Home Energy Management - The Journey

Published on 19 Feb 2010 at 3:07 pm. No Comments.
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OK, enough hacking for the moment. Need to live with current gadgets a while and tune up our energy use. As blogged earlier, we have already made significant savings without any real reduction in comfort.  The savings have more than paid for the few gadgets we’re using and we’ve created a small budget for further investments aimed at cost and carbon reduction.

Next up for scrutiny are:

  • TV etc. aren’t switched off automatically and one can forget - need to add BBSB programmed zapper.
  • Fridges and freezers contribute most of the 365W base load - need to investigate replacements.
  • The attic. Started to clear it out with increased insulation in mind.
  • The kitchen floor has an air gap underneath and the floor feels cold - maybe insulate that
  • Underfloor heating in conservatory was a bad idea - consumes too much power even when turned right down - could go with off-peak power or a small solar thermal installation.
  • Ventilation currently done by leaving windows open - could look at heat exchangers.
  • Cavity walls already filled with foam so may not be fixable.
  • Windows - could upgrade 20 year old double glazing but benefit would be minimal
  • Transport - get a power-assisted bike to get to station without needing shower and change of clothes
  • Buy an eco-home instead? Not yet thanks.

I also want to do more to share the knowledge I’ve gained over the last year and a half. Although my initial investigations revealed a lot of complacency there are many exceptions - people who want to save and are impatient to do so.  Transition Town groups are probably a receptive audience.  Though our local (nascent) one I came across Global Action Plan/ Eco-teams.  They are recording everything (energy and waste) and have demonstrated some useful progress.

My favourite energy book Without Hot Air by David Mackay. It’s online but a paper copy is nicely presented and worth having. His is a rational, science-based approach to the energy crisis.  Accompanying video how-many-lightbulbs is an accessible explanation of some of the key points.

Gadget providers.  You may need some of this kit:

Ok, enough dreaming.  Back to hacking - and maybe some work ;-)

London Hackspace 10th Feb

Published on 13 Feb 2010 at 11:56 pm. No Comments.
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My first outing to a Wednesday session. More or less social but with a topic session, in this case on energy monitoring by Ken Boak @monsonite.  Well attended. Those present were engaged and asked lots of questions.  In my case I knew of Ken’s work but there was much that I had not appreciated.

Ken likes to get to the nitty-gritty.  So, as he went through the various elements of a solution, we got quite a bit of the theory as well as the maths thrown in.  Key elements covered were Gas and Electricity meters, Temperature sensors, Arduino, wireless communications in the home and presentation techniques (featuring Ken’s colleague ???? who is software to Ken’s hardware).

We all clearly agree that you need an appreciation of where the energy is going before you can be effective in doing something about it. The finer grained the data the greater chance of useful behavior change.

At the end of Ken’s talk we also heard from ???? of pachube on their system and ???? of Arup on his desktop monitoring solution.  Ken gave homecamp a plug (no pun intended) and also demonstrated some of the kit he’d brought along.

My own take-aways included:

  • Although I was less interested in current transformer clamps for monitoring electricity I do see the value they bring for detecting and measuring lighter loads such as the fridge switching on and off.  With my pulse-based approach I get precise predictability of bills but lose out on this level of detail.  The perfect solution would be to have both.
  • Those Actaris meters which can be easily read optically are the way to go.  Nice clean pulse too.
  • I’ll stick to pre-calibrated temperature sensors like the LM36 instead of having to worry about calibrating thermistors which are only slightly cheaper.
  • I liked Ken’s clips for measuring water temperature.
  • We need some more discussion about use of remote temperature sensors that are very handy if only we can reverse engineer their protocols.
  • For switching loads from Arduino I will continue to favour devices like the ByeByeStandby sockets which also solve the wiring and isolation problems.

My final thought was that Ken’s somewhat bottom-up approach is fine but we need top-down thinking as well.  Maybe I’ll do a session sometime showing a slightly different approach using more bought-in parts requiring less hacking and therefore appealing to those wanting a quicker solution.  I’d also cover some other presentation techniques such as the smartphone app that I’ve been working on.

There’s an App for this too

Published on 7 Feb 2010 at 4:35 pm. No Comments.
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I decided it was time to bring the energy monitoring experience to the small screen so I grabbed one of the open source toolkits for this, namely Titanium from Appcelerator. These guys have done a great job and, though the tools are still in beta, they are a great way to develop and app quickly and deploy it on Android and iPhone.  Code is written in HTML, CSS and javascript.

The initial functions provided are displays of data as at now, a daily view and a 3-month history. The part not yet finished is the boiler control where I am still working on the algorithm. It currently just allows the thermostat to be overridden. Watch this space for a more complete version of that. At the moment it’s using ByeByeStandby controller but there have been some service interruptions and so it might be wiser to drive the smart socket from an Arduino - probably the same one that’s handing the sensors.

As I already had all this data online this was a relatively easy thing to do. For the graphics not supported by Titanium I identified a javascript library oddly entitled “flot”.  I made versions of my online data viewing pages that deliver JSON data objects.  These were very easily accessed from Titanium-provided classes.

Plenty more to do on this.  I’d like to get it ready for use by others in a pilot project to see how much energy can be saved.  I’ll leave the complex topic of converting awareness into behaviour change for another blog.

Local Transition Towns Initiative

Published on 27 Jan 2010 at 5:25 pm. No Comments.
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It was good to discover a local group putting together a Transition Towns initiative called Chalfonts4Change. I am looking forward to working with people in the local community on various aspects of energy demand reduction. Here are some links that I’ve put here while we wait to get C4C online.

My favourite energy book Without Hot Air by David Mackay. It’s online but a paper copy is nicely presented and worth having.
A proper, rational, science-based approach to the energy crisis.  Accompanying video how-many-lightbulbs is an accessible explanation of some of the key points.

Gadget providers.  You may need some of this kit:

More to follow.

Energy Monitoring - New Year Thoughts

Published on 18 Jan 2010 at 5:38 pm. No Comments.
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After spending all available free time rebuilding my PCs I had lost the thread of finishing the monitoring kit at least to the point where others can use it. Got a Mac to put an end to all that so I can now get back to my main project.

We had concluded that monitoring is very important but is not the end solution. Controlling the heating automatically is the way forward. Until such time as an affordable commercial solution hits the market we need to keep hacking on.

The three key challenges were external temperature, boiler control and the all-important algorithm. The first two because in my own setup I had run a lot of wiring. That would not work for most people. I’m not worried about network wiring as power-line devices are readily available for those who do not want to run Cat5. (Low-power devices like Arduino do not support WiFi.)

External temperature is easily solved by using feeds from the Weather Underground. The node near our house is driven by a nice piece of kit with more than enough accuracy. The server grabs that data as needed. It’s refreshed at least every 15 mins. Boiler control can be done with a ByeByeStandby socket and controller. I think this is reliable enough but if not I’ll package up the controller I was able to build thanks to the nice people at BBSB having documented their wire protocol. This leaves the algorithm where I have something very simple in mind.

I have enough stored measurements to extract two pieces of information: our house loses heat at the rate of about 0.7 deg C/ hour when it’s freezing outside and gains heat at just over 1 deg C/hour when the boiler is firing. The effect of the sun is hard to predict at the moment so more measurements are needed but I can guess a figure and tune it in coming months. These figures can be used by the controller to decide, based on external temperature, when to fire the boiler in the morning and, importantly, when to shut it off. Although it’s too late to shut off the boiler when the target temperature is reached, the internal thermometer can be used to make sure all is working as expected.

Next step is to test this arrangement and see how it performs. It it does the job we can expect further savings.

Advanced Heating Controls

Published on 8 Dec 2009 at 8:22 am. No Comments.
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From earlier deliberations and measurements it had become clear that there are savings to be made in heating a typical suburban property.  This is because the bolier controls are usually quite crude.  In our case we have a 3 year old condensing boiler.  The air temperature is controlled by a thermostat which would have to be adjusted daily for optimum efficiency.  If not the house is either too hot or too cold depending on the outside temperature.

The thermostat works as intended.  However, if the outside temperature is rising the thermostat can’t anticipate the effect of this on the inside temperature.

Some fancy kit is available to compensate for this but it’s expensive and I thought it would be more interesting to rig something up, given the fact that I already have remote-controllable sockets and a continuous stream of temperature data.

Controlling the boiler is easy.  I used a byebyestandby socket plus a relay to produce an isolated contact pair as required by the boiler’s control system.  I left the existing thermostat in the circuit, generously set.  The existing timer is set to always on for heating.  Hot water is unaffected by these changes.

For the moment I am using a BBSB “online controller”.  However, the Arduino that looks after the sensors could just as well do this job if and when I get round to reprogramming it. At time of writing the Arduino has been running for many months whereas the BBSB has fallen over a couple of times.  I may get round to that reprogramming job sooner than I expected.

To control this in line with our requirements I have a simple program on the server which wakes up every so often and checks the time settings and the temperature inside and out.  As appropriate, it can send commands to the BBSB socket to turn the boiler on and off.

As the settings are held on the server I can control them from any browser, including the one on my phone.

I shall be observing gas consumption to see whether this produces the expected savings.  My family will be monitoring comfort levels and I know I won’t need an extra jumper for Christmas.

Home Networking with 433Mhz RF

Published on 17 Sep 2009 at 8:04 am. 1 Comment.
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We seem to use quite a few low-cost wirelessly connected devices around the home.  When thinking about how to realise my smart thermostat project I realised that it should connect to the boiler in the same manner as the current dumb thermostat, at least until some better technology with the right price point comes along.

Many of these devices use 433 Mhz and have undocumented proprietary protocols.  Nevertheless, the price of these devices is right so I thought I would try to reverse engineer some of them, starting with the existing thermostat and an outside thermometer.

First step was to get some RF modules.  I chose the Radiometrix ones as the supplier is nearby and user-friendly. Thx to Peter at the OHH meetup I knew to use a sound card and Audacity as a recording ’scope to see whet we’re dealing with.  Next I wil convert the manchester-encoded stream and log a bunch of readings.  From there I hope to be able to guess the protocol.

Along the way I found someone else doing this.  See Bertrik’s site for details.

Once I’ve crossed that bridge I’ll hook up a transmitter and see if I can drive the boiler relay.  Initially a simple arduino program will be sufficient to create a dumb theremostat.  After that I’ll move on to optimisation taking into account internal and external temperature gradients.

If all goes well I can achieve another reduction in energy for heating without reducing comfort for the family.

Why don’t I just buy an optimising thermostat?  I’ve tried to and failed so far to find anything at a reasonable price.

Open Hardware Meetup

Published on 9 Sep 2009 at 9:14 am. No Comments.
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As I’m going along to this London meetup tomorrow, I’m posting some notes on how I plan to go forward with home automation.  After the session I’ll make some more notes here.

BRE Innovation Park

Published on 5 Sep 2009 at 9:09 am. No Comments.
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I’ve been trying for some time to get a pilot off the ground to see if others can obtain the same energy savings, particularly gas, that we have achieved using detailed monitoring.  The Innovation Park at the Buildings Research Establishment was suggested to me and I was fortunate to meet Mike Perry who has been very much involved with this initiative. 

The park is well work a visit anyway, especially if you plan to get involved in a new build or major rennovation project.  However, I’m going to pick up on just two points here:

1. Monitoring is part of a much bigger picture that includes energy management, telecare, home entertainment etc.  MP stressed the need for standards in this area.  Widescale adoption of proprietary protocols around the home and community will make it very hard to get the full range of benefits economically.  As with mainstream IT, good standards will permit the involvement of many innovators.  Whilst it did happen in IT, it is unliikely that a single vendor’s proprietary will become sufficiently dominant to be considered “open”. 

2. Gas, though important now, is not in most people’s thinking because it is expected to run out in the not-too-distant future.  I wonder about this prediction given recent investment in pipelines from Norway and Russia.  I don’t know the figures but I reckon there are millions of UK homes that will use gas until the price really does go through the roof.  Solar hot water would have the effect of prolonging this.

OK, so I did not advance my grail quest but it certainly was interesting.  I’m getting more and more interested in new build and this throws up a lot of ideas worth thinking about even if some of them, like complete airtightness, do not appeal at this time.

The quest continues: how can we get pulse outputs on existing gas meter installations?  A second private meter in series seems to be the only solution.

Homecamp April 09

Published on 26 Apr 2009 at 7:02 am. No Comments.
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Another great day out with the homecampers, kindly hosted at Bash and organised and sponsored by various worthies including @yelllowpark (he of the t-shirt) and @monkchips.

An unconference but not really? Who cares - it worked.

My own take-aways (no particular order):

  • Streaming via ustream - I think this is the right link
  • Hooking up to projector - cable issues
  • Reactiongrid - (incoming) sound issues
  • Incoming presenter - (outgoing) sound issues
  • Currentcost - some discussion with Martin about protocol/ handshake.  He’s generously offered another piece of kit.
  • Joe Begley house c/o http://www.greenenergyoptions.co.uk/ very cool solution and possibility of free trial
  • Gave my little talk on what I’ve done so far and where I want to take it
  • AMEE fairly focussed in what they do (watts) but could be hooked up via pachube
  • Ask jamieandrews about leak detection
  • Possible use of commercial flow meters for water (may be complications). Various products at Farnell.  Despite suggestion nothing useful on Brita either.
  • Pachube have atom format.  Need to develop an app to get 4 traces on graph.Can fix my broken interface by adding min/max to EML. 
  • dopplr have something to help reduce travel energy costs (tripit too?)
  • Onzo developing smart energy kit for later this year.
  • Flukso have done some great stuff with their box (built inside a wifi router) and analysis software http://www.flukso.net/.  Need correct URL for company.
  • Need to look at http://oss.oetiker.ch/rrdtool/ data logging and graphing system for time series data.
  • Checkout Arduino mega http://arduino.cc/en/Main/ArduinoBoardMega
  • Also look at alt microcontrollers that (will) run linux so we don’t have to develop and RT/OS and rewrite drivers for arduino.
  • Useful input from @folknology on microcontrollers - check out his OHH and the ARM-based http://beagleboard.org/.  (Later @ohh there was talk of creating an even better board.)
  • Some work at Oxford on power signatures??
  • Reactiongrid seems like a very useful alternative VE for education.  Minimal talk on this.
  • http://redcatco.com/ 6 factors in influencing outcomes
  • Pity I missed Techcrunch’s Geeknrolla
  • Need to discuss structure of homecamp wiki with @yellowpark.  Should have separate registration so we get fewer trivial updates and have pages for each meeting plus resources and applications plus links to people profiles if poss. Can’t offer to do this yet but maybe later.

This is a draft.  To be corrected.

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