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July 2014 renewable statistics

We had an exceptionally rainy July, which was lovely for the cistern -- we now have more than 6 feet of water on both sides.  This month also marked one full year with the new solar panels.

As I've noted in previous years, July is historically hot and muggy and therefore our least energy-efficient month.  The generator hours reflect yet another month of running the air conditioning 24/7.

We also had a serious mechanical breakdown this month: our original totally incompetent solar guy strikes yet again.  The connector between the original solar panels and the batteries melted down, and we're lucky it didn't actually cause a fire or other collateral damage.  It turns out that he had installed a much higher voltage going through that connector than it was designed to accommodate. Unfortunately we were about 2 months out of warranty (though I'm not sure it would have covered improper installation anyway).  To further complicate matters, Xantrex doesn't sell the necessary connector as a stand-alone part, so Howard undertook the task of manufacturing a replacement.  The statistics for the month reflect the lack of production from the original set of solar panels for the last 4 days of the month (for the purpose of identifying 35+ production days, I've estimated what our production should have been, based on the output of the new panels), and generator hours are likewise skewed by the fact that Inverter #1 was sending erroneous information to the generator for 4 days before we figured out what was going on, resulting in the generator frequently switching on when it shouldn't have.

In completely unrelated news, we finally have domestic solar hot water fully functional AND feeding the propane hot water tank!  Thanks to the massive amount of solar heat available right now, in the high summer, that means we're using no propane for hot water purposes at all right now.

July 2014 Solar Statistics:
Peak daily production: 40.23 kWh (.73 lower than June)

Lowest daily production: 21.51 (14.24 kWh higher than June) (excludes the 4 days of malfunctioning solar, although even the lowest of those was an impressive 18.38 even without the original panels working!)
Days of 35+ kWh production: 8 (same as June)
Total monthly production:  695 kWh (255 kWh lower than June) (est. 52-53 kWh lower than it would have been if solar panels had all been functional for those last 4 days of the month)
Average daily production:  22.42 kWh/day (9.25 kWh/day lower than June)
Generator hours:  70 (2 fewer than June)

July 2014 wind statistics:
Total generated: 56.81 (21.12 kWh lower than June, 8.17% of solar production)
Windspeed: 6.0 average, 96.6 max
Power: 84 average, 3004 max

Previous July statistics for comparison:

July 2013 Solar:

Peak daily production: 44.44 kWh! (9.3 kWh higher than June)
Lowest daily production: 9.28 kWh (0.91 kWh higher than June)
Days of 20+ kWh production: 25, which is 21 more than May and, obviously, comprises the majority of the month.  I think I'm going to have to shift this parameter to days of 35+ kWh production to make it meaningful at this point, if it's going to remain a measure of extremely good production!  Days of 35+ kWh: 7.
Total monthly production: 882 kWh, 449 higher than June -- ie, a bit more than double June's production.
Average daily production: 28.45 kWh/day (1.89 kWh/day higher than the post-new-panel-installation days in June).
Generator hours: 52 (42 lower than June)

July 2013 wind statistics:
Total generated: 29.28 kWh; 3.32% of solar production
Windspeed: 4.6 average, 80.0 max
Power: 42 average, 2799 max

July 2012 solar statistics:

Peak daily production: 18.30 kWh (0.68 lower than June)
Peak instantaneous production: 3263 watts (152 lower than June)
Lowest daily production: 5.82 kWh (0.74 higher than June)
Days of 20+ kWh production: 0 (same as June)
Total monthly production: 436 kWh (42 lower than June)
Average daily production: 14.06 kWh (1.87 lower than June)
Generator hours: 79, but after enduring June and the first half of July without AC, every single minute felt worthwhile.

July 2012 wind statistics:
Total generated: 53.98 (3.25 kWh more than June, only 12% of solar production)
Windspeed, in mph: 5.5 avg, 59.7 max
Power generated: 75 watts avg, 2975 max

2011, for comparison:

This month's windpower stats are somewhat of a matter of interpolation, since we left on vacation on July 22nd and didn't get back until August 6th, so I wasn't able to get the precise end-of-month figures.  To compensate, I took readings on the 22nd and again on the 6th, and divided the energy generated by 5, and then allotted 3/5 of the resulting figure to July (to account for 9 days) and 2/5 to August (to account for 6 days).  Obviously the power generated wouldn't have been perfectly even from day to day, but it should be a fairly good approximation, and since the total is so low, it's of relatively low importance anyway.

Windpower generated during the gap: 11.44 kWh  (yes, incredibly low!)
Portion attributed to July: 6.86
Portion attributed to August: 4.58

Generator hours were easy, since we had none between the 22nd and 6th.  Solar power required no interpolation, since the solar controller records the output from day to day, enabling me to accurately determine just how much power went with each month.

Peak daily production: 18.05 kWh (0.53 kWh lower than June)
Peak instantaneous production: 3267 watts (399 watts lower than June)
Lowest daily production: 8.35 kWh (3.42 kWh higher than June)
Days of 20+ kWh production: 0
Total monthly production: 418 kWh (6 higher than June)
Average daily production: 13.48 kWh (.25 lower than June)
Generator hours: 65.  It was insanely hot and muggy, we ran the air conditioning a great deal, and the wind turbine contributed almost nothing this month.
Approximated at 30.43 kWh generated.  (63.18 kWh less than June, and only about 1/3 of our previous low).  A record low of only 7.2% of solar output.  I had been hoping that July wind production would be similar to what we had last September, but it definitely wasn't this time around!
Average production: 0.98 kWh/day (2.14 kWh/day less than June)
Average windspeed: 3.9 mph (unchanged between the 22nd and 6th)
Maximum windspeed: 90.6 mph (unchanged between the 22nd and 6th)
Average power production:  45 watts (92 lower than June)
Maximum power production: 3207 watts (164 higher than June)

July 2010, for comparison:

I notice that I labeled last July "insanely hot and humid" as well, and noted that we ran the AC the entire month.  For future projections, I'm going to simply assume that that will be our norm, and that July probably will be our least energy-efficient month of the year.

Peak daily production: 18.94 kWh (precisely 1 kWh higher than June)
Peak instantaneous production: 3287 watts (181 watts lower than June)
Lowest daily production: 5.97 kWh (3.11 kWh lower than June, but still our 2nd best on record)
Days of single-digit production: 5 (tied for 2nd best on record with August 2009)
Days of 20+ kWh production: 0.  The lack of any super-high days is reinforcing my impression that summertime is good for length of days, but not for maximum production overall -- which is consistent with Don's design, of course, which was intended to maximize year-round production rather than taking full advantage of the potential summer maximums.
Total monthly production: 416 kWh (19 less than June)
Average daily production: 13.42 kWh (1.08 lower than June)
Total generator hours: 93.  Yes, 93.  Worst since the solar panels went in -- the direct result of running the air conditioning the entire month.  Still, if I had it to do over again, I'm fairly sure that I would; July was just insanely hot and humid, and having the house remain cool has been well worth the estimated $8 per day of propane.
Estimated renewable shortfall: 558 kWh, an average of a whopping 18 kWh/day
Average daily usage: 31.42 kWh (just about on par with typical KY usage, but our previous worst was around 20 kWh -- this is off the charts for us.)



July 2015

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