node.energy GmbH is a software company based in Frankfurt am Main, founded in 2016 by Matthias Karger and Lars Rinn. Its opti.node platform is a data and software system for the commercial operations management of wind and solar parks and PV systems on commercial properties. It automates electricity tax reporting, municipal participation under § 6 EEG, revenue monitoring, invoicing and contracts.

The company has extended its compliance automation into direct power purchase agreements (PPAs) that allow medium-sized businesses to buy electricity directly from wind and solar plant operators, together with supply process management and energy data reporting for reporting and controlling. Customers and partners named in its materials include Qair Deutschland, DenkerWulf, Sunrock, Landwind-Gruppe, SAB WindTeam, VGP and CTP. It has also partnered with metr for building energy management and with Metergrid on tenant power and onsite PPAs.

node.energy raised a €7M Series A in July 2022 led by BitStone Capital, and a €15M Series B in April 2025 led by DeepTech & Climate Fonds and eCAPITAL ENTREPRENEURIAL PARTNERS. Its platform is deployed across more than 14,000 wind and solar plants, and the company has positioned itself as a market leader in Germany for this segment.