L1 - Introduction

Question 1

Sustainable development

Answer 1

Development that meets the needs of the present without comprimising the ability of future generations to meet their needs

Question 2

Distributed energy systems

Answer 2

Make use of resources as efficiently as possible in a chemical processing site.

Question 3

Chemical processing site

Answer 3

Uses a number of different devices to convert fuel energy into other forms of energy. Processing sites are based on steam (high temperature heat)

Consist of:

• Heat providers: boilers, furnaces, gas turbine exhausts
• Heat users (which use steam): site processing, dearators, steam turbines
• Power providers: steam turbines, gas turbines, electric motors (electricity - either provided by steam turbines or imported)
• Power users - fans, compressors, pumps
• Distributed system: steam mains

Low grade heat (eg temps below 120) are rarely used so not an issue. But can cause inefficiencies

Question 4

Types of renewable energies

Answer 4

• Wind
• Biomass
• Solar - provides electricity and heat
• Geothermal
• Hydroelectric - only electricity
• Wave power
• Nuclear (doesn’t produce any environmental problems such as CO2 or particulate matter). Does cause a lot of end of life waste.
• Waste (MSW, industrial, bio, animal)

Question 5

Energy carriers

Answer 5

A form of carrying energy from primary energy sources to energy converters.

eg. electricity, steam

Question 6

Energy converters

Answer 6

Convert energy into other forms of energy in terms of heat, power and cooling etc.

Comprised of steam turbines, gas turbines, solar pannels etc

Question 7

Why do we need distributed and renewable energy?

Answer 7

• Price of energy constantly increasing
• Higher demand
• Higher consumption
• During energy use there is a lot of lost energy (inefficiencies) which is what distributed systems are trying to make use of

Question 8

Largest factor supporting implementation of sustainable energy

Answer 8

• Climate change.

- Influence of human population has large effect on climate change

Question 9

Radiation balance considerations

Answer 9

• Amount of incoming solar radiation based on watts/m
• Amount that is reflected and absorbed by the earth’s surface
• Amount of surface radiation and how much of that surface radiation is lost to the outer regions of the earths atmosphere and space

This radiation is affected significantly by the nature of the earth’s atmosphere (specifically GHG)

Question 10

Radiation balance calculation

Answer 10

A black body: absorbs all radiation falling on it. Emits radiation as a function of its temperature

Stefan-boltzmann law:

I(T) = oT^4

Radiation balance:

oT^4 (D^2/4d^2)

Calculated based on the distance from the sun, the diameter of the sun and temperature of the sun’s surface.

Question 11

Icoming radiation

Answer 11

Has to take into account total area of the earth.
Area receiving sunline is piR^2, total area of the earth is 4piR^2.
Thus the average radiated flux received by the earth’s surface is S (1370)/4.

Question 12

Climate change influencers

Answer 12

• Solar radiation and radiation balances
  (has overriding effect on climate throughout the globe)

Effects climate in local regions:

• Amount of sea ice (more = more radiation reflected back to atmosphere)
• Water and evaporation of water
• Amount of biosphere
• Nature of landmass
• Volcanic activity.

Question 13

Effect of change in climate

Answer 13

• Precipitation changes

- Ice cover changes (decreased due to increase in global temp)

Question 14

Main findings of the IPCC

Answer 14

• Earth is warming (human activities increase greenhouse gases)
• Strong evidence of human influence on climate