Got Aloha for a Teacher?
I'm not an energy expert or a conservation hound, so to prepare myself for the Energy Challenge I needed a simple plan. And, I needed to know more about where the electricity in my house goes.
So, I recently did an "energy audit for dummies" at home. I borrowed a TED (The Energy Detective) monitor from Kanu Hawaii. The TED is great - its about the size of a cell phone, plugs into any socket, sits on top of your counter, and tells you how much electricity your whole house is using in real time, displaying watts and cost per hour. (It requires installing some clips behind your fuse box, and you can learn more about it at hawaiienergystudy.com).
My "audit" consisted of waking up early a few mornings while everyone else was asleep, and switching appliances on/off, plugging/unplugging electronics, watching the readings on cost and watts change. I learned a few things that I thought might be useful for other energy dummies like me, with households like mine. I rent a 2BR 2BA unit in an older building, and have a household of 3. It's got an older fridge, stove, and washer/dryer, and I don't have solar anything. I have an Energy star dishwasher, rarely run the A/C, have only a few electronics (laptop and cell charger, TV set and DVD player), and (thought I'd) changed all my bulbs to CFLs. My monthly electricity bill is about $112. I want to cut it by $28. Here's what my "audit" taught me:
1. When everything is off and unplugged except for essentials like the fridge and clock, my house uses about 45 watts at $0.01 per hour. If I could keep it that way, my monthly bill would be $7.20 in theory. Actually, it would be higher - around $16 - because we all pay fixed charges to the electric company unrelated to how much electricity we use.
2. Any appliance that has to heat up from a room-temp state, e.g., stove, oven, coffee pot, rice cooker, takes a LOT of electricity to get going. Electricity use "spikes" when these things are heating up (1,000 watts+). Once hot, the electricity use drops (e.g., to about 200 watts for a coffee pot on "keep warm"). I noticed it takes take about 4x as much electricity to boil a cup of water on my stove than in my microwave.
3. The same applies to the fridge: Electricity use spikes up when the motor/chiller turns on, but is drops once the fridge is cool. But I also noticed the motor goes on a lot. Even the mornings, when the house is cool, the motor runs for 6-8 min at a time at a cost of $0.26 an hour.
4. The water heater uses the most electricity, about 4.3 kilowatts at $0.73 an hour, whenever the heater is on. The heater's not running all the time; it goes on when the water in the tank cools down (e.g., in the mornings the heater switches on), and whenever we use hot water. If I take a 3 min shower, the heater runs for 20 min, even after I'm done showering. For a household of 3, taking 1 shower a day costs about $25 a month in electricity. If I could cut the number of hot showers in half, it would save me $12 a month.
5. I turned on the lights one by one and watched the monitor. I discovered 6 incandescent bulbs that I didn't know were there, in the kitchen and bathroom, and an outside light that seemed to be pulling more than 100 watts by itself for some reason. My lights are on about 3 hours per day, so changing those 6 bulbs will save me about $4 per month.
6. My "phantom load" is about 20 watts. The cell phone and laptop charger, the TV and DVD player are using electricity, even when they're off. Twenty watts isn't much, but it's there *all* the time, so it adds up - about 14.4 kilowatts and $3 a month. A $20 "smart strip" (power strip that automatically cuts off electricity flow to electronics when not in use) could cut my phantom load in half, pay back the cost of the smart strip in about a year, and save me close to $20 a year for the rest of its useful life.
Here's some readings from the TED:
- refrigerator (motor on) - 145 watts - 6 min cooling cycle
- stove (small burner) - 1,400 watts - 3 min boil 1 cup
- microwave - 1,000 watts - 1 min boil 1 cup
- AC (wall/thru-window unit) - 1,000 watts - hardly ever used
- water heater - 4,300 watts - 20 min post-shower
- phantom electronics - 20 watts - 1,440 min per day
- TV set (older CRT, not flat screen) - 100 watts - 30 min per day
- lights - 620 watts - 180 min per day
- hair dryer - 1380 watts - 10 min per day
- washer (warm wash/cold rinse) - 550 watts - 30 min
- dryer (normal cycle) - 3,000 watts - 45 min
Based on my findings, here's my plan to save $28 in 1 month:
1. Lower the thermostat on my water heater 5 degrees and see if I can get a timer so it's not heating water when the house is empty or everyone is asleep. Target savings: $8.00.
2. "Navy" showers or cold showers for me in July. Cut the shower-related portion of my bill by 1/3 and save $8.00.
3. Wash clothes and dishes in cold water only. Cut the hot water portion of my bill by another $5.00.
4. Change those few remaining bulbs from incandescent to CFLs and save $4.00.
5. Reduce "phantom load" with a smart power strip and save $1.50.
6. Switch from stove to microwave for heating water and light cooking and save $1.50.
This plan requires me to invest a minimum of $40 in 6 CFL bulbs ($20), a smart power strip ($20). The changes save me $28 a month. That means my investment pays itself back in less than 2 months and then keeps saving me money every month after that. Hope this is helpful
Want to join me in the Energy Challenge? Make a commitment at www.kanuhawaii.org/energy.
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Comments posted prior to adopting Facebook comments.
Our old fridge used 175 watts an hour (averaged over a one month cycle, metered with a kill-a-watt). Our new fridge is much bigger, colder, and quieter...and uses just 48 watts an hour on average. I am amazed by how much more efficient new appliances can be over ones made several years ago. Because a fridge is on always, this one switch saved over 1,100 kWh each year or just under $300 a year in savings. These new fridges are about a grand so essentially they are "free" after three to four years of use.
Here are some tips I've read on how to reduce the amount of energy any fridge uses:
* Keep the doors closed as much as possible. Play the "how fast and how few times" the door opens game :)
* Keep it relatively full. Full freezers and fridges work less hard over time.
* Keep the coils clean. They get really, really linty and need to be cleaned.
I wish fridges came with clear doors so you can peek and plan before you open, just like the ones in the market.
Good luck! Love the plan.
Olin, I thought of the clear fridge thing too! Either the glass doors like you mention or remember the days when they had those clear curtain-strips that covered the frozen section of the grocery store? That would be an effective retrofit to existing fridges to keep the cold air in, even when accessing stuff. I think the clear door idea has the drawback of not having privacy (kind of like a clear dresser). It would work if your fridge had a double door, so you could open the "regular" door open to look through the glass one. I think we're onto something tho. :)
Hey Eathan, cameras are pretty cheap and energy efficient now. Maybe there is some value to having a wide angle picture of the contents of your fridge taken every time the door closes. That way, you can see from a computer or phone what's inside before opening. Or if you are away from home check on what's not in your fridget that you need to buy. Regardless, a fridge that we don't need to keep open for too long can save energy.
Olin! A clear fridge would be fantastic! That would seriously cut material use in manufacturing down as well as energy used while gawking at all the options (and if you're as bad as I am, pondering recipes!)
Thanks for the journal, James, very informative! I will stop heating my daily cup of tea in the hotpot. Olin, if anyone is going to invent a clear fridge, my money is on you!
This is a GREAT posting. Anyone could realize similar benefits in his/her home.
I just got my TED 5000 today and your posting has some great ideas for me. Mahalo nui loa!