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Open-source tools for energy monitoring and visualisation
Updated: 13 hours 54 min ago

Snowdonia household energy study, exploring zero carbon solutions

Fri, 21/11/2014 - 13:44
A couple of years ago Glyn and I and a friend of ours Bethan Gritten carried out an energy study with a local organisation called EcoBro of 17 households in Snowdonia, North Wales including our own.

We looked at the energy used by each household for electric, heating and transport and what the effect would be of applying the solutions outlined in both ZeroCarbonBritain and Sustainable energy without the hot air, visualising the result using David MacKay's energy stack graphics.

I've been looking again at this work recently as I find it a really useful and tangible way of looking at the energy problem and I've taken the opportunity to improve the energy stack graphic visualisation and put it up online here:

Dynamic visualisation:

The code for it is open source and on github here:

Here's a brief run through of what you can see:

Current Energy Use
This first graphic shows each households current energy use and where that energy is used:

24% of the energy used by the households come from renewable sources, whether biomass or 100% green electricity tariffs. The wide range of total energy use per household is quite interesting, using the dynamic tool you can explore the contribution of occupancy and floor area. You can also look at C02 and energy cost per household.

Solutions for reaching 100% sustainable energy for household electric, heating and transport.

In both the ZeroCarbonBritain report and David MacKay's Sustainable Energy without the hot air, building retrofit (insulation and air-tightness), heatpumps and electric vehicles form the cornerstone's of both significantly reducing the amount of energy we need to provide the same amount of comfort/utility and making it possible to power the remaining energy demand from electricity generated by sustainable energy.

The following graphics show's what the effect would be if each household in the study applied these measures:

1) All households switch current electric consumption to a 100% Green Electricity tariff:

2) 100% green electric powered heatpumps, Biomass and electric cooking instead of oil, gas and coal. For heatpumps it assumes replacing existing heat input with a heatpump with a COP of 3.0. See step 5 for a very basic application of building performance retrofit work.

Heatpumps form the cornerstone of supplying the remaining heat demand after retrofit in both Zero Carbon Britain and David MacKay's sustainable energy without the hot air. The performance of a heatpump is highly dependent of course on being designed, installed and controlled correctly.

3) Switch all petrol and diesel cars to electric cars powered by renewable electricity (Assuming mileage stays constant and an electric car performance of 4.0 Miles/kWh)

The ZeroCarbonBritain report from CAT suggests a reduction in the number of miles driven through a combination of increased use of pubic transport, walking, biking and better planning of where we live in relation to work/activities in addition to a switch to electric vehicles which are both more efficient than petrol and diesel cars and can be powered by renewable electricity.

4) Electric trains instead of planes:

In order to achieve the last 15% and still enjoy travelling long distances we would need a switch from flights to electric train journey's, the model here just assumes that the number of flight miles are replaced with electric train miles powered by renewable electricity and that the destination is reachable by train.

5) At least 120 kWh/m2.year primary energy for space heating and home electric.

Improving the thermal performance of buildings by adding insulation and improving the air-tightness should be one of the first measures applied and considered before or at the same time as any heating system changes as in step 2 above. The implementation of applying retrofit measures in the energy stack visualisation model here is only to set a maximum primary energy use requirement rather than to explore what's possible on a house by house basis which would give a better picture of the potential savings from retrofit work.

Powering Up with Renewable Energy

The ZeroCarbonBritain report goes into a lot of detail on how the remaining energy demand after applying power down measures can be supplied by renewable energy and also the need for storage technologies to manage the intermittent nature of a fully renewable energy supply. We didnt look into this as part of our study but it would be interesting to explore it in more detail in the future to answer questions such as: what scale of community energy projects such as community wind, solar and hydro should we be thinking of if we are to supply our energy demands after applying power down measures? and how much should we be thinking about energy storage in a more local context?

There's a lot of things that could be improved about the study. Rather than applying back of the envelope calculations on the effects of applying the various solutions to each house it would be better to look at each house in detail, carrying out a full detailed Carbon Coop home energy assessment for each house on how energy demand can be reduced by up to 70% through retrofit work.

Related links

OpenEnergyMonitor page on Sustainable Energy:

The ZeroCarbonBritain report:
Alice Hooker-Stroud, Centre for Alternative Technology, ‘Zero Carbon Britain (Energy)’

Sustainable energy without the hot air

Carbon Coop
Charlie Baker's talk about carbon coop and 80% retrofit at the radical emissions reduction conference

Where next?
I would be interested to hear any thoughts on how to develop this work further, where it should go next. Feel free to email me if you have any ideas or would like to discuss: trystanlea at
Categories: Blog

Testing KiCad PCB

Sat, 25/10/2014 - 19:54
We are always a fan of using open-source software wherever possible. A few years ago I briefly attempted to use open-source KiCad and gEDA PCB CAD software but found them very limiting, clumsy and buggy.

Recently there have been a raft of shiny looking browser based PCB design tools such as Circuit Maker and Upverter, these look very interesting; the online collaborative development opportunities are obvious and linking into the OctoPart's live component pricing, standard part library and BOM management tools could be a big time saver at the manufacturing stage. Maybe online tools will be the future, however I am a little reserved about having designs locked into a closed online platform.

In particular I have been keeping a close eye on KiCad developments after I heard CERN had got involved in the development. I was very impressed watching this video showing the newly developed KiCad intelligent semi-auto router in action:

I think it's time I gave KiCad another try! Today I managed to install KiCad and put together the RFM12Pi schematic and layout the board. Here's my experience:

I wanted the latest build to get the shiny new features, so I installed the development branch by adding the PPA to Ubuntu:

I installed KiCad build dated 16th July on 32-bit Ubuntu 14.04

I found I needed to add the line "export KIGITHUB="";" to my ~/.profile file to get rid of cannot find github footprint errors when running CvPCB (the program in KiCad which links the schematic parts to PCB footprints)

I followed the fantastic video tutorials from Contextual Electronics to help me get started.

1. KiCad Schematic Editor, net list must be manually exported to move to the next setp
2. Linking schematic parts to PCB footprints
3. Board layout the new interactive router was great (see video above)New router options
Update: the finished Kicad RFM2Pi V2.7 design is up on github:
Obviously we have considerable lock-in to EAGLE PCB with our historic designs and learning a new software tool is always going to be a slow and slightly frustrating process, however I'm quite impressed that after about 5hrs I think I'm got the hang of basic KiCad functions. I will seriously consider using KiCad for new designs in the future. I think the increased effort will be worthwhile to enable us to be using a fully open-source bit of design software to design open-hardware, what do you think?
Thinks I liked about KiCad:
  • Interactive router, very impressed with this. Big time saver
  • More intuitive setup of default track widths and net classes 
  • How net and pin names are displayed in the layout editor 
  • How schematic symbols and PCB footprints are handled as separate entities, more intuitive than Eagle IMHO  
Thinks I miss moving from Eagle:
  • Have a live link between schematic and PCB, KiCad requires exporting and re-importing a new netlist each time there is a change in schematic
  • There are more ready made parts in Eagle libraries then there are KiCad part libraries, but I'm sure this will change. 
  • Being able to highlight all tracks on a particular net by selecting a wire on the schematic (maybe I've just not found this feature yet in KiCad?)
Categories: Blog

Emonhub installation/update, replacing the PHP raspberrypi emoncms module

Fri, 24/10/2014 - 11:58
From Paul Reed's post on the forums here:

Emonhub is now the recommended method of interfacing a rfm12pi to a local or remote emoncms install, and replaces the PHP and Python scripts which we have previously used.

Update: This blog post refers to installing emonHub on existing system, if setting up a new system downloading the ready-to-go pre-built RaspberryPi image is the easiest way to get started.

Thanks to Paul Burnell, the author of emonhub, installation of emonhub can be achieved via a command line, which clones an installation script to automate the installation process.

To install emonhub:

$ git clone ~/dev-emonhub && ~/dev-emonhub/install

If you have the raspberry pi module already installed, it's important that it is removed prior to installing emonhub, as only one software can use the serial UART the RFM2Pi is connected to at any one time.

To remove the existing module, and then install emonhub, enter the following command line;

$ git clone ~/dev-emonhub && ~/dev-emonhub/upgrade

You will notice that after running this command, that emoncms will stop updating, this is expected until the configuration file is updated as follows;

$ nano /etc/emonhub/emonhub.conf

Enter your emoncms read/write api key in [[[runtimesettings]]] and also enter your rfm2pi frequency, group & base id under [[[runtimesettings]]]
Save your settings, and; $ sudo service emonhub restart

View the error log; $ tail -f /var/log/emonhub/emonhub.log

By default this is set to record 'WARNING', however this can be changed to either - DEBUG, INFO, WARNING, ERROR, and CRITICAL by editing the configuration file.


NOTE - This update will not orphan or alter your input processes, feeds, visualizations or feed data, as it only changes the way in which data is fed to emoncms.
Categories: Blog