Algae control at Sellafield 

LG Sonic, a leading international manufacturer of algae and biofouling control systems, has installed multiple LG Sonic Industrial Wet Systems at the Sellafield  nuclear power facility in the UK. This led to a significant improvement in the clarity of the water and the visibility into the storage ponds. As a result of these ultrasonic processing systems there has been an exceptional reduction in blue-green algae and chlorophyll levels in the treated storage ponds.

Sellafield, a nuclear fuel reprocessing and nuclear decommissioning site, handles nearly all the radioactive waste generated by the 15 operational nuclear reactors in the United Kingdom. In 2015, the UK government started a major clean-up of the stored nuclear waste facilities in Sellafield because of the bad condition of storage ponds. One of the main causes of these bad conditions  was poor visibility in the water due to algae growth.

The Solution: Ultrasound technology

To improve water visibility in the storage ponds, four LG Sonic Industrial Wet systems were installed. The systems have 12 ultrasonic programmes to effectively control different types of algae, and are able to treat algae in a relatively short time. GPRS control allows the user to monitor and change the ultrasound programme remotely. Furthermore, status updates and alerts are received when power outages occur.

In only three weeks after the installation of the LG Sonic ultrasonic systems, there was a significant reduction in blue-green algae count and chlorophyll levels. As a result of the this reduction, the water started to clear and it was possible to see vessels and containers in the storage ponds that in recent years were only visible when using a tethered underwater mobile camera device.

Over 10,000 LG Sonic systems have been installed worldwide, including many on the current European FP7 projects.

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A recent picture of a storage pond

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Concern over EDF reactor faults

HazardEx, the UK journal covering industrial hazards and regulations worldwide, has published an interesting update on the state of the EPR nuclear reactor being built at Flamanville, in Normandy. Potential problems at this site are of as much concern to UK residents in Southern England, as will be the case over the future reactors of the same type planned for Hinkley Point in Somerset.

HazardEx says:

The French state electricity generator Electricité De France (EDF) has put the cost of repairing recently discovered flaws at the new EPR reactor being built at Flamanville in Normandy at Euro400 million ($468 million). This takes the total cost of the project to Euro10.9 billion, more than three times its original budget.

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The Flamanville plant – an EDF picture

EDF had previously warned that problems with welds at the reactor under construction in Flamanville were worse than first expected. The utility said on July 25 that out of the 148 inspected welds at the latest generation reactor, 33 had quality deficiencies and would need to be repaired.

The most recent projections envisaged the Flamanville 3 reactor loading nuclear fuel at the end of the fourth quarter of 2018, but EDF said this was now scheduled for the fourth quarter of 2019. The reactor was originally scheduled to come on stream in 2012.

Flamanville was the second EPR reactor to be constructed: the first was Olkiluoto in Finland, which has suffered comparable delays and cost overruns, and this is also now due to enter service in 2019.

This means that the first EPR to enter production will probably be at the Taishan nuclear plant in China. Work on Taishan 1 and 2 reactors has also suffered repeated delays, but not on the scale of the French and Finnish plants. At least one of the Chinese reactors is expected to be commissioned this year.

In the UK, there are currently plans to build two of these EPRs at Hinkley Point in Somerset. These reactors could be further delayed if the new problems at Flamanville are not easily resolved. The UK EPRs are already mired in political controversy over the high cost of the project.

ENDS

MVDC Power Transmission

Azeez Mohammed, president & CEO of the GE Power Conversion business discusses how MVDC technology is creating a more secure and higher-capacity grid for the future. Thanks to the MCDC technology, Scottish Power Energy Networks’ Angle DC project – first of its kind in Europe – will provide a 23% power capacity increase for supplies to Anglesey. Similar technology is being used in offshore wind applications, giving up to  15% cost savings.

Transforming Power Grids for an Efficient Future

With a fast-growing global population and increasing levels of industrialisation, demand for electricity is expected to soar 60% between now and 2040. That means power grids will be called on to transmit more power, more efficiently. And to do so, they’ll have to adapt to an evolving energy landscape.

Today’s grid is still structured around transmitting electricity from a handful of large, centralised power plants running on coal, oil, gas and nuclear. While these will continue to dominate the mix for years to come, renewables are increasingly making their presence felt – and are expected to supply a third of global power by 2040.

With renewables growth comes an increasingly diverse distribution network – from remote and offshore generation sites to microgrids. All must be brought together to ensure we continue to have a reliable, resilient power supply. The challenge now is that the majority of power grids are made up of decades-old infrastructure that’s simply not – yet – up to the task.

Laying the foundations

Creating a future-proof power grid means fusing time-honoured knowledge with forward-thinking technology. For over 100 years, GE electrical engineers have recognised that DC electricity transmission is more efficient than AC. Now, DC is becoming more prominent – both at the beginning and end of the grid. DC is produced by wind turbines and solar PV and used by everything from smartphones, laptops and electric cars to the data centres that keep our digital world up and running. However, having to convert back and forth between AC and DC along the way leads to wasted energy through resistance and heat.

AC may have won the “War of the Currents” that raged between the Edison Electric Company (which favoured DC and would become General Electric) and Westinghouse (which favoured AC) in the 1890s. This was due to its ability to easily step up voltages to the higher levels needed to transmit it over long distances and back down again for safe usage. But today, new power conversion and transmission technology means it is becoming more cost-effective to use DC to transmit at higher voltages, with less energy losses. The same attractive cost story applies when it comes to integrating new, often remote, DC-producing renewables into the wider grid network.

At the GE Power Conversion business, we’re developing the use of DC to enable more efficient power transmission to and from remote areas – both onshore and offshore.

Strengthening the Anglesey power supply

At the GE Power Conversion business, we are delivering Europe’s very first medium-voltage direct current (MVDC) link as part of the Scottish Power Energy Network Angle DC project in Anglesey and surrounding North Wales area. A growing demand for electricity in the region, combined with increasing volumes of renewable generation, is putting the existing 33-kilovolt AC links between the isle of Anglesey and the Welsh mainland under strain.

Converting the existing AC connection to MVDC could help it to carry more than twice the power and do so more efficiently. GE MVDC technology is providing a critical project asset, as it allows for the creation of a more-secure, higher-capacity grid without the need to overhaul existing infrastructure or install new power distribution assets.

Instead, GE will install MVDC power modules at the two existing substations in Bangor and Llanfair PG, where the AC to DC conversion will be performed. GE MV7000 power electronic inverters will transmit the power via the existing 33-kilovolt AC overhead line and cable circuit, increasing the power available to Anglesey by 23% to meet its future needs without additional environmental impact. What’s more, the DC equipment will assist in the provision of further grid support, as the inverters are able to support the AC voltage at each substation.

This MVDC technology works in much the same way as our high-voltage direct current (HVDC) projects, but on a smaller and simpler scale. For example, a comparable HVDC system would operate at 320-400 kilovolts DC, whereas the Angle DC project will operate at 27 kilovolts DC—demonstrating how this technology can be scaled to fit a variety of customer needs.

Lowering the cost of offshore power

From wind turbines stationed far out at sea to solar farms in inhospitable deserts, renewable generation networks are often found in hard-to-reach places. Getting the power generated to a centralised grid via AC can waste energy and keep renewable electricity costs higher than they need to be.

Now, similar technology behind the MV7000 converters used for Angle DC has also been successfully trialed for use in remote power networks. Our PassiveBoost solution will enable DC power transmission, opening up the potential to boost electrical output from these remote sites while also reducing power costs.

PassiveBoost is an MVDC converter which provides a straight replacement, with the same footprint and volume, for the AC transformer inside every wind turbine. This helps to facilitate a direct connection to an efficient MVDC power collection grid, resulting in a lower cable cost and no need for an expensive and complex DC breaker. A 6 megavolt-ampere converter was designed and tested at the GE power test facility in the UK. There, it successfully demonstrated the capability of generation, distribution and protection at MVDC, highlighting efficiency levels that could bring a 15% cost saving for offshore wind electricity by significant reductions in component count, cabling costs and removal of need for offshore platforms.

Greater grid control through data-driven insights

To drive further efficiency across the power grid, GE can also offer VISOR 2.0, an asset management tool that provides remote connectivity to key assets. This not only enables an improved service response time, but also access to real-time support and advice in the event of a fault or problem. By pairing this tool with the GE Data Historian, which collects, processes and stores data, customers can more easily review the capabilities of their MVDC system. Its ability to capture and analyse data about asset performance means customers can then develop optimum control algorithms for the distribution system, helping to ensure the grid is always functioning as effectively as possible.

As electrification within all industries gathers pace and the burden on existing energy distribution networks increases, we’re ready to put our expertise into action where it’s most needed.

 

Plant control systems and the internet

The following is my personal view of the business planning quandary faced by the major automation companies, first expressed in a Comment page published by Technews.co.za in the South African Journal of Instrumentation and Control, SAIC, March 2018 issue:

It is a common saying that the pace of technology change accelerates with time: although possibly as the observers get older, they become set in their ways, and cannot keep up.

This is certainly true, in my experience: I am getting older, set in my ways, and struggle to keep up. However:

It is not only the pace of such changes, but the speed at which the changes are spread across the ‘world market’, that makes new technologies so rapidly applied and, sometimes, profitable. In consumer markets, the effect is most evident, with the spread of mobile phones and mobile computing: possibly this would all not have come to pass without the availability of the Internet fuelling the spread of information. But for automation, and industrial sensors, has the technology change been rapid? I believe it has, and believe it is now accelerating ever faster, taking advantage of the advances made to meet the demands of other users. This has been evident, and mentioned in these columns, in referring to wireless sensors, batteries for self-powered devices, and self-power from solar or vibration or heat energy. There are many more developments that should be included in that list.

The problem for Automation companies

But how are the major sensor and automation companies driving this growth into their businesses using advances in technology: what are they researching? Where are they investing to get a business advantage? I think that their business planners are having a difficult time at the moment.

Around ten years ago, the big new technology coming to the fore was wireless communication from battery powered sensors. The large automation companies, like Emerson and Honeywell, invested heavily into this technology, and there was the inevitable confrontation between two rival systems – WirelessHart and ISA100. The automation marketplace thrives on such confrontations, for example the spat between Foundation Fieldbus and Profibus. It happens in other markets too; think of Blu-Ray and standard DVDs, PAL and NTSC TV systems etc.

Other perceived growth areas

After the wireless investments blossomed, the Internet was looming, and everyone believed they had to take advantage of the data that could be collected, and networked. Certainly Emerson and ABB went heavily into power network control systems, but ABB had major product availability and systems installation capability in the power industry and has made real progress. Emerson eventually sold out of this network power business, but retains the Ovation DCS used for thermal power station control on site.

Automation companies also bought into the long-established, relatively dormant and slow market of condition monitoring systems, by acquiring the companies quoted to be ‘active’ in the field, who had the ‘black art’ knowledge of industrial condition monitoring. Personal experience, back in the ‘70s, has taught me what a hard sell and difficult market even the simpler condition monitors offer, monitoring bearing wear etc, and that hardly suits the major project potential that might be of interest to big contractors. Complex systems, such as those applied to turbines in power stations, did offer potential, but needed real specialist back-up.

Additionally, the people in the business, such as Schaeffler perhaps (once again the product suppliers with the customer base), slowly developed their own bearing monitoring systems, ranging from portable hand-held units to bigger wired/wireless systems – these are the ones that I believe will succeed in this market. An alternative approach adopted was based on wireless technology developments, which needed a central monitoring system, the ultimate goal for the automation guys. Sensors for steam trap monitoring were designed by majors such as Emerson, to expand their plant control systems into condition monitoring for the plant engineers.

Sure enough, after a slower start, steam trap companies such as Anderson (US) and Spirax Sarco (UK) developed their own systems, and had the market entry with the customers using their traps. The opposite approach was adopted by Yokogawa, which is the pioneer of ISA100 industrial wireless systems. They created alliances with people like Bently Nevada, the bearing condition monitoring sensor people, and with Spirax Sarco on steam traps. Maybe this was to be able to reverse sell them the back-up products and technology for wireless systems, or maybe to hope for the potential of a plant monitoring control system supply.

Software systems

Most of the automation majors have alliances with the large software and computing companies, like Cisco and HP. The current approach seems to be to use these alliances to piggy-back a 24/7 plant monitoring system using the Internet, supplied as a service across the world. Again, I believe the companies with the product on the ground, the stuff that needs monitoring, will be the major players. Here it looks like GE, monitoring its own brands of refrigeration compressors, large pumps and gas turbines at power stations and offshore etc. are best placed.

The future

The quandary is where the Internet will help the industrial control systems and sensor suppliers expand their businesses in the future. The answer deduced above is stick to what you know and what you are known for. The irony is that the major with the best potential now is Rockwell Automation, with its systems based around Ethernet communications, interfacing with anything, plus their onsite Ethernet hardware, with control systems already configured to deal with such varied inputs. Maybe this was why Emerson made an abortive take-over offer for Rockwell late last year. The potential has also been seen by Profibus, who are pushing forwards with their Profinet, and where they go, Siemens will always be in the background.

Modern trends in long distance power links

Many of the changes in the way the world works lead to new opportunities for different technologies. This has led to a new approach to electricity distribution using HVDC – High Voltage Direct Current – transmission lines, operating at up to 800 kV. Such power transfer lines are now installed particularly around Europe, and across China.

When power stations were smaller, and based near the major population centres, they tended to serve a local area with electric power, and this was best delivered using AC transmission, via local transformers, to produce the 110–240 VAC power distributed to each street. (As an aside, even more locally around the power station, district heating schemes could distribute some of the power using thermal transmission.) To provide the electrical energy transmission further afield, higher voltage AC transmission lines were used to feed a major substation, then distributing the power to local transformers, creating local networks – like the branches of a tree.

Currently, the new solar farms and wind power sources have been built well away from the major centres of population, where the land (or sea) space is available, and the conditions are right. Plus, hydroelectric plants are necessarily placed near the river or water flows, naturally located in the hills. All these sites are at the end of the thinnest branches of the old ‘distribution tree’, so new transmission lines are needed to take the power back to the population centres.

Long distance transmission

China also faced this problem, with economic development and a growing demand for power by the population in the west of the country, with the major new power stations and hydro plants located in the east. For transmission of power over distances like 500 km or more, the reactive power flow due to the large cable capacitance limits the maximum possible transmission distance, as the power loss becomes high. The installation and maintenance costs for the necessarily taller and wider dual pylon AC overhead transmission lines, also becomes excessive.

For such long distance transmission, HVDC comes into its own economically because the line losses are much lower, as are the line installation and maintenance costs, since HVDC (at around 600 kV) can use a single overhead pylon carrying just two conductors, or can use a buried cable. The higher costs of the HVDC terminal equipment, needed at both ends to convert the power back to AC for local distribution, are more than offset by the savings in the transmission line costs. Plus the environmental impact of the HVDC underground cables is insignificant, compared to overhead AC transmission. The possibility of using underground cables means HVDC links can deliver power into cities and urban areas where the use of pylons and overhead cables would not be tolerated.

So, over the last few years China has installed 24 projects using HVDC power transmission: one of these used a 1670 km line carrying 8000 MW of power to the east. The supplier for 19 of these projects, including the largest one, was ABB Power Systems. ABB also claims to be the major supplier of recent HVDC power transmission projects throughout Europe, and the rest of the world.

Undersea links

In Europe there are many power networks, based around different standards that were developed by the different countries: these AC networks can run at different frequencies, and are not often synchronised. It makes sense to wish to trade power between networks, to make use of surpluses when these are available, and cover for power outages or other unforeseen events. Transferring power using HVDC links makes sense, firstly because the receiving terminal can convert the DC to an AC power source running at the same frequency as the receiving network, plus the local ­engineers can phase synchronise the generated AC power with their other sources.

The second big advantage of HVDC links is that they can run in economically constructed underwater cables, to islands and across major sea routes, such as from the UK to France, or Norway and Sweden to Denmark, Germany and Finland. The NorNed link, from Norway to the Netherlands, is the world’s longest submarine power cable, at 580 km length. Similar HVDC links are used to supply power from hydro schemes and wind farms in the north of Scotland, across the estuary of the Moray Firth to the heavily populated Inverness/Aberdeen area.

The growth of offshore wind farms has led to this green energy being sent onshore using an HVDC submarine cable, and also vice versa, in the sense that offshore oil production platforms are now being supplied with power from onshore, delivered by cable, and just converted to AC power on the platform – saving weight and complexity offshore. Plans are being made to extend this European network, with possible hydro-electric power being delivered by cable from Iceland to Scotland, and from Norway via the Shetland Islands, then also to Scotland.

More importantly, in an African context perhaps, solar farms in North Africa will be able to transmit power to Europe via Spain from Morocco and to Italy from Tunisia and Libya.

This article first appeared in my column in the South African Journal of Instrumentation and Control, November 2017 issue. SAIC is published by Technews in South Africa.

Battery Energy Storage Systems help UK power efficiency

Nidec ASI, of Milan in Italy, part of the appliance, commercial and industrial motor business of Nidec in Japan, has won an order from the UK-based EDF Energy Renewables business for the installation and supply of a second Battery Energy Storage System (BESS), for use on the British National Grid.

EDF ER, a renewable energy developer, is a JV company between EDF Energy in the UK and EDF Energies Nouvelles in France. As a result of this new contract, Nidec ASI will act as an EPC (engineering, procurement, and construction) contractor to supply the 49 MW BESS system that EDF ER is building to serve the National Grid, the British electricity distribution company. The contract, which follows closely after an earlier large-scale deal for a 10 MW battery energy storage system (also for National Grid) makes Nidec ASI reach a 33% market share in the British BESS systems market.

As renewable energy resources are more widely used – to reduce the environmental impact of power generation – investments in battery energy storage systems are becoming increasingly prominent. These stabilise the power grid by temporarily storing any surplus electricity generation, and discharging the saved electricity during power shortages. Last November Nidec ASI delivered the world’s largest (90 MW) BESS system to major electricity firm STEAG of Germany. As a leader in the BESS market, Nidec is committed to stabilizing the world’s power grids and contributing to realizing a low-carbon society via the spread and expansion of battery energy storage systems and high-quality state-of-the-art equipment.

EDF West Burton 2

The BESS will be installed at the EDF Energy West Burton site in Nottinghamshire, pictured above, to support the UK’s National grid.

Advances in battery technology

The opportunities for spin-out businesses and industries from university research projects are multiplying. The growth in this sector comes from the acceleration of technology in general, but also because the increased investment in education means there are a lot more research students, some with good ideas, but others just looking for topical subjects to latch onto for their research project. Also, industry has learnt that by funding some low cost university research, other ideas might emerge that might be of benefit.

A lot of attention is being given to new designs of battery, as there are some well-known major commercial projects where new systems are needed. First to come to mind would be batteries for electric cars like the Tesla. Here, low-cost, lightweight and relatively compact devices are needed, with high-power output and fast charging. Second are the batteries (or systems) needed to store the power generated by solar farms or wind turbines, during the hours when it is not needed, so that it is available for different times of the day. Possibly lower down the priority list are the small long-life battery systems needed for IIOT sensors and industrial sensors in general. These do not have the major numbers, or the (relatively) high price, so do not attract as much attention.

Eliminating standby power drain

So, it was all the more interesting to hear of research at Bristol University, in the UK, where Dr Stark and his colleagues in the Bristol Energy Management Research Group have developed an electronic chip that can switch on a sensor only when that sensor is being asked to provide or monitor data: for the rest of the time the chip and the circuits which it controls consume no energy at all. It may not be a new battery development as such, but it would allow a much extended battery life, by eliminating all stand-by current drain.

The principle is that the chip uses the small amount of energy transmitted in the interrogation signal from the system asking for the data, to trigger a circuit that switches the device on. The interrogation signal could be from an infrared remote control, or a wireless signal. The team developed their circuit using the same principles as those used in computers to monitor their internal power supply rails – to ensure the voltage does not dip below a certain threshold. The trigger signal uses a few picoWatts of energy, and a signal threshold level of 0,5 V, which is achievable from a passive sensor, just using the received wave energy.

The natural follow-on from this concept is that the trigger signal on some sensor applications could be derived from the event being monitored, such as a rapid increase in the sound or vibration levels of plant machinery. Also, for a security alarm, the movement of a hinge or similar could be sensed magnetically. Conventional power management techniques would be used to switch the sensor off once the data has been transmitted to, and acknowledged by, the monitoring systems.

Power storage

With solar and wind energy providing such a large part of the power used by the National Grid in certain areas, many ways are being researched to achieve power storage over the short term, such as 24 hours. There are already companies providing large storage systems with banks of conventional batteries, acting like very large uninterruptible power supply (UPS) systems. In Spain and the USA there are solar collector systems where the sun’s heat is concentrated onto a central collector, melting sodium salts: the heat is later used to drive a steam turbine. Further systems are being trialled where surplus energy is used to liquefy gases, or compress them in a high pressure chamber, later the stored gas can be used to drive a turbine generator.

A novel development of a battery cell reported recently is the use of a low cost electrolyte for use with aluminium and graphite electrodes. Dr Dai, at Stanford University, in collaboration with Taiwan’s Industrial Technology Research Institute, demonstrated such a battery powering a motorbike in 2015, but the electrolyte was expensive. The new electrolyte is 100 times less expensive – it is based on urea. Dr Dai sees this as a useful solution for storing solar power, even domestically – maybe new houses will have such a system underground, and call it a “Power storage pit”!

This article was first published in the April issue of “South African Instrumentation & Control”, a TechNews publication. This journal is kind enough to publish an article from Nick Denbow every month, as a report on stories of interest from Europe.