Sunday, March 1, 2009


We hear about renewable energy a lot, but what is it, exactly? And how come we use so little of it?

These days, we often hear about renewable energy. Actually, I take that back; in the Caribbean we hear less about it now than we did six months ago when oil prices were approaching $150 a barrel – but that’s a discussion for another time. What I mean is: renewable energy is very topical right now. It seems to be the Next Big Thing, the oncoming wave of a brave, new world that is green, clean and eminently desirable to us all.

So what exactly is it? Renewable energy is energy from sources (like sunlight, wind, flowing rivers, etc.) that are replenished by natural processes. This is in contrast to non-renewable energy, as in fuels such as gasoline, diesel and kerosene, which are derived from crude oil, which cannot be replenished once it is extracted and used.

The available renewable energy types are (in alphabetical order):
  • Bio-energy (energy of plant and animal origin)

  • Geothermal energy (energy derived from the earth’s heat)

  • Hydro energy (energy from river flow)

  • Ocean energy (energy from marine sources)

  • Solar energy (energy from sunshine)

  • Wind energy (energy from wind)

In the Caribbean, we use bio-energy, geothermal, hydro, solar and wind in varying degrees but overall, our use of renewable energy is very small in relation to our total energy consumption. For example, most of our energy use is in the form of electricity and in the English-speaking Caribbean (total population 6.3 million) only about 3% of electricity is generated from renewable sources; the other 97% being generated by petroleum products. Compare this to the opposite situation in Costa Rica (population 4.2 million), which generates 98% of its electricity from renewables, or Iceland (population 300,000) which generates 100% of its electricity from renewables!

There are several advantages to using renewable energy. The first is that in general, renewable energy resources are so vast as to be inexhaustible. For example: the amount of solar energy absorbed by the earth’s atmosphere, oceans and land mass in one hour is more than the total energy consumed by all of mankind in one year! The global wind energy resource is far less plentiful, but is still 50 times more than existing global consumption.

The other major advantage is that most forms of renewable energy are considered to be free. If you install a wind turbine, you don’t have to pay for the wind that turns it to produce electricity. A diesel-powered generator on the other hand requires a constant supply of fuel that must be purchased with hard cash.

In addition, renewables are considered to be ‘green’ or at least carbon-neutral, as their use does not result in increasing greenhouse gas emissions, which have been implicated in causing global warming which leads to climate change.

This last point has become increasingly important over the past two decades, as the world has become aware of the looming climate change crisis. Because fossil fuels (oil, gas and coal) are net emitters of carbon dioxide and other greenhouse gases, whereas renewables are not, renewable energy is truly sustainable – it is essentially endless, cheap and using it won’t harm the planet.

Clearly, this is where our energy future lies, so the question is: if this stuff is so great, why aren’t we all like Costa Rica or Iceland? Well, unfortunately, it’s not as simple as that. Although the world is slowly moving towards using more renewables for our energy supply, there are several barriers to the widespread adoption of RE. In general, these are cost, policy, technical and educational barriers, which we will discuss in later posts. But first, here’s an interesting question: Will the world ever return to 100% RE use?

I say return because renewable energy was once the only energy used by mankind! Up to the early 18th century, fuel wood, water-wheels and windmills were the world’s sources of energy. But by the middle of that century, widespread fuel wood scarcities had sparked increasing interest in abundant coal. By the end of the 19th century natural gas and oil had come into their own and over the next 100 years, the fossil fuels had almost entirely displaced renewables. Today, renewable energy accounts for only about 7% of total global energy consumption.

The supreme irony here is this: increased global dependence on fossil fuels, which we now seek to reverse, occurred for sound technical, economic and environmental reasons. Increasing population pressure and use of wood for fuel in the 16th, 17th and 18th centuries had led to massive depletion of forests in England, Europe and other countries. Coal, and later gas and oil, coupled with the development of the technology to use them efficiently, presented better and cheaper alternatives – and thereby averted a global environmental crisis. Now, we're in the same position but with the roles reversed, as we recognise that our rapidly increasing use of fossil fuels has brought us to the verge of another environmental catastrophe – and renewables are needed to save the day!

One moral of this story is that not all renewables are created equal: some are indeed better than others and the viability of renewables also depends to a large extent on where you are. So next we will look at the various types of renewables and their applicability to the Caribbean. We’ll start with solar energy, since it’s currently at the top of our poll on renewable energy types.