Energy resources

Please get in touch with your teacher or tutor in case you have a question related to this lesson

Slide 1

In this presentation we’re going to talk some more about renewable and non-renewable energy resources, how we use them and how we can conserve them.

Slide 2

We’ll begin by looking at how we classify our resources into renewable and non-renewable resources, and talking about some examples of each. Then we’ll do a comparison of renewable and non-renewable resources, looking at the advantages and disadvantages of each. Finally, we’ll talk about the timescales for replacing resources.

Slide 3

Let’s look at the types of natural resources we have. Non-renewable resources are natural resources that are used more quickly than they can be replaced. There are two main types of these: the ones that can be recycled, and the ones that can’t. Renewable resources are resources that can be used repeatedly and replaced naturally over a relatively short period of time. There are three main types of these: flow resources like water, fund resources like timber and biological resources like food.

Slide 4

Recyclable, non-renewable resources can be used again and again. However, energy is required to prepare them for reuse. Recyclable resources such as glass and aluminium can be used infinitely many times. Glass bottles and jars can be recycled to form new bottles, new jars and fibreglass.

Slide 5

Glass is essentially made from liquid sand. When you cool the sand, it never quite sets into a solid, but becomes what scientists call an amorphous solid. This is a cross between a liquid and a solid. It is transparent, inexpensive to make and easy to shape. It resists heat relatively well. Anyone who has ever dropped a glass knows that glass is brittle.

In a glass-making plant, sand is mixed with soda ash and limestone and heated in the furnace. The soda reduces the melting point of the sand, saving energy, and the limestone is used to stop the resulting glass dissolving in water. Once the sand is melted, it is either poured into moulds to make bottles and other containers or poured on top of a big vat of molten tin metal to make flat sheets for windows. Other shapes are formed by blowing the glass. Many other types of glass can be formed by adding different chemicals to the mixture. Once formed, glass can be recycled infinitely many times. Glass waste is first separated by chemical composition, and colour. It is then broken down into rubble, contaminants such as paper labels are removed, it is pulverised and then either used as an additive in materials such as fibreglass and concrete or melted down to form new glass containers. Making new glass containers from recycled glass requires less energy than making new glass containers from sand.

Slide 6

However, there are some non-renewable resources that can only be used once. We call these non-recyclable resources. Some examples are coal, mineral oil and natural gas.

Slide 7

Natural gas is an important non-renewable resource. It is produced by the decomposition of plants and animals under the pressure of rocks and takes millions of years to form. It is not readily replenished: once it is used, it will take millions of years to reproduce it. We burn natural gas when we use it, giving off carbon dioxide, water and other products, so it isn’t recyclable.

Slide 8

We’re now going to look at some different categories of renewable resources. The first ones are flow resources. Flow resources are replaced through the actions of nature, regardless of whether they are used by humans. For example, fresh water flows in streams and rivers. Although water is lost to the ocean at the mouths of rivers, it is replaced by rain, or other forms of precipitation.

Slide 9

So, if water is a flow resource, replaced by nature, why do we need to worry about conserving it? Water continuously moves around the planet in different forms. We always have the same amount of water on Earth. However, it is locked up in different forms. Only 2.5% of the water on Earth is fresh, and it is not distributed evenly around the planet. If communities overuse water, or don’t receive rainfall for an extended period, they can temporarily run out of water. However, eventually the community’s water supply will be renewed, just not as quickly as they might like or need it to be. Water is still a renewable resource.

Slide 10

The second class of renewable resources is fund resources. These are resources that can be replaced (or regenerate) within a reasonable amount of time for their continued use. Of course, we have to be careful that we don’t overuse these resources as it is still possible to completely deplete them. Some examples include grazing land for animals and timber. Even though timber is a fund resource, it takes a long time for forests to be replaced. This is why people look to more quickly replaced resources such as bamboo to use in place of timber.

Slide 11

The third class of renewable resources is biological resources. These include many biotic components of ecosystems such as genetic material, organisms or their parts and populations of organisms. These are all considered to be resources so long as they provide some benefit to humanity. Some examples of biological resources are food, medical resources and timber.

Slide 12

Some examples of the biological resources we use in daily life include writing or printer paper, which is made from timber that is grown in forests, dairy products, which are made from the milk produced by cows, and wooden furniture, which is also made from the timber grown in forest.

Slide 13

Let’s now examine some of the properties of renewable and non-renewable resources, their similarities and their differences. Renewable resources can be replenished by natural processes such as reproduction, but non-renewable resources cannot. They are present on the Earth in fixed quantities. Renewable resources are essentially inexhaustible. By contrast, once you’ve used a non-renewable resource, it’s gone. Human activities do not affect renewable resources such as sunlight and wind, but they do affect non-renewable resources such as coal and oil. All biotic resources are renewable. Some abiotic resources are non-renewable.

Slide 14

Non-renewable resources provide larger amounts of energy than renewable resources. We can always gain energy from non-renewable energy resources, but the amount of energy obtained from renewable energy resources may depend on the weather conditions and season. For example, the amount of solar energy available on a rainy day is limited. We have fewer hours of sunlight in winter, so less solar energy is available in winter. Renewable energy sources do not give off any harmful emissions, but non-renewable energy resources produce greenhouse and other harmful gases. Finally, renewable energy resources are freely available. Non-renewable energy resources can only be obtained using expensive mining operations.

Slide 15

Different natural resources have different timescales for regeneration. This is very important to consider when tapping into natural resources. If we over-use natural resources, we may find that the amount of time taken for them to be replenished increases. This is particularly true of live stock and fish. If we over-fish, for example, we are likely to reduce the number of breeding pairs in a population, and this, in turn, will make it take longer for populations to re-establish themselves.

By contrast, there are some natural resources, such as the air we breathe for which our rate of use is far below the rate at which they are replenished. We consider these resources to be free gifts of nature.

Slide 16

Technological advances change the way in which our actions affect the environment. The accumulation of greenhouse gases from burning non-renewable energy sources gives rise to climate change as the effect of Carbon Dioxide accumulating in the atmosphere is irreversible over several decades. Using one natural resource can have effects on other natural resources. For example, damage inflicted on the soil can limit the number of plants that can be grown. Deforestation can cause soil erosion. So, damage to one resource can have negative consequences for other resources.

Slide 17

The consequences of overuse and misuse of natural resources can have disastrous effects for other natural resources. Some examples of this are the green house effect, the depletion of the ozone layer, acid rain causing damage to forests, soil degradation, deforestation leading to soil erosion and loss of natural habitats, and effects on water availability caused through pollution and/or lowering the water table.

Slide 18

Everyone has an important role to play in protecting our environment and conserving our natural resources. Some examples of things that you and your family can do are switching off electrical appliances when they are not needed, avoiding using plastic bags for your shopping, saving water, planting more trees and plants, using eco-friendly products and trying to reduce the amount of paper you use.

Slide 19

In summary, we have discussed the types of renewable and non-renewable resources in this presentation. Non-renewable resources can either be recyclable or non-recyclable. There are three types of renewable resources: flow resources, fund resources and biological resources. The rate at which a resource can be renewed depends on how long it takes for that resource to be regenerated. Finally, we all have an important role to play in the conservation of natural resources.