genetically modify vegetation so that they store excess sunlight in biochemical batteries in stalk and root

genetically modify grass, bushes trees and agriculture plants so that they store excess sunlight in biochemical batteries in those plants 

so that plants use those biochemical batteries to keep warm when it's cold because of night time, winter weather 

those biochemical batteries would store sunlight energy 

but those biochemical batteries would not produce electricity, 

they would produce heat, which is much simpler to do biochemically 

the biochemical batteries could be in roots of grass, in the wood of bushes, in the wood of trees and in the stalk and roots of agriculture plants 

that will enable more agriculture in colder areas, 

in tundra areas and in mountain areas 

it could keep vegetation in steppe areas and desert areas warm during cold nights 

according to media there has been research about microbial fuel cells and bacteria's ability to function as biochemical batteries, but those projects aim to produce electricity