Wednesday, February 13, 2008

Reset Solar Stand-offs

Several solar experts recommended tilting up the solar hot water panels in order to get more hot water in the winter. One of the experts, Gary of Builditsolar.com, ran a program to show the effect of tilting the panels, see below (need only look at the month in the first column and total BTU in the last column)

18 deg tilt:
Month by Month Summary of Sun on Collector
(100% sunny weather)

Collector Area: 1.0 (sqft)
Collector Azimuth: 0.0 (deg) measured from South
Collector Tilt: 18.0 (deg) measured from horiz
Latitude: 39.0 (deg)
Altitude above SL: 0.0 (ft) Above Sea Level

Date ---- Sun ------------

---- Collector -----------------------
Month Day Direct Di- Total Direct Difuse Total
Normal fuse
1 21 2234 130 2364 1349 127 1475 <---
2 21 2635 158 2793 1710 154 1864
3 21 2931 208 3139 2013 203 2216
4 21 3095 302 3396 2147 294 2441
5 21 3155 383 3538 2188 374 2561
6 21 3164 423 3587 2174 413 2587
7 21 3055 415 3470 2125 405 2530
8 21 2914 354 3268 2040 345 2386
9 21 2727 253 2981 1891 247 2138
10 21 2464 179 2642 1610 174 1784
11 21 2164 136 2300 1306 133 1438
12 21 2032 117 2149 1175 114 1289
Sum 32570 3057 35627 21726 2983 24708

Radiation in BTU/day


54 deg tilt:
Month by Month Summary of Sun on Collector (100% sunny weather)
Collector Area: 1.0 (sqft)
Collector Azimuth: 0.0 (deg) measured from South Collector Tilt: 54.0 (deg)
measured from horiz Latitude: 39.0 (deg)
Altitude above SL: 0.0 (ft) Above Sea Level

Date ---- Sun ---------------- Collector -----------------------
Month Day Direct Di- Total Direct Difuse Total
Normal fuse
1 21 2234 130 2364 1871 103 1974
2 21 2635 158 2793 2078 125 2203
3 21 2931 208 3139 2082 165 2248
4 21 3095 302 3396 1833 239 2072
5 21 3155 383 3538 1604 304 1907
6 21 3164 423 3587 1496 336 1832
7 21 3055 415 3470 1548 330 1877
8 21 2914 354 3268 1734 281 2015
9 21 2727 253 2981 1944 201 2146
10 21 2464 179 2642 1964 142 2106
11 21 2164 136 2300 1816 108 1924
12 21 2032 117 2149 1724 93 1817
Sum 32570 3057 35627 21692 2427 24119

Radiation in BTU/day


/Gary

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Problem was that if I raised the panels in the originally planned location, in the middle of two rows of solar PV panels, I would end up shading the PV panels in the morning and late afternoon. So I re-arranged the standoffs with the solar hot water panels to be mounted horizontally above the PV panels.

I had great help from Don Hiatt, of Hiatt roofing and his assistant Rick (?)

Also shown here are the tilt legs for the panels

A lovely fire sprinkler control valve is placed on the side of the house

Wiring panel

Electrical Wiring


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