Getting smart meters right

By Andy Slater

Smart meters are one of the big energy saving hopes for the future, reducing energy use and lowering energy bills and carbon emissions, but there are still major questions regarding the network technology behind them. Andy Slater outlines the key debates to consider.

There is no doubt that smart meters help users reduce their carbon footprint. To manage the rollout of a smart meter network in the UK, the government this week launched a consultation process and documentation, which will lead to the technical standards and regulatory framework for the UK smart meter network.

Currently the government and industry there are considering which communication solution would be best suited for a UK roll-out; the two most discussed options are cellular and long-range radio, though other solutions including power line carrier and mesh solutions are also possible. British Gas was one of the first to announce a trial of smart meters, using cellular technology in early 2010. However, more recently, BT has announced a partnership with Arqiva and Detica to offer a dedicated and secure long-range radio communications solution for smart metering.

So, which solution suits a smart meter and smart grid network requirement best? Some of the key requirements of a smart meter network are: a high first-time connect rate for meters, data security, interference-free communications over the life of the asset, and suitability of the network to be used for smart grid as well as smart metering applications. It is in these key areas that some technologies fall short, which we believe makes a long-range radio solution, designed from the outset to undertake this function, the most suitable option.

Long-range radio has proven capabilities across a number of critical operational aspects, including meter first-time connect rates, which have been proven to be above 95 per cent in live deployments. Other technologies are not as successful, with cellular sometimes reported as low as 80 percent. Secondly, dedicated radio spectrum as used by licensed long range radio is free from interference from competing radio sources. This can't be said for free access/radiate spectrum, as used by mesh radio solutions, which have to compete to be heard. Whilst this may give acceptable performance in rural areas, the UK is predominantly an urban environment, with many devices competing to use this spectrum. 

Thirdly, smart meters are not just for electrical utilities. Gas and water utilities are also making the move to smart metering and require the same performance that only a long-range, purpose-built communications network can provide. Power line carrier alone cannot provide communication to unpowered gas and water meters, adding significant cost; or as in Italy, the system is owned by the electricity utility and can't be re-used for other utilities. Cellular radio has difficulty reaching water meters, which are often underground and their broadband signals drain batteries within gas and water meters, forcing more frequent replacement.

In the US and other countries, smart meter and grid technology selection has been left to utilities. However the UK is adopting a different approach. We believe this network will be a piece of critical national infrastructure and so must cover both electricity and gas metering and ultimately extend to water meters. It must also support smart grid applications, which enable utilities to manage distribution automation and introduce demand management. Such a comprehensive approach requires high service levels and a designed-for-purpose solution.

Whichever communication network the UK government selects, it must be one that rolls out successfully, offers the best quality of service, builds customer confidence, and ultimately enables energy users to make informed decisions to help reduce their carbon footprint. If the government selects a network that does not meet these needs, any environmental or financial savings could be lost and additional costs experienced.

Biography

Andy Slater is a chartered engineer and Director at Sensus, a global leader in utility infrastructure systems and resource conservation, providing advanced metering infrastructure, smart grid and conservation solutions for electric, water and gas utilities.