Delivering the smart grid with bandwith for the future

 

Increasing the digital connectivity of distributed smart grid assets allows us to remotely monitor and operate distribution assets cost-effectively and safely. However, with a significant increase in the number of devices connected to the utility network, the threat of vulnerability from cyber-attacks increases too.

This makes it essential that communication links are designed to be secure, but encryption and authentication add to the bandwidth needed for these links. For high bandwidth IT links the overhead is proportionally small, but for OT links running at tens or hundreds of bits per second, security overheads can increase this by a factor of up to 100.

The availability of spectrum for the smart grid is a big concern for DNOs, when looking at the fast deployment of any wireless technology. The additional requirements imposed by security protocols must be taken into consideration when planning reliable and cost-effective telecommunications networks for power utilities.

Securing communications between the smart grid entities and complying with cyber security standards is critical, but requires more bandwidth which in turn consumes more spectrum.

The Power Networks Demonstration Centre (PNDC), as part of the University of Strathclyde, is a leading research and demonstration facility working to accelerate, de-risk and validate the deployment of new technologies across energy networks. Working closely with DNOs and technology vendors, the facility provides a collaborative environment for partners to develop innovative solutions across the energy systems domain.

An area of focus for PNDC collaboration with DNOs is minimising risk of disruption to the network and ensuring adequate protection from significant technical failures. Despite an extreme technical failure such as the loss of electricity nationwide being recognised as the least likely of scenarios, the potential risk has recently increased with the move towards digitalisation and decarbonisation.

A smart grid can’t be achieved without a high level of automation and control based on up-to-date and fully secure resilient communications functionality. Securing communications between the smart grid entities and complying with cyber security standards is critical, but requires more bandwidth which in turn consumes more spectrrum.

Efficient, reliable and secure wireless communication technology is crucial for any future deployment. Dedicated wireless communications networks may be required to enable the power networks for the future, so the availability of sufficient and appropriate spectrum is essential to enable the application of these technologies in the smart grid.

It’s also important to note that the rapid growth of distributed digital IP connected devices in power utilities also puts pressure on the available spectrum. Unlicensed spectrum could work for some applications, subject to the availability, where supporting better coverage in hard-to-reach areas is acting as a bottleneck.

The UK’s spectrum regulator (Ofcom) is working with DNOs to estimate the spectrum needed to maintain a stable and secure energy supply for the public, and to assess the case for any dedicated future release for power utilities. This would be best accomplished with a collaboration between the DNOs, the spectrum regulator, mobile providers and support from the research centres.

The PNDC is currently working on a project which addresses the bandwidth and security requirements for the smart grid, with the following aims:

• To estimate the resources necessary to satisfy the DNOs’ requirement for monitoring and control
• To examine the security overhead required for smart grid applications
• To define the scale of any future deployment
• To increase awareness of the importance of dedicated spectrum for safer power utilities
• To prepare documentation for input to Ofcom on spectrum requirements for utilities.

When deploying any radio communication system such as private LTE in critical infrastructure applications, access to licensed radio spectrum is crucial to guarantee the reliability of operation. The overhead traffic required to secure any connection will be quantified, and the compliance with the IEC 62351 [standard on cyber security for power systems] considered. To be able to determine the bandwidth requirements of the secondary substation of the future, current and future applications such as number of terminals, nodes and modems in each secondary substation along with the type of services and locations (rural/urban) per substation are needed. Each application and service will also require a security overhead, for example through IEC 62351.

Dedicated wireless communications networks may be required to enable the power networks for the future

Such overhead traffic will affect the transmission rate of the terminal, which in turn affects the bandwidth and the required spectrum. Any chosen bandwidth should take into account the future updates in devices fed from the secondary substation, such as EV charging points and battery storage. The question of whether the current recommended spectrum of 1.4 MHz or even 2x3MHz can meet the current and future utility requirements will be addressed.

The ongoing activities at PNDC will further consider the recent concerns from the National Cyber Security Centre and the DNOs on the security of future communication for power utilities, as well as requesting inputs from DNOs and vendors on managing the available spectrum and reducing the potential to lose power through enabling reliable communication technology. In addition to sharing the main inputs and test results with the spectrum regulator in the UK.

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