We built the house to be energy efficient, and so the lights were chosen with that in mind. We settled on commercial fluorescent lights from Planet Lighting in Bellingen, which have the ballasts in the light fitting rather than in the bulb. The exceptions are the downlights in the kitchen and the reading lights in the lounge and bedroom which are mainly 12V Halogen. We recently bought two 5W LED’s which are fine for reading but not powerful enough for the kitchen task lighting for which we have not yet found an efficient alternative. We also installed motion detectors in the hall, pantry and wardrobe so the lights turn themselves on as needed and then off after a short period. If you do this make sure the motion sensor is compatible with fluorescent lights as some are not.
We splashed out on an induction cooktop which is a lot more efficient than a normal electric hob and it is certainly a joy to cook with. It emits less carbon than a gas hob given our source of our electricity.
Hot water was provided to both the washing machine and dishwasher. As the hot water system uses virtually no electricity this is considerably more efficient than using the in built electrical heaters. The appliances do have to be designed to use both hot and cold water however.
After having moved in and settled down we completed a full audit of all our electricity use, using a power meter and estimating the permanently connected loads (lights, cooker, oven etc). The meter measures either the energy used at any point in time (in watts) or the power used over a measured amount of time (in KW hours). So appliances that turn themselves on and off like fridges and freezers should have their power measured over quite a long period (maybe a day). Dishwashers and washing machines are best measured over a cycle possibly separating different types of wash (hot and cold, economy and full). The wattage used by many other appliances is quite stable, so the number of hours use per day can just be multiplied by the wattage. Finally each appliance should be checked for standby power use, by checking the wattage used when switched off but still plugged in at the wall. This varies widely and can be quite a shock. A friend’s old stereo system was drawing nearly 40W when switched off, costing her $15 dollars a bill for nothing.
By going through the audit we found we were able to save an extra 20% by changing some habits, and replacing appliances with more efficient ones as they needed replacing. Laptops are considerably better than desktops, 30W versus 180W in my case for example.
The remaining known major inefficiencies are the 20 year old fridge and freezer, which could reduce our usage by 1.5KWHr per day (20%) when we replace them with new appliances, and the downlights in the kitchen which could save .5KwHr per day.
If you are interested in the audit you can borrow meters from a number of councils and / or Libraries, including Taree council (details here), or you can buy them here or here.
I have developed a spreadsheet here which simplifies a lot of the calculations involved.
