
We’re all familiar with energy. Flip a light switch, that’s energy. Take a shower, you’re using energy. Cooking, energy. Driving a car, energy. For most of us, that energy comes from sources that are nonrenewable, meaning once they’re gone, they’re gone. Fossil fuels are the number one example of a nonrenewable resource. As more of the world needs power and we continue to advance our societies, we’re going to need to look at different ways to get energy. Here’s what renewable energy is and what role it has to play:

1. Renewable means “not depleted when used.”
When you go to the fridge and grab a few ingredients to make dinner, you’re depleting your resources. Sure you can go out and buy more, but for the time being, in your home you’re dealing with nonrenewable resources. When you use something, it goes away. Nonrenewable resources are the same. Once we’ve used up all the coal on the planet, we won’t be able to get more, at least not in a reasonable amount of time. Renewable energy, on the other hand, will still be around in the next hundreds or thousands of years.
2. Renewable must be on a human timescale.
An important consideration is our human timescales. Fossil fuels are renewable...if you have a few million years to wait around. We don’t. Renewable energy gives continuous energy that is consistent with human timescales. It is naturally replenished not in thousands of years, but in a few days, weeks, or months.

3. These are the top sources of renewable energy.
So, what are the renewable energy resources we have on our planet? Wind energy is one that is increasing in popularity. Wind is naturally occuring and not going to slow down anytime soon, so there’s no risk of running out. Solar power is another form, since the Sun will continue to shine for another few billion years. Some other notable renewable energy sources are hydropower and geothermal.