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Xcel Time of Use Rates in Colorado

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Thanks. That report is helpful. It sounds to me like Xcel is on it and curtailment is on its way down. They are looking to improve balancing options, have improved forecasting, and as coal plants are replaced by more flexible nat gas plants, cycling costs drop. And then there's the topic of this thread, which will work to increase nighttime base load, which also should help.

And before all that, it should be noted that Xcel's curtailment was in line with other providers, and dropped as a percentage of output even as output rose dramatically.

In short, 0% would be better, but I'm ok with where they're at and their trajectory.
 
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Thanks. That report is helpful. It sounds to me like Xcel is on it and curtailment is on its way down. They are looking to improve balancing options, have improved forecasting, and as coal plants are replaced by more flexible nat gas plants, cycling costs drop. And then there's the topic of this thread, which will work to increase nighttime base load, which also should help.

And before all that, it should be noted that Xcel's curtailment was in line with other providers, and dropped as a percentage of output even as output rose dramatically.

In short, 0% would be better, but I'm ok with where they're at and their trajectory.

Agree completely. The report data is a few years old but curtailment was below 3% then and remains so now despite continued large increases in wind generation. As for the 60,000 hours of free curtailment, that doesn't mean they used that much - just that it was available. That same report points out that the free hours available go down to 30,000 by 2018. Curtailment is expected to continue to go down as coal is replaced by natural gas and, of course, TOU programs and night time EV charging will further help the situation. Xcel doesn't do everything perfectly but I can't imagine they'd continue to expand wind generation at the rate they are if it was all going to get curtailed.
 
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As for the 60,000 hours of free curtailment, that doesn't mean they used that much - just that it was available
That is true, but Xcel would have had to twist the arm of the wind producers to gain that concession, so it was not done for the fun of it. Moreover, it gives Xcel a carte-blanche to run their filthy coal plants at full tilt until further notice while collecting 'reasonable return' on their investments. The situation stinks and we should not be complacent about it.

I think it is an interesting question whether our time shifting affects the coal and wind use overall and in what direction. One thing though seems clear: PV sent to the grid during the day is displacing NG, and a dirtier fuel is used at night. This is the part that leads me to view the TOU deal negatively. As one person mentioned though, perhaps the TOU deal with a rider to pay for wind energy would be reasonable. I wish I knew, but these 'clean energy supply' programs are so easy to game I find it hard to put much faith in them.

Xcel doesn't do everything perfectly but I can't imagine they'd continue to expand wind generation at the rate they are if it was all going to get curtailed.
It was never a question of 'all,' and to the extent that the wind farms are independents who agree to free curtailment, Xcel uses wind when it is most profitable (read: instead of NG) and lets the wind producers sit idle when coal is cheaper.

3% curtailment does not sound like a lot but I urge a skeptical read. For one, I'm not convinced that it is an honest accounting or if some producers are not disproportionately affected. Second, wind production by independents has remarkably thin profit margins and that last 3% of production may be a large fraction.
 
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That's weird; that last quote says it's from me, but I didn't say those words.

I do agree with you that skepticism is warranted (as it usually is!). We should all take every opportunity to urge Xcel to add more renewable power generation, and to use what they have as much as possible. In an imperfect world, this includes, IMO, signing up for the renewable programs they do provide, and being vocal in surveys they send out. Not sure if I signed up for something that opened the floodgates on those, but it seems I get an Xcel survey that includes some discussion of renewables every few months.
 
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So I'm a little confused. I'm looking at the Xcel website explaining TOU, and these are the kWh charges they're saying.

But according to Zaxxon's post, and I've confirmed from the rate schedules, it should be half more or less what they're quoting. What gives? I'm very incentivized if I can charge my EV, and do laundry at 4 cents per kWh after 9pm, vs 8 cents, especially given the tier two for regular residential above 500kWh is only 9 cents a kWh.


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I mentioned in my post but it might have gotten lost in the noise: the website rates also include the same adjustments we see in the general rate schedule.

To be clear: the actual rate you pay for summer tier 2 > 500 kWh is *not* 9¢/kWh. It's substantially more after you add in the adjustments.
 
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I mentioned in my post but it might have gotten lost in the noise: the website rates also include the same adjustments we see in the general rate schedule.

To be clear: the actual rate you pay for summer tier 2 > 500 kWh is *not* 9¢/kWh. It's substantially more after you add in the adjustments.

Add approximately 4.3 cents of adjustments to that 9 cents.

I've made a google docs spreadsheet that lets you put in your hypothetical average usage during peak, shoulder, and off peak along with your expected monthly maximum demand for peak and off peak (5 inputs total) and it shows you what the three plans will cost you (residental, time of use, peak demand). The problem is I don't know how to share it so that it's not associated with my google account. Anyone want that in Excel format?
 
Add approximately 4.3 cents of adjustments to that 9 cents.

I've made a google docs spreadsheet that lets you put in your hypothetical average usage during peak, shoulder, and off peak along with your expected monthly maximum demand for peak and off peak (5 inputs total) and it shows you what the three plans will cost you (residental, time of use, peak demand). The problem is I don't know how to share it so that it's not associated with my google account. Anyone want that in Excel format?

I'll take it in either format; thanks. This was on my to-do list.

Sorry about that .. I added the comment later and entered your (misquoted) name manually. Too late to fix.

No problem.
 
I've made a google docs spreadsheet that lets you put in your hypothetical average usage during peak, shoulder, and off peak along with your expected monthly maximum demand for peak and off peak (5 inputs total) and it shows you what the three plans will cost you (residental, time of use, peak demand). The problem is I don't know how to share it so that it's not associated with my google account. Anyone want that in Excel format?
I'd be interested in the spreadsheet in either format as well. Thanks!
 
Here's the Excel spreadsheet. All the inputs are in the blue outlined area. You can input your usage as kw in each time period for the month or as an hourly average through the month (use the dropdown next to the value). The peak values must be greater than the averages (they'll highlight red if they are not). They're only used in the Peak Demand plan calculations. Each plan's values include two sets of cost figures: the first is without the fixed dollar costs that you pay regardless of usage; the second includes the fixed items so it should be very close to what your actual bill would be (except taxes and franchise fees). If you want to include the windsource charge, add 0.015 to "Other per kwh charges" in the constants area.

Hopefully my understanding of the plans is correct and all the numbers are right. Note that it doesn't handle any kind of solar over-production; that seemed difficult to try to model.
 

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In my little world, energy is kWh and power is kW. I would avoid average hourly kW inputs unless Xcel uses that metric to cost out demand charges.

I tend to agree but there are cases where it makes sense to put in usage in kw, like if you have a home energy monitor that tells you real time usage in kw. I know from my HEM that I have a pretty consistent base load (in kw) all the time so it's handy to be able to input it that way.

I'll move the units to the dropdown choice in the next version to make it more clear.

I noticed an error in the spreadsheet: I forgot that weekends include shoulder hours, so the formula in cell B33 needs to be changed to "=(B31*5/7*8/24)+(B31*2/7*12/24)+2". It doesn't matter with kwh as inputs but it does if using hourly average kw.
 
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I tend to agree but there are cases where it makes sense to put in usage in kw, like if you have a home energy monitor that tells you real time usage in kw. I know from my HEM that I have a pretty consistent base load (in kw) all the time so it's handy to be able to input it that way.
Oh, I see. Well, it was your itch that you scratched after all.

For the wider world I'll make this one last plea:
Folks with power meters are almost assuredly able to convert between power and energy, but in the wider American populace -- even amongst eV owners -- confusion reigns. They need to read off a bill and type in a monthly use.
 
At least I didn't use joules. :) Does the rest of it work okay otherwise?
My wife is one of those that has a terrible time internalizing the difference between an amount and a rate. She would almost surely grasp kW and MJ with less screaming. I've read before that the Aussies use MJ as their retail electricity unit. I'm jealous.

I only played with the SS for a few minutes and it seemed to work fine. It also points out that the savings from TOU w/o PV are pretty modest for most households at $1 - $2 a month.