Renewables - the pitfalls and promises

Who wouldn’t want to see a world in which renewable jet fuel powers the planes we travel in? This dream is becoming a reality faster than you would think, according to Neste, the world’s leading producer of waste-based renewable fuels. Oslo airport became the world’s first airport where one can fuel any airplane taking off from its runways with renewable aviation fuel.

As a part of its Future project, Neste and the American spoken word artist Prince Ea visited Oslo and produced a series of inspiring films that show just how far we have come with sustainable air travel.

“There is no alternative to renewable fuels for aviation. If we want to cut our emissions we have to go down that road," explains Olav Mosvold Larsen, Senior Advisor of Corporate Strategy and Development at Avinor, Oslo.

But with its feet firmly on the ground, an Energy and Climate Change Committee report reflects evidence provided by the Freight Transport Association - outlining the immense pressure the freight sector is under to reduce emissions. The proportion of renewable transport actually fell last year meaning that the challenge of decarbonising transport is getting even tougher.

In its 2020 renewable heat and transport targets report the Committee says that although HGVs must be decarbonised, electrification - even in the long term is unlikely, stating that the Government must ensure HGV operators are sufficiently supplied and incentivised to move to biomethane over the medium-to-long term.

As a result, the Committee has warned that the UK is set to miss 2020 renewable energy targets without a significant step change to encourage more renewable transport. 

Commenting on the report Christopher Snelling - FTA Head of National and Regional Policy, who provided evidence to the Committee said: “This report provides clear evidence that Government must review its current policy on renewable transport fuels. Whilst the UK must meet renewable energy targets, the freight sector is also under enormous pressure to reduce carbon emissions and improve air quality, but we need the policies in place to make alternatives feasible.”

Current Government policies such as the Renewable Heat Incentive provide a much greater incentive for biomethane producers to inject into the grid for electricity and heating, rather than further upgrading the biomethane for use as a transport fuel.

Biomethane to reduce carbon emissions

The UK’s leading biomethane shipper, Barrow Green Gas (BGG), has enthusiastically welcomed changes to the greenhouse gas reporting regulations, which mean that the use of green gas now allows for near-zero GHG emission reporting.

Green gas certificates are now recognised under the Greenhouse Gas (GHG) protocol. This offers companies an opportunity to reduce their reported carbon emissions by using green gas from the gas grid, backed by Green Gas Certificates.

The UK has the fastest growing biomethane market in the world and dedicated biomethane shipper, BGG is the largest shipper of biomethane. In addition, BGG markets green gas certificates (GGCs), the value of which is now considerably increased for companies required to report on emissions.

Thermal imaging protects biofuel stockpiles

The storage of large quantities of organic material always carry the risk of spontaneous combustion and fire. With Europe’s commitment to bioenergy through initiatives, like the Renewable Transport Fuel Obligation, this is a growing problem. For energy producers in this sector, such an outbreak is not only a major health and safety issue but also one that involves loss of raw material and production downtime. 

Thermal imaging has already proved its value in securing wide-ranging critical infrastructures against fire and intrusion and is now becoming established in the renewables sector too. A good example is a Swedish energy provider that has minimised its risk with the installation of FLIR A-Series thermal imaging cameras from the company’s Automation & Industrial Safety Division.

Söderengi produces both heat and electrical power by burning biofuels and recovered fuels. Its output provides district heating to a large area of Stockholm and sufficient energy to power 100,000 homes. At its fuel terminal, just outside the city, forestry waste and wood chips are stored in massive piles. In common with many other biofuel producers, it has relied on visual monitoring and temperature probes to detect elevating temperatures and prevent fire.

The tender was won by Termisk Systemteknik, a FLIR distributor that specialised in integrating fire prevention and detection systems for indoor and outdoor use. One of its flagship products is TST Fire, an early fire detection system that continuously analyses the thermal camera stream in real time and generates an alarm when a pre-defined temperature threshold has been exceeded. Through sophisticated video analytics, the system is also able to minimise false alarms, such as vehicles moving in the field of view.

To monitor the entire eight-hectare biofuel site, twelve fixed FLIR A615 automation cameras were specified and Termisk was able to use the existing lighting infrastructure for the installation. This model of camera was selected for its proven reliability and high resolution which, in turn, allowed the number of units needed to scan the whole area to be reduced. 

Making the most of digestate

The UK’s anaerobic digestion sector has grown exponentially in recent years. From a starting point of fewer than 50 plants in 2009 (excluding the water sector), the industry now boasts over 300 AD facilities, processing in excess of 12m tonnes of feedstock including food waste, farm waste, industrial residues and crops.
Historically, AD operators have focused on generating electricity and heat. But with over 90% of an AD plant’s feedstock coming back out again in the form of digestate (the nutrient-rich biofertiliser left over at the end of the AD process), failure to implement a robust digestate management plan at the start of a project can prove a costly mistake.

Anaerobic digestion (AD) produces many valuable and useful products, including biogas (which can then be turned into heat, electricity or biomethane gas) and digestate, a biofertiliser rich in nutrients and organic matter. However, many farm AD plants also produce incidental heat, which can be captured and used within the AD process or for other on-site operations.

Wasted heat is becoming increasingly important, not only from an economic point of view, put also politically. In the UK the Renewable Heat Incentive is the key policy driver to encourage the utilisation of heat from renewable sources, including incidental heat from the AD process, while some European countries now specify targets for the use of heat from AD plants.

When it comes to anaerobic digestion, trials can range from making minor changes with the feedstock mix or dwell time, to assessing the effects of major equipment upgrades such as new CHP units or digestate processing equipment.

Sadly, recent cuts to incentive schemes – the Feed-in Tariff (FIT) is now severely constrained and the Renewables Obligation (RO) is closing to new applications in March 2017 – mean that AD operators must ensure that every aspect of the AD process is optimised if their business is to succeed.

Heatpumps

Moving away from combustion technologies will help current policies get back on track to meet the UK’s carbon commitments. Jonathan Graham, head of policy for The Association for Decentralised Energy, speaking at the Future of Thermal Energy Conference (Warwick University 10-11 October 2016). He differentiated between technologies that save CO2 in the medium-term such as Gas CHP and those that fully integrate with the grid’s natural decarbonisation progression, making heatpumps a long-term and potentially zero carbon option.

For Trevor Whittaker of Aqualor, who took installation and operational costs into account, heatpumps are also a financially sound solution. “Heatpumps have higher installation cost than a gas CHP but much lower operational costs at only 4% of capex and will last well beyond 20 years,” he said.

Nicky Cowan, technical engineer from Star Renewable Energy, highlighted a number of incentives and benefits heatpumps offer: “According to the Committee on Climate Change, heating may have to almost fully decarbonise if the UK is to hit its long-term goal of an 80% reduction in emissions by 2050. Proven renewable heating technologies that avoid burning gas, particularly large district heat pumps, are becoming one of the most talked about topics for governments and increasingly recognised as the best way to combat climate change. We have shown efficiencies far in excess of those used to model energy systems. This and the rapidly decarbonised electricity grid show large heatpumps to be a solid performer now that only get even better as the grid totally decarbonises."

Turbine inspection in the cloud

SKF has developed SKF Enlight mobile and cloud based data collection, analysis and support system to suit the needs of the global wind energy industry. The new solution is designed to improve inspection efficiency and reduce costs for frontline maintenance teams, and to provide operators with rich, real time data on turbine performance and reliability.

SKF Enlight combines the intuitive ease-of-use of an iOS or Android app, running on a standard mobile device, with the power to access customised workflows for specific tasks, and the ability to collect data from a wide range of sources and sensors. Behind the scenes, the DataCollect app connects wirelessly to the SKF cloud. All inspection data is uploaded and securely stored for review and analysis.

Wind energy companies can take their paper-based maintenance processes online with SKF Enlight, creating data collection forms that guide staff step-by-step through standard inspection activities, aided by images and online manuals. The fully customisable forms can be set up to suit operator standard operating procedures, including items such as mandatory safety checks to protect personnel.

In use, the system is able to connect directly to a wide variety of sensors, allowing photographs and video to be collected and uploaded together with data on temperature, humidity, vibration and a host of other operating parameters.

High reliability slip ring

Moog Components Group has announced a new pitch control slip ring. The EPA3 slip ring is the next generation of advanced slip ring products specifically developed for the wind energy market. A key advantage is its high reliability, modular design that can be scaled and optimised for most requirements, making it well suited for both large and small wind turbines.

The slip ring can be part of a large wind turbine electric pitch control system with the option to integrate hydraulic pitch control systems if required. It can also be used on the yaw axis of small wind turbines. Speeds range from 0 to 100 rpm with through-bore model sizes up to 54 mm available.

In addition to wind turbine applications, the new slip ring can also be used in industrial machinery and medical equipment.

The Moog Pitch System 3, now in operation at a wind farm in Brazil, was developed to meet the growing need for wind farm operators and turbine manufacturers to reduce wind farm capital and operating expenses. A parameter called Levelised Cost of Energy (LCoE) measures the net cost to install and operate a wind turbine against expected energy output over the course of the turbine’s lifetime. Though pitch systems represent less than 3 percent of wind farm CAPEX costs, they account for nearly a quarter of all downtime in turbines.

Most pitch systems used throughout the industry today consist of as many as 2,000 to 3,000 subcomponents depending on the manufacturer. With a highly integrated and optimized architecture that consists of significantly fewer parts, the Moog Pitch System 3 is claimed to be up to three times more reliable than the industry’s standard pitch systems. This leads to a reduction in both turbine downtime as well as scheduled and unscheduled maintenance activities.