There is a tinge of fall in the air although in these parts, the warmest months are September/October. Mornings are slightly cooler, but warms up rapidly during the day. We are in the process of getting the house ready for the rainy season which includes a coat of exterior paint...a different color this time. The rainy season is brutal on exposed wood surfaces so we are going to extremes to seal up everything with caulk. Next task on the list is to clean the chimney and while on the roof, seal up around the plumbing stacks. The gutters have been cleared of debris, but the down spouts probably need to blown out with a leaf blower. After a bit of a hiatus, I got back to scything yesterday. The lower part of the property is slowly starting to take shape. Of course once the rains start, more growth will come, but next year it should not be quite has hard to tackle. I get some good exercise in the process and I have become more intimate with property and nature in general which has been a boon. Now that I have some more practice under my belt, my windrows are becoming neater and the cutting is more clean. So far, the ditch blade has been adequate for most of the work, but at some point I will have to resort to the bush blade to take out the really heavy stuff. You can see from the pic that the place is really starting to open up: http://tinyurl.com/y7tdme7j There has been an ongoing investigation as to where to relocate the solar panel that supplies power for our satellite internet. The current location is shrouded in the shadows of the redwoods for several hours of the day. What should be a fairly simple problem to resolve is made more complex in that the transceiver is housed in the tool shed along with the charge controller, batteries, inverter as well as the router, ip power box, ethernet to fiber etc. The sunniest location to move the panel is around 120 feet from the shed which presents some challenges. A long dc cable run to the shed from the panel will be subject to significant voltage drop unless I use something like 6 AWG cable which might be costly. The other option would be to house the controller, batteries and inverter at the panel location and run an ac cable run to the shed where the transceiver is located thereby reducing the voltage drop to a certain degree. The transceiver is kept in the shed due to its close proximity to the dish. I am also hoping to upgrade the system a bit to provide extra emergency power to run the fridge and a couple of lights for a few days in the event of an extended power outage which does happen from time to time. I placed a killawatt meter on the fridge to get an idea of the power consumption over the span of a week. This will give me a clearer idea of what I need regarding extra panels batteries etc. Of course, all of this requires yet more math. *sigh* *Math and the after math* So let us turn to the math department. I did manage to find some apps for the phone that would calculate sunrise, sunset, solar azimuth, solar altitude etc for our location. The protractor app was a bit of a pain to use as I had to aim the edge of the phone toward a target tree top to get the degree of elevation. At the same time, I had to tap on a certain section of the screen to hold the measurement. I managed to get the measurements for the relevant tree tops, but I could have done better with a regular protractor, string and plumb bob. The proposed site for the panel(s) does have some shading issues, but not as severe as the current location. Another app has a tilt guide feature to assist in tilting the panels to the correct angle for the season. I compared the measurements to the angles I had previously set on the panel mount when I built it. At that time, I used a speed square to mark the angles on a wooden template and mounted it adjacent to the panel to set the correct angle. To my surprise, I found that my original "poor man's solution" was almost identical to the panel angle the phone app was measuring. Not bad for a low tech solution. Next on the todo list is to calculate voltage drop on the wire run from the proposed site to the tool shed. I think I will press the slide rule into service for this one. This biggest challenge for me when using the slide rule was the correct placement of the decimal point. I found one system that on first glance seemed rather involved, but after practicing a bit, I am starting to appreciate the methodology. As an example, we can take the problem .004 * 50: -use the slide rule to get the coefficient of the answer: 2. -the numbers in scientific notation are 4E-3 and 5E1. -add the exponents: (-3) + 1 = -2; -adjust for change of magnitude: 4x5 is 10 or more, so -2 + 1 = -1 -result 2E-1 which is 0.2. Or as an example in division 2 / 3: -use the slide rule to get the coefficient of the answer: 6.67. -the numbers in scientific notation are 2E0 and 3E0. -subtract the exponents: 0 - 0 = 0; -adjust for change of magnitude: 2/3 is less than 1, so subtract 1, 0 - 1 = -1. -result 6.67E-1 which is 0.667. Of course, these are very simple examples, but I think the reader can get the idea. Takes a bit of practice and thinking, but it seems to be a good system to get the decimal in the right place. There is a similar system for squares, square root, cube, cube root etc. Although with the slide rule you can only get down to 3 significant figures, I reckon that since we were able to send men to the moon using slide rules, 3 significant figures must be good enough for my little solar project. I have read, and I am inclined to believe it, that for most applications, more than 3 significant figures is just useless noise.