If a water utility has an asset such as a reservoir, pipeline, pumping station or metering point, that sits beyond reliable cellular coverage, we typically design an architecture to transmit both individual and aggregated gateway data reliably, quickly and cost effectively.
In our network-agnostic design approach we evaluate line of sight, power budget, expected data volumes, latency tolerance, mobility and security requirements, then select the narrowest, simplest bearer that meets the need. Where possible we push analytics to the edge so the system sends only what matters.
Remote hydrology to inform generation decisions
A great example of this is RWE’s hydroelectric power stations in Snowdonia, Wales. When it rains heavily – as it often does in this remote, mountainous region – RWE has the opportunity to generate more renewable energy, by directing more water into leats and waterways, and from there into lakes and reservoirs. RWE needed to know the water levels in real time in order to benefit from the additional rainfall, and so installed solar powered hydrological stations to capture this information.
However, there is no cellular network in this protected area, so Ground Control worked closely with RWE and other partners to integrate satellite connectivity into the hydrological stations. Data is transmitted every three hours, but collected every 15 minutes, and edge computing allows the frequency of transmission to be increased if water levels go above normal parameters. Once the water levels drop, transmissions slow down again automatically, meaning that monthly usage at each site doesn’t exceed 2MB.
In this instance, Ground Control recommended and implemented the Hughes 9502 Viasat IoT Pro terminals (previously called Inmarsat BGAN M2M), as it was possible to establish a clear line of sight between the stations and the overhead satellite, resulting in a stable and economical connection.
Antenna placement is one consideration when selecting a satellite network and service; you’re also looking at location, power budget, latency, data volumes, mobility, data security, and how much control you have over your data – i.e., do you need to transmit over IP, or can you manipulate your data to use a message-based protocol, which is a more power- and budget-friendly option. It is always helpful to have expert advice, particularly as more satellite networks and services become available.
Reservoir monitoring under power constraints
Another customer had a series of reservoirs in Northern Canada that required remote monitoring over the long, harsh winter months. Viasat’s satellites are in Geostationary orbit, which means they appear to be stationary overhead, and your device needs to be able to ‘see’ the satellite. In the far north and south of the globe, this becomes increasingly difficult, and easy to block with vegetation and hills, so for this customer, the Viasat service would not work.
The other major constraint was power; solar panels would be partially effective over a Canadian winter, but the solution needed to be able to report on exception – i.e. wake up to transmit when data fell outside of normal parameters, then go back to sleep when water levels subsided – in order to preserve battery life.
For this, the Ground Control team chose the RockBLOCK RTU, a micro-data logger built for remote sensor capture in harsh, off-grid environments. It sips as little as 380mW at hourly reporting intervals, and can store and bundle sensor readings locally, transmitting only when values breach pre-set thresholds. This maximises battery life and keeps airtime costs down.
The service selected was Iridium Short Burst Data (SBD), a packet-based protocol that has much less overhead than an IP-based transmission (such as used by the Hughes 9502 terminal); again, this means reduced power consumption as only the active payload is sent. Iridium has pole to pole coverage; as long as you have a clear view of the sky, you can send your data.
Renewed momentum for Satellite IoT
Arguably once seen as a last resort, satellite connectivity is enjoying a renaissance, chiefly thanks to the introduction of cellular standards into the satellite ecosystem. The promise is that you can use a single chipset for NB-IoT or LTE Cat-1, and move between cellular and satellite networks seamlessly, lowering the cost of hardware and removing vendor lock-in.
In practice, satellite communication has more constraints than cellular communication; it costs more, you can send less, and it takes longer. But the gaps are narrowing, and while these ‘NTN’ services are in their infancy, they have prompted renewed interest in satellite IoT. While the tried and trusted satellite network operators are in the process of launching NTN services, they’re also launching new proprietary services at more competitive price points, such as Iridium Messaging Transport and Viasat IoT Nano.
This is important because no single satellite IoT service fits all. The new NTN services are designed for very small data volumes and latency-tolerant applications; they’re not designed for high data volumes or frequent transmissions, which are best left to the proprietary services.
Remote sensing for hydropower and dam safety is ultimately a systems problem in unforgiving places. The technologies are maturing, costs are falling, and options are proliferating, but the fundamentals endure: respect the physics, minimise the payload, and choose the simplest bearer that meets the risk. When teams centre those principles, the result is dependable data at the right time, without over‑engineering.
Satellite IoT and hydropower
From Ground Control’s deployments, six considerations repeatedly make or break outcomes:
- Sky view & geometry (LEO vs GEO). For GEO (e.g., Viasat), you need an unobstructed line to a fixed point on the horizon; small changes in mast height/azimuth can make or break the link. For LEO (e.g., Iridium), you don’t need continuous line‑of‑sight to a single satellite, but you do need an unobstructed view of the sky so passing satellites aren’t consistently blocked. Validate with pass simulations and on‑site tests, accounting for seasonal foliage and water level changes.
- Power budget. Start with the worst month of solar yield and temperature. Favour event driven, message‑based protocols; push compression and thresholding to the edge.
- Data minimalism. Separate sampling frequency from transmit frequency. Store‑and‑forward plus exception reporting protects both airtime and batteries.
- Latency tolerance. Decide what truly needs sub‑minute visibility (alarms, control) versus what can be hourly/daily (trends, reports). Map these to different bearers if needed.
- Environmental hardening. Specify for ingress protection, temperature range, connectors, mounting and surge protection. The best modem is useless if the enclosure fails.
- Data ownership and security. Clarify who controls device credentials and routing, how data is encrypted in transit and at rest, and how over‑the‑air updates are authenticated.
