I am right on the cusp of going into the dreaded "DAC" [Domestic Alto Consumo] electric rate for excessive usage over the previous 12 months. To put that into perspective, if in the next week I use three kWh more than I used last year over the same time period, my bi-monthly July-August electric bill will increase from $27 to $105 USD. I take daily meter readings and analyze the data in a spreadsheet, so I know to the nearest kWh exactly where I stand.

It looks like I will squeak by this time, but barely, so I am looking for ways to save; even one kWh per week on average would do it. I am actually running the house pretty economically now as far as usage. If I exclude my refrigerator and the computers (with accessories like router, cable modem, VOIP phone) I am using one kilowatt hour per day for the entire house. That doesn't leave a lot of room for improvement. This isn't guesswork: remember I take and record daily meter readings.

I have 23 light fixtures in my house with halogen bulbs similar to the one pictured below, except that most, if not all of them are 50 watt, not 20 watt. What would I do to change over to LED lights? Can I get LED bulbs to fit the existing fixtures, or do I have to tear up my ceilings and cabinets and install new fixtures? How expensive is this?

tanstaafl.

That looks like a MR16 lamp with GU5.3 socket/base, but Rob would probable know off hand.

If that is correct, then Toshiba make something suitable http://www.toshiba.com/lighting/products/led-lamps/mr16-gu53.jsp although not quiet bright enough, they seem to max out at 35w equivalence.

And don't forget that it might now pay to upgrade to a more energy-efficient computer, as discussed previously.

That's a weird bulb, usually line voltage MR16 will have GU10 bases... you might have to swap out the sockets to use a line voltage led.

This would appear to be the manufacturer's page for that bulb, if that helps.

Would LED strips be better than a bunch of flood lights?

http://www.oznium.com/flexible-home-leds

I would hate to live that close to the line that a light bulb would make or break the situation.

How about a large change like a gas refrigerator or solar panels?

You did not mention water heater so I would guess that is not electric. If so a timer or a more efficient unit could help.

Gas lamps

These are 12V, which is what I would expect in the UK with that GU5,3 connector. Exactly as Larry says, you would want to factor in changing the lampholders over to GU10.

What I would sell here is the Lampholder at 1.25, and a Megaman Modo 4.5W GU10 (42W Equivalent, non-dimmable, available in 3000K and 4000K) at 8.00, that's all inc Tax. This is all in 230V though, but I would imagine you would be able to find something similar in 110V in Mexico, at the same price you're looking at roughly 190 Pesos.

This is not really an answer to your question, but I'm wondering: why don't you consider photovoltaic solar panels? Those would easily cover your electricity needs in the area you live in and give you a lot more breathing room. Heck, even if you don't want them to cover your entire electrical power needs, even one or two panels would be able to create a lot more breathing room for you and keep you far away from that dreaded limit. Of course installing PV panels would cost more than simply replacing your lamps with LED models, but in a few years I'm sure you'll start saving a lot of money with a couple of those, especially in the sunny climate you're living in.

If you already have solar panels, then I guess I have missed that from the other posts and I'll shut up then.

I like that, different.

I reckon you need at least 11w LED to come close to a 50w halogen, 14w would be more convincing. Our new house has these:

http://www.orluna.com/products/mini_recessed.aspx

and these:

http://www.nationallighting.co.uk/LED_Lighting/LED_Fittings/LED_Downlights/LUCIDA/pid/988

The 2nd ones are probably as close to a 50w halogen as I've seen from an LED but definitely not GU10. I know that Phillips, Toshiba and others do higher powered GU10s but the Phillips (which I've seen) has a little fan in it (v annoying).

An alternative might be CFL GU10s, I haven't seen any in operation but might be worth a look:

http://www.tlc-direct.co.uk/Products/GUC...CFc0mtAodfi4A9Q

That is a tough call, Mark, not made easier by knowing you are right.

The LED light idea is a dead end for me, I think. In order to make my goal of <3,000 kWh for the previous year, I have (with her permission) run an extension cord from my downstairs neighbor up to my level, and am running the computer system and associated peripherals plus my refrigerator off of her electric meter. The entire remainder of the household is using slightly less than one kWh per day, and lighting is only a small portion of that. LEDs aren't going to save me much, certainly not on a cost/benefit basis.

So... I am either back to looking at solar panels again, or looking at a more efficient computer. My computer with its peripherals (modem, router, two telephone base stations) uses 220 Watts. The peripherals use 30 of that, the monitor another 36, which brings the tower down to 154 Watts. That tower contains a dual-core 3gHz processor, 4 GB RAM, four hard drives totaling a bit over four terabytes, plus a sound card that replaced the on-board sound when it died, and a pretty good (256 MB) graphics card. The hard drives stay, that's non-negotiable except the system drive might be replaced with an SSD. A replacement computer would have to meet or exceed these specs performance wise.

How much power could I save? Four drives plus 4 GB RAM and a 3 gHz dual core processor (or equivalent) are gonna eat a fair number of electrons. Even if it used only half the present power, that would save me just 77 watts. Of course, 77 watts, 15 hours a day comes to about 35 kWh per month... That's a tough call on a cost/benefit basis, because it comes to less than $2.50 per month, assuming I stay out of DAC through some other means.

At this point the solar panels are looking better. I haven't priced new computers in a long time, but I have studied the local solar panel situation extensively and made up a very intense spreadsheet (I can hear Bitt chuckling clear down here in Mexico ) to analyze cost/benefit, and a 2-panel setup would cost me $1820 (USD) including tax and installation, would keep me out of DAC and save me $609 per year. It would amortize in three years, after which it would continue paying back at $600-$700 per year as the cost for electricity went up.

Ooops. I just talked to the solar people. They require a minimum of six panels in order to make enough voltage to tie into the grid. That doesn't look so good, with a $5500 up-front cost and an eight-year amortization. Ironically six panels doesn't save me significantly more money per year than two panels, because even two panels keeps me at the lowest rate per kWh.

Sigh... Back to square one.

tanstaafl.

Do they pay you if you put excess capacity back into the grid? Could help pay off the panels quicker with the minimum of six.

Have you talked to more than one company? I doubt this is the case for all panels. In any case, I would think the this is entirely a case of using the right transformer. (solar panels produce DC current and this needs to be transformed to AC current)

Is that 154W at idle or peak usage ?

Don't know about how close to "peak" it is... but a fairly intense spreadsheet recalc doesn't change the wattage significantly.

OK, Quake III Arena bumped it up another 50 (!) watts.

So, no, 154 isn't peak.

tanstaafl.

A new computer (carefully chosen) should be able to cut that wattage down by AT LEAST half, probably to 1/3 your current average. On top of that, replacing the hard drives with a pair of modern 3TB drives would give you more storage, speed, and probably cut the energy usage by another 10-15W.

Cheers

I think the solar idea sounds perfect, even at $5500. You would then be able to basically use as much electricity as you want without the worry of prices going up, and you can stop making spreadsheets and use the time to enjoy all your electricity in some new way of your choosing.

Hot Country + Solar = no brainer

Actually, if you like spreadsheets, you'll love Solar. I have a small remote solar system setup, and with the help of Bitt I am able to monitor stats and make graphs from about 120 miles away. Some of the Solar regulators chuck out a huge amount of data if you ask them to.

Cheers

Cris

Seconded. It might a a big investment, but with the climate Doug lives in, it'll pay off for sure.

+2

Yes and no.

They won't pay cash for electricity I put back into the grid, they will give me a credit on future electric bills but I have already factored that into the amortization schedule. What frustrates me is this: The Mexican government subsidizes very heavily the first 100 or so kWh to help out the really poor citizens. Even TWO solar panels would put me into that subsidized rate structure, and adding four more panels, while cutting my annual electric cost by more than half, would still save me just $138 ($USD) per year compared to having just two panels.

Billing with Current usage with A/C 2 hours per day for two months::: $855 annual cost. (on the DAC rate)
Billing with Add two solar panels with A/C 2 hours/day for 2 months:: $230 annual cost. 3.2 year amortization
Billing with Add four more solar panels the same A/C for two months: $ 92 annual cost. 8.6 year amortization

Four additional panels cost $3659 extra, and will save me $138/year. It would take more than 26 years to make up the difference between 2 panels and 6 panels and I would be 93 years old by then. As was said, two panels would be a no-brainer. Six panels... I'll have to think about that one. Another way to think of it is that I would spend $3659 to save $11 per month on my electric bill.

I have the solar people coming over to see me next week, and we'll talk about alternatives. Most commercial solar panels produce 18 volts per panel, although specialized panels can be of other voltages, at considerable expense. I think I'll be restricted to the six panel minimum. We'll have to see.

tanstaafl.

Would it be cheaper to just get a quiet gas generator and run the A/C on a generator?

Looks like you could get a quiet Honda or Yamaha 2kw inverter generator for under $900.

Bicycle hooked to an alternator. Get some exercise and electric.

If you could only harness humming bird power.

Only found the hand crank one on ebay, but there is a pedal version too:

http://www.ebay.co.uk/itm/CLANSMAN-MILIT...3#ht_500wt_1081

The instant you buy the panels they will not be worthless. I would think they would raise your real-estate value or could be sold used. Perhaps weigh in your resale value and compare the cost payback of the panels to the interest rate your money makes in the bank/401k/

I was able to get a solar panel that they use to keep Volkswagen batteries charged on the lot or the boat over to the USA used for around $20 off eBay. Your prices seem pretty high to me.

I probably should take a look at my usage. But the minute I fire up the TIG welder I shoot it all to hell.

Nice, military too

I was going to say – hire a local to run in a big wheel . However that might be a bit insensitive and dehumanizing. But probably still cost effective while boosting the jobs and the economy. I guess practicality isn’t always the correct way to do things, oh well.

Well, there's good news and bad news. The good news is I will never have to worry about DAC again. The bad news is I don't get to buy a bunch of neat new solar panel toys. The solar guy pointed out the error of my ways.

For two years I have labored under a misconception of what triggers the DAC rate. I was sure that once I averaged Exceso rate for a year, that would put me in DAC. But as Maureen Jellison said in Lucifer's Hammer, "That turns out not to be the case."

0-150 bi-monthly = Basico rate
151-250 bi-monthly = Intermedio rate
251-500 bi-monthly = Exceso rate (actually, it's 251-9999, but the 500 matters because...

To achieve DAC I have to average more than 500 kWh each two-months for a year, not the 251 I had previously thought. So I have 3,000 kWh per meter per year to play with, not 1,500.

Today I received my latest electric bill(s). My computer cost me $161 pesos for two months; the remainder of the house cost me the same. That works out to a total electric bill of of about $12.50 (USD) per month, $25 for the bi-monthly bill. The DAC rate for the same electricity would have been just under $100. It really pays to stay out of DAC.

So all this time I have been sweating bullets not to exceed half of the allowable usage to stay out of DAC. Live and learn, I guess.

tanstaafl.

It's a shame that in a country like yours that solar isn't encouraged.

The government are clearly trying to help people by creating such a low rate for lower income families, and I can't really understand why they wouldn't encourage people to be eco-friendly at the same time.

They could create a whole industry that actually pays it's way in a country like Mexico.

I think if I were you I'd still have gone for solar, I like the idea of doing my bit, and even paying a bit into the system.

Cheers

Cris