this post was submitted on 16 May 2024
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Living in vans, cars, RVs, etc
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We're not homeless, we're houseless! By choice or by circumstance we are living in our vehicles. Don't worry about us -- it can be a very good life.
Anything that affects us as vehicle-dwellers is probably on topic.
external resources
- emergency guide to suddenly living in a vehicle <-- start here if you don't have a choice in the matter
- vanlife FAQ
- introduction to power in the vehicle
- gentle introduction to solar power
- overview of charging by alternator
- guides to hygiene and toilet
fedi resources
rules of engagement
- be civil
- use descriptive thread titles. Pro tip: "Help" or "Question" are not descriptive titles.
- old-timers: assume people are different and have different needs, preferences, budgets, and use cases
- newbies: demonstrate effort and willingness to learn; you'll need it on the road anyhow. Links have been added below to help get you started. When asking question state your "use case" (what you are trying to accomplish); we are terrible guessers.
- tire-kickers: yes, we've heard that "in a van down by the river" joke. It was hi-larious in 1993.
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Is there a good online tool for calculating the cosign of solar Zenith so I can know how much solar my my panels could be making in ideal conditions? I see that you've used it in your blog.
It's cos(your latitude-23.44°), or just 1 in the tropics, unless I'm misunderstanding the question. I assume this is for a panel mounted level? Make sure your calculator isn't expecting radians!
If you mean ideal at a specific time and date, you can use the formula from the Wikipedia page. Substituting in 23.44°*sin(years since last March equinox*360°) for the (rough) solar declination, and longitude+UTC for hour angle, you get:
If you're just looking to avoid writing that out every time, I'll happily implement it in the common programming language of your choice. If you really care about the deviation caused by the elliptical orbit of the Earth you'll need more complicated math.
Edit: That should be signed latitude on the second equation, and March equinox, not solstice. Fixed.
I've found these Android apps useful:
There are an online calculators like this one from NOAA. This fork adds the ability to update the time with a click rather than manually. There are others but I haven't played with them much.
Since I travel constantly I've been on casual lookout for an app that does the calcs for us based on local time / position but I haven't seen any. Several apps show the solar zenith angle and we can take the COS of that manually with a calculator with trig functions. The standard android calculator app will do it.
Yeah, it's an imperfect tool for our purposes but better than nothing. Combining it with data from a solar irradiance meter would be great but right now I can't justify ~$100 to devote to the cause. :-)