My energy monitor and control system based on Martin's eMC is working extreme well in this sunny weather. However, there is always room for improvement and I have an addition in mind which may be worth discussion.
My system consists of two tanks both of which are heated under the control of Martin's energy monitor and controller. The primary tank containing DHW is heated first and when the top layer of water is up to temperature energy is diverted to the second larger tank. Tank two contains 'radiator water' and when the top layer is hot a valve opens to allow the water to be pumped from top to bottom to ensure an even distribution of heat within the tank. When the bottom layer of water in tank one cools below the trip point a three port valve diverts the very hot water in tank two through a heater exchanger coil in the bottom of tank one. The net effect of all this is an energy storage capacity of about 18kWh. Consequently my 3.8kW PV system very rarely exports.
Unfortunately the above is not entirely automated. Manual intervention by operating some switches is required to achieve the desired result. Clearly this is a job for another Arduino based box of tricks but the distributed layout of the plumbing system makes a physically wired system difficult. A better solution would be for the components to communicate wirelessly.
Nothing new here except that I already have a remote energy diverter operating wirelessly and it would make sense to incorporate that into the 'network'. In addition, I have been considering adding thermal sensors to the reverse face of some solar panels to allow for some cooling experiments and I would also like these to be part of the network. There are some other things that could also be included so the network protocol is starting to look fairly serious.
So, my initial vision is a very small wireless unit which supports one wire multiple temperature sensors and includes a few digital I/O's. Maybe a Nano with a wireless module or even a custom PCB. The hardware platform sounds simple enough although I would like it to be sufficiently low powered for battery operation.
The software is also fairly straightforward except for the wireless stuff. What I have in mind is an auto configuring multiple node repeating network with multi path capability. At first I thought it would be fairly straightforward to implement a mesh type wireless network especially as there are supposed to be some open source versions out there. The mesh buzz word appears to be BATMAN but this looks seriously complicated and is probably overkill for this application. A description of BATMAN can be seen here. So what do the experts suggest? Is anyone using a network of this sort?
Re: Mesh network widget
Sounds like a fun project Brian.