OwnTech's µVerter Aims to Deliver an Understandable, Reproducible Inverter for Solar Projects
Open source micro-inverter design is built to be completely reproducible, with no components hidden beneath a potting compound.
Scientist and engineer Luiz Villa, part of the OwnTech project seeking to create the "Arduino of Energy," has detailed a work-in-progress effort to give makers more control over their energy sources: the open source µVerter solar micro-inverter.
"Solar power should be open, understandable, and accessible," Villa, who is working with Jean Alinei on the effort, explains of the project. "We're building an open-source micro-inverter meant to be understood, modified, and improved—schematics, firmware, measurements, and mistakes included. The objective is an industry-grade, pre-certifiable open-hardware inverter: open enough to learn from, robust enough to aim at real-world requirements."
A solar inverter turns the direct current (DC) generated by photovoltaic solar panels into alternating current (AC) suitable for being fed back into the power grid, energy storage, or directly powering mains-based devices. It's a key part of any solar generation installation, but there's little out there for those who like to know exactly what's going on in the hardware they use — which is where the µVerter comes in.
The project is targeting support for 230VAC supplies with a rated apparent power of 450VA with support for software-defined power limits. It's designed to be fed from 350–550W panels, operating at 95% efficiency with a near-unity power factor. Its biggest advantage over commercial offerings, though: it's entirely open source, understandable, and repairable — which means it's also easily reproduced.
"By keeping the design reproducible, we support decentralized manufacturing — thinking globally and acting locally. One shared core can serve balcony solar in the North and adaptable solar home systems in the South," Villa explains of this last feature. "Because this is grid-connected power electronics, safety leads: isolation, fault detection, thermal limits, protective circuits, and design choices that map to certification pathways."
More information is available on Hackaday.io, with the current design files and firmware source code available on GitHub under the strongly reciprocal version of the CERN Open Hardware License Version 2.