CHAPTER 18: REDUCING THE IMPACTS OF ENERGY USE (Rehabilitating Mine Sites…
CHAPTER 18: REDUCING THE IMPACTS OF ENERGY USE
We can reduce the impacts of our energy use in many ways, for e.g through modifying our behavior to reduce energy use, by developing more energy efficiency technologies and by managing processes of energy extraction and use to minimise our impact on the environment.
Increasing Energy Efficiency
Achieved by carrying out a particular operation (such as heating a house to a comfortable temperature) by using less energy in the process (such as by using a more efficient fuel or reducing heat loss by installing insulation, double glazing or draught excluders.
The amount of high-grade or usable energy available is reduced with each conversion step.
Conversion of the energy
In contrast, using
natural gas involves only two energy conversions.
Thus, natural gas should be more energy efficient for space heating than electricity produced from coal (although electric heat pumps can improve the efficiency of electricity by a factor of two or three):
Natural gas extraction --> distribution --> space heating (heat energy dissipated)
Conversion of the energy stored in coal to home-heating.
Energy is lost or converted into waste heat at each of the five steps:
Coal extraction --> steam --> kinetic energy of turbine (motion) --> electricity --> transmission --> space heating (heat energy dissipated)
Wood for home-heating: Wood combustion can be quite energy efficient if a high efficiency, slow combustion heater is used and the wood was collected nearby. The efficiency of this process drops if thee wood has to be transported large distances.
Managing waste products
Some of the most detrimental effects of fossil fuel use on environment and society are the waste products, particularly CO2, created at various stages from extraction through to use.
Carbon capture and sequestrian is an emerging technology in which carbon dioxide produced through the burning of coal is captured at the power station and stored underground - thus removing this waste product before it enters the atmosphere.
The transportation industry has made significant advances in reducing waste products
Including particulate matter and greenhouse gases through inventing cleaner combustion motors and technologies. These include fuel-efficient vehicles; cleaner fields that produce fewer emissions and electric cars that produce no exhaust emissions (but the source of electricity must be considered)
Rehabilitating Mine Sites
Process of returning lang to its former state after mining for coal has resulted in damage. (For E.g Open-cut mines can span vast areas, destroying ecosystems and habitats and displacing species.
Three key modes of rehabilitation: mechanical, chemical and biological.
All of these concepts are vital in ensuring our energy consumption is sustainable - ensuring that we get to enjoy both the benefits of energy use and the natural environment, and that future generations and communities around the world also have the opportunity to share in these resources for years to come. Achieving a balance between the positive and negative aspects of energy extraction and consumption is vital for the long-term health of all the species found on Earth.
Involves physically moving components of a site to, from or within the site. This could be removing contaminated soils through excavation or replacing soil lost to the mining process.
Involves ensuring the chemical properties of the mine site are returned to normal and safe levels equivalent to that of the pre-mine site. This may be as simple as applying fertiliser to newly deposited top soil or it may require elimination of harmful chemicals that were deposited due to the mining process.
Often involves replanting and reintroducing life to the mine site. It may also involve the use of biological processes (e.g bacteria) to help rehabilitate and stabilise a mine site.
Use of Science to Reduce the Impacts of Energy Use
strategies for increasing the efficiency of energy conversions, and for the management of waste products in
mechanical, chemical and biological processes involved in rehabilitating sites where energy sources have been
sustainability principles relevant to energy consumption and extraction including conservation of ecosystems
and species that are displaced or impacted by human efforts to acquire energy, and intra- and inter-generational
equity including accessibility to energy.