Friday, June 25, 2010

Taking It Down

In the never-ending quest to bring our eletricity usage down, we've been trying to make some little changes. We've already eaten the low-hanging fruit: changed the lightbulbs, eliminated ghost loads, and stopped using the dryer, and those things have made a difference, but not enough of a difference.

Our electric bill has a comparison chart on the bottom of it that allows us to see what our usage has been over the past year. According to this calculator our 562 kWh/month (40% of which is hydro) is 43% of what the average American uses.

There are two appliances in my house that use an inexcusably large amount of electricity - the refrigerator and the stove. We know this, because we did a quick and dirty comparison of how fast the little wheel on our meter was running with these appliances operating and without them. We also noticed that our average usage is pretty constant. During the winter, we're using more lights, and so it seems like the summer bill should be smaller, but it's not, and we figured out why the other night.

It's me. I like to drink tea, and I drink it hot - all year long (give me a break, okay? I live in freakin' Maine, and hot up here is a cool spring day to you southern folks ;). During the winter, the teapot stays hot on the woodstove. During the summer, I heat up the tea pot, on average, seven times per day.

Deus Ex Machina suggested that, perhaps, I could use the thermos. So, as an experiment, I have been heating up the water, once, and making tea in the thermos. It gets me three or four cups of hot tea (and it's HOT for a LONG time!), before I have to make another pot.

My goal is to reduce our electrical usage to the point that it would make sense for us to purchase a small solar array, and for just around $1000 we could have a system that would generate 1.6 kWh/day with six hours of sunshine (which is what we average in my area). It would cost us a little bit more to purchase the storage equipment so that we could actually have electricity from our system when the sun isn't shining.

Unfortunately, as long as we're using the eletric stove, even with the reduced usage, and the refrigerator, because somebody isn't ready to give it up (sheesh, it's not like it's toilet paper or anything *grin*), we'll be consuming more electricity than we can afford to produce.

And we'll be stuck being dependent on someone else to deliver it to our door.

As such, I've thought of some solutions:

Refrigerator options:

Cheapest: unplug our side-by-side. One half could be used for storage. The other half would be the "refrigerator" and we'd use bottles of ice from the freezer (which we will keep, because we buy meat in bulk, which is the only way to get locally, raised beef on demand, and because we're limited in the space we have and raise all of the chicken we'll eat for the year during the summer - we don't have the space to keep meat birds "on the hoof", as it were) to keep the stuff cool - although not nearly as cold as it is right now.

Best: build a spring house out back over the brook or build a cold closet in the house, which uses geothermal principles to keep the food cool.

Compromise: convert a chest freezer to a refrigerator, which would still use electricity, but only uses 100 to 200 kWh per year.

Electric stove:

Cheapest: limit use and employ some passive cooking techniques, like haybox cookers and using the thermos to store hot water. This is the option we'll be using for now, but it's not likely to save a great deal.

Best: replace the electric stove with a gas stove that uses methane gas we produce ourselves. The nice thing about methane digesters is that they can create a closed system. We input "wastes" (things that would be composted, like kitchen wastes and animal dung) into the digester and create a slurry, which off-gases and produces methane that can be used as a gas for cooking and also for operating an engine to produce electricity. Unfortunately, this option requires quite a large investment in equipment, and it would require us to be very diligent in feeding our digester. The other wrench in the works to the whole plan is that methane digesters like what we'd need, while they are being manufactured, sold and used in some parts of the world, aren't yet available in the American market. The other aspect of this type of system that makes it a little tricky for us, is that the slurry needs to be kept at a certain temperature for the anaerobic action necessary to produce the gas to take place. It would be a good solution during the warmer months here in Maine, but we'd have to have a back-up during the winter ... like a woodstove ... or something.

Compromise: An outdoor kitchen, which would include a rocket stove and/or a propane burner - for heating up water for tea ;). The benefit of this particular option is that we could also use the kitchen for boiling maple sap, and if we were to use the plans for the all-in-one that were developed by Mother Earth News, we'd also have an oven that I could use to bake bread. It would be great during the summer on days like today, when I won't heat up the house to bake anything, which means we don't eat bread ;), and during the winter, we'd end up saving a wad of cash on our electric bill, because I'd be doing all of that baking outside instead of in the electric oven. I might even learn to plan a little better, because each baking session would require just a wee-bit more of a commitment from me than simply turning a knob ;).

Unfortunately, both the best option and the compromise require some amount of work and financial investment on our part, but if we're not willing/able to invest in our lower energy future now, while we have the cash and the choice, later, when we don't have much of either, we'll be hurting.

16 comments:

  1. W
    great posting as ever

    I recently read that (in the UK) just by adding insulation to the fridge it would be possible to reduce its electricity consumption, literally old carpet and cardboard would be a good start, and foam board (free from most construction sites) would be even more efficient. The article reckoned that the fridge was about 10% of the households consumption.

    It made me wonder if a coil of PEX or other plastic pipe could be used to increase the heat loss by exposing the normally enclosed back of the fridge to the airflow outside the house?

    Please keep us posted
    SBW

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  2. Hey, Suburban BW, One chart I read claimed that refrigeration (probably to include the freezer :) was 13% of the average household's electric usage. Either way, it's a pretty hefty chunk of energy usage just to keep all of our eggs cool. You know? ... especially considering there are alternatives - if we would choose them ;).

    So, re: plastic pipe - I'd thought of making a cold closet using an old fridge. The basic idea behind the cold closet is to use natural air flow to cool the space. So, essentially, it would be open to either outside or under the house, and using natural convection (best) or fans, the space would be kept cool for storing things that needed to be cooler than room temperature. My thought was that we could put some holes in the fridge and connect it to the outside. But my imaginings would have the fridge unplugged. How does your idea work?

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  3. Sigh. I have to envy your refrigeration options in a colder climate. Keep in mind, on the chest freezer conversion, that the 100-200 kwh numbers are associated with 10 cu. ft. units. We wanted larger than that, which is why we eventually settled on getting an upright freezer. I just can't rummage around a large chest freezer at my height and be assured of avoiding the food spoilage issue mentioned by a poster (Apple Jack Farms) on Sharon's recent "Sans Fridge" post. The prospect of having to towel up or drain off the condensation from the inside of the bottom every single week, too, as reported by all who've done the conversion was unappealing. We hope to get the upright freezer's use down to an equivalent sized refrigerator with an Energy Star rating. (Will report once it arrives in a couple weeks and we do the conversion.) Oh, by the way, check out kegerator sites for lots more references on converting freezers to refrigerators.

    Totally hear you on the invest now theory, but it sure hurts to see the savings account hemorraging like it has been around here lately.

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  4. If you're mostly just looking to heat a little water for tea, I bet an electric kettle would do it for a lot less kwh than an electric stovetop. You lose a good bit of energy to the air on the stovetop. Plus they're usually well insulated, so it would act as a thermos too. Might be something to keep an eye out for...

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  5. Wendy

    A domestic fridge is probably one of the worst designed things in the home. Typically we keep the things that need to be chilled the least in the coldest part - salad at the bottom and to add to the stupidity the hottest thing is the motor that drives the fluid is positioned at the bottom where it's heat rises, undoing the function it's made for. Stupid or what?

    If the back of the fridge was exposed to the outside of the house the wind would make it far more efficient - not always practical so I'm leaning towards making another heat sink to increase efficiently.

    Copper pipe is very easy to form. Imagine making a flat coil that would fit against the radiator on the back of the fridge, then two 1 inch holes in the wall to run two lengths of plastic pipe trough, then another coil on the outside of the house in the shade where the air can flow over it. As you are not connecting the system to your domestic plumbing it would not need to be coded or approved and plastic push-fit connectors mean doing the joins would be child's play. No pump would be needed as the convection would proved the necessary flow between the heat sink part on the fridge back and the radiator part on the outside of the house. Just gotta remember to top the system up occasionally - preferably with purified water.

    I'm about to buy some thermometers for testing pipework - when I get round to it i'll let you know how well it works.

    Although as a caveat i should add - if in doubt insulate! It's always the best value option.

    Regards
    SBW

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  6. Wendy,
    We are kind of in the same situation as far as investment. We are hoping to build a house in the next year or so and try to keep it economical while building but also keeping in mind the potential financial breaks for the future. I would love to pick your brain a little farther on this subject as we have only gotten so far as to adding in the cost of solar panels and a well for water. I will browse you blog a little farther to see if you have anything about your production of methane gas.... I actually prefer to cook with gas verse electric anyways. Unfortunately our area is heavy regulated as to what codes will allow us to do but the possible benifits are well worth the effort in research. Thanks for planting the seed! :)
    -Leigh

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  7. Leigh - There is a ton of information online about methane digesters. Google "biogas" and "methane digester".

    But in the meantime, this video is a good one for showing what's possible - and what is being done RIGHT NOW in the area of residential biogas production in places like India.

    What they say about the biogas systems being able to be adapted to run off human wastes is what has me most interesetd, because we already have a septic tank, and I would love to find a way for it to be adapted to produce methane gas. Can you imagine? If even only 1/3 of the suburbs in this country are like mine - with private septic systems - and all of them were able to transition to using biogas produced from their own wastes ... imagine!

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  8. Interesting analysis. I just wish we had a good sunny spot closer to any door of our home. It would make cooking outdoors easier. Both our rocket stove and the closest spot to situate our solar oven are 100+ feet from our door. It shouldn't be a deterrent to using them, but it has been.

    Speaking of baking bread...Probably more than ten years back I remember reading the autobiography of a woman who grew up in a remote village in the Alps. The village is/was in France, but the people didn't really consider themselves French and didn't speak French but some dialect. Like all communities which eke out a living in a mountainous region, they were all pretty tough people and thrifty as anything. I remember she wrote about how the village had one bread oven, and it was only used once per year in a week-long workfest. All the women baked all the bread they would have for the entire year, and the oven was kept going around the clock. She remarked about how much of a treat it was to have "fresh" bread for a few weeks out of the year. The rest of the time it was hard as a rock and had to be broken and soaked in some liquid (soup and coffee were specifically mentioned, I think) before one could eat it.

    I think about those older ways of doing things, when resources were scarce, and people just had to make do with what was feasible, and when simply wanting or wishing for something had no effect on reality. And no, unfortunately I can't remember the name of the book. If you're interested, I may be able to track it down.

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  9. Kate - I think about that sort of thing, too, and I love to read books about how people lived before they had all of the conveniences, nay, luxuries, that we have. I just think if we're headed back in that direction it would be wise to understand how people managed to survive (and thrive, in many cases) without flush toilets, indoor plumbing and refrigeration.

    If you can scare up the name of the book, I'd love to read it ;).

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  10. Hey, e4 ... My friends have one of those electric tea pots, and it works great for heating water ... and fast! I should ask them more about it. Of course, ultimately, I'd like to find a long-term alternative to heating water than doesn't use electricity at all, because my understanding is that the appliances the produce heat tend to use a lot of electricity to do their jobs.

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  11. Chile - thanks for that additional information. None of the conversion guides I've read have mentioned condensation on the bottom of the chest and the need to drain it. That would certainly be a reason for me to reconsider the freezer-to-fridge conversion. I mean, I don't clean the fridge (much) now :).

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  12. Wendy: Found it! It's called _A Life of Her Own_. It seems some of the details got fuzzy in my recollection, but I actually found an excerpt from it online which describes the baking and the bread:

    http://joepastry.site.aplus.net/index.php?title=we_interrupt_our_regularly_scheduled_pro&more=1&c=1&tb=1&pb=1

    I may have to get myself a copy of this at least for a re-read. It's been many years since I read it and my focus is very different now. Used copies seem to be available for a song at Amazon, but I may try inter-library loans first anyway.

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  13. Thanks, Kate! I found and ordered a copy from PaperbackSwap.com :).

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  14. Ok, I SO have to catch up with reading your back posts! You say rocket stove and my pulse gives me a happy jolt...I'll comment more after I have the luxury of a great read here in the next couple days. Still putting out fires here on the home front...thanks for your encouragement across the miles, Wendy! :)

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  15. I did a chest fridge conversion, and have been very happy with it. I haven't had to mop up condensation from the bottom "every single week", and neither have others I know who have done it - don't let Chile's claim put you off.

    My chest fridge uses about 0.2 to 0.3 kWh/day - that's around 100 kWh/year, and we're in a pretty warm climate (no frost or snow, and many days over 30C/86F). It's a 210L freezer (about 7.5 cu ft).

    Details here:

    http://green-change.com/2009/05/23/chest-fridge-conversion/

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  16. All of the sites I read at the time of doing that research mentioned needing to mop up condensation weekly. In the case of our upright freezer, manual defrost, the conversion did not work well at all. Each shelf has the freeze lines and the resulting condensation actually simulated rain in the "fridge", especially from the top two shelves. Jar lids of my canned goods rusted and we lost produce that got wet. After several months of suffering through it, we gave up and chose a small energy-efficient refrigerator.

    Try a conversion with an old (read: cheap) chest freezer and see if it works. The most you'll be out is the cost of having it hauled off if it doesn't. The thermostat control is easily resellable to home brewers.

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