The choice of primary communications technology used to connect smart meters to utility companies will have a significant short and long-term impact on the cost, efficiency and carbon footprint of smart grid solutions, as well as their ability to deliver enhanced customer value.
According to the government’s timetable, a decision on the primary technology(ies) that will be used to connect smart meters will need to be taken by mid-2013. There are three main contenders for this role.
Mobile data: The basis of most mobile data networks around the world today is General Packet Radio Service (GPRS), or 2.5G. GPRS enables fast data transfer while requiring minimal changes to basic GSM network infrastructure. It covers more than 98 per cent of the UK population, with good indoor coverage, low power consumption and the necessary bandwidth for smart metering. The technology is already widely used by a large number of organisations, including emergency services who rely on the network for day-to-day operations, and is already successfully being deployed for smart metering in the UK and around the world.
Perhaps the greatest benefit of GPRS is that it is an established open standard technology, with high technical and operational maturity in robust and trusted networks worldwide. Using GPRS for smart metering would not require the building of a new network from scratch, and so avoids the significant cost (several hundred million pounds) and contribution to carbon emissions that a new build would entail.
There is an abundance of GPRS machine-to-machine (M2M) module makers, which helps to drive build quality and competitive pricing. GPRS also offers a proven secure network layer, with A5 encryption and SIM-based authentication.
Off-peak scheduling of communications means meter readings can be transmitted outside busy network periods, if necessary. Where GSM/GPRS infrastructure is uneconomic to deploy, such as in remote areas, economic in-fill technologies such as satellite, long-range VHF radio and wireless mesh technologies are available.
Medium to long-range Ultra High Frequency (UHF): A purpose-built, tower-based UHF radio network – using the same frequency range as analogue TV signals – would be built from scratch to meet smart metering communication requirements.
UHF provides good indoor coverage, low power consumption and adequate bandwidth for smart metering – although the bandwidth is lower than for GPRS. The tower-based infrastructure is a mature technology in broadcast markets and offers a dedicated network for exclusive use by utilities.
The biggest drawback of UHF is that the infrastructure is not yet available, and will require significant investment and lead times to build. Furthermore, UHF solutions would require specialist communications modules, with little likelihood of competitive pricing.
Broadband over Powerline (BPL): BPL uses existing electricity mains wiring to connect homes to a local aggregator (such as a substation).
BPL has the advantage of ubiquitous reach (to every single electricity customer in the UK), ease of installation and widespread use overseas. However, the structure of the UK smart meter rollout makes BPL an unlikely technology choice, because its implementation is supplier-led but distribution network operators control the networks of infrastructure required.
In addition, BPL requires the installation of relatively expensive smart meter modules, as well as a concentrator or repeater at every substation. The network would need to be financed from smart metering revenues alone. Bandwidth is limited and is susceptible to radio interference.
The key advantages offered by GPRS over competing technologies make it the ideal platform for smart meter communications: it is proven, low-cost, fit-for-purpose, and requires minimal additional investment to cover 100 per cent of the population.
Any investment in mobile technology in time for the 2019 rollout is also future proof, because it offers the flexibility to meet changing requirements for speed and capacity over time – for example, by evolving to 3G or Long Term Evolution technology. This is a unique differentiator.
For example, in New Zealand, smart metering solution provider Advanced Metering Services chose GPRS for its immediate availability and national coverage. Smart metering services will eventually encompass more than 500,000 meters when the country’s multi-year national deployment is concluded.
Vodafone itself is already saving £2 million annually by reducing electricity consumption at its 12,000 radio base stations in the UK, thanks to a GPRS M2M-based smart metering solution developed in partnership with Bglobal.
Peter Kelly, enterprise director, Vodafone UK