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Giorgi Gogitidze

Engineering case study

Solar + Battery Microgrid Energy-Management Simulator

Seven-day commercial dispatch benchmark comparing grid, solar, rule-based storage, and mixed-integer optimized storage.

  • Executed simulation
  • Automated test

Problem statement

Determine how control strategy changes operating cost, peak demand, renewable utilization, battery cycling, and outage performance while maintaining interval-by-interval power and energy balance.

A reproducible single-bus simulator that schedules PV, battery, and grid power under time-of-use prices, demand charges, equipment limits, and optional outages.

$1,800.27

Optimized weekly cost

Synthetic tariff; down from $4,169.94 grid-only

$2,369.67

Modeled savings

Optimized case versus grid-only over 168 hours

43.35 kW

Optimized peak import

Versus 101.01 kW in the grid-only case

890.90 kWh

Battery throughput

Active cycling under the simplified wear proxy

Project scope

  • 168 hourly intervals using a fixed-seed synthetic commercial load and PV profile
  • Grid-only, solar-only, causal rule-based battery, and perfect-forecast MILP cases
  • Energy charges, demand charges, export credit, throughput cost, and unserved-energy penalty
  • Single AC bus; no feeder voltage, reactive power, transient, or protection model

System or processing architecture

PV, a bidirectional battery inverter, the utility interconnection, and facility load meet at one modeled AC bus. A controller chooses battery and grid setpoints while the validation layer independently checks power balance and state-of-charge recursion.

My engineering contributions

  • Defined the sign conventions, SOC dynamics, dispatch limits, and cost model.
  • Implemented both a causal self-consumption controller and a SciPy/HiGHS mixed-integer optimizer.
  • Added binary charge/discharge exclusivity, outage isolation, peak-demand tracking, and a terminal-SOC constraint.
  • Built sensitivity studies, CSV/XLSX exports, plots, and automated engineering checks.

Important design decisions

  • Used a binary battery-mode variable so simultaneous charging and discharging are structurally impossible.
  • Required final SOC to meet or exceed initial SOC to prevent artificial end-of-horizon savings.
  • Kept the rule-based controller causal and the optimizer perfect-forecast so they serve distinct operational and benchmark roles.

Engineering methods

  • Hourly AC-bus energy balance
  • Efficiency-adjusted battery SOC recursion
  • Mixed-integer linear optimization
  • Fixed-seed scenario generation
  • Sensitivity analysis for PV, storage, tariffs, demand charges, SOC, and outage duration

Selected evidence

Readable results, with context

Microgrid architecture connecting solar, battery, utility grid, facility load, and energy-management controller
Figure 1Single-bus operational model and control boundary used by both battery strategies.
Seven-day optimized load, solar, grid, battery power, and state-of-charge traces
Figure 2Executed optimized dispatch. Positive battery power denotes discharge; all powers are hourly averages in kW.
Weekly operating cost comparison for four microgrid control strategies
Figure 3Synthetic weekly operating-cost comparison including energy, demand, and battery-throughput terms.

Verification and testing

  • Power-balance and SOC-dynamics residuals remain near numerical precision for all four controllers.
  • SOC stays within 16-144 kWh for the 160 kWh battery configuration.
  • Automated tests verify balance, bounds, mutual exclusivity, and zero grid exchange during outage intervals.
  • Fixed seed 321 and machine-readable run metadata make the published week reproducible.

Honest limitations

  • Synthetic hourly data and a short billing window; savings are scenario estimates, not a utility bill forecast.
  • The optimizer assumes perfect foresight and is not a deployed real-time controller.
  • Fixed efficiency and linear throughput cost do not model electrochemical degradation or temperature.
  • No reactive power, network voltage, inverter kVA, interconnection, or hardware behavior is represented.

Tools and technologies

  • Python
  • SciPy HiGHS MILP
  • pandas
  • NumPy
  • Matplotlib
  • Excel

Skills demonstrated

  • Microgrid controls
  • Optimization
  • Battery modeling
  • Energy economics
  • Scenario analysis
  • Model validation

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