CostingEnergy mass balanceSolar

Building-integrated PV facade

BIPV on a building envelope: cost per m2 of skin net of the cladding it replaces, production read on the real vertical plane, and the levelized cost that comes out of the two.

Open Jack

Founder · OpenJack

Levelized cost

Net levelized cost of electricity (LCOE)

Discounted lifetime cost net of the avoided cladding, over discounted lifetime generation

…EUR/MWh

Gross LCOE (no cladding credit)

Same calculation with the full BIPV cost charged to the electricity

…EUR/MWh

LCOE saved by the avoided cladding

Gap between the gross and the net levelized cost

…EUR/MWh

First-year cost of electricity

Annual cost over first-year generation, no discounting on either side

…EUR/MWh

NPV of lifetime cost per m2

Net capex plus discounted O&M and inverter replacements

…EUR/m2

NPV of lifetime generation per m2

Annual yield summed over the lifetime with degradation and discounting

…kWh/m2

Discount rate (real)

Real discount rate applied to both the costs and the energy. 3% is the source's European assumption; commercial developers use 5 to 8%.

Economic lifetime

Analysis horizon. Because the inverter is replaced every 15 years, the schedule is discrete: a 30-year project pays one replacement, a 35-year project pays two. The LCOE is therefore not monotone in lifetime, and its minimum over the declared box sits at 30 years.

Cost of capital

Lifetime, and the inverter replacement step

Envelope cost and the cladding credit

Envelope type

Vertical facade or roof-membrane BIPV. The choice sets the cost class used when the two cost inputs below are left at 0: 450 / 230 EUR per m2 for a facade, 350 / 130 for a roof membrane (Gholami and Rostvik 2021). It does not change the resource, which you read yourself for your own plane.

Building envelope area covered

Envelope area clad with BIPV. This is the cost base of the whole calculator: BIPV is bought per square metre of skin, not per watt-peak. For scale, the Copenhagen International School facade is 6000 m2.

BIPV cost (delivered and installed)

Leave at 0 to use the benchmark of the envelope type selected above (450 EUR per m2 facade, 350 roof). Enter your own quote to override; quotes below 300 EUR per m2 are refused, since nothing in the IEA-PVPS inventory of real facades is cheaper. Real projects span 250 to 830 EUR per m2.

EUR/m2

Avoided envelope material cost

The cladding you no longer buy because the BIPV is the cladding. Leave at 0 to use the class benchmark (230 EUR per m2 facade, 130 roof). The 60 EUR per m2 floor is physical: BIPV is never installed on a building that would have had no envelope. At Copenhagen the alternative anodised aluminium cost the same as the BIPV, so the credit reached the full capex.

EUR/m2

BIPV cost applied

Your quote, or the benchmark of the selected envelope type when the input is left at 0

…EUR/m2

Avoided cladding credit applied

Your figure, or the benchmark of the selected envelope type when the input is left at 0

…EUR/m2

Specific capital cost after area scaling

Cost per m2 after the area scale law, which is unity for an envelope product

…EUR/m2

Net capital cost per m2 of envelope

BIPV cost minus the envelope material it replaces

…EUR/m2

Share of the BIPV cost offset by the credit

Avoided cladding as a percentage of the BIPV cost

…%

Gross BIPV investment

Before the avoided-envelope credit

…EUR

Avoided envelope material

Cladding budget released by the BIPV

…EUR

Net project CAPEX

What the BIPV actually adds to the building budget

…EUR

Cost of the BIPV product

Value of the cladding you do not buy

Scale: everything grows, the cost per m2 does not

Production on a vertical plane

Annual irradiation on the envelope plane

Irradiation received by YOUR plane, read from PVGIS at the real tilt and azimuth, not at the optimal tilt. PVGIS vertical south: Madrid 1406, Rome 1299, Lisbon 1295, Paris 1024, Berlin 965, Copenhagen 957, Stockholm 933, Helsinki 890. A Paris north facade collects 313 and sits outside this box on purpose.

Module efficiency (STC)

Efficiency at Standard Test Conditions. 16% is the mainstream BIPV glass-glass module. The 12% floor is the measured density of the coloured Kromatix glass at Copenhagen (116.7 Wp per m2); 22% is high-efficiency monocrystalline.

Performance ratio

System losses from plane of array to meter. PVGIS returns 79.14% on a Paris vertical south plane at 14% system loss, with a larger angle-of-incidence loss than a tilted array. The box covers south, east and west facades; a north facade drops to 66% and is excluded.

Installed DC capacity

Clad area times module efficiency at 1 kW/m2 STC

…kWp

Module power density

Watt-peak per square metre of envelope

…Wp/m2

Annual yield per m2 of envelope

Plane irradiation times module efficiency times performance ratio

…kWh/m2/year

Annual electricity generation

Main product, exposed to project mode

…MWh/year

Equivalent full-load hours

Plane irradiation times performance ratio, in kWh per kWp

…h/year

Capacity factor

Equivalent full-load hours over 8760

…%

Envelope area consumed per MWh per year

Square metres of building skin needed for one MWh of annual output

…m2/MWh

Levelized cost against plane irradiation

Module efficiency

Performance ratio of the plane

Annual cost and operation

Annualized CAPEX

Net project CAPEX converted to an annual payment

…EUR/year

Annual O&M

Charged on the gross BIPV cost

…EUR/year

NPV of O&M per m2

Discounted O&M over the lifetime

…EUR/m2

Inverter replacements over the lifetime

One every 15 years, counted strictly inside the horizon

…count

NPV of inverter replacements per m2

10% of the gross cost at each replacement year, discounted

…EUR/m2

Annualized inverter reserve

Replacement NPV spread over the lifetime

…EUR/year

Total fixed OPEX

O&M plus the annualized inverter reserve

…EUR/year

Total annual cost

Annualized CAPEX plus fixed OPEX

…EUR/year

Capital recovery factor

Annual payment equivalent to one euro of capital

…1/year

Annuity factor

Present value of one euro per year over the lifetime

…years

Reality checks

Plane penalty against an optimally tilted array

Equivalent full-load hours over the 1147 kWh/kWp PVGIS delivers at optimal tilt in Paris

…ratio

Plane irradiation against optimal tilt

Entered irradiation over the 1433 kWh/m2/year of the Paris optimal plane

…ratio

Yield against the PVGIS Paris vertical reference

Equivalent full-load hours over 810.66 kWh/kWp

…ratio

Yield against a measured BIPV facade

Per-m2 yield over the 83.3 kWh/m2/year measured at the Copenhagen International School

…ratio

Power density against a measured BIPV facade

Module density over the 116.7 Wp/m2 measured on the Copenhagen International School glass

…ratio

Performance ratio against the PVGIS facade value

Distance to the 79.14% PVGIS returns for a Paris vertical south plane

…%

Plane irradiation against the Paris vertical reference

Entered irradiation over the 1024.4 kWh/m2/year PVGIS gives for a Paris vertical south wall

…ratio

Plane irradiation against the EU building-skin average

Entered irradiation over the 806 kWh/m2/year EU average reported by the source

…ratio

Gap against the published European net LCOE

Distance to the 90 EUR/MWh EU average published by the source

…%

Gap against the published European gross LCOE

Distance to the 150 EUR/MWh EU average published by the source

…%

Levelized cost against the reference case

Net LCOE over the 123.35 EUR/MWh of the Paris reference case

…ratio

Margin against the retail electricity price

Reference retail price minus the net LCOE; negative means the facade costs more than grid power

…EUR/MWh

Annual generation valued at the reference retail price

Indicative only, at 180 EUR/MWh

…EUR/year

Benefit-to-cost ratio

Reference-priced generation over total annual cost; above 1 the facade pays for itself

…ratio

About

Calculator context

A building-integrated PV facade is not a rooftop array that happens to be vertical. Two things break at once, and they are the two things every other PV calculator assumes.

The cost base is the square metre of envelope, not the watt-peak. BIPV glass is a building product, quoted per m2 of skin, and part of that price is refunded on the spot by the cladding you no longer buy. Gholami and Rostvik put a facade at 450 EUR/m2 of BIPV against 230 EUR/m2 of avoided envelope material, a roof membrane at 350 against 130. At the Copenhagen International School the alternative skin, anodised aluminium, cost exactly the same as the BIPV, and that was the argument that won the decision. Nothing in a mounted rooftop system has an equivalent to this credit, so nothing in a rooftop calculator can carry it.

The resource is read on the real plane. PVGIS gives 1024.4 kWh/m2/year on a Paris vertical south wall against 1433.2 at the optimal 39 degrees: the wall collects 71.5% of the tilted plane, and 70.7% per kWp once the larger angle-of-incidence loss is counted. Any generic specific yield in the 900 to 1400 kWh/kWp band is wrong here by about a third, which is why this calculator asks for an irradiation and a performance ratio instead.

At the reference case, 1000 m2 of south-facing facade in Paris at 16% efficiency and a 79% performance ratio: 160 kWp installed, 129.4 MWh a year, 220 EUR/m2 net of the cladding credit, and 123.3 EUR/MWh levelized. Against the same cost set, European south facades run from 89.8 EUR/MWh in Madrid to 141.9 in Helsinki, with Berlin at 130.9 and Rome at 97.2.

That is deliberately above the 90 EUR/MWh the source publishes, and the gap is method, not disagreement. The published figure applies no performance ratio and sums the energy undiscounted; correcting both multiplies the levelized cost by roughly 1.7 at the same site. Both corrections push the number up, which is the direction that survives a financier.

Two things this calculator refuses to do. It applies no scale law to a cost per square metre: an envelope product is priced per m2, so the exponent on the specific cost is zero and it is written out explicitly rather than left implicit. And it clamps no cost: the two cost inputs refuse a quote below their documented floor instead of silently flattening it, so the cost model stays alive across the whole slider.

The bounds were set by evaluating every corner of the input box plus a fine interior scan. The levelized cost turns out not to be monotone in lifetime, because the inverter replacement schedule is discrete: 30 years pays one replacement, 35 pays two. Its true minimum, 19.83 EUR/MWh, sits at an interior point that a corners-only sweep would have missed.

Model

126 variables — inputs, calculations and outputs, with their dependencies.

126 variables shown of 126

Value	Unit	Depends on
1	—	—
1000	m2	—
16	%	—
1024	kWh/m2/year	—
79	%	—
0	EUR/m2	—
0	EUR/m2	—
0.03	ratio	—
30	years	—

Variable	Formula	Unit	Depends on
	`if((<=)+(<=)+(>=)+(<=)+(<=)+(>)+(<)+((>)(<))+(<)+((>)(<))+(<)+(>=)+(<=)+(<)+(>)>,,)`	bool
	`if(==,,)`	EUR/m2
	`if(==,,)`	EUR/m2
	`/max((+)^,)`	ratio
	`*`	EUR/m2/year
	`/max((+)^,)`	ratio
	`if(<,,*(-^)/max(-,))`	ratio
	`(-)/max(+,)`	ratio
	`++`	EUR/m2

Variable	Formula	Unit	Depends on
	`if(<,,)`	EUR/m2
	`if(<,,)`	EUR/m2
	`*(/max(,))^(-)`	EUR/m2
	`-`	EUR/m2
	`/max(,)*`	%
	`*`	EUR
	`*`	EUR
	`*`	EUR
	`***`	kWp
	`***`	Wp/m2
	`****`	kWh/m2/year
	`**`	MWh/year
	`**`	h/year
	`/max(,)*`	%
	`/max(,)`	ratio
	`/max(,)`	ratio
	`/max(,)`	ratio
	`/max(,)`	ratio
	`/max(,)`	ratio
	`(-)/max(,)`	%
	`/max(,)`	ratio
	`/max(,)`	ratio
	`/max(,)`	m2/MWh
	`if(<,/max(,),(*(+)^)/max((+)^-,))`	1/year
	`if(<,,(-)/max(,))`	years
	`*`	EUR/m2
	`max(ceil(/max(,))-,)`	count
	`**`	EUR/m2
	`if(abs(-)<,,*(-^)/max(-,))`	kWh/m2
	`++`	EUR/m2
	`*/max(,)`	EUR/MWh
	`*/max(,)`	EUR/MWh
	`-`	EUR/MWh
	`*`	EUR/year
	`*`	EUR/year
	`**`	EUR/year
	`+`	EUR/year
	`+`	EUR/year
	`/max(,)`	EUR/MWh
	`*`	EUR/year
	`/max(,)`	ratio
	`-`	EUR/MWh
	`(-)/max(,)*`	%
	`(-)/max(,)*`	%
	`/max(,)`	ratio

Assumptions

74 assumptions used in the calculations

Guards every division so a degenerate input returns a finite number instead of throwing.
Market range Not applicable (numerical parameter).
0.000001
Numerical stability constant.
Keeps the DSL free of inline literals so every number in an expression is a named, sourced constant.
Market range Exact.
1
Unit identity.
Same discipline as `one`: comparison thresholds in the validity guard are named, not inlined.
Market range Exact.
0
Additive identity.
Denominator of the capacity factor.
Market range 8760 (non-leap year); 8784 (leap year).
8760h/year
Calendar-year hours convention.
Converts the EUR/kWh levelized cost into the EUR/MWh the fiche reports.
Market range Exact.
1000kWh/MWh
Unit conversion.
Converts the per-square-metre yield in kWh into the MWh/year the project mode consumes.
Market range Exact.
0.001MWh/kWh
Unit conversion.
OpenJack stores percent inputs as 0-100 (CLAUDE.md section 7); the DSL converts to a fraction where it multiplies.
Market range Exact.
0.01
Percent-to-fraction conversion.
Reports derived shares and gaps back in percent.
Market range Exact.
100
Fraction-to-percent conversion.
Expresses module power density in Wp/m2, the figure BIPV product sheets quote.
Market range Exact.
1000Wp/kWp
Unit conversion.
Selects the vertical-facade cost class (450 / 230 EUR/m2).
Market range Not applicable.
1
Calculator convention.
Selects the roof-membrane cost class (350 / 130 EUR/m2).
Market range Not applicable.
2
Calculator convention.
Rejects an envelope type outside the two documented classes.
Market range Not applicable.
1
Calculator convention.
Rejects an envelope type outside the two documented classes.
Market range Not applicable.
2
Calculator convention.
Turns module efficiency into installed capacity per square metre: 1 m2 of a 16% module is 0.16 kWp.
Market range 1.0 kW/m2 by definition.
1kW/m2
Standard Test Conditions irradiance.
Anchor of the area scaling term. It cancels exactly, and is written down so the cancellation is auditable.
Market range 200 to 10000 m2 over the declared input box.
1000m2
Reference case of this calculator.
Exponent e of the TOTAL capex against area. e = 1 here, so the exponent carried by the SPECIFIC cost is (e - 1) = 0 and the cost per m2 is invariant in area. Writing it explicitly is the guard against BUG-099, where a six-tenths rule meant for a total was applied to a specific cost: that error cancels at the nominal point and misprices the capex by the capacity ratio everywhere else.
Market range 1.0 for envelope products; 0.6 to 0.9 for process equipment, which is not this case.
1
No scale law: BIPV modules are an envelope product sold per m2.
Class benchmark used when the user leaves the BIPV cost input at 0.
Market range 250 to 830 EUR/m2 across the IEA-PVPS T15 case studies; 300 to 800 over the declared input box.
450EUR/m2
Delivered and installed BIPV facade cost per square metre of envelope, 2021 EUR.
Class benchmark for the roof-membrane envelope type.
Market range 250 EUR/m2 for a full-roof BIPV single-family case (NL) up to about 430 EUR/m2.
350EUR/m2
Delivered and installed BIPV roof cost per square metre, 2021 EUR.
The cladding you do not buy because the BIPV is the cladding. This credit is what makes BIPV a different asset from a mounted array, and it has no equivalent on a rooftop system.
Market range 60 to 250 EUR/m2 over the declared box; up to the full BIPV price for high-end architectural cladding.
230EUR/m2
Avoided facade cladding material, 2021 EUR.
Class benchmark credit for the roof-membrane envelope type.
Market range 60 to 180 EUR/m2 depending on the membrane specified.
130EUR/m2
Avoided roofing material, 2021 EUR.
Floor of the declared cost box. A positive quote below it is refused rather than silently clamped: a guard belongs outside the domain, never inside it.
Market range 250 to 830 EUR/m2 across the inventory.
300EUR/m2
Cheapest documented BIPV project costs.
Physical floor of the avoided-cladding credit. This is a domain choice, not an output clamp: it binds no formula.
Market range 60 EUR/m2 (basic cladding) to 250 EUR/m2 (architectural glass).
60EUR/m2
Cheapest defensible building skin displaced by BIPV.
Compounds on the annual yield inside the discounted-energy sum.
Market range 0.3 to 0.8 %/year depending on technology and mounting.
0.0051/year
Median crystalline-silicon degradation.
Applied to the GROSS BIPV capex, not the net one: you maintain the whole PV system, not an accounting difference. Only the investment line carries the cladding credit.
Market range 0.5 to 1.0 %/year of capex.
0.0051/year
Annual O&M as a fraction of the initial BIPV investment.
Discounted at each replacement year and charged on the gross capex.
Market range 8 to 12% of initial investment.
0.1
Inverter replacement cost share.
Sets a DISCRETE replacement schedule (years 15, 30, ...), which is why the LCOE is not monotone in lifetime: a 30-year project pays one replacement, a 35-year project pays two.
Market range 10 to 20 years.
15years
Inverter replacement interval.
Default of the discount-rate input. Named with a `reference_` prefix because `discount_rate` is an input key and a constant may not shadow an input.
Market range 3 to 8% real over the declared box.
0.03ratio
Real discount rate of the reference case.
Default of the lifetime input. Prefixed for the same reason as the discount rate.
Market range 25 to 35 years over the declared box.
30years
Economic lifetime of the reference case.
Reference vertical-plane irradiation for Paris (lat 48.85, to be entered in the irradiation input.
Market range 700 to 1450 kWh/m2/year over the declared box.
1,024.38kWh/m2/year
Satellite-derived irradiation on the declared plane.
Reference vertical-plane irradiation for Madrid (lat 40.42, to be entered in the irradiation input.
Market range 700 to 1450 kWh/m2/year over the declared box.
1,406.4kWh/m2/year
Satellite-derived irradiation on the declared plane.
Reference vertical-plane irradiation for Lisbon (lat 38.72, to be entered in the irradiation input.
Market range 700 to 1450 kWh/m2/year over the declared box.
1,295.2kWh/m2/year
Satellite-derived irradiation on the declared plane.
Reference vertical-plane irradiation for Rome (lat 41.90, to be entered in the irradiation input.
Market range 700 to 1450 kWh/m2/year over the declared box.
1299kWh/m2/year
Satellite-derived irradiation on the declared plane.
Reference vertical-plane irradiation for Berlin (lat 52.52, to be entered in the irradiation input.
Market range 700 to 1450 kWh/m2/year over the declared box.
964.6kWh/m2/year
Satellite-derived irradiation on the declared plane.
Reference vertical-plane irradiation for Copenhagen (lat 55.68, to be entered in the irradiation input.
Market range 700 to 1450 kWh/m2/year over the declared box.
956.9kWh/m2/year
Satellite-derived irradiation on the declared plane.
Reference vertical-plane irradiation for Stockholm (lat 59.33, to be entered in the irradiation input.
Market range 700 to 1450 kWh/m2/year over the declared box.
932.5kWh/m2/year
Satellite-derived irradiation on the declared plane.
Reference vertical-plane irradiation for Helsinki (lat 60.17, to be entered in the irradiation input.
Market range 700 to 1450 kWh/m2/year over the declared box.
890.4kWh/m2/year
Satellite-derived irradiation on the declared plane.
Grounds the EXCLUSION of north facades from the declared input box: sweeping 313 kWh/m2/year at 7% module efficiency produced an LCOE near 5800 EUR/MWh, an indefensible domain. The box was tightened rather than the bound widened.
Market range 267 (Stockholm) to 313 (Paris) kWh/m2/year on a north facade.
312.9kWh/m2/year
PVGIS vertical north plane, Paris.
Shows that the input box covers non-south orientations in sunny climates, not only due south.
Market range About 74% of the south facade at the same site.
1,038.8kWh/m2/year
PVGIS vertical east plane, Madrid.
Denominator of the facade penalty. It is why this calculator reads an irradiation on a plane instead of a generic specific yield: a vertical plane receives 0.715 of the optimally tilted one.
Market range 1400 to 1500 kWh/m2/year in northern France.
1,433.2kWh/m2/year
PVGIS optimally tilted plane, Paris.
Reference yield an optimally tilted array would deliver per kWp at the same site; the facade penalty is measured against it.
Market range 900 to 1400 kWh/kWp across Europe.
1,147.1kWh/kWp/year
PVGIS specific yield, optimally tilted.
Benchmark the calculated equivalent full-load hours are compared against.
Market range About 71% of the optimally tilted yield at the same site.
810.66kWh/kWp/year
PVGIS specific yield, vertical south plane.
The number that invalidates a generic PV specific yield for a BIPV facade: a vertical plane collects 71.5% of the optimally tilted plane.
Market range 0.66 to 0.75 across European latitudes.
0.715ratio
Ratio of vertical-south to optimal-tilt irradiation, Paris.
Per-kWp version of the facade penalty; the calculated penalty output reproduces it to within 0.3%.
Market range 0.65 to 0.74 across European latitudes.
0.707ratio
Ratio of vertical-south to optimal-tilt specific yield, Paris.
Anchors the performance-ratio input. The declared box of 72 to 85% covers south, east and west facades; it deliberately EXCLUDES the north facade, where PVGIS returns 0.66 because diffuse light dominates.
Market range 0.77 to 0.80 south, east and west; 0.66 north.
0.7914ratio
PVGIS performance ratio on a vertical plane.
Documents why the performance-ratio box is facade-specific rather than borrowed from a rooftop study.
Market range -3 to -6% depending on plane and glazing.
-4.56%
PVGIS loss breakdown.
Total system loss behind the performance ratio, itemised by PVGIS.
Market range -18 to -24%.
-20.86%
PVGIS loss breakdown.
Default of the module-efficiency input.
Market range 12% (coloured Kromatix glass, Copenhagen) to 22% (high-efficiency monocrystalline).
16%
Module efficiency of the reference case.
Default of the performance-ratio input.
Market range 72 to 85% over the declared box.
79%
Facade performance ratio of the reference case.
Real-building validation case for the area x irradiation x efficiency x performance-ratio model.
Market range Single buildings from a few hundred to several thousand m2.
6000m2
IEA-PVPS T15 case study.
Validation of the installed-capacity model on a real facade.
Market range 120 to 220 Wp/m2 for current BIPV glass.
700kWp
IEA-PVPS T15 case study.
The number this model is checked against.
Market range Site-specific.
500000kWh/year
IEA-PVPS T15 case study.
Real-building yield the calculated per-square-metre yield is benchmarked against.
Market range 60 to 130 kWh/m2/year on European facades.
83.33kWh/m2/year
IEA-PVPS T15 case study, Copenhagen International School.
Grounds the 12% floor of the module-efficiency input box.
Market range 117 Wp/m2 (coloured glass) to 220 Wp/m2 (high-efficiency monocrystalline).
116.7Wp/m2
IEA-PVPS T15 case study.
Reference the entered plane irradiation is compared against.
Market range 631 (Finland) to 1138 (Cyprus) kWh/m2/year.
806kWh/m2/year
EU-average building-skin irradiation.
Bounds the low end of the resource the source itself considers.
Market range 631 kWh/m2/year.
631kWh/m2/year
Gholami and Rostvik EU survey.
Bounds the high end of the resource the source itself considers.
Market range 1138 kWh/m2/year.
1138kWh/m2/year
Gholami and Rostvik EU survey.
Published benchmark the net LCOE is compared against. This calculator corrects both simplifications, so it is expected to land above the published figure: a performance ratio anchored on PVGIS multiplies the LCOE by about 1.27, and discounting the energy by about 1.33.
Market range 65.7 to 118.5 EUR/MWh over the source's own perimeter.
90EUR/MWh
Gholami and Rostvik 2021 headline result.
Published benchmark for the gross LCOE, i.e. the BIPV charged with its full capex and credited with no cladding.
Market range 110 to 200 EUR/MWh depending on site and orientation.
150EUR/MWh
Gholami and Rostvik 2021 headline result.
Reference retail price used for the grid-parity margin and the benefit-to-cost ratio. It is a REPORTING benchmark only: no electricity purchase is booked anywhere in this calculator.
Market range 100 to 400 EUR/MWh across EU markets and years.
180EUR/MWh
European average retail electricity price, 2021.
Reference-case net capital cost per square metre of envelope.
Market range 50 to 740 EUR/m2 over the declared input box.
220EUR/m2
This calculator, reference case.
Reference-case installed DC capacity.
Market range 24 to 2200 kWp over the declared box.
160kWp
This calculator, reference case.
Reference-case annual generation.
Market range 12.1 to 2712 MWh/year over the declared box.
129.4336MWh/year
This calculator, reference case.
Reference-case levelized cost, asserted in the nominal test and used as the denominator of the reference-case ratio output.
Market range 19.8 to 1310 EUR/MWh over the full declared input box.
123.345831EUR/MWh
This calculator, reference case.
The cost base is the square metre of envelope, not the watt-peak. BIPV is bought as a building product, quoted per m2 of skin by the manufacturer, and part of that price is refunded by the cladding you no longer buy. Sizing on kWc and then pricing on EUR/kWc would lose the credit entirely.
Market range Not applicable (method).
methodologicalEUR/m2
Authoring decision, documented so it can be challenged.
The resource is read on the real plane, not at the optimal tilt. PVGIS gives 1024.4 kWh/m2/year on a Paris vertical south plane against 1433.2 at the optimal 39 degrees: a ratio of 0.715 on irradiation and 0.707 on yield per kWp. Any generic PV specific yield of 900 to 1400 kWh/kWp is wrong here by about 30%.
Market range Not applicable (method).
methodologicalkWh/m2/year
Authoring decision, documented so it can be challenged.
O&M and inverter replacement are charged on the GROSS BIPV cost; only the investment line carries the avoided-cladding credit. You maintain a whole PV system, not an accounting difference.
Market range Not applicable (method).
methodological
Authoring decision, documented so it can be challenged.
The energy is discounted like the cost, and degraded at 0.5% a year. The source does neither, and applies no performance ratio either. Correcting both raises the LCOE by roughly 1.7x at the same site: about 1.27x from the performance ratio and 1.33x from discounting.
Market range Not applicable (method).
methodological
Authoring decision, documented so it can be challenged.
No six-tenths rule anywhere. The scale exponent on the TOTAL capex is 1 for an envelope product, so the exponent carried by the SPECIFIC cost is (e - 1) = 0. The area scaling term is written out explicitly with that exponent so the cancellation is visible and auditable.
Market range Not applicable (method).
methodological
Authoring decision, documented so it can be challenged.
No clamp is applied to any cost. A guard bounds what is outside the domain; anything that can bite between the minimum and maximum of a slider is not a guard but a wrong model. The two cost inputs instead refuse a positive quote below their documented floor, and that refusal is surfaced through the validity guard rather than hidden in a clamp.
Market range Not applicable (method).
methodological
Authoring decision, documented so it can be challenged.
The published bounds come from evaluating every corner of the input box, plus a fine interior scan over discount rate and lifetime. The net LCOE is not monotone in either, because the inverter replacement schedule is discrete: the true minimum of 19.83 EUR/MWh sits at 3% and 30 years, an INTERIOR point in lifetime, while a corners-only sweep returned 21.04.
Market range Not applicable (method).
methodological
Authoring decision, documented so it can be challenged.
The input box is deliberately narrower than the physics allows. Irradiation stops at 700 kWh/m2/year rather than the 313 a Paris north facade really receives, and module efficiency at 12% rather than 7%. Sweeping a north facade at 7% produced an LCOE near 5800 EUR/MWh: an indefensible domain. Tightening the box is the honest fix; widening the bound would have emptied the check of meaning.
Market range Not applicable (method).
methodological
Authoring decision, documented so it can be challenged.
The asset declares no inlet. Sunlight is not a purchased flow, and no auxiliary consumption is modelled, so there is nothing to charge twice. O&M is a percentage of capital, booked once as fixed opex, and the variable opex line is fixed at zero.
Market range Not applicable (method).
methodological
Authoring decision, documented so it can be challenged.
The CAPEX exposed to project mode is the NET one, at an installed battery limit. The source figures are delivered and installed project costs, so they are neither ex-factory equipment nor fully financed all-in: the project adds working capital and contingency on top, and nothing else.
Market range Not applicable (method).
methodological
Authoring decision, documented so it can be challenged.
The first-year cost of electricity and the net LCOE do not agree, and should not: the LCOE discounts and degrades the energy, the annual figure does not. At the reference case they read 115.5 and 123.3 EUR/MWh. Project mode consumes the annual lines, so the annual figure is the one that reconciles with a cashflow.
Market range Not applicable (method).
methodological
Authoring decision, documented so it can be challenged.

Sources

6 external sources

Building-integrated PV facade

Levelized cost

Envelope cost and the cladding credit

Production on a vertical plane

Annual cost and operation

Reality checks

About

Model

User inputs · 9

Constants · 63

Intermediate calcs · 9

Exposed outputs · 45

Assumptions

Sources