Update on progress and a revised aim
Over the last few weeks I have been working on monitoring mains AC electricity energy use with the non invasive current transformer method rather than the invasive current sensing resistor method. In my previous post on the current transformer (CT) method I made two errors first the circuit I used was over complicated and secondly the efergy energy monitor seems to be able to estimate real power. Even though the CT method only measures current, I tried to see if it was possible to infer the voltage waveform from the current waveform producing a close estimate of the real power, It seems to have worked quite well. I will upload the details of what I have done soon.
I have also been working on DC energy monitoring for the wind turbine. I built the circuit that I talked about in the previous post. I however managed to blow one of the amps on the LT1495 chip and there seems to be an offset on the other amp which may be due to having blown one side. Id like to find a cheaper amp to replace the LT1495, maybe sacrificing a little on accuracy.
For the next two weeks the wind turbine is going up at two local festivals here in North Wales (Celtic camp and the National Eisteddfod). If your in the area feel free to drop by.
After the festivals I hope to have a look at monitoring the energy captured by the hot water solar panel we have here on our house, at the moment were not sure if it is working properly, it doesn't seem to be heating much water. However its hard to tell; the controller gives the current temperatures of the tank and panel, it would be useful to have graphs of the temperatures over several days and if a flow meter is installed it is possible to measure kWh of heat captured. Hopefully with better information it would be easier to see how well the system is working. It would be great to have a bit of software that analysed the data from the system, compared it to ideal site data and then be able to tell you something like “your system is working at 80% of potential”
All the above applications can all share the same software and similar electronics based on the Arduino. Once one is built, your have a lot of what you need for the others.
Further along the line it could be interesting to investigate possibilities for predicting how much energy it is possible to capture from a wind turbine or a hydro turbine before it is installed at a site using an arduino connected to an anemometer for wind or a river flow meter for hydro. I have also been doing some work with Suneil on trying to characterise how well the generator we built for the wind turbine works. With some detailed data and analysis it might be possible to identify possible improvements. Both the energy prediction and generator development could again share much of the same electronics, software and knowledge required for the energy use and energy capture parts of the project. And finally I would like to look at Internet connectivity, it would be really great to be able to check up on how say the wind turbine is doing from anyware in the world.
And so for the project to encompass all of the above:
"This is a project to develop and build open source energy monitoring and analysis tools for energy efficiency and distributed renewable micro generation."
The project is then divided into 6 areas:
Energy Use
Mains AC electricity and DC.
Energy Capture
Wind turbine, hot water solar, hydro etc.
Energy Prediction
Wind speeds, stream flow...
Energy Technology Development
Tools for the development and building stage rather than the use stage.
Data graphing and analysis and storage.
Using free and open source software
Sharing data with the world
Internet connectivity.
Hopefully this better reflects the direction of the work and will hopefully be a more useful collection of tools for anyone interested.
I will be updating the website soon with the recent work and to reflect the revised aim.
Any comments on the above would be great. Thanks for reading! To engage in discussion regarding this post, please post on our Community Forum.