I have to report first that I had a little trouble getting the installation to work reliably. The TED system contains two units: a "measuring-transmitting unit" which measures the power you are consuming (using current transformers) and the supply line voltage, and an interface which receives the signals from the MTU and puts them onto a local ethernet network. From thence, your computer can pick them up and display them on a web interface.In the picture here, the MTU is the lower "black box" on the right side, the interface is the upper one.
In principle these two units can be some distance apart - not everyone is lucky enough to have a switch on their in-home internet sitting right next to the distribution board , as you can see we do. The units communicate by piggybacking a digital signal on the power lines, and this process is prone to interference. After some discussion with TED tech support they suggested that this was the cause of the problems I was experiencing, and they sent me an in-line filter which I installed on the circuit feeding the TED devices. After that, everything works great. I can see usage information from any networked computer and I have also an app (TEDometer) on my phone which gives an instant readout via the home wireless network.
So, what's this done for us? Well, since installing TED in March our daily electricity use is down something like 40%. I find myself very aware of the electrical consumption of various devices around the house and this has probably made me even more obsessive about switching things off (or not switching them on in the first place). I should mention that we do not heat water or dry clothes by electricity, so the obvious seasonal causes for such a big change aren't there... but of course there must still be some seasonal component, which we'll only know when we have more data.
Significant changes that seem to have contributed to this load reduction are:
- Replacing a number of light bulbs - especially PAR 38 floodlights - with LED units. LED bulbs are expensive but this is cost effective for units that are operated for extended periods of time.
- The house has a recirculating hot water system with a pump. Putting this pump on a time switch (a pretty simple investment) seems to save something like 1kwhr per day, not to mention the heat that is not wasted from the hot water system.
- Installed extra attic insulation (upgraded to R50) and ventilation, including a solar powered roof fan... helps keep the house significantly cooler.
- And the big one... replaced the refrigerator. This was not purely an energy efficiency decision - the old one gave up the ghost - but once we knew we were replacing, we went for an Energy Star Tier 3 model (most efficient) and the savings were instantly visible. (It looks as though the old fridge was using more power than its rating, presumably as it struggled to extract the required cooling out of a dying compressor.)