December EcoHomeLab report

by Blog

And we are now in 2017, happy new year? Let’s hope so…

Last EcoHomeLab of 2016 happened on the 12th of December at Madlab as usual. We were quite a lot of people, 13 of us munching mince pies. I was worried that it was going to be a session without content as the original presentation for the day was cancelled. But it wasn’t, in fact that was a very busy evening.

Trystan, how strange, had many interesting information to share about the new website he is doing with the OpenEnergyMonitor (OEM) with the aim of making energy concepts accessible to a wider public, not only techies.

Dom (Carbon Co-op) and Marianne (Urbed) showed, and chewed it for us as if it was one of the mince pies, the paper they have written with very interesting information about performance gap after retrofit works analysing Carbon Co-op’s Go Early project. Paper that will be published in Spring 2017 and presented at the CIBSE Technical Symposium.

And the cherry on the mince pie was Matt. So much talking makes my work hard and I have to write too much. So he did a cool show of remote control using OpenHab2 and PlugWise plugs. More about this later.

But EcoHomeLab is not only for talking!! My home energy monitor is giving me some ridiculous random readings. I was able to find out that the problem is not the CT sensor, I thought it could be as it used to work ok. So I tried uploading the firmware again (which I knew wouldn’t fix anything) and problem still there, so it must be the board itself. Hopefully next session I’ll finish with my fixing.


Learning OpenEnergyMonitor (OEM)

There is a lot of information out there about OEM: the website itself and the community forum are the main sources. But for them it is not enough and also not clear enough.

With their heart full of opensource wishes and with the aim of making knowledge accessible and understandable they are building a new website that we had the luck to check out (not publicly available yet) and there is plenty of information nicely sorted and well explained. They aim high and this is not only about OEM, what we will find there too:

  • Electricity monitoring: AC power theory, CT sensors, Voltage sensing, OEM networking, pulse counting, time series (how emonCMS stores data), emonCMS internal (yeah with some contribution from me there 🙂 and other useful software.
  • Sustainable Energy: I did say they aim high, well this section should be studied in school. For anybody who thinks we need a Zero Carbon society this is a good place to start. A comprehensive journey to understand the ZeroCarbonBritain model from the Centre For Alternative Technology, energy models for houses, some case studies on how groups have worked with info about their energy use and how they found out the impact some changes would make in their carbon footprint….. Trystan was understandably quite reserved about one feature he has included: the process for calculating the price of energy for the final user in a zero carbon scenario. Reserved and cautious because there are so many variables to take into account. The conclusion is that it seems that a zero carbon scenario would not make energy any more expensive, nice one!
  • PV diversion: another great concept, how to make the most of the surplus generation of a PV installation with the proposal of two possible systems to make it happen.

Trystan said, the website will go live in a couple of weeks, we’ll let you know.


Resilient Domestic Retrofit, Producing Real World

This is the funky name for a great piece of research. Another novelty we have had access to as it is not public yet and despite it’s on draft stage it has already plenty of useful information. As said before, it will be available for the public in Spring 2017.

What the paper does is :

  • Calculate the performance gap (the difference between expected improvements and the post-works reality)
  • Critical analysis of the processes going through initial assessments, model assumptions, design, actual works, quality control, etc. and results of building retrofit focusing on the performance gap.

And the aim: understand how significant this performance gap is and what causes it with the aim of avoiding it.

They have looked into 12 houses that took part in a whole house retrofit scheme. Before the retrofit some of the houses had some monitoring equipment and obviously bills data. More monitoring has been in place after the retrofit allowing to make the before-after comparison.

In the document there are some interesting graphs full of information, but I will summarise it saying that the average performance gap was 25%. In addition to it the paper shows their conclusions about the reasons for the gap and ways to avoid it. Sorry I will not give more information, I can’t spoil it 😉


The controlling show

And to finish this very full session Matt did one of this cool things that gets people excited. Switching things on and off with his phone and visualizing the consumption of specific appliances.

He did it with the WisePlug plugs and OpenHab2. Info about how you can do a similar set up is here.


The plugs look like normal ones but a bit thicker. You can switch them on and off remotely and also query the real time power. They are great specially now that you can access them with OpenHab and not be dependant on the whole PlugWise products (normally you would need to purchase a gateway too), very good!!

And, are you a Carbon Co-op member? If so you will be happy to know we have 20 of these plugs available and are giving them away for free, if you want some just get in contact, you will have another reason to come to EcoHomeLab: setting up your wise plugs.


Next EcoHomeLab

Next session next week: 12th of January 2017 at 17:30 @ Madlab, meet up page here.

Come along to see Trystan’s DIY electric bike while some us deal with our not working monitors….

See you soon,