A logic programming solution to assess the ecological footprint of your ICT system

This prototype implements a simplified version of the model by Drouant et al. (2014) to estimate energy consumption and carbon emission of ICT systems. It is entirely written in the declarative logic programming language Prolog, which makes it very readable and concise (the core of the prototype is only 42 single lines of code).

Model

We declare ICT systems (see the data/lan.pl file as an example) via facts like:

% system(Id, EquipmentIds, ReplacementEquipmentIds).
system(system1, [switch1, link1, link2], [switch1bis, link2bis]).

listing the identifiers of the main equipment and of replacement equipment used throughout the system lifecycle.

Each piece of equipment is specified via facts like:

% equipment(Id, TypeAndParams, IsReusable?, RecyclabilityPercentage, ProductionEnergyKWh, DismantlementEnergyKWh).
equipment(switch1, (switch, 2, [0.1, 0.1], 0.050, 0.015, 0.006), no, 0.7, 750, 400).
equipment(link1, link, yes, 0.9, 1, 1).

and its power profile via predicates like

% powerProfile(TypeAndParams, Power).
powerProfile((switch, TotalPorts, ActivePortLoads, IdlePower, ActivePortPower, IdlePortPower), P) :-
    switchPowerIncrement(D), powerForActivePorts(ActivePortLoads, D, PowerIncrement),
    length(ActivePortLoads, ActivePorts), IdlePorts is TotalPorts - ActivePorts,     
    P is IdlePower + PowerIncrement * ActivePortPower + IdlePorts * IdlePortPower.

powerForActivePorts([P|Ps], D, R) :-
    powerForActivePorts(Ps, D, TmpR),
    RP is min(1,D*P), R is TmpR + RP.
powerForActivePorts([], _, 0).

that give a type and the associated parameters of a piece of equipment to compute the absorbed Power according to some predefined model (the above is taken from Reviriego et al. (2012)).

Last, the model enables specifying the lifecycle duration, the average carbon intensity associated to the design and production, usage, and end-of-life steps and the energetic cost of energy transport as in:

lifecycle(3). % lifecycle(Years).

carbonIntensity(i, 0.389). % carbonIntensity(i/u/f, kgCO2/kWh).
carbonIntensity(u, 0.389). 
carbonIntensity(f, 0.389). 

transport(_, 0.95). % transport(i/u/f, T) 

Instructions

To run the prototype and assess the ecological footprint of your ICT systems:

1. Clone this repository
2. Download and install SWI-Prolog
3. Open a terminal and issue the command swipl main.pl from the root directory of the cloned project
4. Query the Prolog engine by issueing queries like:

?- systemAssessment(system1).

The result on the LAN example will look like:

Architecture: system1
Recyclability: 76.7%
Energy consumption: 4406.4 kWh
         Ei = 1503.0
         Eu = 2102.4
         Ef = 801.0
Carbon emissions: 1804.3 kgCO2-eq
         Ci = 615.4
         Cu = 860.9
         Cf = 328.0