite reaching impressive milestones in recent years, there’s a massive problem with the renewable — and particularly wind sector — power wastage. In 2022, it was reported that Brits paid millions to switch off wind turbines as networks were unable to deal with the levels of power generated.

The UK has set ambitious goals for renewable energy sources for the next few years, aiming for a more sustainable approach while reducing dependency on both fossil fuels and external suppliers. As the past 18 months or so have highlighted, the volatility of global markets means it’s essential that the country is able to secure its own energy supply.

Fortunately, the UK does have the natural resources to do so. With the greatest wind energy potential in Europe, it’s clear why wind power has been a preferred route for planners and developers to take. So why are wind turbines still being switched off, and why is this energy being wasted?

DISTANCE FROM THE GRID

Offshore wind farms are often a significant distance from the Grid. Typically, these farms are connected to the Grid with a specialist, individual cable connection through a converter and into the transmission network, allowing the farm to distribute power.

The issue with this setup is that the offshore system will typically have fewer connections readily available than an equivalent farm on land. Because of this, there are less options available when it comes to distributing power during surges or when there are problems with the on-land network.

DISTANCE FROM DEMAND

Furthermore, many of these wind farm installations are being built in remote areas of Scotland or in the North Sea, where winds are stronger. Though this is certainly positive when it comes to power generation, the issue is that the local area isn’t where the demand is.

More power is needed in the south of the country, far from where the electricity is being generated. And while the transmission networks can transport electricity great distances, without efficient connections and cable routes a lot of power can be lost before it reaches crucial areas.

A FOCUS ON INFRASTRUCTURE

It’s clear from these issues that improving power infrastructure is just as vital as delivering new power generation projects. Reassuringly, there are developments underway to address these issues. One such example is the ‘Eastern Green Link 2’ (EGL2), which involves the manufacture and installation of a high voltage direct current (HVDC) subsea cable from Peterhead in the North of Scotland down to Drax in Yorkshire.

A crucial element of these power transmission systems is the host of resistors within that help to facilitate the safe movement of electricity. Pre-insertion resistors, for example, can absorb and control transient magnetising currents within transformers throughout the network. This control helps keep voltages consistent with minimal dips, reducing potential disturbances for users of the power network. They can also help mitigate against temporary overvoltages, such as those caused by exceptionally strong winds.

Discharge resistors are another vital component, particularly in terms of safety. These can reduce the risk of sudden overvoltages from capacitors and inductors that have become isolated from their networks or in situations where an emergency shutdown is required. In offshore farms that are far from other connections, the inclusion of discharge resistors is essential in having a sufficient ability to remove excess electricity when required.

Implementing resistor technologies as new projects are built helps both to ensure safety from dangerous overvoltages, as well as safeguard electricity on the Grid from fluctuations and dips.

So, as the UK continues to invest heavily in the renewable energy sector, considering how we’ll transport this energy will be just as important as thinking about how we will generate it in the first place. With projects like EGL2 on the horizon, it’s clear that the industry is taking the right steps to secure a reliable network from the turbine all the way to our homes.

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Power Control Chopper

POWER PROVE LAUNCHES POWER CONTROL CHOPPER FOR CRITICAL TESTING

In response to growing demand for more precise power dissipation, load bank manufacturer Power Prove has launched a dedicated IGBT-based electronic power control chopper, for continuous regulation of its load bank product offering. The power control chopper can be easily integrated into load banks to achieve high power dissipation and a degree of precision superior to that offered by any competitor.

Power Prove, the load bank division Cressall Resistors, commissioned the design of the power control chopper to Italian Internet of Things (IoT) solution developer Techmakers. The combination of Power Prove’s in-depth knowledge of load banks and Techmakers’ expertise in electronic and software-controlled devices has resulted in a powerful, yet cost-effective, solution that meets the growing demands of the market.

A power control chopper is an electrically controlled solid state switch that is used to control the amount of current permitted to flow through a circuit. Normally, a high-power variable load requires multiple fixed value load sections ranging in values for power dissipation with contactors and a logic controller. However, by integrating the power control chopper into the system, a near-infinite set of values for power dissipation can be achieved using just a single resistor.

Power Prove’s chopper also has a closed-loop regulation circuit, which is capable of adapting to fluctuations in voltage and cold resistance variation without any input. Multiple units can be combined to reach high-power dissipation, enabling the load bank to withstand even the greatest of power values with high precision.

Anywhere that requires constant power, whether that’s a healthcare facility, manufacturing plant, or IT data centre, simply cannot afford a complete loss of power. These layers of infrastructure are often secured by an uninterruptible power supply (UPS) that provides power for critical operations if supply from the grid fails.

“The challenge for the managers these systems, which are often deployed as sources of back-up power in a black-out situation is how to determine whether the system is operational and will not fail on the relatively infrequent occasions when their use is required at a critical moment. Regular testing of emergency systems using load banks is therefore essential,” explained Andrew Keith, division director of Power Prove.

“Since these systems provide such a critical safety mechanism, a high level of precision is vital,” continued Keith. “The new power control chopper allows us to provide our load bank customers with a customisable load bank that can be easily integrated into an existing system to provide infinite levels of power adjustment at a degree of precision that is simply not available elsewhere on the market.”

An example of the power control chopper’s application is with battery discharge testing. The chopper can be used with a current feedback loop to provide a genuine constant current load on battery systems up to 1000 V DC. Multiple chopper units can be fitted inside the same load bank, or a combination of traditional fixed loads and chopper modules can be used to create a load bank with the current discharge capacity to suit its application.

In addition, the increasing adoption of electrical vehicles powered by batteries and fuel cells is generating a wide range of operating scenarios that need to be simulated. The development of the power electronic control module allows Power Prove to produce load banks that simulate a much more diverse range of operating conditions for research and development (R&D) testing, system commissioning tests and regular planned maintenance load testing.

The power control chopper is available globally from Power Prove, for more information, visit the website.

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