Sometimes people like to ask the hypothetical question: “What would happen if the sun were to stop shining tomorrow?” Well, thankfully, there isn’t much chance of that happening. See, even if all of the nuclear reactions going on inside the sun’s core were to suddenly come to a screeching halt, it would probably take several hundred thousand years before all of that excess energy would be able to shuffle its way out of the bowels of the sun and disappear into the endless night of interstellar space. As such, unless our understanding of nuclear physics is way off base, we’ll be enjoying sunburns and photosynthetic plants for billions of years to come. So, when you hear an alternate-energy enthusiast make the claim that solar energy is the power source of the future, listen up, because he knows what he’s talking about. Here are a few reasons why the sun is destined to become the standard energy source of the next hundred (or even hundred thousand) years.

1. It’s universally available

As a comparison, let’s take a moment to consider a more conventional fuel source: oil. 56 percent of the world’s available oil is located in the middle east, with 16 of the remaining percent being found in North America according to the US Energy Information Administration. The unaccounted for 28 percent is spread around between the other parts of the world. The point here being that when it comes to oil, there is a distinct separation between the “haves” and the “have-nots.” Sunlight doesn’t really have to deal with these limitations. It’s available to everyone (almost) everywhere.

2. It’s inexpensive

How much do you spend on your energy bill per month? If you answered “More than nothing,” then you’re paying too much. In fact, in 2012, the average monthly residential electric bill was $107.28. With adequate solar power, there aren’t any ongoing costs, aside from the occasional bit of solar panel maintenance. Instead, you just set up your solar cells, and let the ball of free energy at the center of our solar system take care of the rest.

Several companies have revolutionized the way we use solar power, especially as homeowners. Solar panels used to be incredibly expensive to install. Now, companies like Vivint, SolarCity Corp (NASDAQ:SCTY), and others have dropped solar power panel costs for consumers, so the initial investment is completely doable for most homeowners. Julie Jacobson, editor-at-large of CE Pro, explained, “More importantly, today’s homeowners have numerous options, including offerings from mass marketers. Consumers can walk into a store, provide their address, and walk out with a signed contract and nothing to spend or do except for scheduling a (free) installation.” Solar power is more affordable than ever, and it’s likely solar power use will increase as solar power panel costs continue to drop.

3. It’s clean

Do you know what kind of harmful chemicals are released when you burn oil? How about carbon dioxide, carbon monoxide, sulfur dioxide, nitrogen oxides, volatile organics compounds, polycyclic aromatic hydrocarbons, hydrogen sulfate, acidic aerosols, and various kinds of dangerous soot and particulate matter? Now, do you know what kinds of harmful chemicals are released when you burn sunlight? None. Yes, the photovoltaic conversion process of light to energy is completely clean. So, once the world’s population has gotten tired of breathing in toxic chemicals, the transition to solar power will seem like an obvious solution.

4. It’s becoming more efficient

This is where things become complicated. See, even though the sun drops more energy on the planet’s surface in a single month than is contained in all of the world’s coal and oil reserves, effectively converting that energy into something usable (such as electricity), can be tricky. As it stands, today’s best and most expensive solar cells only manage to achieve an efficiency rating of about 45%, and most commercial cells actually hover down around 11-15%. However, when it comes to solar power, the future is bright. As new materials and technologies are developed, efficiency will rise as well. It has even been suggested that we may soon begin to see solar cells that reach an unprecedented efficiency rating of 80%.

So, grab your shades and get ready to embrace the sunlight, because given the fact that most all of our forms of conventional energy are quickly becoming scarce, you can be sure that if we use any energy at all in the next century and beyond, it will be solar energy.