WattTime answers a simple question that turns out to be surprisingly complex: how clean is the electricity you’re using right now? The nonprofit provides real-time and forecast marginal emissions data for electricity grids around the world, delivered through an API that software developers and device manufacturers can integrate into their products.
The concept is called automated emissions reduction (AER). When a device or system knows the carbon intensity of grid power at any given moment, it can shift flexible loads — EV charging, water heating, battery cycling, HVAC pre-conditioning — to times when the grid runs on renewables and away from times when gas and coal plants are dispatched. The environmental benefit comes without any user sacrifice; the device just picks the cleaner window automatically.
WattTime’s data feeds are used by companies ranging from smart thermostat makers to large industrial energy management platforms. Partners include Google Nest, Arcadia, Schneider Electric, and the UN’s Climate TRACE initiative, where WattTime helped build a global inventory of greenhouse gas emissions from satellite data. The organization operates as a nonprofit subsidiary of RMI (Rocky Mountain Institute) and keeps its team lean — about 40 people — while maximizing impact through the network effect of its API being embedded in millions of connected devices that collectively shift gigawatt-hours of demand toward cleaner generation.
