Energy efficiency - Smart meters: finding the right network


The UK government is currently looking to smart meters as one of the key initiatives to drive energy efficiency, transforming the country’s consumption of energy by enabling consumers to make informed choices regarding their energy use, lower their bills and reduce carbon emissions. Andy Slater, director at Sensus, explains

Smart metering communication technology enables customers to view on an in-home display their energy consumption as they use it. It also centralises usage data, so meter readers don’t have to visit individual premises for data collection. However, ahead of the UK roll-out there are still important questions regarding the choice of the network technology for smart meters which need clarifying.

The UK roll-out involves potentially 27 million homes at a cost of around £9bn and while the government is looking to accelerate the roll-out, it’s clear the network of choice will play a vital role in the success of smart meters and is therefore a key consideration. Currently it’s assumed all UK homes will be connected to the network but the reality is that connecting some electricity and gas meters is harder for some proposed network solutions than others. This is because meters typically live in hard to reach locations, such as; under stairs, in basements and behind cupboards.

The government and the utility industry are currently evaluating which communication network would be best suited for the UK roll-out; the two most debated options to date are cellular and long-range radio. British Gas announced a trial of smart meters, using cellular technology in early 2010. However, more recently, BT announced its consortium, SmartReach, with Arqiva, and Detica using technology provided by Sensus to offer a utility grade, dedicated and secure long-range radio communications solution.

Selecting the right communication network for the UK smart meter roll-out
Cellular provider Vodafone estimated in its Carbon Connections Report (July 2009) that only 70% of UK homes have cellular coverage to their meter cupboard. This is not because of a lack of coverage, but due to cellular signals not penetrating buildings to where meters are actually located. Therefore if cellular was chosen as the network solution, what would happen to the 30% (9million) of homes that don’t have adequate cellular coverage to the meter?

In addition, analyst house Ovum suggested cellular had been chosen as the communication network for the first significant smart meter deployment in the UK (by British Gas), not because it was the best but because it was believed to be the only viable solution at the time the trial was announced.

Long-range radio has a proven track record in North America for smart meter and grid networks but is a new technology here in Europe (though it is now in trial in Reading).

Long-range radio technology was designed from the outset for smart metering and grid applications. It offers universal coverage, secure, and dedicated communications for what we believe is part of the UK’s critical infrastructure, like the TETRA radio system is for the emergency services. Experience in North America has shown it to have a first time connection rate to meters of greater than 99.5% within coverage areas - ensuring a minimal number of homes are left unconnected or requiring second visits.

Long-range radio is also highly reliable and is cost effective to deploy as it requires minimal infrastructure, also making it easy to maintain. It enables software upgrades and pricing changes to be broadcast to all meters simultaneously and also offers a prioritisation channel for emergencies and alarms.  In addition to the connectivity of the network, some other critical considerations for the smart meter programme success include:

Availability - Public networks like cellular can have a high level of network availability but, because they are used by the consumer market, performance can be affected by network congestion at peak and sometime critical times. To avoid conflict, the communication network needs to be dedicated and designed specifically for the utilities.

Survivability – Smart meter networks will need the ability to continue to deliver a service even in the presence of a failure or accident. Private networks can achieve a high degree of survivability but public network technologies lack adequate back-up power so can become unserviceable after quite short periods of power interruption and can remain unavailable until power has been restored. Using Power line communications means loss of the supply cable can affect the ability to manage the network itself.

Coverage - The diversity of utility environments and the mix of urban and rural areas means achieving a high first-time connection rate for meters with some technologies can be difficult. This could be detrimental to the effectiveness of the roll-out and result in additional engineering costs and second visits to homes adding cost and complexity.

Security - The protection of sensitive data and the control of access to critical systems is key to the success of the roll-out but problematic when the network is not secure and dedicated. The more elements there are and the more public a network is, the harder it becomes to secure it adequately.

Evolution from smart meters to the smart grid
At the moment the GB ‘smart’ project is clearly retailer led, with a focus on smart meters and the customer experience. However, in other markets it has been shown equal benefits are realised through smart grid features, particularly in ensuring security of energy supply. In Europe, where the energy utilities remain vertically integrated, ‘smart’ projects are being specified with the active participation of the distribution network experts. Smart grids enable distributors to manage their networks more efficiently with real data to facilitate better planning and management of peaks.

Within the GB project smart grid requirements are currently very light, and there’s a risk that the functionality required of the network to support future smart grid operations will be missed. If this happens it will be difficult and expensive to fit retrospectively, indeed aspects like network latency, multicast and broadcast features, may not be able to be addressed if the wrong technology is selected at the outset.

Energy efficiency must be a key consideration
Whichever communication network is selected for the UK, it must be the one that offers the best quality of service to consumers and business, supports a roadmap to future smart grid services, is secure and cost efficient to roll-out.