Worldbuilding Stack Exchange is a question and answer site for writers/artists using science, geography and culture to construct imaginary worlds and settings. It only takes a minute to sign up.
Sign up to join this community
This is for a planet similar to earth, in that the main energy source is a sun. Is photosynthesis the only way to obtain energy?
The best example I could find is the Oriental Wasp and it's ability to use a pigment called Xanthopterin to convert solar energy to electricity.
Stars like the Sun emit gamma rays. In a planet where the atmosphere allows x rays and gamma rays to hit the surface, organisms can use melanin to harvest energy from the radiation.
There is a fungus inside Chernobyl which gets energy from the radiation like that, so it's not something out of this world.
There would be little motivation for plants to do that with a star like ours, though. The bulk of the Sun's EM radiation is between infrared and ultraviolet, and those are much safer than X rays and gamma. For plants to evolve to gather from more dangerous forms of radiation, you need an environment where that energy is more abundant. Perhaps an atmosphere that blocks visible light but lets gamma rays pass. Or perhaps a world with lots of surface uranium - plants would use melanin to extract radiation from that, and just coincidentally would be able to harvest some from the star too.
by useing chemosynthesis, which bacteria in tubeworms already do, and it technically comes from suns, otherwise, heat, like a thermal plants (where we get energy from) you could make your plant use heat and turn it into energy, the thing here is the temperature- it has to be high, so either your planet had some sort of catastrophe wich heated the core, is quite new and life evolved vey quickly, or is closer to the sun
edit, tubeworms are in a place with no light what so ever, at the bottom of the sea and they also use some heat as they live near thermal vents, so there, your answer
Thermal Heatpumping
Broadly, if you establish a temperature gradient, you can extract energy from it. This is commonly used in reverse as a fridge/freezer, but Ground-source heat-pumps take advantage of it too. Pumping water through pipes underground cools or warms the water to match the surrounding soil (which is typically a consistent temperature) and the resultant energy-change can be used to heat a home.
A hypothetical thermal-powered plant might have an extensive root-system and big dark leaves, so that it absorbs heat from the sun and disperses it with the roots, using the energy-transfer to power itself. Such a plant would probably have a more developed circulation of sap, so that warm liquid sap would flow down below-ground to cool off.
