Heating and Electricity by Time

Inspired by this Stephen Wolfram (Mathematica) personal analytics, I've visualised my heating and electricity use by 15 minute periods over the last six months. The aim of these is to see when you are using most energy such that it can help you target energy reduction approaches.


This shows the heating demand reducing as the winter turns to spring. I've made a few improvements over the last few years - insulating the main flat roof; insulating the mansard roof; fitting good quality curtains and closing them at dusk; and the latest improvement was fitting the timed thermostatic radiator valve mentioned in the earlier blog.


This shows that the electricity demand remains fairly constant over the period (except for a few long weekends away). The dappled effect over night is the A++ fridge operating every so often. Our peak use is for washing that is normally done once a week on the weekend.

This shows the classic scatter plot of heat used (kWh) vs demand (Heating Degree Days). For a commercial property these can be very accurate, but for a domestic property life is much more variable with evenings out and holidays etc. By removing the holidays (black dots) I've got reasonable results, with higher heating on Wednesdays as that is my wife's day off.

These were done using the R-Project which is a useful tool for easily doing complex charts and statistical analysis. I'll convert it into JavaScript (Flot bubbles) for the OpenEnergyMonitor emoncms project.

Some new energy gadgets

Seeing as we now have a summer, I thought it was a contrary time to post my experiences with some new heating related gadgets.

Smart Thermostatic Radiator Valve (TRV)
My flat has two floors that are connected by an open staircase, so I was heating both rooms all of the time. Now with one of these valves upstairs, I can heat the upstairs (breakfast room) in the morning and the main thermostat will cut off the heating when up to temperature. In the evening the upstairs radiator is turned off so that the downstairs (TV room) radiators provide all the heat letting both rooms get warm.

I got an Energenie Smart Radiator Valve. It is controlled by an infrared remote control so you have to be nearby to operate it. Although this Conrad Wireless TRV is likely to be easier to use and should be controllable using an arduino.

Thermal Leak Detector
This is an interesting tool - point it at a wall and it shows where the cold spots are.
Black & Decker TLD100