Energy Project Interim Report

Colleague David and I have been running this project for 18 months now, each with our separate methodologies. Despite the differences in approach we have achieved comparable results. This is a precursor to a summary report on both approaches which will follow shortly.

Objective: Save energy + Save Money + Reduce Emissions

Focus areas: 1.Heating, accounting for 60% of consumption. 2. Appliances that draw significant current. (Initially less interested in lighting etc.)

Our home: 5 bed detached suburban home in the South East. Built 1970. Foam insulation in walls. Attic insulated and boarded, not recently. Concrete floor is less than ideal although it is insulated to the extent possible. 4 of us at home, I also work from there.

Starting point: Measurement

Appliances: I got a couple of energy monitors, one by simply mentioning the subject to my electricity provider. We went round with the wireless display and noted the consumption of each appliance. Fitted some slave plugs e.g. to turn off the printer when the computer is off or on standby. Also got a zapper to make it easier for family members to turn things off when not in use. Gradually changing the light bulbs. This appliance “scorecard” is a key tool because you never know what “vampires” you will unearth. This also helps to stay focused on changes that are easy and have maximum impact.

Heating: Being a systems guy I thought I needed same data before I could start really saving. I’m not good at anything repetitive so I wanted to delegate that to a ‘bot. Went to homecamp and got inspired. Learned a simple prototyping technique using Arduino modules (reasonably low consumption). Hooked up electricity, gas and internal/ external temperature measurement. In retrospect this was not a perfect solution but I was in a hurry to get my hands on the data. 18 months later you still can’t buy kit like this for any reasonable sum so I’m likely to create a better version. After clearing a few hurdles I have a growing body of good-enough data that reveals several interesting findings.

Impact of weather: When looking at your measurements to judge progress you obviously need to take out the impact of varying external temperatures. The chart shows just how dramatic this is and highlights the cost of a winter like that of 2009-10.

Weather impact 2009-10

Next phase: Interpretation (heating only)

Armed with this data I could see that some adjustments needed to be made. The first was to use less underfloor heating which is only in our “conservatory”. The solution is to not try to keep it warm in winter when we rarely use it. Next were the heating controls that go with our gas boiler. The timer was turning it on too early and off too late; no combination of settings are right for all weathers. Finally the thermostat setting. I work from home quite often and prefer a cooler house than do the rest of the family. So the thermostat needs to be adjusted frequently.

Next phase: Feedback and tweaking in the first instance. I tried adjusting the central heating timer so it would come on at the “goldilocks point”. However, as soon as the weather changed the timers are wrong again. I checked out some fancy thermostats and was put off not only by the price but also because I couldn’t find a plumber to fit one, although any plumber is happy to install a new boiler. So for the moment I settled for approximate settings. I’ll do more in the next phase.

Result: I received a cheque back from utility. As I had not changed my standing order it did not take long at a rate of about 30% saving to build up a balance with the utility. I asked for this to be repaid and got a check for £700 (about 30% of my original cost). The penalty for this saving is minimal. The conservatory is now kept quite cool as it is mainly used in summer. The main house temperature has stayed around 2O degC so a further saving could be made there (family decision not mine).

The proper solution: A smart thermostat is what we need. If I can’t get one at reasonable cost then a remote-controlled timer could be another interim step – I’m putting this in place now. The latest quote received is a possible but I’m not convinced of the payback. There are at least two other smart thermostat suppliers entering the market so things may change soon.

Medium term plan: While this is being sorted out there are some other things to do. Re-insulating the loft is one. Ditching my car is unfortunately not possible without moving house as we have virtually no local bus services. I have also started monitoring my petrol consumption because I think I can improve my driving habits. Having feedback will help me achieve this. Most of our appliances like freezers and washing machines are fairly new but as they are replaced we will be looking for efficient models.

Spreading the benefits: I reckon that comparing notes with David has been an important art of getting to where we are. For this reason I’d like to get involved in a wider project involving many more homes. I have written some notes about what this might look like and am talking to potential partners with whom we might organise this.

Advice for others: Make that checklist of appliances. Just knowing what everything consumes affects your use of them. If you’re changing your boiler see if you can afford one with “optimised start” that compensates for weather conditions.

Watch this space for further energy saving progress…

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