Ensuring pure air in Scottish towns.

15/01/2018

In North Ayrshire, Scotland, monitoring activities have demonstrated that the main local air quality issues are related to traffic congestion caused by a section of the High Street in Irvine, which is being used as a bus terminus, and by queuing traffic at New Street in Dalry. In both locations the pollutant of most concern is Nitrogen Dioxide.

Sensor on street in Irvine.

North Ayrshire Council operates a fixed continuous air quality monitoring station (AQMS) in Irvine High Street which supplies data to Scottish Air Quality website.

“Data from the AQMS is supplemented by portable monitoring equipment that is installed at key locations,” reports the Council’s Willie McNish. “Passive diffusion tubes provide approximate monthly average data, but over the last 2-3 years we have started using AQMesh air quality monitors. Three ‘pods’ have been installed in pollution hotspots and a further AQMesh pod is used as a mobile device; installed temporarily in key locations to assist with air quality strategy development, and planning and development control.”

AQMesh air quality monitoring pods, from Air Monitors, are small, lightweight, wireless, battery or solar -powered air quality monitors that are quick and easy to install. They are able to monitor the main pollutants simultaneously, delivering accurate cloud-based data wirelessly via the internet. “We use the AQMesh pods for air quality screening,” reports Willie McNish, one of the Council’s Officers responsible for air quality monitoring. “The beauty of these monitors is that they provide almost real-time data that we can access via PC. This is really useful for detecting and predicting trends. For example, I can look at the current air quality measured by a pod and then look at the Met Office website for information on wind speed and direction, and this helps us to better understand the factors that affect air quality.”

The ease and speed with which AQMesh pods can be installed in almost any location is a major advantage in air quality investigations related to planning applications. For example, Willie says: “Concerns about dust and fumes from trucks were raised in connection with an application to extend the life of a landfill site by ten years (as less waste is being landfilled more time was required to fill it), but by locating an AQMesh pod (measuring gases and particulates) in an appropriate location, we were able to support the planning decision by demonstrating that air quality would not be harmed by the extension.”

Monitoring is also informing the development of traffic management strategies to reduce exposure to air pollution. In Irvine, Willie says: “The prevailing wind direction is from the South West, which creates a canyon effect, whereby air pollution accumulates within streets that are confined by buildings on both sides. This effect is exacerbated by queuing double-decker buses, so we plan to undertake remedial measures and monitor their effects.”

As a consequence of the elevated levels of Nitrogen Dioxide in Irvine, the Council will undertake public realm works (streetscape improvements) to widen the pavement, and one of the bus stops will be relocated. This will not only move the source of pollution away from the receptor, but also allow better dilution and dispersion of pollutants, without affecting the frequency of service or convenient access to public transport. In Dalry, a new bypass is due to be constructed and it is anticipated that this will lower Nitrogen Dioxide levels. In both locations, modelling has indicated that air quality will improve, but existing monitoring data will be compared with data once the work is complete, so that an effective evaluation of the effects on air quality can be performed.

Summarising the advantages of the Council’s air quality monitoring strategy, Willie says: “The AQMS in Irvine employs standard reference methods or equivalent, to measure air quality, so it is able to provide definitive data for comparison with EU limits. The station is serviced and maintained by Air Monitors and delivers extremely high levels of data capture. Since 2015 it has also included a FIDAS 200 particulate monitor, so we are now able to monitor TSP, PM10, PM4, PM2.5, PM1 and Particle Number simultaneously, which provides greater insight into the types of pollution and their likely sources.

“To complement the AQMS we also operate 4 AQMesh pods which provide the flexibility we need to monitor air quality in precisely the location of greatest importance. Web connectivity combined with Air Monitors’ reliability of service provides us with continuous access to accurate air quality data, which means that we are able to fulfil our statutory obligations as a Council, and also find ways to protect the health of people in North Ayrshire.”

@airmonitors #Pauto @scotairquality @_Enviro_News #Environment

Air pollution – the invisible roadside killer.

14/12/2015

The VW emissions scandal has helped to raise awareness of the deadly threat posed by air pollution in many of our towns and cities. In the following article, Jim Mills, Managing Director of Air Monitors, an instrumentation company, explains why diesel emissions will have to be lowered and how the latest monitoring technology will be an essential part of the solution.

Background
The World Health Organisation has estimated that over 500,000 Europeans die prematurely every year as a result of air pollution – especially fine particulates from combustion processes and vehicles. Of these, around 30,000 are in Britain; however, experts believe that the figures could be substantially higher if the effects of Nitrogen Dioxide (NO2) are also taken into consideration.

London Smog - now less visible!

London Smog – now less visible!

Historically, air pollution was highly visible, resulting in air pollution episodes such as the Great London Smog in 1952. However, today’s air pollution is largely invisible (fine particulates and NO2 for example), so networks of sophisticated monitors are necessary.

The greatest cause for alarm is the air quality in our major towns and cities where vehicles (main diesels) emit high levels of NO2 and particulates in ‘corridors’ that do not allow rapid dispersion and dilution of the pollutants. Urban vehicles also emit more pollution than free-flowing traffic because of the continual stopping and starting that is necessary.

As a result of its failure to meet European air quality limits, the Government was taken to the UK Supreme Court in April 2015 by ClientEarth, an organisation of environmental lawyers. In a unanimous judgement against Defra (English Department for Environment, Food and Rural Affairs), the Court required the urgent development of new air quality plans. In September 2015 Defra published its Draft Air Quality Plans, but they have not been well received; respondents have described them as disappointing and unambitious. CIWEM (The Chartered Institution of Water and Environmental Management) , an organisation representing environmental management professionals, for example, said: (the plans) “rely on unfunded clean air zones and unproven vehicle emission standards.”

Some commentators believe that Defra should follow Scotland’s lead, following the publication, in November 2015, of ‘Cleaner Air for Scotland – The Road to a Healthier Future’ (CAFS). Key to this strategy is its partnership approach, which engages all stakeholders. Under CAFS, the Scottish Government will work closely with its agencies, regional transport partnerships, local authorities (transport, urban and land-use planners and environmental health), developers, employers, businesses and citizens. CAFS specifies a number of key performance indicators and places a heavy emphasis on monitoring. A National Low Emission Framework (NLEF) has been designed to enable local authorities to appraise, justify the business case for, and implement a range of, air quality improvement options related to transport (and associated land use).

Traffic-related air pollution
In addition to the fine particulates that are produced by vehicles, around 80% of NOx emissions in areas where Britain is exceeding NO2 limits are due to transport. The largest source is emissions from diesel light duty vehicles (cars and vans). Clearly, there is now enormous pressure on vehicle manufacturers to improve the quality of emissions, but urgent political initiatives are necessary to address the public health crisis caused by air pollution.

A move to electric and hybrid vehicles is already underway and developments in battery technology will help improve the range and performance of these vehicles, and as they become more popular, their cost is likely to lower. The prospect of driverless vehicles also offers hope for the future; if proven successful, they will reduce the need for car ownership, especially in cities, thereby reducing the volume of pollution emitting vehicles on the roads.

Vehicle testing is moving out of the laboratory in favour of real-world driving emissions testing (RDE) which will help consumers to choose genuinely ‘clean’ vehicles. However, the ultimate test of all initiatives to reduce traffic-related air pollution is the effect that they have on the air that people breathe.

Ambient air quality monitoring
Networks of fixed air quality monitoring stations provide continual data across the UK, accessible via the Defra website and the uBreathe APP. Many believe that this network contains an insufficient number of monitoring points because measurement data has to be heavily supplemented with modelling. However, these reference monitoring stations, while delivering highly accurate and precise data, are expensive to purchase, calibrate and service. They also require a significant footprint and mains electricity, so it is often difficult or impossible to locate them in the locations of most interest – the pollution hotspots.

Public sector budgets are under pressure, so the cost of running the national monitoring network and those systems operated by Local Authorities is a constant source of debate. The challenge for technology companies is therefore to develop air quality monitors that are more flexible in the locations in which they are able to operate and less costly in doing so.

Air Monitors’s response

New technology
Air Monitors has developed a small, battery-powered, web-enabled, air quality monitor ‘AQMesh’, which can be quickly and easily mounted on any lamp post or telegraph pole at a fraction of the cost of traditional monitors. Consequently, for the first time ever, it is possible to monitor air quality effectively, where it matters most; outside schools, on the busiest streets and in the places where large numbers of people live and breathe.AQMesh_podAQMesh ‘pods’ are completely wireless, using GPRS communications to transmit data for the five main air polluting gases to ‘the cloud’ where sophisticated data management generates highly accurate readings as well as monitoring hardware performance. In addition, it is now possible to add a particulate monitor to new AQMesh pods.AQMesh does not deliver the same level of precision as reference stations, but this new technology decreases the cost of monitoring whilst radically improving the availability of monitoring data, especially in urban areas where air quality varies from street to street.The flexibility of these new monitors is already being exploited by those responsible for traffic-related pollution – helping to measure the effects of traffic management changes for example. However, this new level of air quality data will also be of great value to the public; helping them to decide where to live, which routes to take to work and which schools to send their children to.

New monitoring network for Scottish ports!

05/07/2015

Historically, ferry masters operating off the west coast of Scotland would have to sail to a port and on arrival visually assess the weather and tide conditions before deciding whether safe berthing alongside the pier or quayside would be possible. This wastes time and fuel, and can causes immense frustration among passengers, who may see ferries come close to a port, but thereafter depart without berthing when conditions are determined by the ferry Master to be unsafe. These ferries provide a critically important lifeline service to the islands, so the reliability of ferry services is extremely important.

MV_Caledonian_Isles

With multiple sites in island locations, remote access to accurate local data providing live information on tide level and key climatic conditions could facilitate substantial improvements to the service by aiding the Masters to make a more informed decision at an earlier stage in the voyage – in some instances even before departing the previous port or harbour. The berthing of ferries is a highly skilled job, particularly during bad weather, and the decision on whether a specific ferry can safely berth at a specific port is subjective and ultimately can only be taken by the ferry Master.

Following a competitive tendering process Caledonian Maritime Assets Limited (CMAL), which owns many of the ferries, ports and harbours in the region, procured a network of 15 tide and weather stations from instrumentation specialist OTT Hydrometry. The new monitoring equipment provides live data on port conditions to enable the ferry sailing decisions to be made in a timely manner.

CMAL Harbour Master David McHardie says: “OTT installed the first monitoring station in August 2014 and the network is now almost complete with sensors providing data every 1 minute via UHF radio to ‘gateways’ in the ferry offices, which then submit the data via the internet to a central server, which can be remotely accessed by authorised users.

“We have a regulatory requirement to monitor the tide level in our statutory harbours, but this system also provides essential weather information for our ports. In the past, these measurements were taken manually, so the availability of continuous multiparameter data is an enormous improvement – not just in the quality and value of the information, but also in the safety benefits for harbour operations staff, that this provides.”

OTT_Monitoring_Station

OTT Monitoring Station

The safety considerations involved with the berthing of ferries relates not just to passengers and crew but also to the pier hands that assist with mooring operations in a wide variety of often extreme weather conditions. “Mooring operations are inherently high risk activities; handling ropes can become extremely heavy when wet and subject to enormous forces when under strain,” David says. “So, it is important for us to be able to assess the impact of wind, temperature and waves to protect harbour operations staff. Severe weather berthing conditions can also potentially cause damage to ferries and the structures within the ports, so again, detailed data on localised conditions can help prevent accidents and support insurance claims when necessary.”

The availability of live data on port conditions therefore enables the ferry Masters to make better informed decisions at an earlier stage, thereby saving time, fuel and costs. It also means that passengers are provided with earlier warnings of potential ferry cancellation.

Emphasising the growing need for data, David says: “In recent years, severe weather events appear to have become more frequent and they seem to develop faster; for example, since the monitoring network was installed, we have recorded a sudden drop in temperature of 8°C in just 5 minutes at the port of Armadale on the Isle of Skye, and a maximum wind gust of 96 knots at Castlebay on the Isle of Barra. These conditions represent a rapid deterioration of conditions and the monitoring network enables us to respond quickly and effectively.”

Each monitor is located adjacent to the main berthing area on the pier with a lockable GRP control box. The system is comprised of: an OTT radar level sensor; a Lüfft ultrasonic weather monitor measuring wind speed, gust and direction, air temperature and barometric pressure; an Adcon radio unit with back-up batteries and a marine grade antenna. The radar tide level sensor is an OTT RLS, a non-contact sensor employing pulse radar technology with a large 35m measurement range. Both the RLS and the weather sensors, which have no moving parts, have extremely low power consumption, which is vitally important for installations at remote sites. At two locations it was not possible to install a radar sensor so an OTT CBS (bubbler sensor) was installed providing comparable levels of accuracy and reliability.

Robin Guy managed the monitoring network project on behalf of OTT Hydrometry. He says: “We were obviously delighted to be awarded this contract; it’s a good example of the bespoke monitoring systems that we are able to develop, integrating our sensor, datalogging and telemetry technologies to meet customers’ specific needs.

“Before awarding the contract to OTT, David visited four of our existing installations at the Greenock Ocean Terminal near Glasgow to check the reliability of our equipment in demanding conditions. However, in addition to the ruggedness of this equipment, it has also been designed to cope with interruptions to the mains power supply. The monitors are therefore battery powered and data is transferred from the monitors to the port office gateway via low power radio.”

Monitors on end of pier!

Monitors on end of pier!

Now that the CMAL monitoring system is installed, David is looking for ways to leverage the value of the data. For example, radio data transmission works very well over water, so it should be possible to fit the same technology on ferries so that the ferry Masters can access the data directly, instead of having to call the port office for a verbal update. The OTT monitoring network also incorporates an email alert system, and whilst this has not yet been configured, it will be possible in the future for ferry masters to receive email alerts warning them when pre-specified port conditions arise. “We would also like to eventually make the data available to the public as part of an enhanced harbours information system,” David says. “However, when a ferry has berthed, with the monitoring system being located on the pier, the vessel can cause a wind shadow; which means the wind data during that period can be potentially misleading. It has to be remembered that this system remains only an aid to navigation.”

Summarising, Robin Guy says: “This system demonstrates the value of remote monitoring data, but also highlights the importance of low power, rugged, reliable instruments in harsh environments. The modularity of the system is also very important because it enables us to deploy the most appropriate instruments in each individual location.”


New fault current measurement technology shows promising results in trials with Scottish Power

09/02/2012

Outram Research’s new fault current prediction technology developed by John Outram, the company’s MD, has proven to deliver accurate results during the first stage of field trials with ScottishPower. Knowing the peak fault current on their networks is critical to electrical utilities, as it defines the rating of the components such as circuit breakers required to ensure that they can safely withstand the large release of energy that occurs during an electrical fault.

Outram’s patent-pending technique to predict fault current from network measurements has been developed to provide greater accuracy than current approaches. The project, funded by Ofgem’s Innovation Funding Initiative (IFI), consists of three stages. In the first stage of the trials, which measured RMS “break” current, Outram’s solution delivered accuracy to within 2% of the network model. By accurately predicting fault current, utilities can ensure that network components are correctly specified and eliminate the money wasted when over-compensating to provide a safety margin that allows for the existing, possibly inaccurate, approaches to their calculations.

Fault current is measured using an algorithm developed by Outram Research, which runs on their PM7000 power quality analyser. The PM7000 is already widely used by companies wanting to troubleshoot, identify and resolve power quality problems quickly and efficiently. The first stage of the project was to predict the RMS “break” current, which represents the highest possible current that might have to be interrupted in the case of a fault occurring on an already live circuit. Breakers in the network must operate up to this maximum fault current to ensure that the power is safely and quickly disconnected.

“The first stage of the field trials have been very encouraging, demonstrating the huge potential of Outram’s technique to predict fault current,” said Jim Sutherland, SP Energy Network’s Director of Network Development. “We’re optimistic that once all stages are complete, we will be able to use this approach to allow us to accurately specify breakers and other components in the network.”

Stage two of the project, which aims to measure the peak “make” current – the current that flows when a connection is made to a section of the network where a fault is already present, has begun.

Electricity distribution networks are becoming increasingly complex, and can no longer be modelled as a simple “waterfall”, where power flows from the power station to the load. In the event of a fault, components such as motors and embedded generation will deliver power back to the grid. This presents a potentially unknown level of fault current since it is impossible to have prior knowledge of such events without building complex network models and having a full understanding of all customer loads. Local electricity generation from renewable sources presents a similar downstream contribution that should be calculated. The third stage of the project will demonstrate that the Outram approach can elucidate the contribution to fault current from such loads through its measurement technique.

Existing approaches to calculating peak “make” current are less accurate than those for peak “break” current, and they usually ignore the increasingly important downstream contribution.

“ScottishPower has been an excellent partner, allowing us to demonstrate the effectiveness of our new technique in a real-world situation,” said John Outram. “We’re delighted with the results of the first stage of the field trials, and are excited as we move into the second and third stages, where our refined and extended fault current prediction will provide even greater benefits to electrical utilities.”