Sustainable Environmental Engineering

8Efficiency of Renewable Energy

The solar energy harnessed and used measures human civilization.

OBJECTIVES

• To show that coal‐powered plants are inefficient and cause smog
• To demonstrate why renewable energy such as solar, biomass, and wind should be used to power the EEIS
• To calculate entropy, enthalpy, and exergy of organic pollutants in wastewater
• To present energy auditing procedure of WWTP in terms of unit energy consumption
• To estimate solar panels required in designing zero energy residential house
• To quantify energy saving by optimizing pump operation efficiency

8.1 Principle 5

The efficiency of renewable energy such as biomass, solar, and wind should be maximized for all the EEIS. In gauging a civilization, mankind is at its infancy because only 0.75% of solar energy is currently harnessed for human activities. If the efficiency of solar cell were to double, the amount of renewable energy harvested could increase significantly. For example, if 2% of solar energy that reached the Earth could be efficiently utilized, human civilization could reach to the next level. If 2% of energy in the Milky Way galaxy reached the Earth and were harnessed by humans, mankind could colonize most nearby planets. However, it is estimated that about 100 years is needed to harvest 2% of the solar power.

To reduce operation cost of WWTP, the best way is to generate renewable energy such as electricity and heat while increasing energy efficiency of the WWTP. Therefore, energy efficiency ...