Sustainability
Windows
Windows Sustainability: Energy Saver
Energy Saver shipped in Windows 11, version 24H2, as a power mode people can leave on. I designed how its state shows on the taskbar and helped two organizations agree on what that signal means.
My part
Energy Saver states, accessible colour, taskbar signal
Duration
May 2023 – Feb 2025
Crew
Two PM orgs, Shell, design, research, icons
Ships on
Windows 11
Context & role
By 2023 Windows had many ways to save energy: Energy Recommendations, Battery Saver at 20%, power modes tuned by chip makers, Efficiency Mode, and device makers' own eco modes. Energy Saver was planned to replace and extend Battery Saver on every Windows 11 laptop, and to work on desktops with no battery at all. I worked on it from May 2023 to February 2025 across two organizations, with product managers in Windows Fundamentals and Core OS, the Shell team, a design partner, a researcher and Fluent icon designers. My role: I owned the Energy Saver state designs, their accessible colour treatment and the taskbar signal questions; product managers owned the feature decisions. I also planned and ran a cross-team sustainability workshop and supplied the final Settings design used in the launch press briefings.
Stakes
Windows already had many ways to save energy, but almost nobody found them: the features worked well for the few people who reached the Power & battery page. In a moderated study of the energy graph, almost everyone treated battery and energy as the same thing and said they'd only visit the page to find out why their battery drained. For Microsoft, saving energy was tied to sustainability commitments and to battery life as a reason people buy Windows PCs.
Reframe
Asked: add an eco button. Reframed: make saving energy safe to leave on.
The request was an "eco mode" button. A strategy response from Core OS argued Windows had a discoverability problem, not a missing feature, and proposed one switch people could leave on. My part was carrying that thinking to the taskbar. Battery Saver had been a low-battery emergency state, and every surface was built around that model. I raised two questions the spec hadn't answered: what tells someone their PC may be slower because Energy Saver is on, and where else they could discover it. The problem became a state people are comfortable leaving on, on a laptop or a desktop, that still reads differently from a low battery.
Illustration: a low-battery emergency state, versus one switch people can leave on, on any PC.
Evidence
Studies pointed away from the leaf. Accessibility pointed away from yellow.
Early tests of a leaf in the system tray confused people. On a desktop the reaction was "why do I need to know if Energy Saver is on? I don't have a battery," and a leaf on a full, plugged-in battery read as "did my device just get unplugged?" Icon research in spring 2024 found people preferred colour alone, but the colour tested was yellow, and accessibility review found no yellow that passed contrast against the icon in light theme. Research pointed to colour, accessibility pointed to brown, and nobody had tested brown.
01
Battery and energy are the same thing to people. Almost everyone in testing conflated them and couldn't read a unitless energy scale.
02
A leaf means nothing on a desktop. Without a battery, an Energy Saver leaf raised more questions than it answered.
03
Colour worked, but not yellow. People preferred colour to the leaf, and no yellow passed contrast in light theme.
In their words
"Why do I need to know if Energy Saver is on? I don't have a battery."
Desktop user, reacting to an early leaf icon
Key decision
Keep the leaf for now, and test the brown properly
The options were to drop the leaf for colour only, as the research suggested; keep the leaf Energy Saver was shipping with; or change in stages. The feature's PM disagreed with dropping the leaf, worried people wouldn't understand brown and a sudden change could hurt adoption, while Shell partners pushed for a brighter yellow like competitors use. With the Shell PM I proposed a staged path, which was accepted: keep the leaf for the first release but move and rotate it so the battery level stays readable, use the accessible brown fill whenever Energy Saver is on, and run a longer study before removing anything. I chose the staged change because a sudden one risked the confusion the project existed to remove, accepting a busier icon and a slower path to a cleaner one.
Second call
A switch people leave on, not a button they press
The first concepts used a push button: press it to save energy now. After review in September 2023, the team went back to a toggle, because a toggle implies the state persists, which is the whole point of an always-on mode. The brightness control stayed after we learned that removing it would interfere with adaptive brightness. Laptop and desktop designs locked as plan of record that fall, so the same control works whether or not a device has a battery.
Illustration: three ways to change the icon, and why we changed it in stages.
Craft
Accessible in both themes, not just the default
I designed the Energy Saver icon states in light and dark themes with Windows' existing accessible system colours: brown in light theme, yellow in dark. I said openly that I preferred yellow too, but none we tried passed contrast. The leaf moved to the top middle and rotated so it no longer hides the charge level, and the final Settings view I designed was the one used in the launch briefings. Every Energy Saver state was designed to pass accessibility review in both themes.
Illustration: Energy Saver states on laptops and desktops, in light and dark themes.
System
Colour means "performance is reduced", not "a feature is on"
Energy Saver has two behaviours: a standard mode meant to stay on, and High Savings, which starts at low battery. When the new icons shaded amber whenever Energy Saver was on, even at full charge, the teams debated it and aligned on amber only in High Savings, matching how phones signal low-power mode. Colour on the battery icon is reserved for the state that changes performance. That rule drew on the battery state model I built for the parallel battery icon redesign, where both behaviours sat side by side with every other battery state.
Illustration: the colour rule that separates "a feature is on" from "performance is reduced".
What shipped
What shipped
Energy Saver began rolling out in Windows 11, version 24H2, on October 1, 2024, replacing and extending Battery Saver on laptops and working on desktops without a battery. It shipped as a toggle in Quick Settings and Settings, with the brightness control kept so adaptive brightness still works. Microsoft's consumer and IT-pro launch posts highlighted it, and the final Settings design I supplied was the one used in the press briefings. The staged icon change shipped as agreed: the leaf moved so the battery level stays readable, with the accessible brown fill in light theme and yellow in dark. The redesigned battery icons with the Energy Saver colour states followed to Insiders in January 2025.
Outcome
What changed
Energy Saver began rolling out in Windows 11, version 24H2, on October 1, 2024, for laptops and for desktops without a battery, and Microsoft's launch posts highlighted it. I supplied the final Settings design used in the launch briefings, and the redesigned battery icons with the Energy Saver colour states reached Windows Insiders in January 2025. It shipped on schedule and led the launch story, but there is no adoption number yet, so the business case isn't proven here.
Reflection
Settle the meaning before the pixels
Settings, the taskbar and the tooltip all showed both modes as simply "on", and the leaf-versus-colour debate ran for almost a year because nobody had agreed what we were communicating. I would map approvers across both organizations at kickoff and agree adoption and comprehension measures before launch. The principle I took away: a status signal should tell people what changed for them, not which feature is on, and colour should always be paired with a shape or text cue.
