Frequently Asked Questions
Project Setup
What does “Apply shift of days in leap years” do?
This option shifts imported data so the last and first days of the timeseries align correctly when leap years are present.
Front assumes a 365-day year, so enabling this setting ensures timestamps and values stay consistent for leap-year datasets.
Is Front able to pull data for price-strips? How can we import these?
Front does not automatically retrieve price-strips; users must obtain them externally.
Three import methods are available:
Single Price Strip – One file used for every project year.
Multiple Price Strips – Import separate files and assign each to a specific year.
Single File, Multiple Price Strips – A multi-year file where rows = timesteps × years
(e.g., 15 years × 8760 hours = 131400 values).
What if the project life is longer than the imported price data?
If a single file is imported, Front applies it to all years of the project lifetime.
When importing multiple price strips, a dialog will prompt the user to assign each file to a specific year.
Does the program expect a PV profile for one year or the entire project life?
Front expects one year of PV data.
That single profile is treated as representative for all years of the project lifetime.
What does PV Allocation, Wind Turbine Allocation, and Maximum Storage Commitment mean for a hybrid project?
When multiple markets (RT, DAM, 15-Minute) are included, components can be allocated to contribute different percentages to each.
For example, PV could be set to 50% DAM and 50% RT.
If Grid import/export limits are not included, does the program use the interconnection limit as the import and export limit?
Yes.
If explicit import/export limits are not defined, the interconnection limit is used as the boundary for both.
Application
What does it mean to Perform Analysis over BESS only?
When BESS-only analysis is enabled, wind and PV costs are excluded from results.
The model still shows renewable penetration into storage and component behavior, but revenues, costs, and dispatch reflect storage performance only.
Can only PV participate in the Regulation Market?
The program does not explicitly exclude PV; however, standalone PV cannot currently provide Regulation services.
PV must operate together with storage to participate.
For Regulation Up/Down markets, what does Max Reg-Up / Reg-Down Storage Commitment (%) represent?
This value defines the maximum storage capacity committed to Regulation services (capacity payments).
It is based on the full SOC, and actual available export is further reduced by throughput percentage.
Front’s dispatch strategy charges or discharges the battery for Reg-up/down based on price signals and economic benefit.
How is spinning handled in ancillary services?
At present, Frequency Regulation is the only supported ancillary service.
Post-fault corrective response (spinning reserve) is not yet modeled but is on the roadmap.
Is it possible to control how much the battery cycles per day?
Front optimizes economically, cycling the battery to maximize revenue.
The optimizer runs a 24-hour look-ahead followed by a second pass (24–48 hours) to initialize SOC trajectories.
Users may limit cycling using the Limit Cycles per Day option.
How is spinning handled in ancillary services?
Frequency Regulation is currently the only modeled ancillary service.
Spinning reserve is not yet included but planned for future updates.
Equipment
How do I model a custom battery component?
To model a custom battery, open the storage library and choose either to import a sample
(automatically loads a 1 MW / 1 MWh template) or import an .xml file compliant with advanced storage modules in Pro and Grid.
Click the ellipses and select Edit to modify parameters.
Important parameters include:
- Max discharge power and Max charge power (Default tab)
- Nominal voltage and Rate constant (Functional Model tab)
The rate constant controls battery duration.
The capacity curve is generated automatically using the Power (W) to Capacity (Wh) table.
It is recommended to use Peukert-based values.
The Peukert-based capacity equation is:
The conversion from power to current is:
This illustrates decreasing usable energy at higher power due to battery inefficiencies.
The Peukert exponent (k) typically ranges 1.05–1.30 depending on chemistry.
Front can model both simulated and guaranteed degradation.
What is the difference between the simulated and guaranteed degradation models?
Simulated degradation
Uses time and throughput to estimate degradation.
It interpolates from the Lifetime Curve based on depth of discharge and cycles to failure.
Guaranteed degradation
Uses the manufacturer’s degradation table to determine end-of-year state of health based on the number of annual cycles.
Supports non-linear modeling.
Three modes exist:
Default Mode – When multiple defined cycle bins exist, the model chooses the more degraded (higher cycle) bin.
Year-by-Year – Degradation computed independently each year based on actual annual cycles.
Interpolated – Linear interpolation across the table columns to estimate end-of-year SOH.
Economics
Why is the LCOE negative? What causes this?
HOMER’s definition of Cost of Energy (COE) differs from standard breakeven LCOE, allowing results to appear negative depending on project revenues.
HOMER defines:
where
includes capital, replacement, and O&M costs,
and is annualized delivered energy.
Revenues may be incorporated depending on project structure.
For storage, HOMER reports Cost of Storage (COS):
By contrast, standard LCOE (IEA, EIA) is the ratio of present value of total costs to lifetime electricity generated, and does not include revenues.
How is system fixed cost and O&M cost different from equipment costs?
System fixed cost is applied once to the project.
System O&M cost is applied yearly to represent miscellaneous costs not tied to any specific equipment.
How can we generate a report in Front?
Front does not generate a report directly, but users can export results to Excel.
The export creates a workbook where tabs are separated by category and contain the data shown in Selected Overview.
Users may choose which categories to include or exclude during export.