The visit is the real cost
Remote monitoring sites must keep collecting useful data when mains power is unavailable and access is difficult. A buoy, flood-monitoring station, mountain installation or remote pipeline may depend on solar panels and batteries, with maintenance visits measured in weeks or months rather than days.
How do you design a low-power remote monitoring station?
A low-power remote station is designed around its whole energy budget, not the sensor alone. Sensor consumption, sampling rate, heating, data processing and telemetry all draw on the same battery and solar panel, and the system has to keep running through the worst week of the year. A depleted battery means lost data and an expensive visit.
The challenge is not simply to choose a low-power sensor. Sensor consumption, sampling frequency, heating, data processing and telemetry all contribute to the energy budget. The system must continue operating through periods of poor solar generation, when conditions may be at their most demanding and the data most valuable.
Gill’s ultrasonic wind sensors and weather stations use measurement technologies with no moving parts, helping reduce mechanical maintenance requirements. Combined with appropriate sensor selection and system design, this can support longer unattended operation and fewer costly site visits.
Why remote monitoring needs a different approach
At a permanently powered site, a small increase in sensor consumption may have little practical consequence. At a solar-powered installation, every additional load affects the panel, battery capacity and period the system can operate without sufficient recharge.
The consequences extend beyond energy consumption. A depleted battery can mean missing measurements, interrupted alarms and an unplanned visit to a difficult-to-reach location. Depending on the site, that visit may involve a boat, specialist access equipment or a long journey.
Reliable remote monitoring therefore depends on designing the whole system around the available energy, the required data and the conditions the installation must withstand.
Sensor consumption affects autonomy
A sensor with low power requirements can reduce the energy demand placed on the supply system. This may allow a smaller panel or battery, or provide more operating margin during periods of low generation.
WindUltra is particularly relevant where size, weight and power consumption are constrained. It draws below 100 mW when unheated, under calm conditions. This figure must be assessed against the specified output, operating conditions and configuration rather than treated as a universal consumption figure.
WindUltra: below 100 mW unheated, in calm conditions
Heating can dominate the energy budget
Heating may be essential where ice or freezing conditions would otherwise interrupt measurement. However, heater consumption can substantially exceed the consumption of the sensor itself.
The decision is application-specific. An unheated sensor may be suitable where icing is not a material risk. Where heating is required, its power demand and operating conditions must be included in the energy calculation. A heated sensor should not be selected without considering whether the available supply can support it during the coldest, darkest periods.
Maintenance requirements affect the whole-life cost
Mechanical components can wear, stick or become obstructed. Ultrasonic wind sensors remove moving parts from the wind measurement mechanism, while optical rainfall measurement avoids the moving bucket mechanism used in a tipping-bucket gauge.
Reducing these mechanical failure points can lower maintenance requirements, although it does not eliminate the need for inspection, cleaning or checks for environmental damage. The benefit is particularly relevant when each visit carries significant cost or operational risk.
Ultrasonic | Optical
Sampling and transmission must match the decision
Continuous high-frequency measurements are not always necessary. A flood-warning system, a weather station and a research deployment may have very different requirements for sampling, storage and reporting.
Reducing the frequency of measurements or transmissions can save energy, but it can also reduce the detail available to detect short-lived events. The appropriate strategy depends on the event being monitored, the alarm requirements and whether data can be stored locally between transmissions.
Where the energy goes
The sensor is only one part of the load. A practical energy budget should include the sensor, heating, logger, communications equipment and any other connected devices.
| System component | Sensor | Heating | Telemetry | Logger | Complete installation |
|---|---|---|---|---|---|
| What drives consumption | Supply voltage, current draw, operating mode and duty cycle | Ambient temperature, icing risk, heater rating and operating duration | Transmission frequency, connection method and signal conditions | Processing, storage and sampling frequency | Seasonal generation, battery capacity and all connected loads |
| Ways to manage the demand | Select an appropriate low-power model and use power-saving modes where supported | Establish whether heating is necessary and calculate its demand explicitly | Match reporting frequency to operational needs and transmit summaries where appropriate | Use an appropriate sampling strategy and local storage where supported | Size the system for the worst expected operating period, with suitable margin |
Digital outputs can carry multiple measurements and status information through a single interface, but this does not automatically make a digital system lower-power than an analogue one. Compare the consumption of the complete sensor and interface configuration.
For solar-powered installations, the design should account for seasonal generation, battery performance, heating demand and the energy used by telemetry. Sizing against average conditions alone can leave the site vulnerable when solar input falls and power demand rises.
The trade-offs that determine autonomy
Heating versus operating time
Heating can help maintain measurement in icing conditions, but it consumes energy when the supply may already be under pressure. The appropriate choice depends on the severity of the environment and the consequences of losing data. Where heating is necessary, include its demand in the power budget rather than relying on the sensor’s unheated consumption figure.
Sampling detail versus energy consumption
Higher sampling rates capture more detail, but may increase sensor, processing, storage and transmission demand. Lower rates may be entirely adequate for slow-changing conditions but unsuitable for short-lived events or fast control responses. Specify the data required to make the operational decision, then work back to the necessary sampling and reporting strategy.
Published power figures versus installed consumption
Power consumption varies with model, output configuration, network termination and heating. A headline figure is useful for initial selection, but the energy budget should use the consumption data for the exact configuration and operating conditions. Include connected equipment and communications loads rather than calculating the sensor in isolation.
Fewer visits versus no maintenance
Sensors without moving parts can remove particular mechanical failure points, but remote equipment remains exposed to weather, contamination, corrosion, cable damage and other site-specific risks. Inspection intervals should reflect the environment, the importance of the measurement and the consequences of failure.
Gill products for low-power remote monitoring
These products provide options for sites where power, size, weight and access all influence sensor selection. Actual consumption and available interfaces must be confirmed against the datasheet or manual for the exact configuration.
WindUltra
Compact wind measurement with low power demand
WindUltra is a compact ultrasonic anemometer intended for applications where size, weight and power are constrained. Potential uses include buoys, unmanned surface vessels, UAVs and exposed remote installations.
The low unheated power figure makes WindUltra worth considering when building a remote-site energy budget. It should not be used as the total system consumption or assumed to apply under all operating conditions.
WindSonic
Wind measurement for environmental monitoring
WindSonic is a two-axis ultrasonic wind sensor with no moving parts. It offers output options for environmental monitoring and integration with compatible data loggers and control systems.
WindSonic may suit remote monitoring where a straightforward wind measurement is required. The best configuration depends on the available interface and the data the site needs to record.
MetConnect
Bringing environmental measurements together
MetConnect is a weather station hub for remote sites, with inputs for compatible external sensors, including rainfall and other environmental measurements. It can bring multiple measurements into a system through a supported output interface.
When several environmental parameters are required, consider the consumption of the complete station and connected sensors, rather than comparing the hub’s power figure alone. Check input compatibility and the required output protocol before selecting the configuration.
insight
Design for the worst week
A solar-powered station that operates comfortably in summer may struggle in winter. Daylight hours are shorter, solar generation may fall, and heating may run for longer periods. These effects can coincide precisely when storms, flooding or icing make reliable measurements particularly important.
The practical starting point is to build a load budget for the complete installation. Include the sensor, heater, logger, communications equipment and other connected devices. Establish when each load operates, how long it runs and whether it can be duty-cycled without compromising the measurement or alarm function.
Next, estimate the available energy during the least favourable expected period, taking account of panel performance, installation orientation, battery capacity and the conditions at the site. The design needs an appropriate margin for uncertainty rather than relying on average generation.
Sensor selection can then make a measurable difference to the design. A low-power unheated sensor may reduce demand where the climate allows. Where heating is essential, its consumption should be evaluated alongside the benefit of maintaining measurements. Sampling and transmission schedules can also be adjusted to the operational requirement, provided that important events will still be detected and recorded.
The aim is not to minimise every watt regardless of consequence. It is to allocate the available energy to the measurements and functions the site cannot afford to lose.
The full explanation is in How long should a professional wind sensor last?
Applications and resources
Application noteAN0055: Transmitting sensor data back from extremely remote locations
An application note on returning sensor data from sites where access and communications are challenging.
ApplicationFlood warning and water-level monitoring
Remote stations need to keep collecting and reporting measurements through adverse conditions, when access may be difficult and timely data is important.
ApplicationField campaigns and portable deployments
Temporary research and monitoring installations may depend on battery or solar power, with equipment selected for deployment time, portability and the measurements required.
ApplicationUnmanned surface vessels and autonomous marine systems
Platforms that carry their own power need sensing equipment selected around the available energy, payload and operating conditions.
Speak to our team
Tell us what you need to measure, where and under what conditions. We’ll help you work out the appropriate approach.
Remote monitoring questions
Yes, a weather station can be used in a solar-powered system if the available energy and storage are sufficient for the complete installation. The calculation should include the station, connected sensors, logger, telemetry and any heating. Consumption varies by configuration and operating conditions, so use the relevant product documentation when sizing the supply.
Consumption depends on the model, output configuration, operating conditions and whether heating is active. WindUltra draws below 100 mW unheated under calm conditions. This is a product-specific figure, not a universal value for all Gill anemometers or a guarantee of total installed consumption.
Heating can help maintain measurement during icing conditions, but it can add substantially to the energy demand. Assess the site’s climate and the consequences of losing data before choosing a heated model. If heating is required, include its consumption and expected operating duration in the power budget.
Ultrasonic wind sensors remove moving parts from the wind measurement mechanism, reducing exposure to mechanical wear and sticking. Optical rainfall measurement can also remove the moving bucket mechanism used by tipping-bucket gauges. These designs can reduce particular maintenance requirements, but inspection, cleaning and checks for environmental damage may still be necessary.
The best output is one the logger supports and that meets the application’s data requirements. SDI-12 is used in environmental monitoring, while Modbus RTU and serial interfaces may suit other systems. Compare the complete power consumption and required communications hardware rather than assuming one interface is always the most efficient.
Transmission frequency should reflect the decision the data supports. A slowly changing environmental trend may need less frequent reporting than a flood-warning or fast-changing weather application. Lower transmission frequency can reduce communications demand, but the system must still detect important events, meet alarm requirements and retain any data needed between transmissions.
Start by calculating the energy used by every component, including the sensor, logger, telemetry and heater. Estimate demand over the least favourable expected period, then assess solar generation, battery capacity and an appropriate reserve. The design should account for seasonal variation and the consequences of a power shortfall, not just average daily consumption.
No. Low-power operation can extend autonomy, while designs without moving parts can reduce certain mechanical maintenance needs. Neither eliminates the need to inspect the installation, clean exposed components, check cabling and verify measurement performance at suitable intervals.