Do I need one Alva Link per device, or does one Link control everything?

One Alva Link per local device. Cloud devices need none of their own.

Local devices connect through the Alva Link hardware: one for your heat pump, one for your solar inverter, one for your EV charger, and so on. This is driven by how energy hardware physically communicates. Each device needs its own direct wired or wireless connection, close enough to keep a reliable protocol link. Your heat pump is in the utility room, your EV charger is in the garage, your solar inverter is on the wall outside. One box cannot reliably reach all of them.

The upside: each connection is dedicated and rock solid. No shared bus congestion, no protocol conflicts, no single point of failure. If one Link needs a firmware update, the others keep running.

Cloud devices (brands like Tesla, Enphase and Sonnen) are different. They connect to Alva over the internet through Autopilot, so they do not need a dedicated Alva Link at all. You just need an Autopilot subscription.

Every setup includes at least one Alva Link, and all Links in your home share a single Autopilot subscription (€4.99 per month, free for your first 6 months as an Early Bird) no matter how many you have. You are never penalized for expanding your system.