# Levelised Cost of Electricity (LCOE) of Building Integrated Photovoltaics (BIPV) in Europe, Rational Feed-In Tariffs and Subsidies

^{*}

## Abstract

**:**

## 1. Introduction

**Net metering**[21], where the prosumers get a bill based on their power generation and consumption over a period (from days to years). Hence, the prosumer offsets its electricity consumption with renewable energy resources over an entire billing period. It allows the prosumers to use its generated power at a time other than when it is produced. In fact, the prosumers are using the power grid as storage.

**Feed-in tariff (FiT)**[22], where prosumers are paid a fixed price for the energy they deliver to the power grid. Therefore, prosumers get paid at a rate called FiT for the surplus energy produced at home via renewable energy resources and sent on to the grid.

**Export price**[23], where a utility and a prosumer will have a power purchase agreement or PPA. It is usually based on a fixed price per kWh.

**Network charge**, where the prosumers will just pay the network charge for the power they send to the grid and give it back from the grid later. For example, it could be the same as the net metering approach except for paying a charge for using the grid as storage.

**Tax exemption**[24], where the prosumers will be exempted from energy taxes in the retail price of energy.

**Grant Schemes**[6], where governments grant a portion of the investments for the installed renewable energy resources to the owner.

- Define, formulate, calculate, and present the LCOE of BIPV as a building envelope material for the European countries.
- Present a metric to determine the rational amount of subsidy or incentive for the BIPV system in the EU countries.

## 2. Input Parameters

- Operation and maintenance (O&M) cost: 0.5% of the initial investment in Europe.
- Inverter replacement cost: 10% of the initial investment, to be replaced every 15 years.
- BIPV degradation rate: 0.5%.
- BIPV Lifetime: 30 years.
- Building envelope material cost: 230 Euro per sq.m. for the façade and 130 Euro per sq.m. for the roof.
- Transmission line lost power: see Table 1.
- Power delivery cost: 20% of the grid electricity tariff.
- Societal cost of carbon (SCC): 50 Euro per ton with a growth rate of 4%.
- GHG emission: Table 1, with a mitigation rate of 2.1%.
- Electricity tariff: Table 1, with a growth rate of 2%.
- Discount rate: 3%.
- BIPV efficiency: 16%.
- BIPV initial investment: 450 Euro per sq.m. for facades and 350 Euro per sq.m. for roofs.

## 3. Formulation

_{I}, NPV

_{C}and E

_{G}, which are BIPV net present value of incomes, BIPV net present value of costs, and BIPV total electricity production, are discussed and formulated.

#### 3.1. System Income

_{I}can, therefore, be calculated as Equation (1):

_{BM}, I

_{TR}, I

_{PD}, I

_{SCC}, I

_{EG}represent the income from saving in building envelope material cost, transmission line lost power, power delivery cost, societal cost of carbon and power generation, respectively. The quantified value of the saving from transmission line lost power can be calculated as presented in Equation (2):

_{G}, R

_{TR}, NP, D

_{R}, n and y represent annual energy generation, the ratio of transmission line lost power, power grid price, discount rate, the number of the year and BIPV lifespan, respectively. The quantified value of the system due to the saving in the power delivery cost is calculatable as follows in Equation (3):

_{PD}stands for the saving ratio in power delivery cost. The saving from carbon taxing is also presented in Equation (4):

_{GHG}and CP stand for the average GHG emission and societal cost of carbon, respectively. The income from system electricity generation is formulated, as shown in Equation (5):

_{GHG}associated with the nth year of the BIPV system is calculatable as presented in Equations (6)–(9):

_{NP}, R

_{CP}, R

_{EG}and R

_{GH}are abbreviations for electricity tariff growth ratio, societal cost of carbon growth ratio, BIPV degradation ratio and GHG mitigation ratio, respectively.

#### 3.2. System Cost

_{C}can be formulated as Equation (11):

_{Q}, C

_{IR}and C

_{OM}stand for BIPV initial investment, inverter replacement cost, and operation and maintenance cost, respectively. The inverter replacement cost can be easily calculated, as presented in Equation (12):

#### 3.3. System Energy Production

_{G1}can be calculated as follows:

#### 3.4. LCOE Formulation

_{C}, NPV

_{I}, and E

_{GT}represent net present value of the costs of the system over its lifetime, net present value of the incomes of the system over its lifetime and total electricity generation over its lifetime, respectively.

## 4. Results

_{GT}) as a building envelope material for the skins of the buildings in the EU countries. The total production is between 2819 kWh per sq.m. (in Finland) and 5084 kWh per sq.m. (in Cyprus). The average production for the EU is 3601 kWh per sq.m.

#### 4.1. Scenario 1

_{C}). Figure 4 illustrates the electricity price of the grid and LCOE of BIPV as a building envelope material for the entire building.

#### 4.2. Scenario 2

- If the grid is obliged to buy the surplus generated electricity of the BIPV from end-user at the same price that sells it to the end-user, then the technology is already mature in EU as figure shows and there is no need for additional incentive.
- If the buying price of the grid is less than its selling price but still more than the calculated LCOE, then the system is still profitable, and no subsidy is needed to make the system economically viable.
- If the buying price of the grid is even less than the calculated LCOE, then the end-user needs to either consume all the generated power of the BIPV system or receive an appropriate subsidy (normally equal to the difference between LCOE and buying price of the grid) in order to make the investment profitable.

_{E}for the investigated sites. As can be seen from the figures, LPOE in the EU varies from 0.09 € per kWh in Slovakia to 0.022 € per kWh in Germany and Estonia. The average value for the EU is 0.015 € per kWh.

_{E}in the EU, Norway with a net present value of 30 € per sq.m. has the lowest amount, which is basically because of its low GHG emission in power production (thanks to hydropower production potential) and a quite low lost rate in the power transmission lines. The highest amount belongs to Cyprus because of its relatively high electricity price and GHG emission of its power plants.

## 5. Performance of Non-Optimal Solutions

## 6. Conclusions

## Supplementary Materials

## Author Contributions

## Funding

## Acknowledgments

## Conflicts of Interest

## Abbreviations

Units | ||

€ | Euro | - |

BIPV | Building integrated photovoltaics | - |

BIPV_{EFF} | Efficiency of the BIPV system | % |

BIPVT | Building integrated photovoltaic thermal | - |

C_{IR} | inverter replacement cost | (€/sq.m.) |

C_{OM} | operation and maintenance cost | (€/sq.m.) |

CP | Societal cost of carbon | (€/g) |

C_{Q} | BIPV initial investment | (€/sq.m.) |

DG | Distributed generation | - |

D_{R} | Discount rate | % |

E_{G} | BIPV total electricity production | (kWh/sq.m.) |

FiT | Feed-in tariff | (€/kWh) |

G_{BS} | Average incident solar radiation on the building skins | (kWh/sq.m.) |

GHG | Greenhaus gas | - |

I_{BM} | Income from saving in building envelope material cost | (€/sq.m.) |

I_{EG} | Income from power generation | (€/sq.m.) |

I_{PD} | Income from saving in power delivery cost | (€/sq.m.) |

I_{SCC} | Income from saving in societal cost of carbon | (€/sq.m.) |

I_{TR} | Income from saving transmission line lost power | (€/sq.m.) |

kWh | Kilowatt-hour | - |

LCOE | Levelised cost of electricity | (€/kWh) |

LPOE | Levelised profit of environmental benefits | (€/kWh) |

MWh | Megawatt-hour | - |

n | The number of the year | - |

NP | Power grid price | (€/kWh) |

NPV_{C} | BIPV net present value of cost | (€/sq.m.) |

NPV_{E} | BIPV net present value of environmental benefits | (€/sq.m.) |

NPV_{I} | BIPV net present value of incomes | (€/sq.m.) |

O&M | Operation and maintenance | - |

R_{CP} | Societal cost of carbon growth ratio | % |

R_{EG} | BIPV degradation ratio | % |

R_{GH} | GHG mitigation ratio | % |

R_{GHG} | Average GHG emission | (g/kWh) |

R_{NP} | Electricity tariff growth ratio | % |

R_{PD} | Saving ratio in power delivery cost | % |

R_{TR} | The ratio of transmission line lost power | % |

UET | Urban energy transition | - |

y | BIPV lifespan | years |

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**Figure 1.**Average incident solar radiation on the building skins (G

_{BS}) of the capital of the investigated countries.

**Figure 2.**Lifetime electricity production of the BIPV system (E

_{GT}) as building envelope material.

**Table 1.**Electricity tariffs, GHG and electric power transmission and distribution losses of the European countries.

No | Country | Capital | Transmission Line Lost Power (Percent) [31] | GHG Emission (g/kWh) [32] | Electricity Tariff (Euro/kWh) [33] |
---|---|---|---|---|---|

1 | Austria | Vienna | 5% | 156 | 0.20 |

2 | Belgium | Brussels | 5% | 233 | 0.29 |

3 | Bulgaria | Sofia | 9% | 585 | 0.10 |

4 | Croatia | Zagreb | 13% | 282 | 0.13 |

5 | Cyprus | Nikosia | 4% | 773 | 0.22 |

6 | Czechia | Prague | 5% | 587 | 0.16 |

7 | Denmark | Copenhagen | 6% | 386 | 0.31 |

8 | Estonia | Tallinn | 7% | 1152 | 0.14 |

9 | Finland | Helsinki | 6% | 209 | 0.17 |

10 | France | Paris | 4% | 92 | 0.18 |

11 | Germany | Berlin | 4% | 567 | 0.30 |

12 | Greece | Athens | 4% | 755 | 0.16 |

13 | Hungary | Budapest | 12% | 368 | 0.11 |

14 | Ireland | Dublin | 8% | 555 | 0.25 |

15 | Italy | Rome | 7% | 444 | 0.22 |

16 | Latvia | Riga | 9% | 185 | 0.15 |

17 | Lithuania | Vilnius | 22% | 262 | 0.11 |

18 | Luxembourg | Luxemburg | 6% | 283 | 0.17 |

19 | Malta | Valleta | 5% | 868 | 0.13 |

20 | Netherlands | Amsterdam | 5% | 582 | 0.17 |

21 | Poland | Warsaw | 6% | 929 | 0.14 |

22 | Portugal | Lisbon | 10% | 355 | 0.23 |

23 | Romania | Bucharest | 11% | 413 | 0.13 |

24 | Slovakia | Bratislava | 2% | 211 | 0.15 |

25 | Slovenia | Ljubljana | 5% | 351 | 0.16 |

26 | Spain | Madrid | 10% | 305 | 0.25 |

27 | Sweden | Stockholm | 5% | 25 | 0.20 |

28 | UK | London | 8% | 584 | 0.20 |

29 | Norway | Oslo | 6% | 19 | 0.19 |

30 | Switzerland | Bern | 7% | 37 | 0.17 |

Country | I_{BM}(€/sq.m.) | I_{TR}(€/sq.m.) | I_{PD}(€/sq.m.) | I_{SCC}(€/sq.m.) | I_{EG}(€/sq.m.) | C_{Q}(€/sq.m.) | C_{IR}(€/sq.m.) | COM (€/sq.m.) | NP (€/kWh) |
---|---|---|---|---|---|---|---|---|---|

Austria | 210 | 7 | 30 | 7 | 623 | 430 | 43 | 65 | 0.20 |

Belgium | 210 | 10 | 39 | 9 | 821 | 430 | 43 | 65 | 0.29 |

Bulgaria | 210 | 7 | 16 | 27 | 335 | 430 | 43 | 65 | 0.10 |

Croatia | 210 | 13 | 20 | 12 | 429 | 430 | 43 | 65 | 0.13 |

Cyprus | 210 | 9 | 46 | 47 | 971 | 430 | 43 | 65 | 0.22 |

Czechia | 210 | 5 | 22 | 23 | 460 | 430 | 43 | 65 | 0.16 |

Denmark | 210 | 12 | 41 | 15 | 866 | 430 | 43 | 65 | 0.31 |

Estonia | 210 | 6 | 17 | 39 | 353 | 430 | 43 | 65 | 0.14 |

Finland | 210 | 6 | 20 | 7 | 419 | 430 | 43 | 65 | 0.17 |

France | 210 | 5 | 26 | 4 | 539 | 430 | 43 | 65 | 0.18 |

Germany | 210 | 8 | 40 | 22 | 845 | 430 | 43 | 65 | 0.30 |

Greece | 210 | 7 | 33 | 44 | 699 | 430 | 43 | 65 | 0.16 |

Hungary | 210 | 10 | 17 | 16 | 367 | 430 | 43 | 65 | 0.11 |

Ireland | 210 | 13 | 31 | 20 | 663 | 430 | 43 | 65 | 0.25 |

Italy | 210 | 14 | 40 | 24 | 844 | 430 | 43 | 65 | 0.22 |

Latvia | 210 | 8 | 19 | 7 | 392 | 430 | 43 | 65 | 0.15 |

Lithuania | 210 | 15 | 13 | 9 | 281 | 430 | 43 | 65 | 0.11 |

Luxembourg | 210 | 7 | 23 | 11 | 487 | 430 | 43 | 65 | 0.17 |

Malta | 210 | 7 | 27 | 51 | 566 | 430 | 43 | 65 | 0.13 |

Netherlands | 210 | 6 | 23 | 22 | 477 | 430 | 43 | 65 | 0.17 |

Norway | 210 | 7 | 22 | 1 | 475 | 430 | 43 | 65 | 0.19 |

Poland | 210 | 6 | 19 | 36 | 392 | 430 | 43 | 65 | 0.14 |

Portugal | 210 | 23 | 45 | 20 | 959 | 430 | 43 | 65 | 0.23 |

Romania | 210 | 12 | 21 | 19 | 448 | 430 | 43 | 65 | 0.13 |

Slovakia | 210 | 2 | 22 | 9 | 459 | 430 | 43 | 65 | 0.15 |

Slovenia | 210 | 6 | 23 | 14 | 495 | 430 | 43 | 65 | 0.16 |

Spain | 210 | 25 | 51 | 18 | 1077 | 430 | 43 | 65 | 0.25 |

Sweden | 210 | 6 | 25 | 1 | 521 | 430 | 43 | 65 | 0.20 |

Switzerland | 210 | 9 | 25 | 2 | 530 | 430 | 43 | 65 | 0.17 |

UK | 210 | 11 | 26 | 22 | 559 | 430 | 43 | 65 | 0.20 |

EU_{AV} | 210 | 9 | 27 | 19 | 578 | 430 | 43 | 65 | 0.18 |

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## Share and Cite

**MDPI and ACS Style**

Gholami, H.; Nils Røstvik, H.
Levelised Cost of Electricity (LCOE) of Building Integrated Photovoltaics (BIPV) in Europe, Rational Feed-In Tariffs and Subsidies. *Energies* **2021**, *14*, 2531.
https://doi.org/10.3390/en14092531

**AMA Style**

Gholami H, Nils Røstvik H.
Levelised Cost of Electricity (LCOE) of Building Integrated Photovoltaics (BIPV) in Europe, Rational Feed-In Tariffs and Subsidies. *Energies*. 2021; 14(9):2531.
https://doi.org/10.3390/en14092531

**Chicago/Turabian Style**

Gholami, Hassan, and Harald Nils Røstvik.
2021. "Levelised Cost of Electricity (LCOE) of Building Integrated Photovoltaics (BIPV) in Europe, Rational Feed-In Tariffs and Subsidies" *Energies* 14, no. 9: 2531.
https://doi.org/10.3390/en14092531