I am looking for ways to reduce my electric bill. But first, a bit of background.

The complexities of my electric company's billing are beyond penetration. Nobody I know understands them fully. In simplified (!) form, if you average <300 KWH/2-month period, you are on the "Basico" rate, which is billed at .71 pesos/KWH. and at that rate you also receive a government subsidy on 50 of the 299 KWHs..

To add another layer of complexity, the billing is bi-monthly (every two months, not twice a month) so that heavy usage one month can negate frugality during the previous or following month.

If you average 300-499 KWH per two-month period, you lose the government subsidy and instead pay a monthly connection fee of something like 73 pesos, and you go on the "Intermedio" rate of 1.414 pesos per KWH, assessed not on the 300-499 KWH portion of the bill, but on the entire 1-499 KWH amount. Someone who averages 299 KWH per two-month period will pay (including tax and connection fee) 414 pesos; someone who averages 300 KWH over two months will pay around 652 pesos. The figures are misleading in that the same fixed costs (tax and connection fee) apply in each case. The cost of the actual electricity doubles. That next kilowatt hour is expensive!

Then, of course, there are the people (like myself) who are on the DAC rate, the "Domestica Alto Consumo" rate that applies to people who average >=500 KWH per two month period. It works like the "Intermedio" rate, except that the rate per KWH jumps to 3.02 pesos/KWH. Someone who averages 499 KWH/2-month will pay 973 pesos. Someone who averages 500 KWH/2-month will pay 1920 pesos. That next KWH costs more than $80 USD!

Note that I never said the word "use" above, but instead said "average". That's because your rate per KWH in any given month is not determined by the number of KWH you consumed in that month, but by the average consumption over the previous 12 months. So even if I dramatically reduce my consumption, it will be at least six months before I see any reduction in my cost per KWH.

The above is a simplified summary of the billing procedure. It does not take into account the 1A, 1B, 1C etc. "tarifas" that vary with location, summer temperature averaged over the previous five years, what is the current season, the 16% sales tax that is only charged for consumption greater than 149 KWH/month, and myriad other things that affect the rates.

My downstairs neighbor and I share the same electric meter. My local bank auto-pays the electric bill, and SWMBO and I figure that we use 3/4 of the power and the neighbor reimburses me 25% of the total bill. She (the neighbor) has a refrigerator, a laptop computer, and maybe half a dozen light bulbs. SWMBO and I have two desktop computers, two scanners, a color laser printer, a cable modem and wireless router that run 24/7, two cordless phone systems (shared with the neighbor, one local, and one OOMA for long distance), a larger-than-the-neighbor's but efficient (top 3% in it's size class) refrigerator, a dishwasher, three ceiling fans, a domestic water supply pump (downstairs neighbor is gravity-fed), close to a dozen wall-warts each taking a watt or two of parasitic power, and maybe a dozen light bulbs.

The most recent electric bill, including 16% tax and monthly connection fee, came to 2445 pesos. At first glance that seems high, but remember it is for two months, shared however asymmetrically among two families. Here is the breakdown for 650 KWH over two months:

Energia..........1963.00 pesos (straight DAC rate at 3.02 peso/KWH)
Cargo Fijo....... 144.76 pesos (connection fee, two months @ 72.38)
IVA @ 16%..... 337.24 pesos (sales tax)
Total:.............2445.20 pesos (about $211 USD)
(Figures are in pesos, about 11.6 pesos per US Dollar)

If you've had the patience to wade through all of the above, you will have seen that the key to electric bill happiness is to get off of the dreaded DAC rate. A quick look shows this to be improbable. My previous 12 month average was 647 KWH/2-month period, my goal is <500 KWH/2-month. That requires more than a 23% reduction in average usage, and I am already being careful, not mlord-fanatical, but paying attention to my usage. [For example, it is 93 degrees (34 degrees C) at my computer right now, and it would be more comfortable if I turned on the ceiling fan (about 75 watts). I'll accept the mild discomfort instead.] So how can I cut 23% off my usage?

The biggest reduction will come from splitting the electrical service between myself and my neighbor. This can be done! I have a worker contracted for 2407 pesos to install a second meter for the downstairs neighbor. This means we will each have 249 KWH to use before the DAC rate kicks in. IF my estimate that she is using 1/4 of the total electricity is valid, then by splitting the service I would just squeak under the DAC rate by about six KWH per month. That is too close a margin, so I am looking for additional reductions.

I am pretty sure my computer is the single biggest electricity user in the house. AMD dual-core 3.2GHz, 256 MB Nvidia video card, 4 GB RAM, 22" LCD monitor, I think there are no less than 7 cooling fans inside the case, four hard drives and a DVD burner. Add some more for the color laser printer... If I had to guess, probably something around 300 watts when running, and that is about 18 hours a day. That's 324 of my 499 KWH all by itself. According to the yellow sticker on my 25 cubic foot refrigerator, it's running 100 KWH per 2-month, so that leaves me 75 KWH left for lights, dishwasher, ceiling fans, etc. every two months. If I left a porch light on for one month it would put me back into DAC.

One thought I had was to install an external power switch to control two of the four hard drives on my computer. There is a 1-TB and a 2-TB drive (E: and F:) that are used only during backups (maybe once a week), but would this save any significant amount? I think those drives are configured to spin down after 30 seconds of non-use. How can I check this?

Probably the most certain thing to do and still remain cost-effective while not drastically changing my life-style is to install solar panels on my roof to carry some of the load. I haven't investigated the costs recently or thoroughly, but I think I can put a kilowatt up there for about 20,000 pesos. That should provide at least 5 KWH per day, and probably more since my house is ideally situated for solar, with 350+ days a year of cloudless sunshine at 5000+ feet elevation and an unobstructed 180 degree view of the sun track. Getting off the DAC rate and having to pay CFE for only 499 KWH/month would reduce my bill (at the current usage level of 650 KWH/2-month) from 1834 pesos for two months (after subtracting out the neighbor's 25%) to 973 pesos for two months, a savings of 430 pesos each month, plus a little bit more than that (optimistically, another 100 pesos is all, call it 500 total reduction) for however many KWHs under 499 I achieve. At that rate it would take 40 months to amortize the cost of the solar panel, more like 45 months if I factor in the earnings I won't receive from the 20,000 pesos. That's a pretty good ROI, I think.

My apologies for dragging this out, I sort of used this as an exercise to get clear in my mind more or less how the CFE ("Comision Federal de Electricidad") billing system works, and perhaps a few of you might find it interesting. I got to write a pretty neat spreadsheet to lay it out as best I could understand it [sample: =IF(A2<50,$B$27,IF(AND(A2>=50,A2<300),A2*$B$24,0)) ] and now I really do have an idea of what my options are.

Thanks for your patience.

tanstaafl.

How about three meters

It seems like a load of crap that there are two residencies on one meeter and you are still supposed to use what one household would use.

Some quick suggestions:

Get rid of anything that uses resistive heat. This includes but is not limited to an electric water heater, hair dryers, curling irons, clothes irons, toasters, etc. These items pull a massive amount of current.

Get efficiency light bulbs. You can cut your power usage for lights by up to 90%.

Put all computer peripherals that you don't use constantly on a power strip. Only turn them on when needed.

Get a Mac already. Just kidding, but consider a notebook computer. They are far more efficient.

Consider a propane or butane refrigerator. They use a lot less power. They're less convenient because you have to switch tanks once a month or so and re-light the pilot. We have both electric and butane fridges for redundancy.

If you get a solar electric system, get a grid-tie system. Maintaining a battery bank is a pain.

That's all I can think of at the moment. Will come back if I think of more.

Really? I would have thought an electric heap pump design (conventional fridge) to be more efficient than anything relying upon direct combustion to move heat. Strange.

Cheers

That's a great description of the billing "system", Doug! I can see how it puts a strong incentive to maintain low usage over time, though the bumps are quite dramatic there!

With billing like that, replacing your energy hog computer would seem a no-brainer --> or at least disconnecting the power from it for much of the time. 18 hours a day seems an unlikely "necessity".

I practically "live" on the internet here, but my main computer (big notebook) is rarely on for 18 hours a day.

Our 24/7 server is on all of the time though. I'm in the process of replacing that 25W power hog with a new (hopefully) ~18W 20W power hog: a Jetway mini-ITX board with a single-core Atom N455 CPU. Hey, the new board even handles 1080p video playback under Linux!

Cheers

Although the heat pump is the most efficient design, I'm assuming that like here, electricity is such a rip-off that it's more cost effective to run a combustion device. My house has both a heat pump and natural gas heater, and it's half the price to run the gas heater even with half the heat going up the vent pipe.

My next fridge will be gas...

You didn't say anything about air conditioning, which I've observed to be the single largest source of electrical draw in our house (two zones, each of which consumes ~2.5KW). All the usual advice about passive mods to your house (avoiding air leaks, reflective films on windows, light-colored roof, etc.) can add up, as can using an electric ceiling fan in lieu of dropping the temperature even further.

Your computer, of course, is a power hog, and I'd imagine that you don't need such a monster to be on 18 hours per day. My MacPro tower at home goes to sleep when I'm not using it, saving me its 150-200W power draw when idle (monitor off, disks asleep, CPU on).

And, if you've got lights that are on 24/7, consider getting a timer. I've got this solar timer model for our porch lights, which you program with your lat/long, and then it can do dusk-to-dawn or dusk-to-specific-time modes. You might also consider replacing tungsten bulbs with CFL or LED alternatives, which also have the benefit of putting out much less heat, and thus saving you money on the air conditioning it takes to remove all that heat you don't want in the first place.

Actually, there already are three meters, but...

No, it makes sense, actually. You have to understand the construction of the house. It is a four-story house with the top two floors sold as a single condominium, even though each of those floors is really a separate domicile. This is because the only access to the top (fourth) floor is through the open deck area of the third floor. This meant that the third-fourth floors could only be legally defined as a single unit, thus a single meter. The bottom two floors are on their own meter already.

This living arrangement would be difficult under most circumstances, but the downstairs neighbor is a long-term (nearly 25 years) close friend of my wife, and they were next-door neighbors in California for all of that time. Privacy issues are just not... an issue.

We will be able to separate the two floors electrically, although not legally from a domicile perspective, because they are complete, separate living units (kitchen, dining room, bedroom, bathroom, etc.) occupied by separate families. Under other circumstances, CFE would not allow multiple meters for a single legally-defined residence, otherwise everybody would have multiple meters on their houses.

tanstaafl.

Ok... we have a toaster that gets used maybe once every 10 days. Nothing else in the house falls into that category.

Unfortunately not possible. All but two of the lights in the house are the compact halogen type (see photo) and not cost-effectively changeable. The two exceptions are run less than an hour a month between them. At that rate it would take 7 months to use 1.4 pesos worth of electricity (1 KWH at the intermedio rate), lets call it 2.4 pesos per year, so replacing the six incandescent bulbs with $15 worth of compact fluorescents would save me 1.8 pesos per year, requiring 72 years to amortize the cost of the bulbs. Not an acceptable ROI.

My UPS has a master outlet that turns off all peripherals when the computer is off. The only exception is the laser printer (never run a laser printer through a UPS!), which draws 6 watts when in sleep mode, so I leave it on. Since it is a shared printer I don't turn it off, although doing so could save me nearly six cents per month.

No. I despise laptops even more than Macintoshes, with their squinchy little keyboards and tiny screens. The most frustrating deterrent to productivity I have ever experienced is the touchpad on my wife's laptop.

Too late. Three weeks ago I purchased a new, very energy-efficient electric refrigerator. It is ridiculously large (25 cubic feet) but we were wasting so much food with the old refrigerator (less than half the size) that we decided we wanted something where we wouldn't forget about food stacked behind and under other food until it went bad. Out of sight, out of mind... This refrigerator, large as it is, uses less electricity than the old one. With a cursory look it appeared that propane refrigerators were smaller and more expensive than conventional models.

Absolutely. It would be strictly a supplement. CFE, in a surprising act of modernity, will provide "smart meters" for solar power users where any solar power generated goes through the meter and "counts down" your KWHs. I seem to recall that if you generate more electricity than you receive from CFE, they will issue you a credit instead of a bill, but they won't ever pay you money.

Thanks for taking the time to read through all this and respond!

tanstaafl.

Thanks, Mark. Coming from you that means a lot!

My computer is a heck of a system, and it does get used a lot. Even when I am not sitting at the keyboard, it is frequently working, downloading and transcoding audio books, running backups, etc. I spend a fair amount of time on the internet (including this bbs!), and I do not watch television, ever. (Nor does my neighbor, that's why TV sets were not mentioned in the catalog of electrical consumption.)

My computer is my vice, and since I do not smoke, nor drink, nor chase women (except for SWMBO), nor drive fast cars (my car averages 44 mpg on the highway!), nor indulge in fancy high-tech toys (I own a single very good point-and-shoot camera and an iPod Shuffle, and that's it), I consider myself entitled to one lavish extravagance.

If it costs me a bit extra to run it, oh well... A single 1KW solar panel will produce daily more electricity than my computer uses. I'll just consider the cost of the panel to be another piece of computer equipment.

tanstaafl.

If (and that's a big if!) you can get below the DAC rate (i.e, average <250KWH per month) electricity is reasonable here, running about 12 cents per KWH. If you can keep it <150 KWH/month, then it is about 6 cents per KWH.

Even so, gas (propane) is even cheaper. I pay about 6,400 pesos per year, for cooking and hot water for two residences, one of which is using an ancient, inefficient 50-gallon upright hot water heater (as opposed to my on-demand system.) That's $23 per month per household.

tanstaafl.

Going with a notebook doesn't mean you have to use the built in screen, keyboard, and trackpad. For about 5 years, I used only notebooks attached to desktop monitors, keyboards and mice. The convenient thing for me at the time was that one portable machine was my main system both in the office and at my home office.

Though if you have no intention of ever using the system as a portable, you can look into desktops that use mobile parts. You would get the same power efficiency benefits, without the extra monitor, battery and other components going unused. The Mac Mini for example uses 0.24W while off and plugged in, 1.45W while in sleep mode, and 9.14W while fully booted and idle. At absolute maximum, the system will use 85W. With the age of your current system, a modern Mini is likely to also bring more CPU and GPU performance. An alternative small form factor system is the Dell Inspiron Zino. Just be careful there, as some of the lower end configurations use AMD chips similar to the Intel Atom, ie low performance. While Atom's and AMD's equivalents have gotten better, they would probably still be a downgrade from your current system.

The main issue with a system move (beyond all the work involved with the transition) would be how to handle the massive amount of storage you use. With the current Mac Mini, Firewire 800 would be the fastest external port for disks. A future Mini (likely to happen in the next 3 months) may add Thunderbolt, but accessories for the new connection are still rare right now. The Dell systems have external eSATA ports, so that might make more sense for your current needs.

That is because there is no air conditioning. Our climate is so temperate here that neither heat nor air conditioning is required at any time of the year. The average daily high temperature, from coldest month to hottest month, ranges from 76 to 86 degrees. Yesterday was atypical, with outside temperature approaching 90, but May is the "hot" month. June through September is the rainy season and temperatures will moderate. BTW, during the rainy season, just like Camelot, it only rains at night. Really. Fantastic electrical storms (I counted 70 lightning flashes a minute during one storm with absolutely continuous thunder) at night, clear, cloudless days. Perhaps 15 days a year there is rain during the day. The last drop of rain that fell here was September 30, 2010.

I may have over-stated the power draw of my computer. It does go into sleep mode after 10 minutes when not being used. I really haven't been able to get a handle on how much power it consumes, either in-use or in sleep mode.

Nearest thing I have to that is an LED light over the entrance that is motion-activated and stays on for 30 seconds unless someone stands in front of the door and moves occasionally. Since it is battery operated and recharged by solar cells, I don't think it is having a large impact on my electric bill.

As I explained in Jason's post, unfortunately that isn't a workable alternative. However, it is unusual to have more than 160 watts (4 of the compact halogens on one switch) of lighting on at any time in the whole house. Three of the four outside walls are glass floor to ceiling, and natural light fills the entire house during the day. From 7am until 7pm (or later) there is never a light bulb lit. After dark, usually just a single 40 watt reading lamp.

tanstaafl.

You can replace GU10 (mains) or GU5.3 (12V) compact halogens with LED equivalents at 1/10 the power draw. The light is detectably less pleasant though (cold and ghostly and somehow dark).

Peter

Those MR-16 halogen bulbs can indeed be replaced by LED versions. The cheap ones cost $10-15. Tolerables ones are $30. Beautiful ones that are absolutely indistinguishable from halogen are, sadly, $70/ea. I expect this to change rapidly over the next few years.

Also, current MR-16 LED bulbs require that the 12V transformer be of the "magnetic" type, producing nice pretty sine waves of power, but they're more expensive. "Electronic" transformers generate choppy, ugly power, which is completely irrelevant to a classical light bulb filament but just doesn't work at all for LEDs.

(Fancier LED fixtures can work with just about anything, but there's nothing like that, yet, in the MR-16 form factor.)

It's also entirely possible that your power draw is coming from something unexpected and unpleasant (e.g., a wire going from your place to a neighbors' place). It's sounding like you're already living a fairly low-wattage lifestyle.

Sounds just like the weather here, except we're slightly closer to hell than you are It probably averages 10 degrees warmer during the rainy season. Also, during the rainy season, we get random rain storms and squalls coming off the sea any time without warning. Thirty minutes later the rains moves on and it's not only torridly hot, but incredibly humid as all that water evaporates off. Then the mosquitoes come out. My part of Belize is miserable during the rainy season and paradise for most of the dry season.


It's actually John. But you can call me Jason if you want.

That possibility has been checked pretty thoroughly. The power comes in off the pole and down a steel pipe into the meter. (photo) Someone could easily steal power ahead of the meter, but the meter is set into an 8" steel-reinforced brick wall, and the only way to tap into the metered power is inside the house.

You have me thinking, though. I will have my contractor check VERY carefully that no circuits from the two bottom floors of the house are somehow going through my meter. Carlos, a man who I have good reason to trust absolutely and completely owns the bottom of the house, and he mentioned that his electric bills are a small fraction of mine...

tanstaafl.

Jason Uhh, John -- I think it's terrible when someone doesn't even know his own name! Must be all that religion confusing you. But if you insist, I'll humor you and call you John.

A few weeks ago I looked up "Jbjorgen" in Google, and found a website (that I can no longer find) with a profile for Jason Bjorgen with the same birthday you list on your profile here, so I figured...

tanstaafl.

You could always hook up a TED5000 and then go about figuring out exactly how much power each and every device you own uses.

Can you shut off your main breaker and see if the meter is still going up?

Funny... I was just about to suggest a TED.

For those who aren't familiar with it, it monitors total electrical consumption at the panel. It should match your meter within a percent or two.

I thought someone would have mentioned it already. I don't have one yet, but I want to hook one up here at the house to help rack down the bid energy sinks and what time of day they're most active.

We have a smart meter, but the software at the power company site isn't very good and our municipality isn't hooked up with Google's web offering either.

The TED can be browsed from an iPhone/iPad so that's also a plus.

Yes and no. I don't have a main breaker, but I can turn off each individual circuit breaker (there are only 10 of them).

The results would be inconclusive unless the meter did continue to turn, because if the meter stopped it would only indicate that the extraneous circuit (if there indeed was one) was not at that moment drawing power.

It's an excellent suggestion, though, and I am going to try it right now.

OK, I had an aha! moment when I found the meter still turning with all my breakers off. Then I realized that the neighbor's breakers go through the same meter, and when I switched all of hers off, the meter stopped.

Doesn't prove anything...

tanstaafl.

I have considered something along those lines, although the TED5000 is a bit pricey.

The most commonly referenced device is the Kill-A-Watt, which comes in several models at various price levels. I have avoided the Kill-A-Watt primarily because of bad reviews on Amazon. The preponderance of reviews is favorable, but the negative reviews consistently point out the same failings, i.e., a sizable number of them fail in the first couple of weeks, technical support is nonexistent, build quality and components inside are of very poor quality, the instructions are completely worthless, the screen is difficult to read.

On the other hand, for $20 plus shipping (in my case, the shipping plus the import duty will cost more than the Kill-A-Watt) how much can you expect? If I get one and it works for a couple of hours before it fails, that would tell me everything I need to know.

Does anyone have specific recommendations?

tanstaafl.

Are you sure? LED replacements are available for a lot of the traditional halogen/reflectors with base type like MR16. Not sure on payoff/ROI, but I wouldn't get stuck on 1 single ROI element if the overall goal is to get below a certain threshold that drops the who cost factor by half.

The billing system (and my guess at the rationale) seem to make sense.

I have one of the older versions of TED. It sends it's monitoring on the home's wiring. But only on one circuit of the home's wiring. Newer ones use wireless communications.

With the TED and multiple transformers and transmitters you can actually monitor kwh's used over time for both you and your neighbor.

The software can even be taught monitor specific appliance usage based on recognizing the demand each creates when switching on and off. No need to put transformers on everything. Though it takes a computer on 24/7 to keep track at that level.

I think it would be unlikely that the extraneous circuit would be pulling no power but I supposed it's possible. I suppose someone could be tapped in and only using it to run one thing off it.

Can you point me in the right direction? There are some do-it-yourself options (build your own circuit board, find LEDs, somehow put it all together) that don't excite me. What I want is a simple solution where I can just unplug/unscrew/unwhatever the fixture and put in the replacement.

Cost is a consideration. I did a recount, and find that I have 25 of the little beggars in the house, the majority of which are never used, but if I replaced them all it could run a couple thousand dollars. Maybe just the 10 that do get used (two sets of three, one set of four) but even those probably don't add up to more than five or ten hours in a month.

I agree that the rationale makes sense. But why make it so complicated? For instance, in less than 5 minutes I put together a billing scheme that provides remarkably similar results to the CFE plan, and is much simpler. In words, multiply the KWH used in the billing cycle by a fixed rate factor, in my example 0.0500, to get the rate per kilowatt hour. See the attached spreadsheet for how it works, note how quickly the heavy-usage penalty escalates as you increase even slightly the rate factor.

But that would be too easy. Without the electric company's FUD factor, more people would complain about the rates.

tanstaafl.

If you throw "LED MR16" at Google, you'll see lots of solutions on offer, but many are poorly made. LED vendor Cree has built a LED module expressly for this market. Hunting around, there's at least one vendor claiming to have this in production, but I can't find anywhere to actually buy it.

This is a rapidly evolving market. My intent is to wait a year or two for these things to shake out, then go for it.

Warning: if you do choose to buy one of these things now, pay careful attention to two numbers: the color temperature (reported in degrees Kelvin) and the CRI (color quality, with 100 being "perfect"). If you want to match your existing halogen bulbs, then you want a color temperature of 2700K and as good a CRI as you can find (80 minimum).

EDIT: Warning #2: one other thing worth waiting for is that newer controller boards for these LED MR16 fixtures will be compatible with the electronic dimmers that are commonly used.