What Exactly is Renewable Energy?
Renewable energy is energy that’s generated from a continuous natural resource, such as sunlight, the wind or tidal flows. In other words, unlike fossil fuels and nuclear energy, renewable energy is energy that never runs out. Currently, about 13% of the world’s energy consumption comes from renewable energy, of which 10% comes from biomass and 2% comes from hydroelectricity. The remaining 1% comes from a variety of other renewable sources including, wind energy, solar energy and tidal energy.
Why Use Renewable Energy?
The big advantage of renewable energy is that, in the majority, no greenhouses gases are emitted from its use. This means, if we use renewable devices to supply our energy demand, we could take a huge step towards stopping all human-made greenhouse emissions. When you add to this that renewable devices can provide an unlimited supply of energy, you have to wonder, why don’t we use them to a greater extent already?
Why Aren’t We Using Renewable Energy?
Currently, renewable devices have a reputation for being expensive and unreliable, as well as taking up vast amounts of space. Added to this, many people believe renewable devices cannot capture enough energy to meet our current demand. While these criticisms may have been valid some thirty years ago, things have changed dramatically. Today, not only do renewable devices have the potential to meet all our energy demand, but they also have the potential to do it more cost-effectively than fossil fuels. Not every renewable energy source can deliver on this promise though, and to separate the good from the bad, and to identify the genuine contenders from what are quite simply token gestures, we have created a set of concise data sheets that explain the advantages, disadvantages and costs of all the key large-scale renewable devices available to us. Using the United States of America as an example, we also show how much land would be required to meet the energy demand of an entire country, as well as where the devices are best located around the globe. We then pick the best of the bunch and really put them to the test, by comparing them with fossil fuels. Before we get started though, there a few terms that we need to understand. Let’s find out what they are.
Title image taken by NoraDoa and reproduced under license from Adobe Stock.
All figures presented in this section are estimates based on best available data, assume optimum locations, and, wherever possible, are based on comparable studies. That said, many of the studies assume different economic conditions, climatic conditions, time frames and locations. Furthermore, the technologies discussed in this section are in a constant state of development. As a result, the figures presented within this section provide a rough guide only and should not be viewed as a definitive performance level.
For the total world energy demand, a figure of 104.4 million GWh has been used. The figure is based on 2012 data and sourced from International Energy Agency – 'World Balances for 2012' – www.iea.org.
All UK to USA currency conversions have been set at $1.656 USD for each £1 GBP. The figure is based on the conversion rate as of the 1st January 2014 and sourced from XE – 'XECurrency Table: USD - U.S. Dollar' – www.xe.com.