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TEA Analysis

Introduction

This document presents the methodology for calculating the Levelized Cost of Energy (LCOE) in the ENLITEN model, drawing on the foundational work of Short et al. [1]. The LCOE represents the average price per kilowatt-hour ($/kWh) at which electricity generated by the energy system must be sold to recover the total revenue requirements over the designated analysis period.

It is important to note that the analysis period—the duration over which costs are recovered—may differ from the project life. To simplify the analysis, the analysis period and project life are equal. A residual value calculation can be established if analysis period and project life vary.

Levelized Cost of Energy

LCOE ($/kWh) can be calculated by equating the total present value of all project revenue requirements over the analysis period – including taxes, depreciation, and other components – to the total present value of the LCOE ($/kWh) multiplied by the energy output (kWh) for each year within the analysis period. For the purposes of this analysis, we assume that the energy system becomes operational in Year 1, which simplifies the LCOE calculation. By rearranging this equation, we can solve for LCOE ($/kWh).

Revenue Requirements

Revenue requirements encompass the total revenue necessary to recover all costs associated with the project. This includes overnight capital costs (OCC), project financing (such as interest paid on debt used for capital financing), operations and maintenance (O&M) costs, tax depreciation, investment tax credits (ITC), costs for charging the energy system (accounting for round-trip efficiency (RTE) losses), as well as any augmentation, replacement, or major overhaul (ARMO) costs incurred to maintain operations.

The net present value of each cost component is calculated noting that the overnight capital costs (OCC) are already expressed in present value. These values are then annualized to derive the annualized revenue requirement (ARR), which represents the constant annual payment that must be made each year during the analysis period to cover all costs.

Internal Rate of Return (IRR)

The IRR represents the discount rate that makes the NPV of all cash flows equal to zero. Cash flows are determined from all in and out cash flows. IRR is calculated by solving the following equation for the discount rate(r):

TEA Assumptions and Financial Parameters

Term (Units)

Definition

Formula

Value

system_capex_USD (USD)

Total system capital expenditure.

User-defined

system_annual_OM_USD (USD)

Annual fixed O&M costs.

User-defined

system_annual_VOM_USD (USD)

Annual variable O&M costs.

User-defined

system_to_load_annual_MWh_e (MWh)

Annual renewable energy production.

User-defined

system_augment (USD)

Additional system costs over the analysis period.

User-defined

ITC (%)

Investment Tax Credit.

0.5

DF (%)

Debt Fraction, fraction of capital financed with debt.

0.5

COE (%)

Cost of Equity, assumed rate of return on equity-financed assets.

0.13

I (%)

Interest rate on debt.

0.08

grant_percentage (%)

Grant percentage, reduces upfront capital costs.

0

tax (%)

Combined state and federal tax rate.

0.257

inflation (%)

Inflation rate.

0.028

property_tax (%)

Property tax rate.

0.0084

insurance (%)

Insurance rate.

0.004

depreciation_period (Years)

Depreciation period.

5

esc (%)

Escalation rate for O&M costs.

0.028

analysis_period (Years)

Analysis period.

30

VOM (USD/kWh)

Variable O&M cost per kWh.

0.003

e_sale (USD/kWh)

Electricity sale price per kWh.

0.07

Examples

Notebook Examples

Modules

Indices and tables

References

[1] W. Short, D. J. Packey, and T. Holt, “A Manual for the Economic Evaluation of Energy Efficiency and Renewable Energy Technologies,” National Renewable Energy Laboratory, Golden, Colorado, 1995. [Online]. Available: https://www.nrel.gov/docs/legosti/old/5173.pdf

[2] https://eta-publications.lbl.gov/sites/default/files/land_requirements_for_utility-scale_pv.pdf

[3] https://www.ny-engineers.com/blog/breaking-down-the-price-of-solar-power-systems#:~:text=The%20November%202021%20technical%20report,scale%20system%20without%20solar%20tracking

[4] https://atb.nrel.gov/electricity/2023/utility-scale_pv

[5] https://www.teslarati.com/tesla-megapack-pge-monterey-ca-moss-landing/