Like other "-punk" philosophies, solarpunk is a rebellion/protest movement. Specifically it is a protest against future where humans increasingly damage the environment, corporations have more and more control over society, technology is primarily for surveillance/profit, social/inequality worsens, and economics defines progress. Solarpunk is an optimistic vision of the future that combines sustainable technology, environmental harmony, and social justice. Some common solarpunk themes are:
Because solarpunk believes that responsibly implementd technological progress is the path forward, it is essentially accelerationist
Solarpunk has a strong visual aesthetic, often showing walkable cities, small, diverse communities, and comfortable/human centric implementation of technologies. Often solarpunk cities are shown as very green with few cars. Unlike cyberpunk's dystopian, technologically driven corporate future, solarpunk envisions humanity solving climate change and social issues through sustainable innovation. In essence it is high tech futurism set in lush, naturally integrated environments.
A video called Dear Alice that went viral for its depiction of a solar punk lifestyle. Notice the abundance of technology, community, and integration with the natural environment. Note: this was originally a yogurt ad, but this version has been decommodified.
Solarpunk x Cypherpunk = [Lunarpunk].
For a thorough comparison to solarpunk see Lunarpunk and the Dark Side of the Cycle.