Every sensor, pump, light, and controller on a farm runs on power, and power is the first thing that fails. Understanding Power, Lesson 3 of the Fundamentals, covers the concepts. This section is the practical side: what to fuse, what to size, and the words to work from before you buy or build anything.
Safety first.
This section leads with safety on purpose. A do-it-yourself battery or solar system arrives with no protection installed, and the danger runs opposite to your household intuition: low-voltage DC mostly cannot shock you, but it starts fires with enthusiasm. Electrical Safety and Protection is the first page to read, before the shopping list, and it closes with the ten words that make every video, forum, and supply-house conversation afterward make sense.
Solar on a farm.
Solar shows up in agriculture three ways: powering loads (pumps, fences, gates, lights), powering sensing (the small panel that keeps a remote monitoring node alive where no outlet will ever be), and sharing the land itself with crops, which has a name worth knowing: agrivoltaics. The Solar page walks all three, with the vocabulary to work from and a good video tour of the land-sharing idea.
The math, ready to use.
The Library already carries the working tools for power and solar questions: size a solar pump, see your sun across the year, design passive solar into a greenhouse, audit where the energy goes, and estimate heating cost. Passive solar (capturing heat with glazing and mass) and photovoltaic solar (making electricity) are different subjects that share a sun; both live here.