Hello, I am Robin Emley, designer of the Mk2 PV Router as featured on the Open Energy Monitor website. Having trained as a Domestic Electrical Installer, I have re-designed the hardware to make it more accessible to a wider audience, hence the appearance of this website.
In a domestic premises with solar PV panels, a PV Router can be installed to divert surplus power for some useful on-site purpose. This prevents
surplus energy from drifting away to the grid at no benefit to the
owner. A comprehensive article about the underlying principles is available at Diverting Surplus PV Power.
Why "Mk2"? When I first looked into the idea of diverting surplus power, most existing designs used a commercial AC controller. Every few seconds, its setting would be adjusted in order to match the amount of surplus power that was available. This design does work, and many tanks of hot water have been heated by this means, but a system of this type can be expensive and has a poor response time.
My main contribution was to recognise that the measurement and control aspects could be combined within a single software routine. This design is based around an accumulator, or "energy bucket", which operates in a similar way to an electricity meter. Using inexpensive hardware, a DIY constructor can now build a powerful control system which diverts all surplus energy to a suitable load. When I first published this open-source design in July 2012, it was a significant step forward from previous offerings, hence the name "Mk2".
Section 8 of the above article explains how a Mk2 PV Router system can be constructed using readily available components such as the Arduino Uno or emonTx. Although plenty of supporting information is available, it soon became clear that the
assembly of a complete PV Router system could be seen as a daunting project
for many home constructors.
I therefore set about developing a new version of hardware for the Router. This new implemention allows a
complete Mk2 PV Router to be assembled and tested in isolation by the
home constructor. The finished unit can then be installed and verified
by a suitably qualified person.
Having never commissioned a
PCB before, or run my own business, this venture has been a steep
learning curve for me. I trust that this website will prove to be a
useful resource for anyone who is interested in diverting their surplus
One of the first entries in the "General Discussion" section of the original forum is a summary of my various postings to date. This summary features my software tools and home videos on the subject of surplus energy diversion.