There are a few different answers to this question, depending on what you are asking. I'll go over the main ones.
1. The Earth's axis is tilted in comparison to the Sun, so days get shorter in the winter months. This is due to less light, and therefore energy, hitting the Earth directly. Instead, that energy either misses entirely, or hits nearer to the Equator. This is why the poles have twenty-four hour days and nights depending on the season. (Night in the winter, day in the summer.)
2. In terms of the food chain, energy from the sun is converted to basic sugars by plants in a process known as photosynthesis, inside the plant's cloroplasts. Small animals such as mice and insects consume the plants, and the energy those plants converted from sunlight. This continues up the food chain until you get to apex-predators (tigers, bears, wolves, owls, etcetera).
3. In terms of electricity, solar panels are made of tons of 'solar cells' which tend to be lots of silicon atoms, which like to share electrons, and a conductive backing. (Pardon me if some of this section is incorrect, I only have a basic understanding of solar panels) When a photon (that is, a light particle) hits the silicon, it bumps off an electron, and the conductive backing catches it, resulting in a electrical current. This current is incredibly small per solar cell, so you need a ton of them to make any sort of useful power out of them. Solar panels do degrade over time, but incredibly slowly, there are some from the 1970's that still generate just as much power as they did originally (if not, only ever so slightly less).
I hope I answered what you needed to know! If you wanted a different answer, feel free to comment with some clarification and I would love to fill you in :)
Trees serve as a natural force to prevent erosion and hold soil together during rainfall and other periods of weather that might impact the integrity of the soil. However, trees were cut down to build a new shopping center there could be an increased flow of water to a river and also lead to great soil erosion nearby thus increasing the amount of sediment being deposited into the river. Also this new shopping mall could increase the pollutants in a river as well.
here are some topics though: greenhouse gases (global warming), forest fires, WV cars putting more emissions that they claim they are in America WV vehicles, and for more just Google north America environment problems. then summarize the problem and write what you think about it. promise it will be done quickly. that isn't even a whole page single spaced typing.