1.4 Model description
1.4.1 End-uses demand sub-model
The “End-uses demand” sub-model computes the electricity and heat demand for the households, industry and services sectors. The inputs for this model fall into the General (population, economic growth and eco-friendly behaviour) and Efficiency (building, industry, appliances and lighting specific demands) categories.
The model is based on data from a report commissioned by the Swiss government [12]. The report presents three energy scenarios for Switzerland: “Business as Usual” (BAU), “Political Measures of the Federal Council” (PMF) and “New Energy Policies” (NEP). These three scenarios represent the evolution of the Swiss energy sector from 2010 to 2050, sharing common assumptions about population and economic growth. They consider different evolutions for efficiency in each sector, “New Energy Policies” being the scenario with the highest effort in terms of specific energy demand reduction, and “Business as Usual” presenting the most conservative hypotheses. The values of specific energy demand assumed by these two scenarios have been used to respectively define the minimum and maximum limits for the “Efficiency” inputs.
Table 1.3 contains the six types of energy demands (k) considered in the model, together with the sector they belong to ( j ). The “Specific Demand” column shows which specific demand from the
Table 1.2 – Model nomenclature. In this particular case the italic format does not necessarily indicate that the entry is a parameter, since some of the entries in the table are used as both parameter and variable in the model.
Variable/Paramater Description
Dj ,k Annual energy demand of type k in sector j
SpDk Specific energy demand for energy demand type k
GDP Gross Domestic Product
Pop Population
S f Inhabited surface percapita
Space Heat i ngi Heat demand for space heating for the three sectors in month i
HotW at eri Heat demand for hot water for the three sectors in month i
P r ocessHeati Process heat demand for the industry sector in month i
Eng i nesi Electricity demand for engines for the industry sector in month i
Li g ht i ngi Electricity demand for lighting for the three sectors in month i
Ot her El eci Electricity demand for other uses for the three sectors in month i
BusC oachDemand Annual passenger transport demand to be covered by bus & coach pt Busi Annual passanger transport demand for bus&coach with power train i
L Heating load
P Installed power
Gr oupj Percentage of total installed power for the technology group j
Techj, k Percentage of total installed power for the technology k of group j
TechF uelj ,k,l
Percentage of total installed power for the combination of group j , technology k and energy vector l
Heat Ii ,k,l
Heat supplied by technology k with energy vector l during month i in industry sector
HeatCi ,m Heat supplied by combination of technology m during month i
Power Cm Installed power of the combination of technology m
P r i cei Price for fossil fuel in year i
C Economic cost in CHF
i Interest rate
n Lifetime in years
Table 1.3 – Specific demand for the interpolation of each demand and sector to whom each demand belongs.
Demand type (k) Specific Demand (SpDink) Sector ( j )
Space Heating (Sh) Building: specific demand Households, Industry and Services Process Heat (H w ) Industry: specific demand Industry
Engines (En) Industry: specific demand Industry
Lighting (Li ) Lighting: specific demand Households, Industry and Services Other Electricity (Oe) Appliances: specific demand Households, Industry and Services
input (SpDink) is used in Eq. (1.1) for calculating each Dprj,k.
Dprj,k= DN E Pj ,k + SpD in k − SpD N E P k SpDB AUk − SpDkN E P · (D B AU j ,k − D N E P j ,k ) ∀j ∈ {H, I,S},∀k = Hw,k ∈ {Sh, Hw,Ph,En,Li,Oe} (1.1) Eq. (1.1) is used to do a linear regression between the energy demand of the two extreme scenarios (DB AUj ,k and DN E Pj ,k ) considering the specific demand based on the input (SpDink). Thus the efficiency improvements in each sector are adapted to the input. For the household sector, DH ,kpr is then adapted to the population in the input (Popin) as in Eq. (1.3). For the industry (DprI ,k) and services (DprS,k) sectors, the demand is adapted based on the Gross Domestic Product (GDPin) as in Eq. (1.2).
Dj,k= Dprj,k· GDPin GDPpr ∀j ∈ {I,S}, ∀k ∈ {Sh,...,Oe} (1.2) DH,k= DprH,k· Popin Poppr ∀k = Sh (1.3)
The space heating demand for the households sector (DH,Sh) is calculated as in Eq. (1.4). It depends on the inhabited surface per capita (Sfin), which is defined by the eco-friendly behaviour value, as shown in table 1.4. DH,Sh= DprH,Sh· Popin Poppr · Sfin S fpr (1.4)
The outputs of the demand sub-model are the monthly heat and electricity demand (HeatDemandi and ElecDemandi), which are two vectors containing respectively the heating and electricity de- mand divided by type, as in Eq. (1.5) and (1.6). The monthly values for Space Heat i ng are calculated using the Heating Degree Days (HDD) for Switzerland. The remaining monthly heating and electric-
Table 1.4 – Inhabited surface per capita values depending on the “Eco-friendly behaviour” value.
Eco-friendly behaviour Inhabited surface per capita (S f )
2011 2035 2050 1 57.7 [12] 67.0 [12] 69.9 [12] 2 57.7 57.7 3 46.2 46.2
ity demand values are computed taking into account the number of days of each month.
HeatDemandi= [SpaceHeatingi, HotWateri, ProcessHeati] (1.5)
ElecDemandi= [Enginesi, Lightingi, OtherEleci] (1.6)