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.
