Wireless Smart Grid
There is a lot of talk about the push and mandates about modernizing and moving our electrical system to the Smart Grid. The electrical grid in the USA is out of date and doesn’t allow for the use of modern technology to provide more efficient and cost effective power generation, delivery, and consumption of electrical energy. The goal of modernizing our electrical grid by using current technologies is to provide more reliable distribution, improve fault detection and allow self-healing of the network without the intervention of technicians, create greater efficiencies in monitoring and load adjustments based on peak using times and locations, provide greater security to the grid, and to empower the consumer to be able to better manage their usage and costs.
To make the Smart Grid a reality the implementation of modern communication technology needs to be deployed. Technologies such as, smart meters, intelligent thermostats and appliances, real time sensor metering and controls, and remote monitoring all require the use of reliable IP based communication infrastructure networks. The problem is electrical utility organizations’ electrical network (substations and end consumers) covers vast geographic areas. Many of which are not always near readily available fiber connectivity. This is especially true in rural areas. Even in urban areas there is sometimes difficulty in last mile connections where needed.
In order to build out the Smart Grid wireless backhaul plays a vital role and solves many problems by providing necessary high-speed bandwidth for the use of Smart Grid technologies. By the utilities using wireless Ethernet bridge technologies the utilities gain greater security by having a private network, they can also build in wireless redundancy for greater reliability, have quicker implementation time, realize huge cost savings, provide their workforce with wireless mobility, and have the flexibility for future expansion and growth.
Since the utilities have right-a-way access and easements it becomes easy for them to build out a wireless backhaul network using point to point wireless bridges. Fiber equivalent networks can be achieved with licensed microwave backhaul (see more at “Understanding Microwave Communication Frequencies and Point to Point Wireless Bridge Compared to Fiber”). Today a licensed microwave link can provide 6Gbps+ full duplex wireless connectivity. Using a wireless repeater can allow for long distance wireless backhaul. A typical microwave link can be deployed beyond 20 to 30 miles in a single point to point wireless bridge.
With a core high bandwidth microwave backhaul infrastructure, the use of high speed point to multipoint wireless can be deployed for last mile wireless connectivity. Technologies like WiMax backhaul and LTE allow for licensed interference free point to multipoint wireless bridge connections. True usable IP bandwidth of 10Mbps to 100Mbps can be delivered to the field using point to multipoint wireless Ethernet bridge systems. Wireless Mobility can bring high-speed data connections to workforce vehicles allowing for remote access of data files, email, work orders, and VoIP.
Bringing wireless Ethernet connectivity to the grid and to substations provides the ability to not only perform RTU / PLC monitoring and management, but also opens the way for wireless video surveillance and perimeter security, access control, alarm monitoring, remote workforce capability and access, and real time data collection. Most of all, wireless backhaul allows the integration of other third party Smart Grid devices like Smart Meters, remote switching, and SCADA.
Wireless Ethernet bridges bring the necessary infrastructure to Smart Grid technology. The main issue is that electrical organizations are really good at power generation and delivery, but they are not necessarily experts in telecommunications. It’s not best practices for them to build the internal expertise to build or maintain a large complex wireless backhaul network. Recently attending a Smart Grid conference it became apparent that many electrical organizations have relied on manufacture vendors, whose only goal is to move their product, to guide and influence the type of wireless hardware and wireless network topology they are trying to use for their telecommunications infrastructure. This becomes very problematic when it comes to the quality of RF (radio frequency) devices being used and the overall wireless network design.
In order to provide a long-term, reliable, interference free, and scalable wireless infrastructure it is important to use best of breed, carrier grade infrastructure, along with the use of proper frequency spectrum. Also from a security standpoint the proper wireless devices should be used and configured properly. It’s amazing to see how many electrical organizations have deployed value line, Wi-Fi chipset based, unlicensed wireless Ethernet bridges using 900MHz, 2.4GHz, 4.9GHz, and 5.8GHz for their mission critical network. Many of these systems only have a five year mean to failure time rating and are easily effected by wireless interference. These systems are in themselves not bad or lack some quality, but they fit where they fit and the Smart Grid infrastructure may not be the best use of these unlicensed wireless Ethernet bridge systems.
Electrical utilities have a lot of licensed microwave spectrum available for their use for free or at a very low cost basis. On the flip side many microwave radio systems are built for true full duplex operations, operate at the lowest possible latency, run interference free, and are built for a 20+year life cycle. There is also hardened point to multipoint wireless systems and SCADA telemetry radios designed for EMI protection precisely for use around high voltage applications.
As with any technology there is value level and enterprise level equipment and software. For mission critical wireless networks there is a large distinction between the quality, performance, and reliability of the two. Smart Grid implementers need to receive more education and proper knowledge transfer from the wireless backhaul industry so that the right business choices can be made on behalf of the country’s critical electrical infrastructure and ultimately the end consumer.