I think a lot of people don’t understand electrical power, limitations, and how these off-grid systems work. That’s why I wrote a tutorial on installing solar.
Success in terms of electrical power while living in a vehicle, requires a paradigm shift to a minimalist mindset. Expecting the conveniences of brick & mortar living leads to an expensive and oversized system that’s too large and complex and much harder to maintain. The biggest part of a successful system is understanding your electrical budget, and part of that is understanding that heating and refrigerated air conditioning are the biggest power hogs and don’t fit well into a small and streamlined off-grid system. Heating should use carbon-based fuels such as wood, charcoal, coal, propane, diesel, kerosene, etc. and water should be used for cooling. These methods consume little to no electricity.
If I lived in Seattle, or any other place where it’s dark and dreary most of the time I’d probably double the size of the solar array, and look for other ways to supplement charging such as a smart battery charger plugged into shore power. I carry a 10 amp Genius 10 charger in case it’s needed, but haven’t needed it so far - it also doubles as a charger for the starting battery in an emergency.
Solar installation tutorial: