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CSP Plant Surface, Cost Breakdown & LCOE Calculator (DNI-based)

Screening-level CSP (solar thermal) sizing and economics from DNI, capacity factor, plant MW, and thermal storage duration, with CSP type selection.

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alexi

I do low-carbon energy stuff for 10 years & build things I wish existed.

Context

Annual DNI at the site. CSP performance is strongly dependent on DNI.

min 1200 · max 3200 · step 50 · kWh/m2/year

Expected net annual capacity factor (fraction of nameplate). Use a value consistent with storage and DNI.

min 5 · max 85 · step 1 · %

Real or nominal discount rate consistent with your cost basis; used only for annualization via CRF.

ratio

min 0 · max 0.2 · step 0.005 · ratio

Amortization period for CAPEX annualization (CRF).

years

min 15 · max 45 · step 1 · years

Results

Estimated land area

Aperture-to-land factor applied (layout + spacing)

…ha

Solar field aperture area

Estimated reflector/heliostat aperture required

…m2

Estimated number of turbine blocks

Capacity divided by a typical block size

…count

Annual electricity production

From plant capacity and capacity factor

…MWh/year
New chart

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LCOE

Levelized cost of electricity (simplified, no fuel)

…EUR/MWh

Total CAPEX

Scaled total installed cost (solar field + power block + storage + BoP)

…EUR

Thermal storage energy (electric-equivalent)

Storage duration multiplied by plant MW

…MWh

CAPEX: Power block

Scaled turbine/generator island and auxiliaries

…EUR

CAPEX: Solar field

Scaled aperture-area-driven cost

…EUR

CAPEX: Thermal storage

Scaled cost proportional to storage MWh

…EUR

CAPEX: Balance of plant

Scaled EPC, civil, grid interconnect, and misc.

…EUR

Design

Select the CSP sub-technology to apply typical efficiency, solar multiple and cost assumptions.

Nameplate net electrical capacity delivered at the grid connection.

MW

min 1 · max 1000 · step 1 · MW

Storage hours at rated power (electric-equivalent). Higher values typically require a higher solar multiple and increase CAPEX.

min 0 · max 20 · step 1 · h

About

Calculator context

Introduction

This calculator provides a pre-feasibility (screening) estimate for a concentrating solar power (CSP) plant using Direct Normal Irradiance (DNI) as the primary solar resource driver (global applicability). It estimates required solar-field aperture and land area, CAPEX/OPEX breakdown, and LCOE for common CSP configurations.

It follows an engineering “calculation sheet” approach aligned with common public benchmark sources (e.g., IRENA, NREL ATB, and SolarPACES) while keeping user inputs limited to parameters typically known by a project developer early in development.

Methodology

The model is organized into three blocks: energy (annual output), sizing (aperture/land/storage), and costing (CAPEX annualization + O&M).

Key calculations include:

  • Annual generation
    • load_hours = hours_per_year * capacity_factor
    • annual_production_output = capacity * load_hours
    • Variables: capacity (MW), capacity_factor (-), hours_per_year (h/yr).
  • Solar-field aperture sizing (DNI-driven design point)
    • DNI is converted to an approximate design-point irradiance: design_dni_w_m2 = clamp(dni_avg_w_m2 * peak_to_avg_dni_factor, min_design_dni_w_m2, max_design_dni_w_m2)
    • A technology-dependent solar multiple increases with storage duration (hours) and is clamped to plausible bounds.
    • specific_consumption (interpreted here as m2 per MW) = w_per_mw * solar_multiple / (design_dni_w_m2 * optical_eff * thermal_to_elec_eff)
    • load_penalty = clamp(1 + penalty_coeff * (1 - cf), 1.0, max_penalty); effective_consumption = specific_consumption * load_penalty
    • solar_field_area_m2 = capacity * effective_consumption
  • Costing and LCOE
    • Component CAPEX is estimated (solar field + power block + storage + balance of plant), then scaled by plant size using a typical exponent.
    • CRF = (r*(1+r)^n)/max(((1+r)^n-1),eps)
    • annualized_capex = capex_total * CRF; total_annual_cost = annualized_capex + capex_total * om_fraction_scaled
    • levelized_cost_output (LCOE) = total_annual_cost / annual_production_output

Primary reference anchors: IRENA cost reports, NREL ATB CSP benchmarks, and SolarPACES technology context.

Applications

  • Project developer (origination): rapid comparison of tower vs trough and storage-hour options to understand land take and LCOE sensitivity to DNI.
  • Investor/analyst (screening): quick CAPEX breakdown and LCOE estimate for early-stage diligence before vendor EPC quotes.
  • Grid/planning team: scenario sweeps (e.g., DNI or storage hours) to assess dispatchable solar economics and siting implications.

Model

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

98 variables shown of 98
VariableValueUnitDepends on
2——
100MW—
45%—
2300kWh/m2/year—
8h—
0.07ratio—
30years—
VariableFormulaUnitDepends on
if(((<1)+(>2)+(<=0)+((*0.01)<0)+((*0.01)>1)+(<=0)+(<0)+(<0)+(<=0))>0,1,0)bool
(*0.01)—
MW
*(*0.01)h/year
clamp(1+*(1-),1.0,)—
(*)/max(,)W/m2
clamp(*,,)W/m2
if(==1,,)—
if(==1,,)—
if(==1,,)—
if(==1,,)per h
clamp(+*,,)—
(*)/max((**),)m2/MW
*m2/MW
if(==1,,)—
*m2
*kW
if(==1,,)EUR/m2
if(==1,,)EUR/kW
if(==1,,)EUR/kW
if(==1,,)EUR/kWh
*EUR
*EUR
*EUR
**EUR
+++EUR
/max(,)EUR/kW
(/max(,))^—
clamp(*,,)EUR/kW
/max(,)—
(*(1+)^)/max(((1+)^-1),)—
*EUR/year
if(==1,,)—
(/max(,))^—
clamp(*,,)—
*EUR/year
VariableFormulaUnitDepends on
ceil(/max(,))count
*m2
/max(,)ha
*MWh
*MWh/year
*EUR
*EUR
*EUR
*EUR
*EUR
+EUR/year
/max(,)EUR/MWh

Assumptions

43 assumptions used in the calculations

  • Prevents division-by-zero and unstable behavior in edge cases.

    Market range Not applicable

    0.000001
    Numerical safeguard constant

  • Converts capacity factor to annual full-load hours.

    Market range 8760

    8760h/year
    Calendar constant (non-leap year)

  • Converts MW to kW for CAPEX expressed per kW.

    Market range 1000

    1000kW/MW
    Unit conversion

  • Converts kW to W for irradiance conversions.

    Market range 1000

    1000W/kW
    Unit conversion

  • Converts MW to W for design-point aperture sizing.

    Market range 1000000

    1000000W/MW
    Unit conversion

  • Converts MWh storage to kWh for storage CAPEX per kWh.

    Market range 1000

    1000kWh/MWh
    Unit conversion

  • Converts land area from m2 to hectares.

    Market range 10000

    10000m2/ha
    Unit conversion

  • Screening approach to relate annual DNI to a representative high-irradiance design point used for aperture sizing.

    3.4
    Heuristic mapping from annual-average DNI to a design-point DNI

  • Prevents unrealistically low design-point DNI when annual DNI is low or the heuristic mapping underestimates peaks.

    650W/m2
    Model clamp bound

  • Prevents unrealistically high design-point DNI from inflating thermal power density.

    1000W/m2
    Model clamp bound

  • Imposes a mild oversizing penalty (area intensity) as capacity factor decreases, reflecting non-ideal utilization and additional solar multiple needs.

    0.3
    Heuristic coefficient

  • Limits oversizing penalty to a plausible upper bound for screening calculations.

    1.5
    Model clamp bound

  • Used to estimate an integer number of generation blocks for early sizing.

    50MW
    Heuristic turbine block size

  • Represents mirror reflectivity, intercept factor, cleanliness, and receiver losses at design conditions.

    0.55
    Typical optical efficiency (aperture to thermal input) for trough fields at design point

  • Captures cosine, atmospheric attenuation, spillage, and reflectivity impacts.

    0.6
    Typical optical efficiency for tower heliostat fields at design point

  • Represents net cycle efficiency including parasitics at rated conditions.

    0.38
    Typical net thermal-to-electric efficiency for trough plants

  • Higher-temperature receiver and cycle can yield higher net efficiency.

    0.42
    Typical net thermal-to-electric efficiency for tower plants

  • Represents typical field-to-block oversizing without storage-driven increase.

    2
    Base solar multiple for trough

  • Tower designs often use higher solar multiple for higher dispatchability and receiver constraints.

    2.3
    Base solar multiple for tower

  • Longer storage typically requires additional solar field to charge storage while meeting generation.

    0.07per h
    Heuristic slope of solar multiple vs storage duration

  • Tower plants with higher storage tend to adopt higher SM for dispatchable operation.

    0.08per h
    Heuristic slope of solar multiple vs storage duration

  • Prevents unrealistically small solar multiples for CSP plants.

    1.3
    Model clamp bound

  • Prevents unrealistically large solar multiples in simplified screening mode.

    4
    Model clamp bound

  • Accounts for spacing, roads, drainage, and non-aperture areas for trough fields.

    2.8
    Layout factor

  • Tower heliostat fields typically require larger spacing and exclusion zones than trough.

    3.5
    Layout factor

  • Represents installed trough solar field cost per aperture area.

    170EUR/m2
    Component CAPEX benchmark

  • Represents installed heliostat field cost per reflective area.

    200EUR/m2
    Component CAPEX benchmark

  • Power block and related island costs for trough CSP.

    900EUR/kW
    Component CAPEX benchmark

  • Power block cost benchmark for tower plants (often higher-temperature designs).

    1000EUR/kW
    Component CAPEX benchmark

  • Balance of plant / EPC / civils allowance for trough projects.

    500EUR/kW
    Component CAPEX benchmark

  • Balance of plant / EPC / civils allowance for tower projects.

    600EUR/kW
    Component CAPEX benchmark

  • Represents installed storage system cost per kWh of rated output stored (simplified).

    40EUR/kWh
    Thermal energy storage CAPEX benchmark (electric-equivalent)

  • Tower plants often pair molten-salt storage; cost expressed here as a simplified electric-equivalent metric.

    45EUR/kWh
    Thermal energy storage CAPEX benchmark (electric-equivalent)

  • Defines the reference size for CAPEX scaling exponent.

    100000kW
    Scaling reference size

  • Captures modest reductions in specific CAPEX with increasing capacity.

    -0.08
    Economies-of-scale heuristic

  • Lower bound for screening CSP total installed cost.

    2500EUR/kW
    Model clamp bound

  • Upper bound for screening CSP total installed cost.

    8000EUR/kW
    Model clamp bound

  • Reference size for O&M fraction scaling.

    100000kW
    Scaling reference size

  • Allows slight reduction of O&M fraction with larger plants.

    -0.05
    O&M scaling heuristic

  • Lower bound for annual fixed O&M as a fraction of CAPEX.

    0.015
    Model clamp bound

  • Upper bound for annual fixed O&M as a fraction of CAPEX.

    0.05
    Model clamp bound

  • Represents typical annual O&M cost as a fraction of installed cost at benchmark scale.

    0.025
    Reference fixed O&M fraction for trough

  • Tower plants can have higher O&M due to heliostat cleaning and receiver-related maintenance.

    0.03
    Reference fixed O&M fraction for tower