Update July 09: Got my 1st bill since monitoring my power consumption and it was 840kW/h for the quarter. More on it here!
Update Oct 09: Got my 2nd bill since monitoring my power consumption and it was 820kW/h for the quarter. More on it here!
Update Jan 10: Got my 3rd bill since monitoring my power consumption and it was 760kW/h for the quarter. More on it here!
I have several reasons for picking 4000kWh as a target.
Unlike just about everything else I buy in bulk, the more I buy the cheaper it is per unit, my electricity supplier charges more per unit the more I use. My electricity meter is read quarterly and the first 1000kW hours are at a lower rate than any over that. With four readings per annum and 1000kWh per quarter gives me my 4000kWh per year target.
| Electricity Prices | |||
|---|---|---|---|
| GST Exclusive | GST Inclusive | ||
| Peak Rates Quarterly | First 1,000kWh | 16.5400 c/kWh | 18.1940 c/kWh |
| Balance of kWh | 17.6000 c/kWh | 19.3600 c/kWh | |
| (* I receive a 3% discount because of the plan I'm on and another 8% if I pay on time (paying by direct debit takes care of that) so knock 11% off the price and it's my actual cost.) | |||
Happy happy joy joy. The cost of electricity (and gas) is going up on the 3rd November 2009
| Electricity Prices from November 2009 | |||
|---|---|---|---|
| GST Exclusive | GST Inclusive | ||
| Peak Rates Quarterly | First 1,000kWh | 19.1200 c/kWh | 21.0320 c/kWh |
| Balance of kWh | 20.3500 c/kWh | 22.3850 c/kWh | |
| (* I receive a 3% discount because of the plan I'm on and another 8% if I pay on time (paying by direct debit takes care of that) so knock 11% off the price and it's my actual cost.) | |||
At work we are promoting an in-house designed load shedding device that can be applied from small domestic installations through to large industrial installations that minimises as far as practical the maximum demand an installation puts on the supply grid. We also promote and install efficient automation systems to control lighting and air conditioning systems in commercial, industrial and school environments. Installing light fittings that use efficient T5 fluorescent tubes with electronic control gear and sensors that automatically dim the fittings to keep the lighting at constant and acceptable levels save energy consumption and the total of the monthly bill. The carbon impact of these installations is also lower than conventional systems. Although I'm tackling this on a micro scale at home, I'm practicing what I preach.
I'm not a greenie or a tree hugging hippy but cutting down on my electricity consumption benefits the environment as I lower my carbon footprint by being responsible for less greenhouse gas emissions from our coal burning power stations.
In Summary:
No.1 priority was that this exercise didn't become a major pain in the butt. I want to achieve my goal by changing my habits and not by having to change my lifestyle much.
One change that was probably more of a lifestyle change rather than a habit change was that I stopped using my clothes dryer. I would tumble dry all of my washing. I now hang every load of washing I do to air dry. I did this before I started taking notice of my electricity bill and I have no data on how much my consumption dropped due to this change. My initial figure of 6000kWh PA is after I stopped using the tumble dryer, I can only surmise that pre 2005 I was using more than 6000kWh / year.
One other major change was that I got rid of my pigeon paired 420 litre fridge and 380 litre freezer, that was two compressors and 800 litres, for a 350 litre single two door unit. It's all I need. It was given to me by a friend who moved house so was a freebie. This change would have effectively cut my fridge / freezer running costs in half.
I switch off lights where they aren't needed.
I used to just turn the TV off when I was finished watching it. Now I turn the VCR, Set-top box and pay TV box off when I'm done but leave them in stand-by. I've stopped short of switching them off at the wall at this stage as for me as that would be a pain in the butt change.
The laptop and computer get turned off at a night instead of being left on. The computer stays in standby mode though, as my UPS is left on. The UPS runs my main PC and it runs my wireless ADSL router. At this stage it would be too much of a hassle to shut the UPS down as it would cut my internet connection off and it is shared between my laptop, desktop computer, xBox and iPod Touch.
I've replaced normal incandescent globes with compact fluorescent (CFL) ones where I can. My bedrooms have dimmers fitted to the lights, so they're still normal incandescent globes. I still have 8 X 50W low voltage dichroic downlights (5 in my hallway and 3 in the kitchen) that I'm still exploring options for replacements for. Either CFL's or LED's.
Update: I've replaced the 3 kitchen 50W low voltage dichroic downlights for 3 X 5W 240V LED's. They're not as bright as the 50W lamps, but they are a lot brighter than some 11W CFL's I tested. I tested both Cool White (4200K) & Warm White (3000K) CFL type lamps with a lux meter. Also the CFL's also have a 5-10 minute warm up time before reaching their full brightness.
My lounge room has no fixed lighting (hey, I'm an electrician). When I moved in I inherited a 300W QH light stand that was 2 metres tall and illuminated the room by shining light onto the raked ceiling. When the bulb blew, I put a 1 X 36W diffused fluoro fitting on top of my book case that now illuminates the room by the raked ceiling reflecting it.
Lamp changes to date.
CFL's are constantly dropping in price. I checked the shelves at the local supermarket recently and an incandescent globe cost $0.98c and a twin pack of CFL's was $6.00. Typical life expectancy of an incandescent is 1000 hours and for a CFL it's between 6,000 and 10,000 hours. CFL's are effectively a cheaper replacement for incandescent globes @ $6.00 ~ $10.00 of replacements compared to $3.00 and the CFL's only use a fraction of the energy for an added saving.
| Click any of the images for a larger one (It will open in a new window). | ||
 9W Warm White 827 / 2700K CFL in bed side lamp replaced a 40W incandescent. (Less 31W) |
 2 X 9W Cool White 4000K CFL's in Range Hood replaced 2 X 40W incandescents. (Less 62W) |
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CFL alternative
Government legislation is phasing out normal incandescent light bulbs over here in favour of more energy efficient lamps. Direct replacements are available in the most popular range of sizes and wattages. They contain a halogen bulb inside a traditional shaped outer bulb. These lamps are more efficient because they can put out the same light as the traditional incandescent using less input wattage saving up to 30% i.e A standard 40W light bulb is replaced with a 28W Halogen energy saver, 60W replaced with a 42W bulb etc. A 42W halogen energy saver cost $3.79 today. More expensive, shorter life and higher consumption than CFL's though.
Advantages of the Halogen Energy Saver over standard incandescent light bulbs
Osram Halogen Energy Saver Light Bulb Examples
More can be read here on the Osram website Osram Halogen Lamps
The following graph is my annual consumption, I only have complete data back to 2006.
My 2006 / 2007 consumption was similar at 6139kW/h and 6070kW/h respectively. A difference of 69kW/h. That's less than a 1.2% change so my usage was pretty consistent. This is after I'd stopped using my electric clothes dryer as I mentioned earlier. My consumption pre 2006 would have been even higher. (2009 is a little low as it is a work in progress.)
The 1440kW/h - 23.7% drop from 6070kW/h to 4630kW/h is mostly from replacing my 800 litres of fridge and freezer with a 350 litre two door unit and changing to CFL's where possible. Changing my lounge room 300W QI fitting to a 1 X 36W fluoro would have knocked a fair portion off too.
Now it's time to work on the remaining 630kWh. This will take some habit changes. I've purchased a wireless energy monitor to help me cut down my consumption. I can see what I'm using at a glance and take any action necessary to alter it.
Once I've reached my goal of keeping my annual consumption below 4000kWh it will be a 34.1% drop from the 6070kWh usage before I made changes. At the current higher rate of 19.36 c/kWh (because everything over 4000kWh is at the higher rate) means an annual saving of $400. (More than enough to cover the cost of the replacement bulbs).
This next graph shows my average daily usage for each quarter per year.
I was initially surprised at which quarters had the highest usage. The lines don't cross, so the overall usage per quarter is consistently higher and lower in the same quarter each year. (Remember I'm from Australia, and our seasons are upside down too).
Off the top of my head I would have thought the coldest and darkest quarters were when I used the most electricity and the lighter and warmer 1st and 4th quarters were the ones when I used the least amount of electricity. I can only guess at this stage that my evaporative cooler fan draws a lot more power than my central gas heater fan does even though I think I use it less than the heater. The milder seasons of Autumn and Spring (2nd & 4th quarters) are when I use the least amount of electricity due to not using the heating and cooling systems as much. Now I'm aware that these use more power than I gave them credit for, I will monitor their use more carefully.
(This year might be a bit different as I've put a wooden disk over the fan in the evap cooler to stop so much heat escaping into the air. Hopefully the central heater wont need to run anywhere near as much as it has in the past. It was easier for me to put a disk over the fan rather than closing all the cooling vents. - Update: Check my October 09 Update below. The disk made a big difference.)
Updated 03 July 2009. I received my first quarterly bill since monitoring my power consumption and it came in under my maximum target level of 1000kW/h / quarter. It was 840kW/h for 92 days with an average of 9.13kW/h per day. I've updated the graph. My plan is working and the monitor is pretty close to actual with 862kW/h vs. 840kW/h billed.
Updated 06 October 2009. I received my second quarterly bill since monitoring my power consumption and it too came in under my maximum target level of 1000kW/h / quarter. It was 820kW/h for 94 days with an average of 8.72kW/h per day (Compared with 13.37kW/h per day this time last year - a drop of 34.7%). The monitor was again pretty close to actual with 847kW/h vs. 820kW/h billed.
The wooden disk I put in my evaporative cooler has done more than I thought it would. I should have done it every year in the past. What has traditionally been my 2nd highest quarter for electrical consumption - Winter, dropped to below what I consumed in Autumn. Not only has it saved me on my electricity bill, my Winter gas consumption was 43% less than for the same time last year.)
Updated 06 January 2009. I received my third quarterly bill since monitoring my power consumption and it too came in under my maximum target level of 1000kW/h / quarter. It was 760kW/h for 87 days with an average of 8.73kW/h per day (Compared with 11.05kW/h per day this time last year - a drop of 21%). I've updated the graph and it's the lowest quarter I have recorded. The monitor difference recorded compared to actual was a fair bit. With a lot of the Evaporative cooler running in December it has thrown the monitor out due to power factor. While the cooler fan is running at low speeds, the monitor displays the incorrect kW/h consumption with 872kW/h recorded vs. 760kW/h billed.
To help me trim the last of the fat off my bill I purchased an 'Energy Monitor'. It is made by Watts Clever There are various software packages available for download to extract the information from the monitor, but these are written by others and not by Watts Clever. I'm using Dale Lane's "Current Cost." (I'm currently trialling another software package Techtoniq's "Current Cost Agent". It's still in a beta development stage, but it's looking interesting.) The monitor is an invaluable tool for anyone who wants to lower their energy usage. "If you cannot measure it, you cannot improve it." — Lord Kelvin. It has the potential to pay for itself many times over.
It consists of two main items:
| Click any of the images for a larger one (It will open in a new window). | |||
 Current transformer and transmitter. |
 Display unit / receiver. |
 Energy monitor, transmitter & software. |
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I think this is an excellent device and great value for money. I do have one issue with it, mainly because I'm technically bent. For most people, the issue I have with it wont mean much. The device can help anyone, including me to cut their electrical energy usage down. (If I really wanted to address the issue I have with it, I could spend 10 times as much and get a commercial unit).
The only issue I have with it, is its ability to accurately reflect the actual cost of the electricity usage. As a guide it works quite well though.
This monitor only measures current (amperage), there is no connection to measure the voltage. This means the unit is displaying amps that has been converted to kWh using a fixed value for the voltage and power factor. To measure actual wattage we need the voltage measurement and the phase angle between the voltage and current for power factor. (W = V * A * p.f.) The big advantage of only having a clamp type CT to measure the current it that no physical connection to any live wires needs to be made. Installation is very simple.
Looking at the specs for the unit I see it says "Rated energy source: European 230VAC 50hz" my supply fluctuates from 240V through to 250V. Using the formula above (and because we don't know the actual power factor it is taken as unity / 1) if I'm drawing 5 amps of current and the unit is configured for 230V then it will show I'm using 1150W or 1.15kW. But if I'm drawing 5 amps and my supply voltage is 245V my actual usage is 1225W or 1.22kW. An inductive load has a power factor component to consider. If it was an electric motor I was using that was drawing the 5 amps and it has a power factor of .85 then my actual usage is 5A X 245V X .85pf = 1041W or 1.04kW. But once again, this is not a commercial power meter. Near enough is good enough though and it gives a reasonable idea of what is going on. (Now I've been using the unit for more than 6 months and have received two quarterly bills, I can compare the monitor total with actual usage and it's pretty close. 862kW/h on the Monitor vs. 840kW/h billed (~2.5%) and 847kW/h on the Monitor vs. 820kW/h billed (~3.1%).
The display cycles through how many kWh's have been used in the past 24 hours, the last 7 days and the last 30 days. The cost cycles through cost per day and cost per month, they are instantaneous values based on the usage at that moment. Also displayed is the difference in cost compared to the last measurement (displayed as a difference per day and difference in cost per month). If you wanted to know how much something costs to run continuously. i.e A lamp or TV etc, turn it on, note the reading, turn it off and note the difference. (Devices that cycle are a little harder to work out what the cost to run as the switch off and on during normal operation, air conditioners, refrigerators etc. The unit also has a clock, thermometer, a graph of yesterday's usage and of course, current kWh consumption.
I find the software useful. The unit is not a full blown data logger, but can use a computer as one if you want to leave it on. To graph real time usage the unit must be plugged into a PC running the software. You must download everyday if you want to keep continuous data for every 2 hour period. You have to download once a week to maintain continuous weekly data, but I believe the unit will store up to 4 years of monthly usage data.
By entering a cost per year I want to spend, the software will display a line indicating what I must keep my usage at or below to stay under that amount. I want to stay under 4000kWh's so had to come up with annual cost and enter it i.e. 4000kWh X 18.1940 c/kW = $726 annually.
Graphs
Some of the data I'm interested in.
| Click any of the images for a larger one (It will open in a new window). | ||
 In this real time graph, my son is in the shower with the heat lamps running in the bathroom while I'm cooking dinner in the George Foreman grill. You can see the grill cycling on and off and see when Gav got out of the bathroom. We ate, I cleaned up in the kitchen and the load settled. |
 Here I shut everything down, jump in the shower with the heat lamps on, get out and go to bed. 7 hours later I'm up and out the door after a short time. The base load is obvious (but higher than normal with the computer left on to capture the data), the fridge cycling on and off during the night is obvious too. Looks close to a 50/50 duty cycle. I must try it with more stuff in it to see if it makes a difference. |
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Here's some of the graphs generated by the software. Because I've set a person target, there is a line across the graphs that shows the value I shouldn't exceed to achieve that target.
| Click any of the images for a larger one (It will open in a new window). | ||||
 Power usage by hour (2 hourly). |
 Power usage in an average weekday. |
 Power usage by day. |
 Power usage in an average week. |
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Base Load
My base load is ~140W day in day out. It is made up of the following items.
What is the base load costing me?
24 hours in a day, 7 days in a week, 52 week in a year = 8736 hours in a year. 140W (= 0.14kW) X 8736 hours = 1223kWh X 18.1940c/kWh (lower rate as it's in the 1st 1000kW hours) = $222.52 / year or 305.76kWh - $55.63 / quarter. More than 30% of my planned annual usage will be consumed while I'm sleeping, while I'm at work, while I'm out. I didn't realise the base cost was so high until I did that. Now maybe some of the things I wasn't going to do, I will end up doing. Time to take note of those instantaneous cost values displayed on the monitor and work out what I really should turn off.
I have to include some information on the impact these changes will have on the green house gas emissions I'm responsible for.
According to my bills, with an annual consumption of 6139kw/h I'm responsible for 8.07 tonnes of greenhouse gas emissions or 2.02 tonnes per quarter on average. With an annual consumption of 4000kw/h I'll be responsible for 5.26 tonnes of greenhouse gas emissions or 1.315 tonnes per quarter on average.
This works out to be 2.81 tonnes less per year or 702.5kg less per quarter. Using the data from this website ABC Science - What should I plant to balance my carbon footprint? the savings in my carbon footprint equals about 9 eucalypts per year. I'm small fry in the over scheme of things. Reducing my output is the best thing, trying to be carbon neutral by buying credits is not always as good as it seems according to this article Tree-planting projects may not be so green
Coal Fired Power Stations
Dirty coal fired power stations don't just release a large amount of CO2 into the atmosphere, they release huge amounts of other pollutants. Sulphur dioxide, nitrogen oxides, toxic mercury pollution, and they're large contributors of hazardous air toxics, and particle pollution. Planting a tree isn't going to off-set these.
Smog and Ozone
When nitrogen oxide (NOx) reacts with volatile organic compounds (VOCs) and sunlight, smog (ground level ozone) forms. Of the major criteria air pollutants regulated by the EPA, NOx emissions have historically been the hardest to control. One of the contributing factors is that NOx emissions from huge dirty coal plants in one region can easily pollute areas hundreds of miles downwind.
Particle Pollution and Soot
Coal-fired power plants are also one of the largest single sources of sulphur dioxide (SO2). Sulphur dioxide, which can travel long distances in the atmosphere before falling down to the land, can cause problems on its own as well as when it combines with other pollution to form other dangerous compounds. SO2 can combine with nitrogen oxide (NOx) and other particles to form particulate matter, which is sometimes called soot. Particulate matter, which can also be released directly from the smokestacks of coal-fired power plants, is often divided into categories based on the size of the particles-coarse, fine, and ultrafine-but all three are hazardous to your health and the environment.
Acid Rain
Acid rain, or acid deposition, occurs when sulphur dioxide (SO2) and nitrogen oxide (NOx) react with water and oxygen in the atmosphere to form acidic compounds, most commonly sulphuric and nitric acid. These acidic compounds then either mix with natural precipitation and fall to the earth as acid rain, or remain dry and then settle to the ground. Acid rain destroys ecosystems, including streams and lakes, by changing their delicate pH balance making them unable to support life. Acid rain can destroy forests, devastate plant and animal life, and eat away at man-made monuments and buildings to effectively destroy our natural and historical treasures.
Air Toxins and Mercury
Coal-fired power plants are the largest single man-made source of mercury pollution, and are the largest contributor of hazardous air pollutants. In smokestack tests, coal-fired power plants were found to release 67 air toxins, many of which are known or suspected carcinogens and neurotoxins that can cause development problems, respiratory problems, and aggravate asthma. Of these air toxins, one of the most dangerous is mercury. Mercury from coal-fired power plants is released into the air through the exhaust system when coal is burned. The primary exposure occurs when this mercury falls to the earth and runs into our lakes, rivers, and streams and contaminates the fish. Humans can be contaminated when they eat these fish and shellfish. Mercury is a developmental toxin, primarily affecting foetal development. In unborn children, it can cause brain damage, mental retardation, blindness, and many other problems. Infants are also exposed to these dangers through contaminated breast milk. While the dangers of mercury are most often associated with women and children, eating fish high in mercury has also been found to put middle-aged men at a greater risk for coronary heart disease.
Right! Now where are those gas bills? :) Steve.
