11 Assignments

11.1 The brief: energy efficiency infographic

Work in your teams to produce an infographic showing how much contribution to reducing emissions can be made by improving energy efficiency of a specific (assigned) conversion device or passive system.

Specifically, each group has an emissions-saving target of 1 MtCO_2e per year (i.e. 1 mega-tonne of carbon dioxide equivalent). This saving is easier to achieve in some cases (where currently lots of energy is used relatively inefficiently, there are bigger potential savings) and harder to achieve in others (where little energy is used, or it is already used very efficiently). You need to work out how widely your specific efficiency improvement would need to be deployed to meet the target, if it can be met at all, or else how close it can get.

The infographic should:

Introduce [graphically] the efficiency improvement your group has been assigned.
Quantify and present visually the answer about how widely deployed the efficiency improvement would need to be to reach the target, and/or to what extent the target can be reached.
Add context: e.g. discuss whether this is a lot or a little, give examples of recent news stories or press releases about new products, comment on how difficult the change would be – this is your chance to be creative!

Please read the general instructions below, which direct you to further specific data and information about your specific assignment.

11.2 General instructions for all groups

To get started:

Look up your specific assignment (e.g. “H2”) in the sections below to find out which specific energy efficiency measure you should consider, and any other information specific to that assignment.
There is a page of information about each conversion device or passive system (one of Chapter 4–Chapter 10), which together with the data on emissions factors (\(\beta\)) in Chapter 3 contains all the data you need. The introduction (Chapter 2) explains the concepts and equations that you need. Read these first.

Then, you need to do some calculations to understand quantitatively how big a difference the specific energy saving measure you are looking at would make. To do this, the following steps are recommended:

Calculate the current emissions \(E\) associated with this use of energy (\(E = F \beta\)). Here, \(\beta\) is the emissions intensity of the type of final energy you are looking at; look up the appropriate value in Chapter 3. \(F\) is the quantity of final energy currently used in the device or system you are considering. This data is included on the page about your specific conversion device or passive system. Take care of any additional instructions given there (e.g. sometimes the available data is for a combination of energy uses, which must be split apart following the information given), and take care of the units of \(F\) and \(\beta\): it is easiest to convert \(F\) to TWh first using the conversion table in Chapter 3.
Calculate how much these current emissions would change (\(\Delta E\)) by improving energy efficiency: use Equation 2.4 or Equation 2.5 as appropriate.

If your answer is that \(\Delta E\) is less than the 1 MtCO2e emissions-saving target, then that’s it, you have the answer: we can’t meet the target by applying energy efficiency to this device or system. On your infographic, show how far we can get (even if less than 1 MtCO_2e). Consider discussing in the “additional context” whether this situation could change in future (e.g. is this form of energy use growing or declining?).

Otherwise, if the emissions saving \(\Delta E\) is more than 1 MtCO2e, then consider different ways to present this information. Why? In some cases, the potential efficiency improvement involves some fairly extreme assumptions; so if you find that a large emissions saving is possible by applying the maximum improvement across the board, it would be useful to show what more modest change would just reach the \(\Delta E = -1\) MtCO_2e target. Two ways to do this are:

Adjust the equation slightly so that instead of upgrading all the devices or systems, you only upgrade a fraction \(k\):

\[ \Delta E = k F \beta \left( \frac{\eta_0}{\eta_1} - 1 \right) \]

Then, you can set \(\Delta E = -1\) MtCO_2e, and solve for \(k\) to find out what fraction of current devices (measured by their energy use) need to be upgraded to reach the target. (This only makes sense if the saving you calculated first, with \(k=1\), is already greater than the target).

This is based on Equation 2.4, but you can do something very similar with Equation 2.5 for passive systems.
Alternatively, you could keep \(k=1\) and upgrade all devices/systems, but only by a little bit: again, set \(\Delta E = -1\) MtCO_2e, and solve for the ratio \(\eta_0/\eta_1\) or \(e_1/e_0\) for conversion devices and passive systems respectively. This answers the question: what is the minimum efficiency improvement needed to reach the target, if applied to all devices/systems.

You can get feedback on your calculations using the tool linked in Appendix B.

11.3 Details of specific assignments/groups

Because each conversion device can operate using different forms of final energy, each of which is more of less polluting (i.e. has a different emissions intensity factor \(\beta\)) and is more or less common (i.e. consume different quantities of final energy \(F\)), a different group will do the calculations for each specific combination of device/system and final energy form. These specific combinations are listed below.

11.3.1 Conversion devices

These assignments look at improvements to conversion devices:

Assignment		Comment	Details
A1	Industrial gas turbines burning gas	Does not include jet engines or power stations	Chapter 4
A2	Industrial gas turbines burning liquid fuel	Does not include jet engines or power stations. Assume the fuel is the same as aviation fuel.	Chapter 4
B1	Jet engines burning aviation fuel	Excludes improvements to the plane (passive system) e.g. to reduce drag	Chapter 5
C1	Boilers in buildings burning coal		Chapter 6
C2	Boilers in buildings burning gas		Chapter 6
C3	Boilers in buildings burning oil (liquid fuel)		Chapter 6
C4	Boilers in buildings burning biomass		Chapter 6
D1	Industrial boilers burning coal		Chapter 6
D2	Industrial boilers burning gas		Chapter 6
D3	Industrial boilers burning oil (liquid fuel)		Chapter 6
D4	Industrial boilers burning biomass		Chapter 6

11.3.2 Passive systems

These assignments look at improvements to passive systems:

Assignment		Comment	Details
E1	Cars using electricity		Chapter 7
E2	Cars using liquid fuel in diesel engines (i.e. diesel)		Chapter 7
E3	Cars using liquid fuel in spark ignition engines (i.e. petrol)		Chapter 7
F1	Trucks using liquid fuel in diesel engines (i.e. diesel)	Almost all trucks currently run on diesel, only one group here.	Chapter 8
G1	Planes using liquid fuel in jet engines	Almost all planes currently burn aviation fuel, only one group here.	Chapter 9
H1	Passenger trains using electricity		Chapter 10
H2	Passenger trains using diesel		Chapter 10
H3	Freight trains using electricity		Chapter 10
H4	Freight trains using diesel		Chapter 10