Offshore wind

ADVANCING OFFSHORE WIND

HOW CAN WE EXPAND OFFSHORE WIND TO REACH 2030’S 40 GW TARGET?

The UK’s history is enriched with maritime activity. Surrounded by water from John o’ Groats to Lands’ End, the surrounding waters have played a pivotal role in trade, travel, and most recently, electricity production. Achieving the Government’s target of generating 40 gigawatts (GW) of offshore wind power every year by 2030 will require continued investment and development in power equipment.

Offshore wind power plays to the nation’s geographical strengths while also providing a clean energy source to fuel the country’s path to net zero. The North Sea’s high quality wind resources and relatively shallow water make it an ideal location for offshore wind farms. According to the International Renewable Energy Agency (IRENA), around 90 per cent of global offshore wind capacity is located in the North Sea, which is why the UK is already a world leader in this renewable power source.

However, to reach the Government’s 2030 production goal, energy suppliers must make advancements in wind turbine technology, while simultaneously considering how their generated power will be safely transferred to the grid.

IMPROVED TURBINE TECHNOLOGY

Turbines capable of producing more power per rotation are essential for the development of efficient offshore wind farms. One way of improving turbine efficiency is to increase the blade length.

An increased blade length means that stronger forces will act on the turbine, so the blade material needs to be appropriately chosen. To achieve an adequate stiffness-to-weight ratio to avoid deflection, carbon fibre or fibreglass blades are typically favoured. However, there is an expanding market for hybrid reinforcements, which combine the two materials together for optimum sturdiness.

Improvements in wind turbine technologies have already triggered a move into deeper waters to use sites with better wind resources. Static wind turbines are still restricted to waters at a maximum depth of 60 metres, so to upscale the UK’s wind power output, floating wind turbines will be essential.

MORE SUITABLE SITES

Once all viable sites within 60 metres of shore have been constructed, floating wind projects will become vital to offshore’s growth. Floating offshore wind farms, which can be located up to 80 kilometres (km) from land, could play a key role in the long-term decarbonisation of the power sector.


Floating wind turbines sit on a steel and concrete floating system instead of a fixed base, meaning they can be placed in a larger number of sites up to 200 metres deep. They can also be towed, allowing them to be relocated without much additional cost. This broadens the potential output that offshore wind could provide and brings it one step closer to the 40 GW target.

SECURED POWER SUPPLY

Like all renewable energy, offshore wind can be unpredictable and inconsistent, which can make grid connection challenging. In periods of high wind, large inrush currents occur, which can lead to overvoltages on the grid and subsequent equipment malfunctioning.

It’s important to prepare for these inevitable inrush currents by integrating technologies such as pre-insertion resistors (PIRs). Already in use across many of the UK’s windfarms, Cressall’s PIRs have a high thermal mass, which allows them to absorb excess energy produced by the inrush current and safely dissipate it as heat. This prevents damage to the grid and improves the reliability of offshore wind’s power supply.

Offshore wind holds great potential in the shift towards renewable energy and could be the key to decarbonising electricity generation. However, we must continue to advance critical power protection technologies to prevent any obstacles in its upscaling and to enable this powerful resource to flourish.

CR456

Battery show

IMPROVING ELECTRIC VEHICLE EFFICIENCY AT THE BATTERY SHOW EUROPE

Electric vehicle heavy duty resistor

Cressall Resistors, is exhibiting at The Battery Show Europe from June 28 to 30, 2022 at Messe Stuttgart, Germany. At the show, Cressall will be showcasing its EV2 dynamic braking resistor (DBR), which improves electric vehicle (EV) performance and contributes to the widespread rollout of commercial and passenger battery, hybrid and hydrogen fuel cell electric vehicles.

Over 480 exhibitors will be showcasing their latest technologies at Europe’s largest showcase of advanced battery and hydrogen and EV technology. Visitors will have the opportunity to learn about the latest market innovations for increased battery efficiencies and reduced manufacturing costs. Additionally, live product demos will enable visitors to get a closer look at cutting-edge battery technology.

Cressall will be exhibiting its EV2 DBR, which is suitable for use in both battery electric vehicles (BEVs) and fuel cell electric vehicles (FCEVs). The advanced resistor safely dissipates excess energy during regenerative braking and ensures the vehicle’s braking system remains operational. Cressall’s EV2 is uniquely designed to separate the resistor elements from the coolant.

The EV2 is water-cooled, meaning that it can safely dissipate heat without the need for extra components, such as fans, unlike air-cooled resistors. This results in a total weight 30 per cent less than a conventional DBR, improving the EV’s energy efficiency and respecting EU safety testing regulation.

“One of the biggest barriers to widespread EV adoption is range anxiety,” explained Simone Bruckner, managing director of Cressall Resistors. “To ensure we can electrify the automotive sector and reach net-zero carbon emissions, manufacturers must ensure EVs are energy efficient and can travel the furthest possible distance on the smallest possible amount of power.

“Regenerative braking technology is crucial to EV efficiency. Cressall’s EV2 resistor is a lightweight, compact resistor that is suited to every EV application. Its modular design means that up to five units can be combined in a single assembly to achieve a power rating between one kilowatt (kW) and 125kW, with no real upper limit using multiple assembly.”

Cressall’s recently-launched, dedicated load bank division, Power Prove, will also be exhibiting it load bank offering for battery discharge testing. Power Prove’s standard range of portable AC and DC load banks are easy to operate and suitable for the on-site load testing of most battery systems. Its experienced team of engineers and manufacturing experts provide ongoing, comprehensive support for all manufacturers that require fixed and portable load bank testing.

CR462

Cleaning up automotive emissions

CLEANING UP AUTOMOTIVE EMISSIONS

IT’S TIME TO START ADDRESSING NON-EXHAUST EMMISSIONS

 Road transportation is widely recognised as a large contributor to carbon emissions, responsible for 24 per cent of the global total. However, carbon isn’t the only thing the world’s vehicle fleet emits —non-exhaust emissions also have a detrimental impact on the health of the population and the planet.

Electric vehicles (EVs) are often referred to as ‘zero emission’, but this is not entirely true since non-exhaust emissions are produced by all vehicles, irrespective of their fuel source. In fact, the EV rollout is not expected to have any impact on non-exhaust emissions.

IT’S NOT JUST CO2

Non-exhaust emissions are particles released from brake, tyre and road surface wear, resulting in the production of particulate matter — all chemical compounds and materials in the air that are not gas. Particulate matter is classified depending on the diameter of the particles. PM10 and PM2.5 refer to particles less than ten micrometres and 2.5 micrometres in diameter.

Particulate matter from non-exhaust emissions originates from surface wear, which leads to abrasion and the release of small particles that become airborne. Friction between brake pads and the rotating disc and between the tyre and the road both lead to abrasion, component wear and the release of particles from the surfaces into the atmosphere.

THE PROBLEM WITH PARTICULATE MATTER

The minute size of these particles means that some of the toxins that they include are small enough to enter the human body through the bloodstream, where they can cause serious damage to the heart, brain and respiratory systems. According to the World Health Organisation (WHO), nine out of ten people worldwide breathe polluted air, and seven million people die a year because of the health effects of air pollution.

In addition to the detrimental effects on human health, particulate matter can seriously damage the environment. Once airborne, it can be carried large distances and settle on the ground or in water where toxins can lead to catastrophic ecosystem disruption, altering the nutrients of water and soil and contributing to increased acidity and agricultural destruction.

With so many issues, it comes as a surprise that several nations lack a policy regulating non-exhaust emissions. The current legal limit for PM2.5 is 25 micrograms per cubic metre air (µg/m3) in the UK, 20 µg/m3 in the EU and 25 µg/m3 in Australia, all of which exceed the WHO’s recommended limit of 15µg/m3. Therefore, it’s essential for vehicle manufacturers to consider how they can reduce non-exhaust emission through design.

SUSTAINABLE BY DESIGN

When considering how to reduce particulate matter emissions, it’s important for transport manufacturers to consider the factors that determine the production of non-exhaust emissions. Reducing brake wear is the key area for transport manufacturers can concentrate their efforts to reduce emissions thanks to regenerative braking technology.

In regenerative braking, upon deceleration, the vehicle’s kinetic energy is recovered and stored in the vehicle’s battery, increasing EV range and improving energy consumption. However, it’s important that these systems have a safety mechanism in place for when the vehicle’s battery is in a high state of charge. If the battery is full or there is a failure it will be unable to store additional energy from thebraking system. Therefore, the energy must have an alternative pathway to keep the vehicle’s power system functional.

A dynamic braking resistor is an essential component of a regenerative braking system, safeguarding the EV by removing excess energy and dissipating it as heat. Most of the time, electric brakes will be sufficient to slow the vehicle, meaning that the mechanical system will only be used at very low speeds when the motor cannot generate sufficient braking force to stop the vehicle quickly. Less reliance on the brakes leads to minimised brake wear, resulting in a reduction in particulate matter and non-exhaust emissions.

The 2030 ban on petrol and diesel vehicles will ignite the elimination of exhaust emissions, but the idea that this will result in a zero-emission fleet is incorrect. Although some of the contributing factors to non-exhaust emissions may be out of our control, it’s important to minimise those that we can, like vehicle mass and brake wear, to reduce risks for the population and the planet.

CR465

HYDROGEN CATALYST

THE HYDROGEN CATALYST TO THE EV REVOLUTION

 IS HYDROGEN KEY TO THE NET ZERO EV ROLLOUT? 

In November 2021, UK Prime Minister Boris Johnson announced the dawn of the electric vehicle (EV) revolution, fuelled by new regulations and investment pledges across all stages of the EV supply chain. From charging stations to electricity generation, new projects will begin across the United Kingdom in 2022. But there’s one key ingredient that will transform the sector’s sustainability credentials — hydrogen.

With bans on the production of new diesel and petrol-powered vehicles looming, encouraging widespread consumer uptake of more sustainable vehicle choices is becoming an urgent matter. Uptake seems to be increasing — according to The Society of Motor Manufacturers and Traders (SMMT) demand for battery electric vehicles (BEVs) more than doubled between November 2020 and November 2021. But if transport is to decarbonise before its 2050 deadline, there’s more to do to make BEVs carbon neutral.

BEVS’ SUSTAINABILITY SHORTFALLS

Fully decarbonising BEVs is tricky. Using energy from the National Grid means that the sources used for electricity generation directly affect BEVs’ environmental impact. The grid is becoming more renewable and is set to be net zero by 2050. But there is an added challenge. According to The Committee on Climate Change, electricity demand is set to double from today’s 300-terawatt-hour (TWh) requirement to 610 TWh by 2050 thanks to BEV uptake.

So, to complete the dual task of increasing supply and decarbonising electricity generation, the Government is investing in dispatchable low-carbon sources to support variable weather-dependent renewables in powering the grid when production falls short of demand. In the meantime, fossil-fuelled electricity generation is negatively impacting BEVs’ sustainability.

BEVs also have some additional environmental concerns regarding their reliance on lithium-ion batteries. Rare earth metals including cobalt, nickel and manganese are all major components of lithium-ion batteries. Mining these materials can result in huge environmental destruction, disrupting entire ecosystems, while the heavy machinery used contributes even more emissions. So, is there a more sustainable option?

HYDROGEN : THE FUEL OF THE FUTURE

Hydrogen is a promising resource that is key to delivering transport’s decarbonised future. Industrial production of hydrogen is typically delivered through electrolysis — using an electrical current to split water into hydrogen and oxygen. If a renewable source is used to produce electricity, then this creates an entirely carbon-neutral hydrogen fuel, known as green hydrogen.

The Government has set a target to produce five gigawatts (GW) of green hydrogen by 2030 and has already announced investments into projects like Whitelee Windfarm near Glasgow, which will use wind power to generate electricity for hydrogen production.

Hydrogen produced in this way can then be used as a fuel source for an alternative to BEVs: fuel cell electric vehicles (FCEVs). FCEVs are powered by proton exchange membrane fuel cells. FCEVs turn hydrogen into electricity by combining the hydrogen fuel with air and pumping it into the fuel cell. Once inside the fuel cell, this triggers a chemical reaction, resulting in the extraction of electrons from the hydrogen. These electrons then create electricity, which is stored in a small battery used to power the vehicle.

FCEVs fuelled with green hydrogen are completely carbon-free, thanks to the renewable origins of these fuel cells. The only end products of the fuel cell reaction are electricity, water and heat, and the sole exhaust emissions are water vapour and air. This makes them a more-aligned choice with net zero goals, enabling a widespread, carbon-neutral EV rollout.

MAKING HYDROGEN VIABLE

Although the benefits of FCEVs are clear, the technology behind them still needs refining. Fuel cells are unable to work under heavy loads for a long time, which presents issues when rapidly accelerating or decelerating.

Studies into fuel cell function have shown that, when an FCEV begins accelerating, the fuel cell’s power output increases gradually to a point, but then it begins to oscillate and drop despite velocity remaining consistent. This unreliable power output presents a challenge for automakers.

The solution is to install a fuel cell for a higher power requirement than necessary. For example, if a FCEV needs 100 kilowatts (kW) of power, installing a 120-kW fuel cell would ensure there is always 100 kW of power available, even if the fuel cell’s power output drops. Opting for this solution requires a resistor to remove the excess energy when not required, to perform a “load bank” function.

Cressall’s water-cooled EV2 is designed specifically for heavy-duty applications including hydrogen-powered FCEVs. It absorbs excess energy from the system and dissipates it as heat, which can be used to warm the vehicle’s passenger cabin. This protects the electrical system, allowing FCEVs to be very reactive to high-power demands, and accelerate and decelerate rapidly without storing excess energy in a battery.

The EV rollout is well underway, with pressing deadlines for the retirement of fossil fuelled vehicles edging closer and closer. Although BEVs are the main player in the decarbonisation of transport, it’s important to not rule out the distinct benefits that FCEVs bring to the market. But combining the two could be the key to unlocking the EV revolution

CR469