8,760-hour preliminary design engine

Advanced Microgrid Sizing Calculator

Size solar PV, wind turbines, battery storage, generators, converters, transformers, transfer equipment, and resilient islanding capacity. Compare design strategies, inspect dispatch, estimate lifecycle economics, measure emissions, and export a complete planning report.

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Balanced scenario

Community Resilience Microgrid

Sample Site · Commercial · Grid Connected

Solar PV434 kW789 modules
Battery storage6,000 kWh3,000 kW power
Generator capacity250 kW1 modular units
Renewable fraction62.8%62.2% self-sufficiency
Critical service100.000%0.00 kWh unserved
Net capital cost$3,584,344After incentives
Net present value$-3,012,68246.5 year payback
Carbon reduction55.6%320.4 tonnes annually

Project configuration

Define the site, architecture, electrical service, study period, and project context.

V
Hz
years
%

Electrical load and prioritization

Enter consumption, demand, power quality, load growth, profiles, and critical tiers.

kWh/year
kW
kW
kW
%
%
%
%
%
years
kvar
kW
×
kWh/day
kWh/day
×
×
×
×
×
kW

Solar PV

Configure resource, modules, losses, area limits, existing capacity, and costs.

h/day
×
W
%
°
°
fraction
%
%
%
%
%
%
%
×
kW
kW
USD/kW
USD/kW-year

Wind generation

Configure wind resource, turbine size, losses, availability, and capacity constraints.

m/s
m
m
kg/m³
kW
fraction
%
%
%
units
kW
USD/kW
USD/kW-year

Battery storage

Set chemistry, operating window, efficiencies, C-rate, degradation, reserve, and costs.

%
%
%
%
%
%
%
%
C
kW
kW
%/month
years
cycles
%
%
%
kWh
kWh
kW
USD/kWh
USD/kW
% capex
%

Generator and fuel

Configure modular dispatchable generation, fuel, loading, reliability, emissions, and redundancy.

kW
units
%
%
%
L/kWh
USD/L
L
L/start
seconds
%/minute
minutes
minutes
%
%
hours
USD/hour
USD/kW
USD/kW-year
g/kWh
kg/kWh
dB(A)
hours/year

Other distributed resources

Add CHP, fuel cells, hydro, thermal storage, hydrogen, and vehicle-to-grid resources.

kW
%
%
%
kWhth
kW
kW
fraction
kWhth
kW
kWh
%
kW
kWh
%

Grid connection and tariff

Model import, export, transformer limits, outages, time-of-use rates, and demand charges.

kW
kW
kVA
kW
%
events/year
hours
hours/year
% nominal
% nominal
USD/kWh
USD/kWh
USD/kWh
USD/kWh
USD/kWh
USD/kW-month
USD/month
USD/month
kg CO₂/kWh
%/year

Islanding and resilience

Define outage duration, transfer requirements, reserves, redundancy, and component stress tests.

hours
%
%
%
days
days
ms
days
hours
%

Converters and protection

Size inverters, transformer, transfer switch, overload capability, and grid-forming capacity.

%
%
% rated
seconds
%
%
%
%
%
%
%

Control and optimization

Choose dispatch architecture, operating strategies, scenario, objectives, and constraints.

hours
minutes
%
%
%
%
%
USD
hours/year
kg/year
hours
¤

Financial assumptions

Configure financing, soft costs, escalation, incentives, replacement, salvage, and outage value.

%
%
%
years
%
% direct
% direct
% direct
USD
USD
USD
% capex
%/year
%/year
% capex
USD
years
% capex
USD/tonne
USD/kWh

Environmental and uncertainty

Estimate lifecycle emissions and define uncertainty ranges for sensitivity analysis.

kg/kWh
kg/kWh
kg/kWh throughput
%
USD/kg
USD/kg
USD/kg
±%
±%
±%
±%
±%
±%
± points
runs
%

Scenario comparison

Compare alternative design priorities using the same site, load, tariff, reliability, and equipment assumptions.

ScenarioPVWindBatteryGeneratorRenewablesCritical serviceCapexNPVLCOECO₂ reduction
Low capital 282 kW0 kW 2,770 kWh
1,385 kW
250 kW40.8%100.000% $1,974,528$-1,454,071$037.3%
Minimum lifecycle cost 390 kW0 kW 4,493 kWh
2,247 kW
250 kW56.5%100.000% $2,860,794$-2,203,822$050.5%
Balanced
Active
434 kW0 kW 6,000 kWh
3,000 kW
250 kW62.8%100.000% $3,584,344$-3,012,682$055.6%
High renewable 585 kW0 kW 6,000 kWh
3,000 kW
250 kW79.3%100.000% $3,736,136$-2,651,333$068.2%
Maximum resilience 477 kW0 kW 6,000 kWh
3,000 kW
500 kW69.0%100.000% $3,758,863$-3,069,233$060.5%

Energy and dispatch analysis

First-week hourly dispatch

Monthly energy balance

Annual energy sources

Project cash flow

NPV sensitivity

Monte Carlo NPV distribution

Monte Carlo percentiles

Simulation runs200
NPV P10$-3,489,544
NPV P50$-2,996,229
NPV P90$-2,601,695
Critical service P1099.874%
Critical service P5099.950%
Critical service P9099.999%

Detailed annual results

CategoryMetricResultInterpretation
EnergyTotal load1,200.0 MWh/yearModeled demand before any unserved energy.
EnergyPV production753.6 MWh/yearSynthetic AC-side solar output.
EnergyWind production0.0 MWh/yearOutput after availability and losses.
EnergyOther DER production0.0 MWh/yearHydro, CHP, and fuel-cell output enabled by the user.
StorageBattery charge135.6 MWh/yearEnergy accepted before charging losses.
StorageBattery discharge126.9 MWh/yearUseful energy delivered from storage.
GridImported energy453.3 MWh/yearUtility energy serving demand.
GridExported energy0.0 MWh/yearEnergy sold under the export constraint.
GeneratorGenerated energy0.0 MWh/yearDispatchable output during modeled outages.
ReliabilityUnserved energy0.000 kWh/yearDemand remaining after all resources.
ReliabilityModeled outage hours32 hours/yearEvents generated from entered outage statistics.
RenewablesCurtailed energy0.0 MWh/yearGeneration not consumed, stored, or exported.
FinanceAnnual operating cost$192,316Utility charges, maintenance, fuel, and insurance.
FinanceAnnual project benefit$77,063Energy savings, demand savings, and resilience value.
FinanceBenefit-cost ratio0.16Discounted benefits relative to initial investment.
FinanceBattery replacement yearYear 15Estimated from calendar and cycle limits.
EnvironmentProject emissions255.6 tCO₂e/yearGrid, generator, and simplified lifecycle emissions.
EnvironmentAvoided emissions320.4 tCO₂e/yearDifference from the grid-only baseline.
EnvironmentNOx emissions0.0 kg/yearEstimated from generator production.

Formula used

Solar PV capacity

PV kW = Target renewable energy ÷ (peak sun hours × 365 × system derate)

The result is limited by module area, maximum capacity, existing equipment, and the selected scenario.

Battery energy

Battery kWh = Critical kW × islanding hours × reserve factor ÷ usable SOC window ÷ discharge efficiency

Battery power is sized separately from critical peak demand, motor starting demand, C-rate, and user power limits.

Generator capacity

Generator kW = Critical peak kW × redundancy factor, rounded to complete generator units

The hourly model applies minimum loading, maximum loading, fuel use, battery charging, and outage-only dispatch.

Transformer and inverter

Transformer kVA = Future peak kW ÷ power factor × 1.20
Inverter kVA = Required inverter kW ÷ power factor × harmonic margin

Net present value

NPV = −Net initial cost + Σ [annual net cash flow ÷ (1 + discount rate)^year]

Cash flow includes avoided utility costs, operations, fuel, battery replacement, escalation, resilience value, and salvage.

Renewable fraction

Renewable fraction = Renewable energy used onsite ÷ annual load × 100

How to use this calculator

  1. Enter annual energy, peak demand, power factor, load growth, motor starting, and profile assumptions.
  2. Allocate critical, important, and discretionary load tiers for island operation.
  3. Configure solar, wind, battery, generator, and existing distributed resources.
  4. Enter utility limits, tariffs, outage statistics, demand charges, export rules, and grid carbon intensity.
  5. Set islanding duration, reserve, black start, transfer, redundancy, and component failure scenarios.
  6. Select control architecture, optimization objective, financial assumptions, and uncertainty ranges.
  7. Press Run sizing and simulation to execute all calculations and hourly dispatch.
  8. Review validation warnings, scenario comparisons, dispatch charts, costs, emissions, and exports.

Start with the balanced scenario. Compare low-capital, minimum-cost, high-renewable, and maximum-resilience alternatives before refining assumptions.

Included features

Technical sizing

  • AC, DC, and hybrid architectures
  • Single-phase and three-phase service
  • PV module and area calculation
  • Wind turbine count
  • Battery energy and power sizing
  • Generator modular redundancy
  • Inverter, transformer, and ATS ratings
  • Motor starting and harmonic margins

Operational simulation

  • Synthetic hourly load profile
  • Hourly solar and wind production
  • Battery charging and discharging
  • Time-of-use grid purchases
  • Export and curtailment
  • Grid outage generation
  • Critical-load service calculation
  • Fuel and cycling estimates

Economics

  • Direct and soft costs
  • Tax credits and grants
  • Fuel and O&M escalation
  • Replacement cost
  • Simple and discounted payback
  • Net present value
  • Benefit-cost ratio
  • Levelized energy cost

Reporting

  • Five scenario comparison
  • Validation warnings
  • Hourly and monthly charts
  • Sensitivity chart
  • CSV and JSON export
  • Print-to-PDF report
  • Browser project storage
  • Equipment presets

Model scope and engineering limitations

This application is a preliminary screening and conceptual sizing tool. It does not replace load-flow, short-circuit, protection coordination, grounding, arc-flash, harmonic, dynamic stability, transient, electromagnetic, structural, fire-safety, or detailed interconnection studies.

The annual profiles are synthetic. Detailed design should use validated interval demand, site weather files, manufacturer efficiency maps, generator fuel curves, battery degradation models, forced-outage distributions, and local tariff schedules.

Final ratings must follow local codes, utility requirements, environmental permits, equipment certifications, cybersecurity policies, ventilation requirements, fire protection rules, and qualified engineering review.

Calculation log

Project: Community Resilience Microgrid Scenario: balanced Annual load: 1,200,000.0 kWh Peak load: 310.0 kW Critical peak: 170.5 kW Future peak: 377.9 kW PV capacity: 433.5 kWdc PV inverter: 346.8 kWac Wind capacity: 0.0 kW Battery: 6,000.0 kWh / 3,000.0 kW Generator: 250.0 kW Main inverter: 3,587.0 kVA Transformer: 492.9 kVA ATS: 741 A Grid import: 453,294.7 kWh Grid export: 0.0 kWh Unserved energy: 0.000 kWh Fuel: 0.0 L Net capex: $3,584,344 NPV: $-3,012,682 Carbon reduction: 55.63%

Project manager

Save inputs in this browser, restore them, duplicate a design, download input JSON, or apply equipment presets.


Battery preset

Generator preset


Import interval load CSV

The importer reads numeric interval values, estimates annual energy, average demand, and peak demand, then populates the load inputs. Hourly, 30-minute, and 15-minute series are supported.


Local browser storage is not encrypted engineering document control.

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