ENABLING GREAT BRITISH ENERGY

ENABLING GREAT BRITISH ENERGY

A ZERO-CARBON GRID REQUIRES SPECIFIC TECHNOLOGIES TO ENSURE RELIABILITY

As part of Labour’s plan to boost the UK’s renewable energy production, ‘Great British Energy’ will see the production of a greater number of floating offshore wind farms and tidal power projects. However, for these technologies to be a success, it’s essential to have the right enabling mechanisms in place. Here, Mike Torbitt, Cressall’s managing director, explains the role of resistor technology in making GB Energy a success.

While the exact details about what GB Energy will involve are still uncertain, we can paint a pretty good picture of it from the current information at hand. Starmer’s government intends to invest £8.3 billion of funding into a new, publicly owned green power company as part of wider energy security and sustainability goals.

DELVING INTO GB ENERGY

GB Energy will work with the private sector to provide investment into emerging energy technologies like green hydrogen, floating offshore windfarms and tidal power. It will also scale investment into existing renewable technologies like onshore wind and solar power.

By boosting the UK’s renewable energy power, GB Energy is projected to create 650,000 new jobs across the UK, lower energy bills, increase energy security and create a zero-carbon energy system to the UK by 2030. Labour has pledged to establish GB Energy within its first few months of parliament by passing a new Energy Independence Act, meaning we could see GB Energy materialise by the end of the year.

While the benefits of transitioning to a 100 per cent zero-carbon energy system are abundantly clear, there are certain logistical and technological considerations to make to eliminate fossil fuels from the energy system completely.

THE CHALLENGES OF RENEWABLES

Whether it’s energy from the Sun, sea or wind, renewables have one thing in common — their input energy is extremely variable. For tidal and wind projects, the turbines work in a very similar way, so manufacturers must ensure they can safely manage what can often be high and unpredictable surges of power.

There may be times where winds or waves are so strong that high inrush currents occur. These can result in overvoltages in the system, leading to component damage, or even failure in extreme cases. When renewables like these make up the entire energy system, preventing component failure from scenarios that we know will occur at some point is essential to continuity of supply.

As renewable resources grow in sophistication, it is vital that other systems also keep pace in order to effectively manage the power they create.

GETTING IN CONTROL

Overvoltage issues can be remedied by using resistor technologies, which all work by limiting or regulating the flow of electronic current in a circuit. Depending on the specific renewable application, there are different solutions to prevent overvoltages.

For tidal turbines, a dynamic braking resistor (DBR) can be integrated into the generation and control circuit to protect against any excess power generated by strong currents. Cressall’s EV2 advanced, water-cooled resistor is designed for these applications. The range is modular, so multiple resistors can be combined to handle power outputs up to one Megawatt. The EV2 also boasts an IP56 ingress protection rating, making it able to withstand harsh marine environments and suitable for tidal turbine applications.

In wind turbines, overvoltages are avoided by using a pre-insertion resistor (PIR). Insulated for the full system voltage, PIRs like Cressall’s mitigate against temporary overvoltages, such as those caused by exceptionally strong winds. They also 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.

While the specifics of GB Energy are still yet to be announced, a fully renewable energy grid is certainly on the cards in the coming years. The industry will need to consider the importance of having the right technology in place to deal with the challenges that renewables bring, and make green energy a viable system nationwide.

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Supporting renewable energy transmission

SUPPORTING RENEWABLE ENERGY TRANSMISSION

CRESSALL SECURES HVDC PROJECT CONTRACTS WORTH £10 MILLION

Cressall has been awarded contracts to supply resistors for five major high-voltage direct current (HVDC) projects in the North Sea. The HVDC systems will be built by GE Vernova with consortium partners Sembcorp (Seatrium) for Netherlands and McDermott for Germany. The projects will support transmission system operator TenneT’s aim to connect 28 Gigawatts (GW) of offshore wind power in the German and Dutch North Sea as part of the 2GW Program.

Cressall is to supply resistors for Ijmuiden Ver Beta and Gamma, Balwin 4, Lanwin 1 and Nederwiek 2, at a value of £2 million per project. The HVDC system will support 2GW of energy transmission with commissioning expected to be completed by the end of 2031.

HVDC supports the efficient transfer of power over long distances between offshore wind farms and the grid, due to its uniform current density. Resistor technology plays a key role in this HVDC system, providing protection against grid failure by absorbing the windfarm energy until transfer is safely switched off. In addition, protection is provided to the system using DC neutral earthing resistors both on and offshore on the HVDC convertor transformers.

“Cressall has extensive experience in providing resistors for power generation projects. Given the UK and the EU both aim to have net zero emissions by 2050, we are particularly excited to support the green energy transition by collaborating with GE Vernova and their consortium partners on these projects.” explained Mike Torbitt, managing director of Cressall.

Resistor technology can support a wide range of renewable applications, including solar and wind farms, biomass plants and tidal power. Cressall is an expert in resistor design and manufacture for renewable energy testing, generation and control.

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WATER VERSUS CONVECTION COOLING — WHAT’S THE DIFFERENCE?

WATER VERSUS CONVECTION COOLING — WHAT’S THE DIFFERENCE?

Cressall dynamic braking resistor

CHOOSING THE RIGHT COOLING SYSTEM FOR YOUR APPLICATION

For applications relying on an electrical drive system, such as those in the marine and automotive sectors, overheating poses serious risks to equipment performance. Employing an appropriate cooling system helps to safeguard equipment, but knowing what to look for can be tricky. Here, Mike Torbitt, managing director at resistor manufacturer Cressall, explains the differences between water and convection cooling and how to determine the best-suited system.

When engines operate significantly above their optimum working temperature for long periods of time, they are at risk of engine failure due to overheating. Excessive heat not only reduces the ability of lubricants to protect engine parts from wear and tear, but it can also lead to thermal shock. This phenomenon occurs during rapid temperature changes, causing application components to expand and contract at different rates, resulting in cracks and fractures.

There are several steps you can take to protect against overheating. Firstly, it’s important to understand that optimum operating temperatures differ between applications. For example, the ideal temperature for car engines ranges between 75 and 105 degrees Celsius, while for boats this can vary depending on engine type. Selecting dynamic braking resistors (DBRs) with insulated components can help to prevent thermal shock, but employing an effective cooling system is also essential in avoiding overheating.

However, with both water and convection cooling options to choose from, it can be difficult to select the right cooling system for your resistor. So, what’s the difference?

CONVECTION VERSUS WATER-COOLED DBRS

While both options require minimal maintenance and are cost-effective to run, there are several key differences between air and water-cooled resistors.

Convection cooling, also known as air cooling, refers to the transfer of heat into the ambient air using airflow. There are two types of convection cooling systems available: natural and forced convection.

Natural convection relies on the buoyancy effect to cool the application. Since warm air is less dense than cool air, it naturally rises upwards away from the heat source and is replaced by cool air. Natural convection is therefore able to generate a consistent air flow without the need for ventilation mechanisms in applications where the ambient airflow meets thermal demands.

However, where increased heat transfer is required, forced convection cooling is preferable. Since forced convection uses fans, more air can be moved through the system in the same amount of time.

Despite generally being more effective than natural cooling, forced convection also has its limitations. Fans can be noisy and take up a lot of space, meaning they are not well suited to compact applications.

Consequently, water cooling often provides a more effective solution. Not only does the water-cooling method use less space and energy than convection cooling, but it is also better suited to applications with higher continuous power requirements. Since liquid has a higher density than air, it has a higher capacity for heat carrying.

MARINE COOLING

Water-cooled DBRs are especially useful in maritime applications. Cooling often proves difficult as the drive system is usually placed within the ship’s innermost parts and surrounded by heat-sensitive equipment.

To tackle this, most vessels use a chilled water system for machinery cooling and air conditioning. Adding resistors into systems such as the closed air/ closed water (CACW) is relatively simple and allows for up to 95 per cent of the energy from a DBR to be transferred to the ship’s water supply. This recirculation protects the equipment in the machinery room from detrimental ambient temperature increases.

Some marine applications also utilise a sea water cooling system. Provided the DBR is coated in a suitable material such as titanium to safeguard against erosion, this method is a sustainable way of reducing fresh water usage.
Cressall has several decades of experience in designing and manufacturing convection and water-cooled DBRs for applications ranging from automotive and railways to cranes and maritime. In addition to matching continuous power requirements of up to 1500 kilowatts (kW) for convection-cooled DBRs and up to 1800 kW for water-cooled DBRs, Cressall also offers custom options tailored to individual applications.

Safeguarding your application from heat is crucial but proves challenging without a thorough understanding of the different cooling methods available. Choosing a reliable convection or water-cooled DBR provides the assurance that your equipment is protected against overheating.

To discuss the right cooling system for your application, get in touch with our expert team.

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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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