As I mentioned in this entry about the Belkin Power Usage Meter I bought I’ve been monitoring the amount of power being used by the devices in this house when they are in standby mode. Eliminating the power used is simple, just turn the power off at the wall when it’s not getting used. Trouble is that the power points are hard to reach, and in one case here, impossible to reach without having double jointed shoulders.
The answer is some sort of remote switching. I’ve seen some power boards that sense the current draw by one device (say your TV) and when these drops below a certain limit they power down (via relays I imagine) the other devices on the power board. Trouble with this is that the master device is still in standby mode. The other idea I had was to put an inline switch into an extension cord and stick the extension cord somewhere that could easily be reached. Trouble with this is that it would be ugly and one of my friends would have to come and do the actual work for me because playing with 240V makes me nervous.
While reading the Whirlpool Forums last week I came across a mention of a product called the EcoSwitch. Basically it’s an extension cord with a T junction with an illuminated rocker switch at the end the leg of the T. You plug one end of the EcoSwitch into the power, the other into whatever powerboard/devices you want to control and stick the switch somewhere easily accessible. The rocker switch is illuminated when the power is on, and dark when not. Just turn off the switch at night when you’re finished with TV, Computer, or whatever. You can see a picture of one of the EcoSwitches above with the rocker switch visible at centre bottom of the image.
The EcoSwitches cost about $20 plus shipping so I ponied up for 4 (3 I needed and one spare) of them direct from the supplier. They arrived 5 days later. The EcoSwitches work exactly as advertised and even come with double sided tape to stick the switch end down somewhere that is easily reached. However, the tape is useless and in all three spots that I am using them the switch kept coming unstuck and dropping back behind whatever I was trying to switch off. Very annoying. However, it was easily fixed by using some proper 3M double sided tape we had laying around.
My three EcoSwitches are plugged into two TV/Media centers that were drawing 40W in standby mode for 20 hours day and into a PC/Laptop setup that was drawing 10W in standby mode for 8 hours a day. The EcoSwitches will prevent 321kWh of standby power being wasted annually which is about $80.25 saved on our power bill each year. Not a bad return on investment for $60 worth of EcoSwitches.
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.
So I’ve spent the last week evaluating different suppliers/installers of our rooftop solar panel system. Basically I drew up a shortlist based on the various experiences written about on the Whirlpool Forums and the equipment I wanted. Here was my key selection criteria:
- Be able to install Suntech mono-crystalline panels and a Sunnyboy inverter.
- Not be universally disliked on the above mentioned Whirlpool forums.
- Be able to explain to me in no-nonsense (ie no BS) terms what signing up for the September 30 deadline for the South Australian State Government feed in tariff (FIT) actually meant. I knew already what this meant but wanted to use this as a litmus test to detect any attempt at deception on the part of the supplier.
- Be able to answer (or ask) questions about roof type, roof facing, system size, and accreditation of installers
I rang about 8 companies and the winning company pretty much popped out straight away. Some companies didn’t return calls, some couldn’t (wouldn’t) supply the right equipment that I wanted, and one in particular just annoyed me with their hard sales spiel and wishy washy answers to my technical questions. So, we’ve ended up choosing Braemac (http://www.braemacenergy.com.au/), who are also a large electrical and automation company who I’ve had some dealings with back in the days when I pretended to be an engineer. Their main point of contact was very helpful and booked in a rooftop inspection for the 5th of September.
I’m moving house in a couple of weeks and will be a home owner for the first time in a while and because of this I’m planning on doing a lot of work on the new house. One of these projects is to get a rooftop photo-voltaic (PV) system installed and cut back on power costs and (hopefully) benefit by selling excess generated power back into the grid. The South Australian state government (I live in South Australia, a southern state of Australia) is offering a $0.44 per kW/h feed in tariff (FIT) for rooftop PV systems approved by 30 September 2011 and installed by the end of 2011. FIT payments are guaranteed until 2026 and power retailers may also offer up to an additional 8c / kWh giving a total of $0.52 / kWh for excess power generated by your rooftop PV system.
The real benefit of a rooftop PV system only really comes into play when the power it generates exceeds the power used. For example, if your system is generating 10 kW/h during the day but you are consuming 12 kWh the system only offsets the power you use. My last power bill was charged at almost exactly $0.25 kWh so a PV system that generates under my average daytime use is only going to benefit me at that rate. However, a bigger system that exceeds my daily usage will benefit me at $0.52 / kWh and my return on investment in the rooftop PV system will be much better.
We’ve booked in a couple of PV installers to come take a look at our new house on September 3. I’ve not settled on a system size yet but I have settled on the components, Suntech mono-crystalline panels and a Sunnyboy Inverter. These are reputable brands that should just work. No point skimping on quality on a system that will cost multiple thousands of dollars whether a good quality or rubbish brands are used. More on this later.