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Solar power supplies are not all equal for full-year, consistent AQ monitoring

16-Jan-2024Networks | Performance | Power supplies | Product | Solar

Solar power supplies are not all equal for full-year, consistent AQ monitoring

Autonomous power can make all the difference in hyper-local air quality monitoring. With particulate matter sampling needing a little more power than passive gas sensors, solar is the go-to power option, rather than internal battery. Most systems require sufficiently little energy that they can be powered by a relatively small solar panel, but it’s the back-up power management that makes all the difference.

For much of the higher latitudes of Europe and North America, the challenge is to achieve full-year monitoring – just. What we want is to be sure that no readings are missed in December, but that we manage that without a huge solar panel or battery. Most small sensor air quality monitoring systems are mounted up lamp posts, so weight and size (wind resistance) are real considerations. As always, the devil is in the detail. Users should beware of ‘winter sampling’ settings, which reduce PM sampling during low solar power months, meaning each 15 minute reading may be based on as little as one minute of sampling. This is particularly relevant when the sampling regime is linked to certification, such as MCERTS.

The AQMesh smart solar pack power supply option provides consistent, smooth and autonomous power all year round for an AQMesh pod. The pack is much more than just a solar panel, with the true benefit lying in back-up power management: it’s about powering the pod when the sun is not shining.

The solar pack is quick and easy to install – even up a ladder – and comes with flexible mounting options for posts and walls. Guidance is offered for safe, straightforward installation of the pod and ‘all in one’ solar pack, working at height. The solar pack is a compact unit with an adjustable angle for maximum solar harvest. Setting the direction and angle of the panel correctly at installation makes a significant difference to solar yield, even if no further adjustments are made for years. The simple single connection to the pod is the same as that used with the AQMesh standard weatherproof DC power supply, so solar can be easily interchanged with direct mains power, if ever required. The solar pack also features an additional connection to power a second pod at the same time, which helps when co-locating pods for short periods.

Smart functionality allows the charger to efficiently maximise solar harvest, maintaining battery health and extending the life of the battery. Using ultrafast maximum power point tracking (MPPT), the system monitors the voltage and current outputs of the panel to ensure optimum solar harvest during changing weather conditions and light intensity throughout the day. It also features an intelligent load output function with over-charge protection – preventing excessive drain on the batteries – and ensuring that a full 100% recharge will be attempted every day. Charging and battery voltages are among the key pieces of information that can be checked on site using a smart mobile Bluetooth app. Used by AQMesh and customer technicians around the world, quick access to information allows speedy diagnosis of any issues on site, and battery voltage information is also available alongside readings on the secure AQMeshData.net server.

Another consideration is the type of back-up battery used. Many systems use lithium ion batteries, which should not be charged – or re-charged, as a back-up battery – at temperatures below 0°C, with a recommended operating range of 15°C to 35°C, making them unreliable for winter solar back-up. Lithium ion batteries can also be problematic for shipping, with even a small quantity of lithium classed as ‘dangerous goods’, bringing transportation limitations and delays. The AQMesh solar pack uses an AGM lead acid battery, which has sufficient capacity, will continue to operate throughout cold temperatures and is easy to ship and replace.

This efficient solar charger means that even during periods of poor weather, the smart solar pack can power an AQMesh pod consistently – all year round – across the UK and Europe, based on standard measurement settings, with no need to reduce the sampling regime.

From Alberta to Scotland – and many points at lower latitude – AQMesh users around the globe are benefiting from uninterrupted power supply thanks to our bespoke and proven solution for autonomous, wireless power.