Building custom hardware is well-understood engineering — mature design patterns, modern toolchains, accessible prototyping. The hard part is deciding when it's justified, because certification (IEC 61010, 61850, 62443, UL), integration and long-term support dominate the cost. Often a certified off-the-shelf device plus a custom interface beats a bespoke all-in-one. Real value lies in building the right hardware, for the right reasons.
At Full Stack Energy we specialise in building bespoke energy systems. That often means integrating off-the-shelf hardware — industrial sensors, controllers, gateways — into robust, compliant, intelligent platforms. But occasionally the demands of the application go beyond what’s commercially available, and we design and deliver custom hardware. Not because it’s our default, but because it’s the only viable solution for a very specific need.
When does going custom make sense?
Custom hardware development is expensive, complex and long-term. The difficulty isn’t in building it — it’s in deciding when it’s justified. In our experience, it makes sense when commercial devices fall short on functionality, integration or environmental resilience; when legacy infrastructure needs modernisation that standard PLCs or gateways can’t bridge securely or flexibly; when system-level optimisation demands tight coupling between hardware, firmware and analytics; or when lifecycle control is critical in regulated, mission-critical environments.
But when compliance with multiple standards is required — especially beyond CE marking — custom hardware must be considered very carefully. Standards like IEC 61010, IEC 61850, IEC 62443 and UL introduce significant design, documentation, testing and cost burdens. Often a certified off-the-shelf device paired with a custom-designed hardware interface dramatically reduces cost, time-to-market and regulatory exposure compared with a fully bespoke, all-in-one solution. Unless the application is truly unique or the deployment volume justifies the investment, this hybrid approach usually makes far more sense.
Bridging legacy and modern systems
Many energy systems rely on legacy hardware — decades old, undocumented, built for a different era. Making it cyber-secure, remotely controllable and interoperable with modern protocols often requires a custom hardware interface, because off-the-shelf PLCs or protocol converters may lack the necessary security features, timing constraints or IO flexibility. Custom hardware lets us implement secure boot, encrypted comms and tamper resistance; translate between legacy protocols and modern standards like MQTT, Modbus/TCP or IEC 61850; and integrate directly with edge analytics or cloud platforms.
Why building it isn’t the hard part
Custom hardware isn’t inherently mysterious. A capable team can build a data-acquisition board for a substation or a control module for a solar inverter using well-established methods: mature design patterns (power measurement, motor control, industrial comms are well-understood); modern toolchains (Altium, KiCad, SolidWorks, STM32, TI C2000); and accessible prototyping (PCB fabs, dev kits, pre-compliance labs). The technical challenge is rarely getting hardware to work — it’s getting it to work in context, within the constraints of certification, integration and long-term support.
Why it is contextually complex
Energy systems impose unique burdens from day one:
- Harsh operating conditions: −40 °C to +85 °C, vibration, dust, salt spray or oil mist, and 4–6 kV surges from lightning or switching events.
- Integration with legacy systems: multiple protocols (Ethernet/IP, RS-485, CAN), undocumented equipment, and cybersecurity standards (NERC CIP, IEC 62443) demand firmware-hardware co-design.
- Support and lifecycle: even in low-volume deployments, supply-chain resilience, DFM/DFT and field upgradability are critical for long-term support.
Being full stack means owning the whole system — from the sensors that touch the field to the insights that drive decisions. Sometimes that means designing a custom board; other times it means knowing when not to.
Rethinking “full stack”
In energy systems, “full stack” often stops at the gateway — hardware integration gets handed off, and the link between physical layer and digital intelligence fragments. For us, the real value isn’t in building more hardware; it’s in building the right hardware, for the right reasons, within a resilient, supportable system. It’s the same judgement at work in our bespoke hardware design and the BLE technology choices in indoor positioning systems.