Hello, George,
This is a fun question that can have many answers. I'll ramble for a bit, and you can choose which avenue to take.
A simple answer would be solar photovoltaic cells from solar arrays. The sun's energy is produced by the fusion reaction of hydrogen and helium. Part of that energy is released as light of many wavelengths. Photovoltaic cells capture that energy and convert it into a DC current, which can then be converted to an AC current and voltage that is compatible with a country's transmission system grid. From there it is delivered to a home or business.
A more interesting answer is based on the fact that the sun's energy can be captured by plants. Leaves contain the chemical means to take that energy and convert CO2 and H2O into cellulose and other plant products. The cellulose contains the sun's energy in the form of chemical bonds. These molecular bonds represent energy that can be released at some point, either to the plant as part of it's life cycle, or the wood can be burned to produced heat to generate steam which is passed through a turbine to product electricity.
The sun evaporates Earth's water, which under the proper conditions of temperature and saturation (relative humidity) will precipitate to form rain or snow, many times in mountainous areas where the temperature is lower. The rain and snow form rivers and lakes that are well above sea level and thus contain potential energy that can be converted into kinetic energy when released from a structure such as a dam. The flowing water goes through turbines to generate power. The flow of a river is an expression of that potential energy becoming kinetic energy as the river flows to lower elevations. Paddle wheels may be inserted to produce rotary motion that can power not just grist mills, but also the power turbine.
Going back in time, the sun also accounts for Earth's oil and gas supplies. As Earth began to develop life, it was the sun that provided the energy. As plants took hold, animal life followed and consumed the plants for food. Each step of the process is using the sun's energy that has been captured in the plants via chemical bonds. Animals digest these chemicals (foods) and their bodies have the chemical pathways necessary to be able to break those bonds in a way that produces both energy and compounds they need for survival. Over the millennia, these plants and animals would die and, in those areas of the world conducive to such life, the remains of both slowly decompose and are covered by additional layers of debris to a point that they are pushed down into pockets of highly rich organic materials. Left alone, the end product of this decomposition is an oil or gas trapped within the Earth. By drilling, these crude byproducts can be brought to the surface and refined to make gasoline, kerosene, synthetic compounds such as plastic, and fill pipelines with natural gas. The oil and gas are made up of organic chemicals that had their original bonds made from the energy of the sun. That energy can be released in a power plant to provide electricity to the home.
You are probably getting the idea by now: The sun provides Earth's energy. One could also argue that our nuclear power plants also arise from a sun. Radioactive elements in Earth's crust are the result of high-energy sources, such as a nova. Perhaps they did not all come from our sun, but they are the result of the energy inherent in these events in the universe.
I hope gives you some ideas how to answer. Keep looking, and the originating source is often the sun. One might consider thermal energy generated by Earth's tectonic plate movements. I don't know the answer, but some of that movement must be due to the sun's gravitational pull. The sun's energy also gives rise to temperature differentials that create the wind, which can power wind farms to supply power to homes.
I hope this helps,
Bob
