Open supplier

An open supplier (avatud tarnija) is a market participant who sells electricity to a customer with the formal commitment to make up any shortfall in real time. The construct is common to the Nordic-Baltic balance regime — Estonia, Finland (avoin toimittaja), Latvia and Lithuania all use it — but is not standardised across Continental Europe. An open supplier is by definition either a registered electricity seller or a BRP, and is the legal counterparty for every retail-customer relationship in Estonia.

How "open" differs from "closed"

A traditional closed supply contract specifies a fixed quantity at a fixed price. An open supply contract instead commits the supplier to deliver whatever the customer consumes, in real time, regardless of forecast accuracy. The supplier carries the imbalance risk; the customer just pays the agreed tariff for actual consumption. This is what every household in Estonia gets — you turn on the kettle and the supplier handles the wholesale-market consequences.

Estonia's regulatory hierarchy

The Elektrituruseadus mandates that every connection point in Estonia must have an open supplier at all times. If a customer's open supplier exits the market, Datahub automatically reassigns them to a default supplier. There is no possibility of "no supplier" status. Behind every open supplier sits a BRP — sometimes the same legal entity, sometimes a separate one — who absorbs the imbalance into a wholesale-market portfolio.

Volton as open supplier

Volton Home is an open supply contract: the customer pays for whatever they actually consume at the agreed tariff (typically Nord Pool day-ahead spot price plus a margin); Volton handles the wholesale-market imbalance. This is the legal frame inside which all the smart-home flexibility, EV charging optimisation and battery dispatch happens.