Energy Types
- Energy sources are classified as either renewable or non-renewable
- A renewable energy resource is one that can be replaced after use by regrowth, reproduction or replacement within a reasonable time frame (usually one human lifespan). Examples include solar, wind, tidal, thermal and hydroelectric
- A non-renewable resource is one that cannot be replaced after its use. Examples include fossil fuels including coal and oil as well as nuclear
Current Fossil Fuel Use
- Today most of the world’s energy is obtained from burning fossil fuels
- Fossil fuels were first used in the form of coal and oil during the industrial revolution for transportation purposes alone.
- Now we are now deeply dependent on fossil fuels for transportation, heating, industrial purposes (refining, extracting, production) and electricity
- This shift to dependence on fossil fuels mainly occurred because they are reliable and cheap sources of energy
- Cost and reliability are 2 of the most important factors that are considered when researching a new energy source
Other Considerations
- availability
- accessibility
- efficiency
- environmental impact
- Technology involved
- current usage
- locally or not-locally available
- Shift in Energy Perspectives
- Recently we have started placing higher importance on the environmental impacts of an energy source
- Initially energy researchers were mainly focused on developing new ways to locate, extract and use fossil fuels
- Now research has shifted to discovering and harnessing new energy sources and adapting old technologies and developing new ones to utilize these new sources.
What is motivating the search for new energy sources?
- There is much debate over “when will the oil run out”
- In reality, societies never completely use up nonrenewable resources or exploit the entire flow of renewable resources.
- In the words of Sheikh Zaki Yamani, a former oil minister of Saudi Arabia, “The Stone Age did not end for lack of stone, and the Oil Age will end long before the world runs out of oil”
- The shift towards a non-fossil fuel dependent energy source has been driven mainly by rising prices and secondly by a growing awareness of the impacts of fossil fuel use on our planet
- Cost is by far the greater motivator
What drives up price?
- Stock and Flow are the two main contributors to the increase in price of fossil fuels
- Stock is the amount of material in a certain deposit or reservoir
- Flow refers to the rate at which new material is added to the stock (inflow) or removed from the stock (outflow). The net flow rate (inflow minus outflow) determines whether the stock grows, shrinks, or remains constant.
- What drives up price continued
- Nonrenewable resources are limited by the amount of stock available.
- Increased demand for fossil fuels along with increasing difficulty in extracting usable fossil fuels has driven up base prices
- Renewable resources are limited by flow. The causes fluctuation in energy prices when they are obtained from these types of sources
Why can’t we switch now?
- The shift away from a fossil fuel dependent energy society is not going to be a fast one
- Changing from one energy resource type to another involves more than simply discovering, harnessing or developing a new technology.
- It also means altering the systems that produce, process, and distribute that energy.
- Commercial energy fuels like coal, natural gas, and uranium are mined, cleaned, processed, refined, and delivered through multi-stage systems that represent billions of dollars in infrastructure
- Energy facilities typically operate for 30 to 50 years, so they cannot change to different resource or technology mixes overnight.
- Retiring them prematurely to replace them with something “better” is very costly even if the new plants are not more expensive than the old ones.
