Renewable resource

Renewable resource (called also renewable energy) is a kind of energy from sources that are naturally replenishing but flow-limited, such as sunlight, wind, rain, tides, waves, and geothermal heat. They are virtually inexhaustible in duration but limited in the amount of energy that is available per unit of time. Renewable energy often supplies energy in four important areas: electricity production, air/water heating/cooling, transport, and rural energy services (off-network).

Some are considered “inexhaustible,” in the sense that they regenerate at least at the same speed with which they are consumed or are not “exhaustible” in the scale of “geological eras times.” Exceptions are some energy resources which, although renewable, are exhaustible; for example, forests are considered renewable but can be depleted due to excessive exploitation by humans.

Renewable resources, whether they are material or energy, are natural resources which, due to natural characteristics or due to the production of man, are renewed over time (at a higher, or equal, renewal rate than the rate of consumption/use) and can be considered inexhaustible, or may be available for use by humans almost indefinitely. A renewable resource is also said to be “sustainable” if its rate of regeneration is equal to or higher than the rate of use.

There are many forms of renewable energy. Wind and hydroelectric power are the direct results of differential heating of the Earth’s surface which leads to air moving about (wind) and precipitation forming as the air is lifted. Solar energy is the direct conversion of sunlight using panels or collectors. Biomass energy is stored sunlight contained in plants.

Other renewable energies that do not depend on sunlight are geothermal energy, which is a result of radioactive decay in the crust combined with the original heat of accreting the Earth, and tidal energy, which is a conversion of gravitational energy. It is useful to highlight how the forms of energy present on our planet (except nuclear energy, geothermal energy, and tidal energy) almost all originate from solar radiation, in fact:

  • without the Sun there would be no wind, which is caused by the irregular heating of air masses, and with it wind energy;
  • biomass energy can be considered chemically stored solar energy, through the process of chlorophyll photosynthesis;
  • hydroelectric energy, which uses waterfalls, would not exist without the water cycle from evaporation to rain, triggered by the Sun;
  • fossil fuels (coal, oil, and natural gas) derive from the sun’s energy stored in the biomass millions of years ago through the process of chlorophyll photosynthesis.

Leave a Comment