Lessons learnt from CLP’s smart meter pilot

The ‘Internet of Things’ (IoT) connects every day physical objects via Internet Protocols. Smart metering is an implementation of IoT in the energy sector.

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Sep 27, 2017
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Author(s): Lap Shun Wong and Wayne Pales

Abstract

CLP Power Hong Kong (CLP) launched the 18-month smart metering pilot, named myEnergy Program, in May 2013. The key objectives were to investigate the costs, benefits, and challenges of implementing the smart metering integrated platform, such as seeing if customers are interested in tools and services which can help them conserve energy and to find out if smart metering is technically feasible in Hong Kong’s unique densely populated, high-rise environment. This study discusses the technical challenges encountered with networks near customers’ end, namely Neighbourhood Area Network and Home Area Network. Making use of high mobile penetration rates in Hong Kong, user-friendly web portals and mobile apps were designed to allow customers to track their electricity consumption anytime anywhere. Furthermore, CLP paid considerable effort in maintaining cyber security for the network and its data. The myEnergy Program was a rewarding experience for both CLP and its customers, providing many technical lessons learned as Hong Kong begins its journey to a Smart City and embraces IoT.

Introduction

Smart meters provide the capability to support better information and more options for customers, advanced energy efficiency and conservation services, a safer, more reliable and efficient grid and the increased uptake of distributed renewable energy generation and electric vehicles.

Recent research [1] show that the penetration of smart meters by 2023 will reach 80% in the United States, almost 60% in Europe, and above 45% in Asia, with China leading the way with 300 million smart meters due to be installed by 2015 [2,3].

Responding to these worldwide trends, in May 2013 CLP Power Hong Kong Limited (CLP) launched South East Asia’s first comprehensive study on smart metering and its supporting technologies (collectively referred to as Advanced Metering Infrastructure or AMI). The objective was to test the costs, benefits and challenges of introducing such system to Hong Kong, with a view to this technology supporting Hong Kong’s journey towards a Smarter City. This initial study, referred to as the ‘myEnergy Smart Metering Pilot Programme’ (myEnergy) covered 4500 residential and Small Medium Enterprise (SME) customers and continued through 2014.

With Hong Kong being one of the most densely populated cities in the world, with one of the highest penetrations of smart phone usage; adopting myEnergy is based around the principles that define the Internet of Things (IoT) and had never been done before. While operating environment in the city is unique, CLP faced a number of technical challenges to get the program implemented.

This paper starts with CLP’s 2020 Smart Grid Vision and design of the smart metering system to realise IoT for provision of better services. Followed by technical lessons learned from networks at customers’ end, namely (i) Neighbourhood Area Network (NAN), (ii) Home Area Network (HAN) and (iii) Cyber Security, there will also be an outlook for future smart metering development in Hong Kong.

CLP’s myEnergy program

Balancing Energy Trilemma in Hong Kong

According to the World Energy Council, all energy providers should ensure a balance is achieved between the ‘Energy Trilemma’, including energy security, environmental sustainability and energy equity [4]. In Hong Kong, CLP operates a vertically integrated electricity generation, transmission and distribution, and marketing and customer services business, providing power to approximately 5.8 million people, equivalent to 80% of the population. Being socially responsible, CLP aims to strike a balance the three core policy ingredients of the Energy Trilemma:

  • Reliable and safe supply – Security of energy supply refers to diversity and reliability of energy supply from external sources, also the ability of energy providers to meet current and future demand.
  • Care for the environment – Achievement of supply and demand side energy efficiency, and usage of renewable energy.
  • Reasonable tariff – Accessibility and affordability of energy supply across the population.

CLP’s 2020 Smart Grid Vision

As one of the key measures to support CLP’s Energy Trilemma, CLP published its 2020 Smart Grid Vision [5], where edge devices of power network, particularly smart meters at customer premises, are critical to provide a level of visibility and control that was not previously possible (Fig 1).

Fig 1: CLP’s 2020 Smart Grid Vision

In CLP’s 2020 Smart Grid Vision, by integrating information and communication technologies into the grid, customers will be provided with more energy options for helping them to save energy. The grid will also be more reliable with increased efficiency and enhanced operational safety. Smart grid will also bring a higher fidelity ‘situational awareness’ and enable the following features when it integrates with consumer driven technologies:

  1. timely visibility of external event;
  2. event information process at the edge of the grid;
  3. insights delivered to field workforce quickly;
  4. business-wide situational awareness;
  5. grid and asset management analytics;
  6. insights to deliver personalised services to customers; and
  7. data to customers to leverage external services.

Launch of myEnergy program

Since smart meter is the key enabler of smart grid, to test the costs, benefits and challenges of introducing such system to Hong Kong, CLP launched the 18-month myEnergy Program in May 2013. It is the first system in South East Asia that works from billing system all the way through the meters in the field. By enabling two-way communication between CLP and customers, this system provides around 3000 residential and 1400 SME customers with timely energy consumption information.

While smart metering system is completely new to Hong Kong, objectives for myEnergy include:

  • Explore if smart metering technically work in Hong Kong’s unique densely populated, high-rise environment.
  • Investigate if customers are interested in tools and services enabled by the smart metering integrated platform for energy conservation.
  • Determine if customers are willing to conserve energy during critical peak times through demand response events when it is hot and humid.
  • Examine if smart metering has the potential to enhance safety and reliability of power supply in Hong Kong.

The high-level smart metering architecture consists of networked devices located in customer premises displaying timely information on their energy consumption. Smart meters capture consumption data and transfer them between CLP and customers via telecommunication networks such as NAN and HAN. There are also various data management systems for billing and customer services (Fig 2).

Fig 2: Smart metering srchitecture for myEnergy. ‘Routers’ are also known as ‘data concentrators’ [6]

How smart metering realises IoT

IoT is defined as ‘a global infrastructure for the information society, enabling advanced services by interconnecting (physical and virtual) things based on existing and evolving interoperable information and communication technologies’ [7]. It has a sea of potential applications, with smart metering being one of them and is being implemented in developed countries as part of smart city initiatives [8].

Fig 3 illustrates data flow in myEnergy and how it transforms electricity consumption data into a series of useful actions [9]. CLP adopted IPv6-compliant wireless technology for its scalability and interoperability. With smart meters connecting in mesh networks and establishing two-way communications with Headend systems, it enables value-added services that were never possible and realises IoT.

Fig 3: Data flow in myEnergy

Customers with timely consumption data on various platforms, such as web portal and mobile apps, are empowered to make informed decision to support energy efficiency and conservation, and to participate in demand response events. CLP can benefit by gaining a more detailed insight of the grid, for example taking periodic reads every 30 min for a comprehensive load profile or receive last gasp alerts that indicate power outage at particular customers. All of these are helpful to CLP for enhancing reliability and safety of power supply and improving operational efficiency.

Challenges encountered and lessons learned

Most, if not all, projects encounter challenges at some point and myEnergy was no exception. This section discusses few technical challenges relating to (i) NAN, (ii) HAN and (iii) Cyber Security, and how CLP overcame them to achieve project success.

Neighbourhood area network

Field Area Network is the last-mile localised network to consolidate data from tens to hundreds of smart meters in data concentrator and transfer these data back to Headend via cellular network. Between data concentrator and smart meters there is NAN, which CLP experimented thoroughly for meeting various operating conditions in Hong Kong (Fig 4).

Fig 4: Communication network architecture for typical utilities [10]

During the design of myEnergy, the following operating conditions were considered when selecting the technology for NAN:

  • High rise buildings (on average around 50 floors high).
  • Densely populated commercial area/buildings.
  • Centralised metering rooms in residential buildings.
  • Shopping mall with meter rooms that are spread out in corners.
  • Mountainous areas with large rocks or trees potentially obstructing signals, or low valleys which makes the signal difficult to reach data concentrator.

With the above in mind, CLP conducted a comprehensive desktop assessment on common NAN technologies used worldwide given in Table 1.

NAN

Advantages

Disadvantages

RF Mesh (−900 MHz)

• Complies with international standards

• Limited spectrum at 900 MHZ in Hong Kong

• Running on quiet spectrum

• Quick deployment

Wi-Fi Mesh (2.4 GHz)

• Complies with international standards

• Overlaps with domestic Wi-Fi appliances

• Quick deployment

• Low penetration power

Power Line Communication (PLC)

• Can leverage existing power cables to ease implementation effort

• Open standard is still at infant stage

• Deployment flexibility in various buildings such as high rises and village houses

• Need permission from building management offices to use their LV rising mains

Direct Cellular

• Ideal for certain sparsely populated areas

• Cost effectiveness becomes a concern in high density meter rooms

• Weak coverage in some villages or confined areas in basements

Table 1: Comparison of various technologies as NAN in myEnergy

CLP decided to opt for RF Mesh (920–925 MHz, 400 kHz per channel) as the primary technology since it is standard-based, running on a quiet spectrum, which do not interfere with any domestic Wi-Fi appliances and quick to deploy. The myEnergy sites were in high rises, low rises, shopping malls and village houses; with direct cellular as the technology to transfer data back to CLP.

Before actual site deployment, CLP engaged a local university to assess RF emission from smart meters and data concentrators to ensure there was no health and safety concern to the public [11]. Readings were taken before and after devices installation at test sites, and it was found that results in both cases were very similar. Even some higher power emissions only resulted in emissions of several to hundreds of mV/m, which at similar level with mobile phones or WIFI router. There was neither adding effect nor superposition from smart meters and other household communication devices, hence the devices brought no critical concerns to the public.

Despite detailed planning, some technical challenges were encountered in high rises after installation:

  1. Inter-Building RF Mesh Communication – Signal strength decreased among buildings significantly due to multiple steel reinforced concrete walls surrounding meter rooms in high rises.
  2. Unstable Cellular Signal at Data Concentrator– Data concentrator is usually situated in the meter room at the building centre to facilitate RF Mesh formation with other smart meters. This results in poor cellular reception as most mobile operators’ antenna is either on roof top tilting down to face the street or at lower level for optimal coverage.

Relocating data concentrators resolved the above issues. To improve inter-building RF mesh communication, the data concentrator was moved to the rooftop of nearby CLP substation, which faced the buildings, so signal from smart meters pass through less barriers before reaching the data concentrator in neighbouring building. As for the latter issue, the data concentrator was relocated to the meter room at lower level for wider coverage.

For village houses, there were hard-to-reach meters in low valleys. They were mitigated by evaluating strength of RF mesh formed and replacing few neighbouring electromechanical meters with smart meters to reinforce link between meters and data concentrator.

To minimise missing links and mitigation effort, and to improve meter-to-data concentrator ratio in making the overall solution more cost-effective, CLP conducted extensive field tests targeting customers of typical environment. These include (i) high density residential towers with shopping mall, (ii) medium density low rise tenement buildings and (iii) low density village houses. Few RF types, namely Frequency Shift Keying (FSK), Long Range (LoRa), lower power radio, and PLC were tested. Key findings are

  • High density residential towers with shopping mall:
    • FSK radio offered good connectivity within a single building, and LoRa radio links were established between buildings. However as bandwidth of LoRa radio link is narrow, it is critical to ensure there are enough LoRa radio links for stable inter-building connectivity.
    • Low power radio transceiver with 13 dBm (both FSK and LoRa radio are with average output power of 29 dBm) achieved similar connectivity with FSK radio within a single building and with improved signal-to-noise ratio.
    • PLC completed missing links between floors without meter rooms, e.g. carpark, where RF Mesh could not be formed (Fig 5).
  • Tenement buildings:
    • As tenement buildings are located closely with meters located at staircase entrance, FSK radio formed good RF mesh with neighbouring buildings.
    • PLC was also tested and it linked meters across buildings well as long as they were supplied by the same transformer. In particularly it established fast and effective connection with some hard to reach meters.
  • Village houses:
    • Performance of FSK radio was satisfactory. Some occasional LoRa radio links observed for distant meters.
    • Low power radio did not result in good connectivity because it could not travel long distance nor through trees.
    • Although PLC is proven as an alternative to FSK radio and is able to reach distant meters, some smart meter features may not perform under certain scenarios, e.g. under power outage. Most village houses are radially fed, so the smart meter may not be able to issue last gasp signal if there is a disruption to the power line.

Fig 5: Meter rooms distribution within a tested high rise buildings with shopping mall and carpark [12]

Considering time and effort required for deployment and mitigation, the result from these sites suggested that a combination of RF and PLC would be optimal for smart metering’s NAN to work effectively in the Hong Kong environment.

Home area network

HAN connects a smart meter and smart electrical appliances of a household. For example, it can link between a smart meter with an in-home display (IHD) that shows energy consumption or receive demand response notification from the utility. Some usual interfaces for HAN include Zigbee, wired or wireless Ethernet and Bluetooth [13,14].

As overseas utilities launched HAN program for customers to get energy monitoring device and connect it to their smart meter [15] in early 2013, at launch of myEnergy, CLP also studied feasibility of pairing IHD with smart meter using Zigbee. The preliminary site survey result done by CLP revealed an expectation gap. It is because most people in Hong Kong live in apartments, where smart meter for every household are located collectively in a single meter room on each floor.

Fig 6 is a floorplan showing connectivity of HAN during preliminary site survey on one typical floor in a housing estate. Even meter room is located at almost centre of the three wings, Zigbee signal strength decreases sharply within metres after passing through doors and concrete walls. Range extender might be possible to improve signal strength; however, it requires an available power socket at door of the flats as supply and has to be in line of sight with the meter room. In parallel to these tests, CLP also held a series of focus group in which customers indicated their preference on receiving information via smartphones and Internet. Considering technical pre-requisites and customers’ expectation that aligns with the IoT concept, CLP decided to replace dedicated in-home displays with access via smart phones and the Internet.

Fig 6: Floorplan Showing Connectivity of HAN in a Public Housing Estate

According to a report by the Hong Kong Government, as in May 2013, household broadband penetration rate is at 85% and mobile penetration is at 231%, which is one of the highest worldwide [16]. CLP made use of this high Internet penetration rate by developing myEnergy Web Portal and myEnergy Mobile Apps as cost-effective solutions for customers to obtain their own energy consumption data with tailored energy saving tips.

CLP’s myEnergy Web Portal and mobile apps provide timely and meaningful electricity consumption information to customers through various features, including projected bill, usage comparison, tariff analysis and consumption alerts, aiming to drive their behavioural changes. Similar features are also available in myEnergy Mobile Apps. Furthermore, as some customers may not have access to the Internet, myEnergy Paper Report was also developed to send along with electricity bill. The report contains comprehensive information on daily usage and energy smart tips (Fig 7).

Fig 7: Home Page of myEnergy Web Portal and mobile apps

Cyber security

The network and data of CLP’s smart metering system is secured from end-to-end based on risk assessments for three key properties, i.e. identification, confidentiality and authentication. Leveraging guidelines listed in the National Institute of Standards and Technology (NIST) IR-7628 Guidelines for Smart Grid Cyber Security, CLP developed a comprehensive Security Governance Lifecycle to effectively apply relevant controls to manage risks to an acceptable level from technical, people and process perspectives.

Communication network and security key management for field devices are the potential vulnerabilities. CLP protected the former from unauthorised access by applying various encryption, digital signature and authentication measures as shown in Fig 8 [17]. As the latter is the foundation to safeguard communications all the way from the devices to the Headend systems, CLP set up a dedicated server, which is embedded with a Hardware Security Module (HSM), to store all meters’ keys centrally and achieved security that levels with those for financial transactions in the banking industry.

Fig 8: Secured communication network for CLP’s smart metering system

To ensure the setup and controls were properly implemented to protect customer’s data with the highest level of security, CLP appointed external experts to conduct independent cyber security assessments before the system was launched. This included security testing of smart meters and data concentrators. CLP also assigned a 24/7 operation team to monitor the operation and security events of every component in the system and to take immediate action as required.

Outlook for future smart metering in Hong Kong

As South East Asia’s first comprehensive study on smart metering, myEnergy demonstrates the integration of traditional power grid with Information and Communication Technology in many ways:

  • First IPv6-enabled end-to-end smart metering platform running live in South East Asia that can scale to cover all 2.4 million customers of CLP Power in Hong Kong.
  • Timely consumption information provided to customers through uniquely-designed web portal and mobile apps.
  • New tariff products to incentivise customers in energy efficiency and conservation.

Positive response from myEnergy customers indicate there is a potential for a mass rollout of smart metering in Hong Kong. Based on technical results obtained, CLP is working on cost-effective strategies to scale up the network and exploring new services enabled with other components in the IoT, as IoT is an emerging trend which is forecasted to have connected devices of about 20–30 billion units worldwide by 2020 [18].

Conclusions

CLP has always been aiming to achieve a balance between the core objectives in Energy Trilemma, which is to provide safe, reliable and affordable power without increasing burdens on environment. One of the key measures to support CLP’s Energy Trilemma is to deploy smart meters as an important enabler to allow further insight to the power grid.

To evaluate the costs, benefits and challenges of introducing smart metering system to Hong Kong, CLP launched the 18-month myEnegry Program in May 2013. The key initiatives is to encourage customers to make informed decision and hence proactively control their own electricity consumption when they are given timely information, and to find out if smart metering is technically feasible in Hong Kong’s unique operating environment. It is running on IPv6-enabled end-to-end smart metering platform, making it a realisation of IoT.

Telecommunication technologies for NAN and HAN were tested. For NAN it is recommended to use a combination of RF and PLC. There were difficulties during HAN implementation. Making use of the high Internet penetration rate in the population, web portal and mobile app were developed to display electricity consumption information. Besides, CLP protected customer’s data with the highest level of security, as proven by the security assessments.

The myEnergy Program was a rewarding experience for both CLP and its customers. Smart metering enabled platform and services can drive energy efficiency and conservation, paving the way for a sustainable future for Hong Kong and an era of IoT.

References

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Go to the profile of Wayne Pales

Wayne Pales

Co-founder, The Chapel Group

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