Economic parameters for the design of energy systems

Economic performance is a key criterion when planning and optimizing energy systems. The net present value is commonly used to compare different system configurations. Its calculation requires data on investment costs, maintenance costs and the lifetime of the components. All values are intended as reference points and are based on our own research and experience. Despite careful data preparation, no guarantee can be given as to their accuracy or completeness.

Investment costs of energy system technologies

The table below lists specific investment costs for different technologies. Investment costs cannot be stated in general terms, as they depend strongly on plant size and other factors. The values are therefore rough reference points only and can be adjusted freely in nPro.

Specific investment costs (linear default values)

Table 1: Specific investment costs (linear default values)

Technology	Investment
Generation and conversion
CHP unit	1,300 €/kW_el
Boiler	150 €/kW_th
Electric heater	80 €/kW_th
Fuel cell	3,000 €/kW_el
Electrolyzer	2,500 €/kW_el
Heat pumps
Air-source heat pump	1,100 €/kW_th
Combi heat pump	900 €/kW_th
Booster heat pump	900 €/kW_th
Cooling
Absorption chiller	750 €/kW_th
Compression chiller	900 €/kW_th
Renewable generation
Photovoltaics	1,100 €/kW_p
PVT collectors	1,300 €/kW_p
Solar thermal	400 €/m²
Wind power	1,000 €/kW_el
Hydropower	1,000 €/kW_el
Heat sources
Geothermal (boreholes)	1,000 €/kW_th
Heat source (heat exchanger)	100 €/kW_th
Storage
Heat storage	500 €/m³
Cold storage	500 €/m³
Combi storage	500 €/m³
Battery	600 €/kWh
Hydrogen storage	750 €/kWh

Non-linear investment costs (cost curves)

A single value per kilowatt only partly reflects reality: as plant size grows, specific investment costs fall considerably due to economies of scale. In nPro, investment costs can therefore be defined either linearly or as a non-linear cost function. The cost function is described by breakpoints with piecewise linear interpolation in between.

The following tables show the default values used in nPro for energy hub technologies. They are reference points from our own research and do not replace a cost estimate based on actual quotations. All breakpoints can be edited in the tool.

Generation and conversion

CHP unit

Table 2: CHP unit: Cost function breakpoints

Capacity in kW_el	Specific investment in €/kW_el
6	8,500
13	6,000
30	3,600
110	1,950
500	1,100
1,000	820
5,200	580

Boiler

Table 3: Boiler: Cost function breakpoints

Capacity in kW_th	Specific investment in €/kW_th
10	1,000
20	575
30	430
60	285
200	180
600	140

Electric heater

Table 4: Electric heater: Cost function breakpoints

Capacity in kW_th	Specific investment in €/kW_th
6	300
20	200
100	150
500	120
2,000	100
10,000	80
50,000	65

Fuel cell

Table 5: Fuel cell: Cost function breakpoints

Capacity in kW_el	Specific investment in €/kW_el
1	25,000
5	11,000
20	6,500
100	4,400
400	3,300
2,000	2,600
10,000	2,200

Electrolyzer

Table 6: Electrolyzer: Cost function breakpoints

Capacity in kW_el	Specific investment in €/kW_el
50	5,000
200	3,500
1,000	2,600
10,000	1,900

Heat pumps

Air-source heat pump

Table 7: Air-source heat pump: Cost function breakpoints

Capacity in kW_th	Specific investment in €/kW_th
10	1,900
30	1,450
100	1,250
500	1,120
2,000	1,020
10,000	940

Combi heat pump

Table 8: Combi heat pump: Cost function breakpoints

Capacity in kW_th	Specific investment in €/kW_th
10	2,300
30	1,630
100	1,330
500	1,170
2,000	1,060
10,000	970

Booster heat pump

Table 9: Booster heat pump: Cost function breakpoints

Capacity in kW_th	Specific investment in €/kW_th
10	1,600
30	1,150
100	950
500	850
2,000	780
10,000	720

Water-source heat pump

Table 10: Water-source heat pump: Cost function breakpoints

Capacity in kW_th	Specific investment in €/kW_th
10	1,600
30	1,150
100	950
500	850
2,000	780
10,000	720

Cooling

Absorption chiller

Table 11: Absorption chiller: Cost function breakpoints

Capacity in kW_th	Specific investment in €/kW_th
50	1,600
200	900
1,000	550
5,000	400
20,000	330

Compression chiller

Table 12: Compression chiller: Cost function breakpoints

Capacity in kW_th	Specific investment in €/kW_th
20	700
50	500
200	360
1,000	270
5,000	220

Water-cooled chiller

Table 13: Water-cooled chiller: Cost function breakpoints

Capacity in kW_th	Specific investment in €/kW_th
10	600
30	400
100	300
500	220
2,000	170
10,000	135

Renewable generation

Photovoltaics

Table 14: Photovoltaics: Cost function breakpoints

Capacity in kW_p	Specific investment in €/kW_p
5	2,000
10	1,550
30	1,150
100	900
500	720
1,000	660
5,000	610
20,000	520

PVT collectors

Table 15: PVT collectors: Cost function breakpoints

Capacity in kW_p	Specific investment in €/kW_p
9	4,000
18	3,560
45	3,060
90	2,670
180	2,390
450	2,170
900	1,970
1,800	1,810

Solar thermal

Table 16: Solar thermal: Cost function breakpoints

Capacity in m²	Specific investment in €/m²
5	1,300
10	1,000
30	700
100	500
500	380
2,000	300
10,000	230

Wind power

Table 17: Wind power: Cost function breakpoints

Capacity in kW_el	Specific investment in €/kW_el
5	6,000
30	3,800
100	2,800
500	2,300
3,000	1,900
6,000	1,800
30,000	1,700

Hydropower

Table 18: Hydropower: Cost function breakpoints

Capacity in kW_el	Specific investment in €/kW_el
5	12,000
30	8,000
100	6,200
500	4,600
2,000	3,600
10,000	2,800

Heat sources

Geothermal (boreholes)

Table 19: Geothermal (boreholes): Cost function breakpoints

Capacity in kW_th	Specific investment in €/kW_th
5	2,200
15	1,700
50	1,450
200	1,300
1,000	1,200
5,000	1,120
20,000	1,080

Heat source (heat exchanger)

Table 20: Heat source (heat exchanger): Cost function breakpoints

Capacity in kW_th	Specific investment in €/kW_th
50	900
200	550
1,000	350
5,000	220
20,000	150
100,000	110

Storage

Heat storage

Table 21: Heat storage: Cost function breakpoints

Capacity in m³	Specific investment in €/m³
0.2	7,000
0.5	4,000
1	2,800
5	1,500
20	950
100	600
1,000	300
10,000	120
100,000	40

Cold storage

Table 22: Cold storage: Cost function breakpoints

Capacity in m³	Specific investment in €/m³
1	3,100
5	1,680
20	1,060
100	670
1,000	340
10,000	180

Combi storage

Table 23: Combi storage: Cost function breakpoints

Capacity in m³	Specific investment in €/m³
0.2	7,000
0.5	4,000
1	2,800
5	1,500
20	950
100	600
1,000	300
10,000	120
100,000	40

Battery

Table 24: Battery: Cost function breakpoints

Capacity in kWh	Specific investment in €/kWh
5	1,000
15	700
50	480
200	380
1,000	300
10,000	200
100,000	140

Hydrogen storage

Table 25: Hydrogen storage: Cost function breakpoints

Capacity in kWh	Specific investment in €/kWh
10	300
100	120
1,000	55
10,000	32

Maintenance costs of energy system technologies

Annual maintenance and servicing costs are applied as a percentage of the investment costs, following VDI 2067.

Annual maintenance costs (share of investment)

Table 26: Annual maintenance costs (share of investment)

Technology	Maintenance	Source
CHP unit	8 %	VDI 2067
Boiler	3 %	VDI 2067
Electric heater	3 %	VDI 2067
Fuel cell	6 %
Electrolyzer	6 %
Air-source heat pump	2.5 %	VDI 2067
Combi heat pump	2.5 %	VDI 2067
Booster heat pump	2.5 %	VDI 2067
Absorption chiller	3 %	VDI 2067
Compression chiller	3.5 %	VDI 2067
Photovoltaics	1 %
PVT collectors	1 %
Solar thermal	1.5 %	VDI 2067
Wind power	1 %
Hydropower	1 %
Geothermal (boreholes)	0 %	VDI 2067
Heat source (heat exchanger)	1 %
Heat storage	1 %
Cold storage	1 %
Combi storage	1 %
Battery	1 %
Hydrogen storage	2 %

Lifetime of energy system technologies

Together with the interest rate, the calculatory lifetime determines the annuity of an investment. If it is shorter than the observation period, nPro accounts for a replacement investment; if it is longer, a residual value remains at the end.

Calculatory lifetime

Table 27: Calculatory lifetime

Technology	Lifetime in years	Source
CHP unit	15	VDI 2067
Boiler	20	VDI 2067
Electric heater	20	VDI 2067
Fuel cell	15
Electrolyzer	15
Air-source heat pump	20	VDI 2067
Combi heat pump	20	VDI 2067
Booster heat pump	20	VDI 2067
Absorption chiller	20	VDI 2067
Compression chiller	20	VDI 2067
Photovoltaics	20
PVT collectors	20
Solar thermal	20	VDI 2067
Wind power	20
Hydropower	40
Geothermal (boreholes)	50	VDI 2067
Heat source (heat exchanger)	20
Heat storage	20
Cold storage	20
Combi storage	20
Battery	10
Hydrogen storage	18

Sources

VDI 2067: Wirtschaftlichkeit gebäudetechnischer Anlagen: Grundlagen und Kostenberechnung, 2012.
Danish Energy Agency and Energinet: Technology Data: Generation of Electricity and District heating. March 2022.
Institut Wohnen und Umwelt GmbH: Energetische Kenngrößen für Heizungsanlagen im Bestand. 2002.
Institut für Energie- und Umwelttechnik e.V. (IUTA): Ableitung von Kostenfunktionen für Komponenten der rationellen Energienutzung, 2002.
Forschungsstelle für Energiewirtschaft e.V.: Kostenanalyse Wärmespeicher bis 10.000 l Speichergröße, 2016.