If you want to know how much energy a piece of software uses, the obvious place to measure is the wall socket. A plug-in meter tells you what the whole machine drew. It cannot tell you whether that was the processor, the graphics card, the drives or the fans, and for our work that is the part that matters.
In June 2025 we went looking for something better through the Innovation Exchange (iX) programme run by Innovate UK Business Connect. iX lets an organisation with a specific technical problem publish it as a challenge and brings back proposals from innovators across the UK. We had watched iX challenges for some time as a potential supplier. This was our first as the challenge holder.
It is not enough to monitor the bulk power draw at the socket outside of the machine.
Why the socket is not enough
GreenCode, the ITEA programme we lead, works on reducing the energy that software consumes. To do that we need to measure how software processes affect energy use inside the hardware, component by component, while the machine is stressed under benchmarking conditions.
Power supplies deliver power to internal components over standard connectors, such as the ATX format, on separate rails at 3.3V, 5V and 12V. Only a small number of power supplies monitor those rails at all. Where they do, the readings are typically locked inside vendor software built for other purposes, such as lighting control and overclocking, and are not easy to log or to feed into anything else. When we wrote the challenge we were not aware of any vendor-agnostic way to take component-level measurements in a workstation or server without intrusive modification or specialist equipment.
Software-side counters help, but only so far. RAPL, the processor interface our PHP Energy tool reads, reports on the processor and memory. It says nothing about drives, fans or add-in cards.
What we asked for
The challenge was titled Component-level energy monitoring for greener IT operations. It asked for an independent monitor that sits between the power supply and the components it feeds: the motherboard, graphics cards, interface cards, drives and cooling. The route we had in mind was a pass-through cable system, where the standard power connectors plug into the monitor and the monitor plugs into the components, with the electronics housed in something the size of an internal disk drive that mounts in a spare bay. We said we were open to other approaches, embedded or external.
- Vendor-agnostic and non-invasive, with no modification beyond intercepting the standard power connectors
- Current and voltage on every power line at high frequency. We asked for microsecond sampling and microvolt and microamp resolution, and said we were open to discussion on what is practical
- Onboard logging to simple CSV files, plus live readings to a separate device over USB, WiFi or Bluetooth, preferably through an HTTP API, so that collecting the data does not distort the energy use being measured
- No interference with airflow, cooling, safety or performance, including over long unattended runs
- Built from widely available components, with full design files, and manufacturable at scale in the UK
- A target unit cost of £50 to £150, against the £1,500 to £2,000 typical of a bench-top digital multimeter
We asked for solutions at or close to technology readiness level 6 that could be ready for field testing within six to twelve months, and said we would consider earlier-stage work with a clear route to that level within a year.
Why we made it a challenge
We build software, and a device like this falls outside the scope of the main GreenCode project. iX gave us a structured way to put the problem in front of electronics, sensor and sustainability innovators. Innovate UK Business Connect worked with us to shape the challenge statement, published it on 24 June 2025 and promoted it through its networks. Applications closed on 12 September 2025. Under the iX process, Innovate UK Business Connect assesses the applications and shortlisted applicants are invited to pitch to the challenge holder.
Why it matters beyond GreenCode
The number of servers and workstations keeps rising alongside the adoption of AI, which makes energy-efficient software more pressing each year. You cannot make software more efficient with confidence if you cannot see where the energy goes. A reliable, open, component-level monitor has a use across GreenCode partner experiments internationally, for the people who adopt GreenCode-based tools, and for anyone who needs accurate energy reporting from IT systems.
If component-level energy measurement is your field, or you need it for your own benchmarking, get in touch.
