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.

CRE660/08/24

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.

CRE654

Floating wind farms for the future

FLOATING WIND FARMS FOR THE FUTURE

pre-insertion resistors for turbines

ARE FLOATING WIND TURBINES THE ANSWER TO RENEWABLE POWER?

Back in 2019, then-Prime Minister Boris Johnson promised 40 GW of UK offshore wind power by 2030. In early 2022, the Government raised that target to 50 GW, with an additional five GW from floating wind turbines. But are floating wind farms the solution to existing offshore power problems?

Many of us will be familiar with the sight of wind turbines. After all, there are more than 10,000 of the structures on land and at sea in the UK. In terms of efficiency, offshore wind turbines often have more favourable wind conditions, producing more electricity per turbine than their onshore counterparts.

But traditional offshore wind turbines have their limitations. Traditional offshore turbines are built onto a large steel column, fixed into a concrete foundation on the seabed. These can only be installed in relatively shallow waters, up to depths of around 60m. Not only does this limit the potential areas for turbine installations, it also means that the turbines have less access to the stronger winds that are often found further out to sea.

FLOATING FARMS

To capitalise on the stronger winds further out, floating wind turbines can be built instead. These are turbines built on huge floats, anchored to the seabed with weighted subsea cables.

Operating in much deeper water, floating wind farms make use of vast areas that were previously considered not suitable for offshore wind power. Being further out to sea also means that turbines can be a lot larger in size than their counterparts, producing even more electricity per turbine.

Kincardine, the world’s largest floating wind farm based in Scotland, has five operational floating wind turbines. Three cylindrical floats arranged in a triangular formation support each turbine, and pipes between the floats allow liquid ballast to be pumped around the structure. In this manner, the weight of the turbine can be shifted to stabilise it in harsh conditions, as well as orientating it for the wind direction.

Are we on track to meet solar power targets?

ARE WE ON TRACK TO MEET SOLAR POWER TARGETS?

MAXIMISING EFFICIENCIES TO MEET RENEWABLE TARGETS

In April 2023, a report published by the House of Commons stated that, at the UK’s current pace of change, it will miss its target of decarbonising the power sector by 2035. As the UK fights to secure its energy supply, what progress is being made in the renewable sector, and what needs to change? In this article, Simone Bruckner, managing director of resistor manufacturer Cressall, explores.

More and more applications are going electric. Whether it’s the cars we drive or the heat pumps in our homes, rising electrification is putting more pressure on the grid. In fact, the UK’s electricity demand is expected to double by 2035.

60 per cent of our current electricity usage comes from low-carbon sources, which includes renewables and nuclear power. But within the next twelve years, renewables are expected to supply up to 90 per cent of the country’s power if we’re to meet decarbonisation targets. In real terms, this sets a target of around 150 GW of renewable energy. But this is a long way off our current capacity of just 40 GW.

Further efforts to secure the UK’s energy independence while meeting decarbonisation targets have resulted in additional goals. The British Energy Security Strategy has outlined a 50 GW target for offshore wind by 2030, as well as a 70 GW target for solar by 2035.

But with a current solar capacity of just 14 GW, is the UK on track to meet such targets?

DELVING INTO SOLAR

One of the biggest issues faced by those in the solar sector is obtaining planning permissions and approvals. Industry body Solar Energy UK reported back in 2021 that around 17 GW of new projects were in the planning pipeline, with just under 800 MW of new projects entering the pipeline each month. But typically only around 500 MW of capacity is added each year, much lower than the approximate 4.5 GW required to meet the Security Strategy’s 70 GW target.

In Sleaford, Lincolnshire, a 600 MW solar farm able to power 190,000 homes is currently undergoing consultation with local residents. Despite being in talks now, if the plans for the farm are approved, it’s not expected to start construction until at least 2026.

Another problem with solar power is efficiency. Solar panels tend to operate with efficiencies between 15 and 20 per cent, compared to between 30 and 50 per cent for wind. Evidently, there’s improvements to be made to the efficiency of solar power if the UK is to hit its targets. But what can be done?

SAFE, EFFECTIVE MAINTENANCE

Maintenance is a key factor in improving efficiency. Regular cleaning and inspection ensures that the solar panels are working properly. But there might be times when the solar panel needs to be disconnected for more extensive maintenance or repairs, presenting an electrical safety challenge.

While there is still sufficient light, the solar panel will continue to produce electricity. This electricity must be discharged so that the panel can be handled safely. This can be done using a load bank, which dissipates excess electricity to allow safe disconnection, installation, and maintenance of solar panels.

THE BENEFITS OF MOTORISATION

Ground-mounted solar panels have the advantage of space, compared to those fixed onto rooftops. This means that the panels can be tilted and moved with respect to the sun’s position in the sky. An electric drive system is used to move the panels, either along a pre-programmed path or using information obtained via solar radiation sensors.

Moving the solar panels helps to maximise their efficiency throughout the day, as well as accounting for minute changes in the sun’s position and trajectory throughout the seasons. In fact, these systems can increase the output of solar farms by up to 35 per cent.

Motorising solar panels requires electronics that can ensure they move precisely and safely. To achieve this, a dynamic braking resistor (DBR) can be used. A DBR dissipates the excess voltage generated by the motors as they decelerate. As a result, the panels stop exactly when required, resulting in a more accurate positioning.

Though these slight changes in positioning may only be minute, when multiplied across an entire solar farm, they represent a significant proportion of its overall output and efficiency.

Finding suitable resistors for the solar sector can be a challenge. Cressall has vast experience in providing resistors for a variety of applications, including renewables. Offering resistors with no wearing components, they can last as long as the solar panels themselves, minimising downtime.

As deadlines get closer, pressure is mounting to provide a secure supply of green energy. Evidently, governments, planning regulators, energy companies and manufacturers will all have a part to play in the UK’s journey to green energy. As the House of Commons’ report states, the achievement of a decarbonised energy system will not come easily ─ but it is not impossible.

CR539