What Is Renewable Energy?

Renewable energy has a future.

Exactly what is renewable energy? A good question for you to ask.

Thank you for coming along with me so far.

I hope you find it is worthwhile and helping you to make choices towards a world that you and me, our children, and theirs can continue to enjoy.

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What is renewable energy, you asked. A common definition is:

Renewable energy is derived from an energy source that is rapidly replaced, or renewed, by a natural process.

Such renewable energy sources include

  • Wind
  • Sun
  • Hydropower
  • Biological processes and
  • Geothermal processes

When asking "what is renewable energy" most people do not include nuclear power. There are people who argue it is at least a clean, non-greenhouse gas energy, but being uranium-based, it is not renewable.

Do you realise that you are applying renewable energy when drying your washing on the clothesline, in the wind and sun? You are. Other applications of renewable energy include hi-tech solar panels, fuel made from agricultural crops and the largest hydropower schemes.

What is renewable energy when you look at its sources?

The sun’s warmth and light produce solar energy. Passive use of solar energy involves directly capturing its warmth and light through building design. Active use happens by using technology to transform the sun’s energy into electricity. Photovoltaic cells and solar hot water systems are examples of active use.

Wind energy is the world’s fastest-growing energy source. It is a form of solar energy as weather processes that are influenced by the sun cause wind. Windmills have been used for hundreds of years. Large and small wind turbines in many countries now generate electricity, for industry, homes and remote dwellings and villages. Wind turbines can be situated on land or off-shore.

The force of flowing water, or the movement of tides and waves, can be used to generate electricity. Again, the sun is a prime influence on natural cycles that create rain and melts ice that makes rivers flow into oceans and lakes.

Many great rivers have been dammed to use this power. Whereas hydropower is clean in that it does not produce harmful emissions, other effects are problematic. For instance, habitats have been harmed and many people have been displaced from their traditional villages by damming rivers for hydropower.

So you can see how “renewable” does not always equal “good”, cannot you?

What is renewable energy as well?

Biological processes
The sun’s energy, stored in plant matter and animal waste, is bioenergy. There are many biofuel sources, including...

  • Agricultural crops, e.g. sugar cane, corn and rapeseed
  • Agricultural residue
  • Paper mill residue
  • Urban wood waste
  • Forest residue
  • Landfill methane, and
  • Animal waste and sewage
These sources of energy are renewable as their replacement is rapid compared to that of fossil fuels.

Geothermal processes
Geothermal energy is not solar but is renewable. It is derived from heat that is stored deep in the Earth's crust. Where this heat rises to the near-surface and heats groundwater, hot water and steam is produced. It can be directly used for domestic heating or for generation of electricity.

I guess now you know what is renewable energy. Click below to view a great Danish on-the-ground practical example of living with solar, wind, biomass and hydrogen energy.

Conscious choices about renewable energy

We accept many things unconsciously, led by technological development. Perhaps it would be better to make conscious choices about what renewable resources we need.

So, before we rush into anything labelled “renewable energy” it is a good first step to ask what fossil fuels are and what is renewable energy.

The power of wind

When you drive your petrol-driven car, switch on your electric light, provided by coal-powered plants, or turn on your natural gas-fired heater you use energy that cannot be replaced easily, and is a major cause of global warming.

Because the use of renewable energy exploits existing, natural processes that do not involve combustion, such uses do not generally contribute greatly, if at all, to global warming and pollution.

When thinking what is renewable energy, people do not always realize that...

Almost all renewable energy sources are really solar in origin.

Rain, wind, the movement of waves, growth of plants (biomass) are all significantly derived from processes started by the sun, many millions of years ago.

We live on a planet with all kinds of limits in an ultimately finite solar system. That is why, in theory only, there is no such thing as a straightforward division between “renewable” and “non-renewable” energy sources. They are renewable or non-renewable only as seen from human perspectives of limited human life-spans and needs.

Coal, gas and oil took millions of years to form from decomposed plant matter, plants that first had directly used sunlight to grow.

It’s an outside chance that this could happen again if forests became once more abundant on planet Earth and we could wait long enough. This possibility makes these fossil fuels “renewable” — in theory.

Of course most of us could not wait that long before filling up our cars with cheap fuel again.

And then there is the small matter of global warming caused by the burning of fossil fuels, not to mention pollution caused by the industries that are powered by those sources.

The sun’s clean and free energy is available every day. And the sun is going to continue to hang up there for quite a while yet, just as it has been doing for more than four billion years already. You want more info on renewable energy? Energy Planet is another good place to go. But meanwhile...

Critical thinking

Doing something about those problems is not just a matter of using any or all renewable resources and their technologies.

The example of hydropower shows that clean energy must also be environmentally and socially ‘clean’ — and we should think critically about any use of energy. Fossil fuel or renewable.

Again, how you and I relate to each other and to our environments is perhaps more important than technological answers to global warming.

Both a change in thinking about our place in the world and appropriate use of technology are needed.

Did that quench your thirst for knowledge on what is renewable energy — or did I just whet your appetite?

If you agree with me that living well with global warming starts with personal thought and action, then you will be practically inspired by this site on The Law Of Attraction. Check it out!

Read more: What is renewable energy and what are the advantages.