Sustainable energy is defined as energy that meets the needs of the present generation without compromising the ability to power future generations. Sustainable energy is strongly tied to the concept of renewable energy, in which energy is generated from sources that are naturally replenishing and nearly inexhaustible but is limited in availability due to time.
For example, sunlight is a renewable energy source, but we only get a certain number of hours of sunlight in a day. While we can count on the sun rising every day, we are unfortunately limited in how much light can be used as an energy source per day. The same goes for energy created by wind, a natural renewable source. However, if there is no wind at any given time, there is no energy being generated from that source.
Fossil fuels (oil, gas, and coal) are not renewable or sustainable energy resources; they are limited with the amount in the ground. Also the energy from fossil fuels is created by combustion or burning the material creating CO2 emissions harmful to our atmosphere. As environmentalism has come to the forefront of mainstream attention, climate change and the effects of global warming have forced us to re-examine our energy sources.
Exploration of renewable energy sources such as the sun, water and wind, as well as energy storage systems to use that renewable energy during downtime is now more important than ever. These renewable energy sources feed into the sustainable energy movement. Companies such as EnergyX believe that renewable energy generation as well as cost effective energy storage have the potential to replace fossil fuels as our societies go-to energy sources.