Why your smart meters are not lasting as long as they should

Leading smart meter manufacturers like Itron, Kamstrup and Growatt design their meters to last 20 years or more. But many start having operational issues within just seven years in the field. In the UK, for example, nearly four million smart meters did not work properly in 2024.

While hardware issues often take the blame, the real problem might lie somewhere less obvious: in your file systems and flash software controllers. In this article, we will shed light on a hidden threat to smart meter longevity and share practical solutions to help engineering teams extend their lifespan.

Key takeaways

• Smart meters are often designed to last 20 years or more, but many start having operational issues within 7 years in the field.
• Write amplification, where flash memory writes more data than the application asked for, wears out NAND flash early and is an often overlooked cause of meter failures.
• Constant logging to SQLite databases on resource-constrained MCUs, combined with file system overhead such as metadata updates and journaling, drives write amplification up.
• Adding more flash raises the bill of materials of a low-cost meter, while flash-friendly file systems and flash software controllers reduce write amplification without new hardware.
• In a customer test with Tuxera NitroFS and FlashFX Tera, a smart meter platform passed more than 20 years of simulated use, and further optimization extended its lifespan to up to 32 years.

Why your smart meter longevity is at risk

Smart meters work around the clock, logging data, recording events, and updating firmware, with data and event logs typically stored in SQLite databases. This constant activity puts a lot of pressure on NAND flash memory.

Most meters run on real-time operating systems (RTOS), with resource-constrained microcontroller units (MCUs) and limited memory. In this environment, flash storage becomes the weakest link. Factors like file system overhead, metadata updates, journaling, and garbage collection (moving valid data around to reclaim free space) all worsen the issue.

In an unoptimized system, these factors add up, causing flash memory to exceed its endurance limits sooner than expected. Many engineering teams overlook this risk, assuming default file systems are enough for smart meters. However, standard file systems are designed for general use, not the demanding endurance requirements of long-life embedded devices.

Smart meters are typically low-cost devices, often costing around 40 euros or less, so adding more flash memory might seem like an easy solution to extend lifespan. But this increases the bill of materials (BoM) and the hardware cost per device, which original equipment manufacturers (OEMs) cannot afford if they want to stay competitive in a cost-sensitive market.

The hidden threat: write amplification in NAND flash

Write amplification means a system writes more data than intended. For example, if your application writes 1 KB of data, NAND flash memory could end up writing 8 KB or more due to storage inefficiencies. The higher the write amplification, the faster the flash memory wears out, cutting device lifespan short.

Write amplification in smart meters causes premature wear on NAND flash memory, which can lead to data loss, unexpected failures, and costly replacements. This overlooked issue is dramatically shortening the life of smart meters across the industry.

Our recent SQLite workload tests show that write size, sync intervals, and concurrent processes significantly increase the write amplification factor (WAF). While longer intervals between syncs can help merge writes, they also raise the risk of data loss, which is a real problem for field devices like smart meters. Our white paper How write amplification kills designs covers the topic in more depth, including Linux and FreeRTOS comparisons.

The real challenge is to solve the write amplification problem without increasing hardware costs or the risk of data loss.

The best approach: file systems and flash software controllers designed for longevity

Standard file systems are not designed for NAND flash, leading to excessive write amplification and premature wear. Flash-friendly file systems, however, significantly reduce this write amplification factor (WAF) and improve flash endurance.

Smart flash software controllers also make a difference. They manage how data gets written, erased, and redistributed across the memory. With better wear leveling and garbage collection, they prevent any single flash block from getting overworked, extending your device’s life and improving flash endurance in smart meters.

Power outages are inevitable for smart meters. When they happen, data corruption becomes a major risk. The right combination of file systems and flash software controllers provides robust protection, keeping your data intact and your operations stable.

A senior R&D manager at a leading smart meter company shared their experience with Tuxera NitroFS™ (formerly Tuxera Reliance Nitro™) file system and FlashFX Tera™ flash software controller: “We successfully completed lifespan testing, simulating over 20 years of product use with more than 1.2 billion SQLite3 write transactions.”

While their testing met the minimum lifespan requirement, our engineering team helped them optimize their system even further, extending the meter’s lifespan up to 32 years. This shows that even a small component like the file system can have a huge impact on overall device longevity.

White paper

The smart meter storage decision

Write amplification is one of two mechanisms that end a meter early, and power loss during an in-flight write is the other. This paper compares buying reliability in hardware with engineering it into the storage stack, and gives you a framework to score both against your own platform.

Read the paper

Ensure a 20-year smart meter lifespan with smarter storage

Consider file systems and write amplification from the start of the design. By choosing the right embedded solutions for your smart meters, you can:

• Prevent early storage failures
• Reduce maintenance costs
• Meet regulatory requirements

For utility companies, this is more than a technical detail, because it directly affects whether your meter readings are accurate and reliable, which impacts everything from billing to planning. Investing in optimized embedded file systems for smart meters today will save you from costly replacements down the road.