As heavy users of electricity, commercial customers such as hotels are hit hard when power utilities increase their rates in response to high demands. To protect against these expenses, the director of engineering for a hotel in San Francisco is using an intelligent energy storage and usage tracking system. A sophisticated software system developed by start-up Stem uses comprehensive algorithms to track the business’s electricity usage—past and present—as well as weather, in order to predict demand spikes. When rates are low, energy is stored in on-site lithium-ion batteries—for use when demand and prices rise. The system is fined-tuned to minimize energy bills and operate the storage and release processes to minimize wear and tear on the batteries.