Hourly output of West facing (270 azimuth) panels

[J.P.M.]

17 minutes was the total range over a year. Bruce

Actually, over the course of a year, the actual time difference from the earliest solar noon to the latest solar noon is about 30 minutes, 43 seconds and wobbles around +/- by some fraction of a second or so per year.

Check a nautical almanac or NREL, or see Duffie & Beckman, 2d ed., eq. 1.5.3a, or any decent solar text (Iqbal is a solid solar reference, but it's out of print) for an estimate of the time offset for solar noon as f(day of the year). For 2016, the day of earliest solar noon will occur on 11/02, with the date of latest solar noon occurring on 02/10. Note they are not 183 days apart. The actual civil (clock) times of local solar noon are f(longitude, time zone, daylight saving time). For my location, those times are 11:31:54 P.S.T. (11/02) and 12:02:37 (02/10) P.S.T. The Nov. time will most likely be under standard time unless 1st Sunday in November happens to be 11/01. In that case, solar noon will be at 12:31:54 P.D.T.

[bcroe]

Actually, over the course of a year, the actual time difference from the earliest solar noon to the latest solar noon is about 30 minutes, 43 seconds and wobbles around +/- by some fraction of a second or so per year.

Check a nautical almanac or NREL, or see Duffie & Beckman, 2d ed., eq. 1.5.3a, or any decent solar text (Iqbal is a solid solar reference, but it's out of print) for an estimate of the time offset for solar noon as f(day of the year). For 2016, the day of earliest solar noon will occur on 11/02, with the date of latest solar noon occurring on 02/10. Note they are not 183 days apart. The actual civil (clock) times of local solar noon are f(longitude, time zone, daylight saving time). For my location, those times are 11:31:54 P.S.T. (11/02) and 12:02:37 (02/10) P.S.T. The Nov. time will most likely be under standard time unless 1st Sunday in November happens to be 11/01. In that case, solar noon will be at 12:31:54 P.D.T.

Right, I found a chart showing it varying between 11:40:24 and 12:11:05 at this location. Bruce

[J.P.M.]

Right, I found a chart showing it varying between 11:40:24 and 12:11:05 at this location. Bruce

Understood. Thank you.

[cnil1]

On the same subject, keep in mind that APS has proposed to raise their off-peak rates by 32% in next year's rate case. While the strategy to do a "peak shaver" may be good today, in my opinion the best long term solution is still a full offset system...especially if you can get grandfathered into the plans they have today.

And that $0.06 off peak rate is really more like $0.075 when you add the taxes associated with usage...so the new rate would be roughly $0.10.

HX...

1. Are these estimates or your real numbers? When I look at my bill, the taxes and "other fees" that vary with usage only total about 13% of the charge for the actual electricity.
2. Is that 32% increase going to hit the off peak rates on the to-be-phased out ET-2 plan, too? I think it is at $.06118 / kWh now.

[HX_Guy]

HX...

1. Are these estimates or your real numbers? When I look at my bill, the taxes and "other fees" that vary with usage only total about 13% of the charge for the actual electricity.
2. Is that 32% increase going to hit the off peak rates on the to-be-phased out ET-2 plan, too? I think it is at $.06118 / kWh now.

Looks like the ET-2 Legacy is going to $0.29201 on-peak summer, $0.23677 on-peak winter and $0.07299 off-peak summer and $0.07296 off-peak winter.

The current ET-2 is $0.24477 on-peak summer, $0.19847 on-peak winter and $0.06118 off-peak summer, $0.06116 off-peak winter.

Looks like about a 19.3% increase.