Zenseio Blog

Key considerations for IoT sensor devices: 2 – Power consumption efficiency
A pile of batteries

Executive Summary:

  • Battery replacement impacts the bottom line
  • Power efficiency reduces operating expenses
  • Energy harvesting eliminates battery replacement
  • Power efficiency enables new energy sources, miniaturizes size, and slashes cost
  • Power optimizations is an expert domain


Many, if not most, of the IoT sensor device deployments are in remote or difficult to access locations without any power grid access, and, thus, are battery operated. This makes replacement of depleted batteries a major cost factor. While the batteries themselves may not be very expensive, the labor to access and replace them can be very high, negatively affecting operating expenses. Therefore, power consumption efficiency is one of key factors behind business case profitability, or, even, feasibility. Anybody intimately familiar with embedded hardware understands that there is no free lunch when it comes to optimizing for low power. There are many conflicting tradeoffs to balance, and it takes considerable effort, skill, and experience to produce an optimal solution – a subject, in itself, covered by scientific publications, academic books, and PhD dissertations.

However, in general, the more computationally powerful the embedded hardware, the more power it will consume or the harder it is to optimize. So, as the starting point, right hardware has to be chosen for a given task. For example, running Linux-based software to make a simple sensor readings with a powerful processor will almost always take significantly more energy than doing the same readings with a power-optimized microcontroller with no Operating System (OS).

The benefit of low power consumption of a device is not only less frequent trips to replace batteries, but also a possibility of getting rid of batteries altogether. It opens a possibility of powering a sensor device by harvesting the available energy from the environment. And, while true that even the whole households can be powered from collected solar or wind energy, the size, cost, maintenance needs of such equipment are huge. Needless to say, the lower the power consumption, the smaller, cheaper, and easier to use the energy harvesters can get. Also, more types of energy harvesting sources become feasible, for instance motion/vibration, thermal, or electromagnetic fields in addition to solar and wind.