Free electricity!

TXU Electric now has a plan where all your electricity from 10pm to 6 am is free! If you had a big honkin' storage system (battery, hyrdo pumping, compressed air), you could really make out like a bandit!

Let's see... my peak electric demand (hottest month of the summer) is around 0.1 MWh/month (gotta keep those air conditioners humming). Call it 3500 kWh per day. A123 20ah cell holds 64 Wh... Only 55,000 cells needed. At $20/cell, call it a megabuck. Yearly electric bill is around $8000. 135 year payback. Darn!

Baseline load (no heating/cooling) is around 1/4 of that. Still no joy.

Pyro, we need to really, REALLY think about this! It may be a wave of the future to clamp daytime demand. We need to figure something practical out! BTW when I am working in my lab full time in the summer, I peaked at 4,000 kWHr/day... That monthly bill really knocked me off the chair. I am another guy that likes it cool with AC. My Dad was a cryogenic guy and knew how to make "cold." We had the only car whose A/C could frost the windows in June! ... good ol' Dad!

Edit: Luke's right, of course! Think it was 4,000 KwH for the month... think that comes out right.

texaspyro said:

Call it 3500 kWh per day.

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3500kWh/24hr/day= 145kw average daily power consumption?? You're off by a couple orders of magnitude somewhere my friend.

You're also not using 0.1MWh per month if your electric bill is only $8000/year, or you're paying $0.006/kWhr.

wow, i have no A/C. mine is about 15kWh/day max.

i wonder how they can afford to offer the power for free. you could save the cold as ice overnight and use the air handling system to use the ice as a heat sink during the day with a water to air heat exchange and circulate the water into the ice storage, or use heat a exchanger there too.

Ye Gods! How the heck can anyone use 3500 kWh a day? My average electricity consumption through the year (2 people, modest house size, gas heating) is around 12 to 15 kWh/day, at an annual cost of around $830 to $1040. Electricity cost here is around $ 0.19 per kWh, I don't know how that compares to US electricity prices, but suspect it's higher.

We here in LA (Lower Alabama) pay about 12 cents per KWH and think it is high. It ain't real high but it ain't free like in Texas! I got a pool and what about running A/C through it all night (when it is free!) and recovering the cold during the day? Well it may be wet suit weather since we like the suns heat to warm up the pool! Oh well another plan bites........the dust!
otherDoc

Maybe you don't need to store it in a battery. Maybe you could store it as some sort of potential energy, like lifting a heavy boulder with an electric motor. Then recapturing the electricity from that. What about heating your swimming pool to 200 F, then using the heat from that, etc...

My electric bill for the months with no heating/cooling is around $300 (down from $350 since I converted to LED light bulbs ). Peak bill ever was $1200 (at around $0.12 per kwh). I bought $8000 worth of electrons last year (probably got shipped used, over-spec'd Chinese ones with wobbly wave functions). $4000 went to overhead, $1000 to heating, $3000 to cooling.

Let's do the math again: $1200/$.12/kwh is 10,000 kWh (ahh... there she was... not $.012). 10,000/30.5 days -> 333 kWh/day. Gee, I only need 5200 A123 cells.

Actually, I will need less. I blew two 13 year old air conditioners last week. They are being upgraded from 12 SEER to 14.5 and 16 SEER (@$6000 ea), so that peak load would go down by around 0.8... so I only need 4000 cells. Could probably do with 2/3 to half that since the typical max summer bill is around $900.

If one had a solar powered house, you could replace your panel expense with those free TXU electrons and make out like a bandit. Or store whatever you could all night and sell it back to them during the day.

itchynackers said:

Maybe you don't need to store it in a battery. Maybe you could store it as some sort of potential energy, like lifting a heavy boulder with an electric motor. Then recapturing the electricity from that. What about heating your swimming pool to 200 F, then using the heat from that, etc...

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There has been quite a bit of work done on mechanical storage of electricity. It's quite a bit harder to do than you would expect. Apparently the most viable technique for large scale operations to compressed air into humongous underground formations. Water pumping sounds good, but is rather inefficient (but who cares if the electricity is free). It takes up a lot of space. Falling rocks aren't viable.

Actually the numbers are beginning to look quite doable! Since the system would be sized to the peak demand of a hot summer month, for the rest of the year it could store a lot of those free night-time electrons which would get sold back to the utility during the day. If the system can store $1200 of electrons every month that would be $14,400 a year. If the system could be built for say $60-70,000 that's looking like a 4-5 year payback!

They can afford to make electricity free at night because the demand is so low compared to during the daytime that it costs them very little- in addition it's a clever way to incentivize nighttime electricity use- if they can reduce cumulative daytime use by .1% by giving it away at night (at tiny cost) the whole system will become more efficient and operate less close to "danger zone" maximum capacity (when everyone's blasting their A/C during the day). If they can increase that to 1% they may save building a new power plant/transmission lines and all the infrastructure related to that.

The "localized approach" to grid storage you guys are pondering is interesting, it's similar to the Vehicle-to-Grid idea. Sometimes allowing individuals to build infrastructure for themselves one person at a time will see faster progress than building centralized infrastructure- argument is well applied to home and business solar installations, as opposed to sprawling desert installations.

It's a sure bet that grid storage will be a mega massive market in the future, whether it be underground compressed air (very location specific, a little tricky), batteries (of various sorts, with their own pros and cons), pumped hydro (site specific and inefficient), flywheels (sigh...)...

As for A123, I get the feeling they have a pretty good idea their cells are unlikely to make it into a mass production EV at this point- they've been evaluated and rejected from several projects (as evidenced by the market flooding with cells of questionable origin-) and they hope to be able to float the company in the grid storage market-



LiIon grid storage is cheap per Kw, but very expensive per KwH compared to other (on the market, or in development) technologies.

My personal opinion, based on what I've seen and heard around is that A123 Systems may not be around with us tooooo much longer :wink: Basically they seem to have been f**king everything up lately And, as it has been noted on the board before, locking themselves in to the LiFePO4 chemistry was likely not a good long range strategy!

There's flywheel storage. There's temperature storage (steam?). There's stone storage, yeah (I have in the back of my mind a project of a small spaces lamp where you pick a weight, move it up and you have a few minutes of light)! No space? Dig a hole. Compressed air. You just need to store enough energy for 1 day's needs.
And there's running AC on solar panels, just a minor battery as transient buffer.

Everything I use is electric for heat, cooking, and drying clothes. With the December power bill in front of me - which is the highest consumption of the entire year, the figures are:

• Average kWh use per day: 34.8
  Average temp per day: 41*F
  Average cost per kWh in December after all the taxes and energy credits: $0.1048 USD

Caveat: This is a little deceptive cos I cut the power back to bare minimum for 9 days during my Hexmas holiday. Still, this is outright 10 kWh/day more than the consumption in November and January.

Interesting… If I tapped into my ebike resources:

• My preset cross-country LiPo pack is 78 * 5S1P @ 5Ah batteries.
• Figure (5S*4.2V) * 5Ah = 105 Wh, right?
• 105 Wh * 78 = 8.19 kWh.
• My present charger takes about 8-9 hours to recharge this pack at about 1kW/h.

So, other than December – I could make a go of this with 3X capacity (forgetting the cost of batteries). If I switched the charger over to a 30A and ran off the Dryer circuit, this is certainly doable. Plus… I get to use these batteries for cross-country!

Of course there will be losses converting back to AC and meeting demand. Maybe if the pack just focused on home heating, that would be very simple to configure without messing with the electrical interface and trying to run the meter backwards.

Hmmm, tempting… KF

itchynackers said:

Maybe you don't need to store it in a battery. Maybe you could store it as some sort of potential energy, like lifting a heavy boulder with an electric motor. Then recapturing the electricity from that. What about heating your swimming pool to 200 F, then using the heat from that, etc...

Click to expand...

Yeah! That would be warm enough to lose my wetsuit and do lobster while I do my laps!
otherDoc

[quote}
Of course there will be losses converting back to AC and meeting demand. Maybe if the pack just focused on home heating, that would be very simple to configure without messing with the electrical interface and trying to run the meter backwards.

Hmmm, tempting… KF[/quote]
Very sharp (as usual Kingfish!) Solar in the day and free at night. Win-win! As long as the Solar rebate holds up!
otherDoc

Damm $300 a month with no AC? Amazing how much power a really big grow light uses eh?

I never even beat that bill when I was firing an electric ceramic kiln to 2000 F 5 days a week. I was a professional pyro at that time.

For the hot months, it could make a lot of sense to buy a big ice machine, and run it only at night. About noon, go out and bury your AC's coils in ice.

texaspyro said:

... is 10,000 kWh (ahh... there she was... not $.012). 10,000/30.5 days -> 333 kWh/day.

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Do you live in a house or in a factory? I'm in Texas too, my house is not big but not small either, 2,600sqft. 1,000kWh is about my monthy average.

Jeremy Harris said:

Ye Gods! How the heck can anyone use 3500 kWh a day? My average electricity consumption through the year (2 people, modest house size, gas heating) is around 12 to 15 kWh/day, at an annual cost of around $830 to $1040. Electricity cost here is around $ 0.19 per kWh, I don't know how that compares to US electricity prices, but suspect it's higher.

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My average for last year is 0.11USD per KWh in Houston, Texas.

Woah - some cheap electricity there in the states! Here in Aus we have TOU metering in a lot of places (time of usage) Peak (1pm to 8pm) at $0.35c per Kwh, shoulder (7am to 1pm and 8pm to 10pm) at $0.27c, off peak (10pm to 7am) at $0.13.

IIRC we have the most expensive energy prices in the world (or are at least in the top 3).

heathyoung said:

IIRC we have the most expensive energy prices in the world (or are at least in the top 3).

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No, you have cheap energy prices. And OUTRAGEOUS energy taxes. Sound like the convicts need to toss a few politicians on the barbie...

dogman said:

Damm $300 a month with no AC? Amazing how much power a really big grow light uses eh?

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Ha ha ha... I didn't think of that. Good one.

heathyoung said:

Woah - some cheap electricity there in the states! Here in Aus we have TOU metering in a lot of places (time of usage) Peak (1pm to 8pm) at $0.35c per Kwh, shoulder (7am to 1pm and 8pm to 10pm) at $0.27c, off peak (10pm to 7am) at $0.13.

IIRC we have the most expensive energy prices in the world (or are at least in the top 3).

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What else is new? Especially when compared with down under country. When my Sydney friend came to Houston, she couldn't find a single item here that is more expensive than in Sydney. She thought and thought real hard and finally found one: "Gasoline", she said. I didn't have the heart to tell her that she paid by the liter and not by the gallon.

Did some more looking at the bills:

Jan 5620 kWh
Feb 8220
Mar 4290
Apr 3000
May 3440
Jun 5600
Jul 8600
Aug 6100
Sep 9900
Oct 4460
Nov 2850
Dec 2800
total: 65000 kWh
avg:5410 kwh (178 kWh/day)

That summer was the hottest on record. February was freaky cold. We had power blackouts in Feb and Sept due to totally incompetent/corrupt power generation cartel/regulators (hence my shiny new 20kw backup generator). The utility companies purposefully shut down several power plants so that they could cause shortages and gouge customers (wholesale price of electricity increased over 1000 times the normal rate at the peaks!)

dogman said:

Damm $300 a month with no AC? Amazing how much power a really big grow light uses eh?

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Remember... I'm totally LED now I wonder how viable LED grow lights actually are?

Geez - in the summer we open the windows and let the (rainy) breezes blow through.

Earlier I wanted to post that in the PNW/western-WA we have about 2-4 weeks of really warm weather where you'd want A/C, but the rest of the time its' bundle up and layer on.

"Goin' where the climate suits my clothes..."
- 'Goin' down the road feelin' bad', The Greatful Dead (1970s)

Wearin' black on a 78°F day, KF 8)

texaspyro said:

That summer was the hottest on record. February was freaky cold. We had power blackouts in Feb and Sept due to totally incompetent/corrupt power generation cartel/regulators (hence my shiny new 20kw backup generator). The utility companies purposefully shut down several power plants so that they could cause shortages and gouge customers (wholesale price of electricity increased over 1000 times the normal rate at the peaks!)

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I did a little research about this online just now- sounds like a royal clusterf**k, but not sure if I'm convinced about the purposeful nature of the event-

texaxtribune said:

Initially, it appears, some coal plants went offline due to cold-weather problems, taking a large chunk of electricity out of the grid. Luminant, a major power-generation company, confirmed that its two coal units at the Oak Grove plant in Robertson County failed, as did two units at a coal plant in Milam County. "We are in various stages of start-up and operation for that group," Allan Koenig, a Luminant spokesman, said via e-mail. Three of these four units only began operating in the last few years; Fraser, who chairs the Senate Committee on Natural Resources, noted that they had new emissions-control technologies, and said one question was how those technologies had handled the cold.

Dave Knox, a spokesman for NRG, another power company, said that a cold-weather problem also caused a shut-down of its Limestone coal plant near Jewitt, Texas. The problem occurred yesterday, albeit after the early-morning crisis, and the plant returned to operating early this morning.

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Thinking about this economically- if you disable enough generation capacity maybe you'll hit the limits of what is able to be supplied, at any price- there will not be enough plants to turn on and there will be a shortage, in which case sure, the plant operators can charge any price (characteristics of a monopoly) and make big profits per unit- but mostly the high price would be driven by the high cost of operating the inefficient peaker plants that stepped in to contribute the power during the shortage. The high price was the only reason they turned on as many peaker plants as they did, and reduced the severity of the blackouts. If there were a cap on the bulk price the blackouts would have been even worse.

If the plants are run by companies motivated by their own self interest (of course they are), I don't think that the strategy of "shut off some plants now for some extremely short term profits, at the risk of expensive government inquiry and public backlash" isn't a strategy that the shareholders are going to choose! I don't think anyone would do that on purpose- like I've already said, it's likely the people controlling the plants didn't actually make that huge profit (because the peaker plants are so expensive to run) and if they did it's in such a small period of time (.09% of a year- this industry operates 24/7) that I doubt it is even noticeable on the bottom line.

If you can afford it and you value the security then sure, go buy a generator- but recognize that the grid operates the way it does for generally good reasons (because simply providing good service is the best long-range plan for the people running it) and it is possible to bring it down out of chance, or incompetence, not just malice.

http://stateimpact.npr.org/texas/tag/2011-blackouts/
http://www.texastribune.org/texas-e...lling-chain-of-events-behind-texas-blackouts/

Led will work if the led's are 5w. for growing the ufo's have 2w and not the right color. But you got to get the 1000w out for flowering. 5x5 ft.
One other word ERON. Georgie bush, the maket will level out. No they wanted the Dem. governer out and we got anold. Then Eron stole all the retirement money. Ken lay is not dead be lives.