Infrasync Newsletter #18 -Get the Data – Are all sensor communication types created equal?

One water utility had a very complex water distribution system. Two large treatment plants, dozens of pump stations, water tanks, and pressure valves. They wanted to connect their data sources and infrastructure to have more real time knowledge about their system.

However, with hundreds of pumps, tanks, values, and other equipment they needed to know. Was all their data coming in equal? Or was some data more trusted and reliable than others?

Don’t make the mistake of assuming all your sensor data is equal. If you are working to make real time decisions based on your utility data, then the type of sensor communication technology is critical to get right. The utility team that understands their options and uses the right communication type for each purpose will have a huge advantage during times of crisis. With sensor and communication technology you don’t have to be an expert, but it helps to know the basics.

SCADA – Supervisory Control and Data Acquisition

This is best utilized at treatment plant sites as it’s typically a wired connection.  Most utilities already have a form of SCADA in place. It is typically the faster form of communication with latency in the milliseconds for processing on site. The downside is it’s almost all directly powered. So, if you lose power at the plant, you lose all your sensors. So critical facilities often have standby generators or at least a 2^nd powerline feeding them.

The big downside is most SCADA design and equipment is custom and expense to implement. So, implementing a whole system to capture just a single data point doesn’t make much sense. So they are often at all treatment facilities, most pump stations, but rarely in the distribution or collection piping systems.

Cellular Networks

This can be very easy to implement. You can just deploy sensors and then the big cell carriers (AT&T, Verizon, T-Mobile) will read it for you and give you data access. This has a lot of popularity because the utility doesn’t have to set up or maintain any of its network. The big upside is the ability to stream audio or video files from a device thanks to 4g and 5g. The big downside is the ongoing costs for the cell carriers. It’s also typically a bigger drain on battery than other options. Your communications are also owned by the cell networks, not by the utility so you have to make sure your devices will be supported for the long term.

Radio

The utility will either contract out or provide their own radio towers for this. It can be extremely flexible as the utility owns or controls their equipment and network. So if there is an area of town with poor cell coverage they can just extend their own radio network to cover it. The big downside is instead of the cell companies coving all the towers and maintenance, now the utility must do it. On the plus side the ranges and battery life are typically better.

There are also mesh options for radio. It’s often used for electric metering as there is a strong power feed at the meter/sensors. It works by hopping from one sensor to the next until it hits a collector which then has a cellular or satellite backhaul.

Satellite

Many utilities us this to monitor remote assets or when they cannot get reliable coverage from radio or cellular. This uses satellites in low orbit around the earth to get reads from basically anywhere. It’s very common to see these for water quality monitoring on streams or oceans with no nearby cell signals. The down sides are latency can be up to a few seconds and battery life is drained quicker.

One of the most popular networks for utilities is Iridium as it’s not very effected by weather. There is a live tracker here: 

Manual Reads

While not often discussed this can be a good option. If you deploy a traditional sensor, meter, or equipment it requires someone to be onsite, observe the reading, and then log the reading. Examples can be chemical samples, high water marks, visual observations, or other data that is gathered less often.

A hidden benefit of this approach is it can also be used to validate the workers and their performance. If you are making a quick data checklist as part of their responsibilities to fill out each data then it provide both a quality check on any sensors plus a accountability check on the worker.

What did they do?

After reviewing what they already had in place vs what their other options were they decided to map out the following:

All water treatment plant data and pump stations – SCADA

This gave then almost instant information about their most critical assets. For security purposes they implemented an on-site historian to log all the data and then a one-way connection out to a database for analytics.

All water quality and pressure sensing – Cellular

For dozens of water quality sensors, pressure monitors, and other sensors they could move every few months, produced lots of data, and battery life wasn’t a critical factor they placed all that on a cellular network. This gave them flexibility to start/stop service and move sensors around as needed.

All water meters – Radio

For their thousands of water meters, they wanted to keep the battery life for 15+ years. Those sensors also didn’t need to be moved, really ever. And some of the locations were in places that cellular couldn’t reach. The data type was very low volume and just sends a few times a day. This gave them a low-cost option for thousands of devices and the ability to move radio collectors to make sure every location was covered.

All wastewater level sensors – Satellite

Their wastewater system was overwhelmed during bad thunderstorms and rain events. Often during those events the utility facilities would lose power or cellular coverage would get bottlenecked. They chose the satellite communication for their wastewater level sensors. The higher monthly fee was worth it for data communication completely independent of location conditions.

What about for your utility?

There is no silver bullet for communication technology. It depends on each utility and exactly what their needs area. A good approach is to have most of your devices on a single platform but provide redundancy at a few critical areas and locations. Take an assessment of all the devices you rely upon for getting data for your water operations. Do you have any gaps? What about redundancies?

For example, all your wastewater lift stations should have SCADA to monitor and control the pumps. If there is a big power outage you could do for days or weeks without a reading. So, it may be a good idea to have a cellular or radio device backup just monitoring the level for your team as the backup.

It does make sense to press the vendors for the full communications platform they use. Make sure you know the full data handling chain and their responsibility vs others. If they rely on a cellular network, they will have limited control over future updates. Likewise, if they have a radio network see how much work is required of your utility vs the vendor.

Know someone who could benefit from this info? Forward this newsletter to them!

Make sense to connect?

Are you working to help your utility or technology company take the next step forward? If you want to talk through a challenge or share something interesting your team did please shoot me a note at [email protected] or schedule a utility technology review here.