I rang ETSA (Electricity Trust of South Australia) today to give them the code to open the automated front gate on our yard. ETSA own all of the power infrastructure in South Australia and with the impending installation of our rooftop PV system we need an import/export power meter to get paid for any power we feed back into the grid. I wasn’t expecting the meter changeover any time soon as all the research I had done had suggested a 2-3 month install time. Colour me surprised when I rang to give them the gate entry code as they said they could come do the changeover next Wednesday! Part of me doesn’t believe this is actually possible but we shall wait and see. Mental note to self, turn off all power points next Wednesday before going out for day just in case.

Belkin Conserve Insight

Given that you cannot improve what you cannot measure I decided to purchase an inline power use monitor the power consumption of various devices around the house. The idea being that I can determine what electrical devices are using the most power during the daylight ours when our planned rooftop PV system is generating power that could potentially be put back into the grid. There’s quite a few power use devices available ranging in price from just $10 right up to several hundred dollars for professional measuring equipment. I set a budget of $50 and decided on the Belkin Conserve Insight Energy Use Monitor which happened to be $49.95 from Dick Smith Electronics. You can see the read out on the Belkin above while it’s plugged into our 50″ Plasma.

I picked this unit because of good results in several reviews I read on the cheaper units and because it has correct power factor correction calculations which is important for measuring loads into switched mode power supplies (as found in PC’s). There’s a fairly high powered PC here that is on for nearly 16 hours a day and I need to measure the power usage of it accurately.

The Belkin unit is well made and easy to use. Just plug one end into the power socket and the power cord of the device you want to measure into the other. A digital readout can give you power draw, power cost, or kilograms of CO2 being produced. Each of these can be shown as an instantaneous amount, a per month amount, or a yearly amount. I’m not quite sure how the cost of power is determined but I’ll look into that further if and when I can be bothered. The power draw is what really interests me.

As a first up test I plugged the Belkin into the smaller TV/HDD Recorder/Media Player unit we have here. It’s a 32″ LCD TV, a Panasonic HDD/DVD recorder, and a WD media player with an external HDD drive. According to the Belkin this setup draws 20W when all three devices are in standby and 100-200W while all are playing. Given that we only watch the TV for 4 hours a day that leaves 20 hours a day that it is in standby. This adds up to 146kWh per year or $36.50 potential savings by turning off the three units properly when not in use rather than leaving them in standby. I’m looking forward to using the Belkin on some other devices around the house over the coming weeks. Stay tuned for me.

We took ownership of our new house a couple of days ago and one of the multitude of tradesmen to pay us a visit in this time was an inspector from Braemac who did an inspection of our roof for a potential rooftop PV system. Half of our roof area is north facing (I’m in the southern hemisphere) which is idea for a solar install. The roof itself is “colourbond” which is a trademark name for painted galvanised iron with an orb profile and the roof surface is pitched at 30 degrees. Basically this means the install is quite simple with no need for tilted mounts for the solar panels and no need for any tedious mucking about with a tiled roof.

I’ve asked for the Sunnyboy Inverter (a 4.2KW unit) to be installed in our garage rather than on the side of the house next to the power meter. This was for two reasons, firstly it helps protect the hardware from the elements. Secondly, it stops an expensive bit of hardware being visible from the road and potentially being stolen. The Braemac inspector said this would be no problem and that the install was actually quite simple and would result in our initial cost of the system being a little lower. Lower cost is always good 🙂

Next thing for me to do is find a bluetooth dongle for my PC. The Sunnyboy Inverter (a SMA SB4000TL-20 to be exact) has built in bluetooth for remote monitoring purposes and I’d be neglectful not to be monitoring the PV system output during the day. More on this later.