Energy Within Environmental Constraints

 

By today environmental pollution has become the worst-case all over the world. Environmental Pollution is any discharge of material or energy into an environment that causes acute (short-term) or chronic (long-term) detriment to the Earth's ecological balance or that lowers the quality of life. As mentioned above energy is one of the major reasons for environmental pollution. Today the world uses various types of methods to generate energy. Generating energy without any environmental constraints is very harmful to the world environment. For example, ceasing the industrial processes due to the COVID-19 outbreak leads to a climate. Without considering environmental polluting, generating energy will lead to climate change and will harm the entire ecological system.  In this article, we discuss many aspects of energy within environmental constraints.

ENERGY OVERVIEW

Energy is normally defined as the ability to produce change or do work. Energy can simply be divided into two categories, renewable which uses energy sources that are continually replenished by nature. Nonrenewable which has a fixed quantity in Earth’s crust. These two types of energy sources are used to generate energy and these energy use for different kinds of uses. Energy as a commodity can also be divided according to its efficiency and efficacy. Energy efficiency is output energy divided by input energy to give you an idea of how much value for your investment you are getting. Energy efficacy is defined as the ability to produce the desired result. Efficacy is when you put energy in and get something else out. 

In industrial cases to figure out the cost of energy, the standard unit is required. If there are two or more alternative energy sources for some industrial purposes, using standard units helps to choose either it is cost-effective or not. This unit is created using heating values which tell how much energy release when fuel is combusted

Sankey diagram

Not only cost is important, how energy flow throughout the system which is considered is also important. To represent the flow of energy a diagram called the Sankey diagram is used. Sankey diagrams are a specific type of flow diagram, in which the width of the arrows is shown proportionally to the flow quantity. The illustration shows a Sankey diagram that represents all the primary energy flows into the system. Figure 3 shows how energy flowed through in the US economy in 2019.

  

Land use

Extracting and transforming energy requires land. Wind farms, coal mines, biofuel plantations, etc. Power density is one of the simple metrics to evaluate and compare the diverse land use footprints of energy technologies, the rate at which energy is extracted per unit of land. One common measure of power density is watts of primary energy per square meter of the land surface. Finally, note that the power density of renewable sources is generally much less than the power density of fossil fuels or nuclear power. This means that if humanity moves from fossil fuels to renewables to protect the climate, there will be an increase in the energy systems' land footprint. We need to think about the environmental and social impacts of disturbing more land. In here disturbing means because of land is never used up. Rather, it is disturbed or impacted by various human activities. This is what we mean when we say land use. Land is the ultimate finite resource. Land use plays a central role in mediating many of the social and environmental impacts of energy extraction. And if other human activities like agriculture or urbanization impact water, endangered species, and societies are all linked to land use. It is very important to think about what fraction of land would be required to run a future energy system using various energy technologies.

3      Written by 

S.Heshanka

Department of Civil and Environmental Technology

Faculty of Technology, University of Sri Jayewardenepura