DOLPHYN

Overview

DOLPHYN is a configurable, open source energy system optimization model developed to explore interactions between multiple energy vectors and emerging technologies across their supply chains as part of a future integrated low-carbon energy system.

In its current form, the DOLPHYN model evaluates investments and operations across the bulk supply chains for electricity and Hydrogen (H2), including production, storage, transmission, conditioning, and end-use consumption. Importantly, the model is able to capture interaction effects between the electricity and hydrogen infrastructures through different technology configurations for: a) using hydrogen for power generation and b) the ability to produce hydrogen using electricity. The model is setup as a single-stage investment planning model and determines the least-cost mix of electricity and H2 production, storage, and transmission infrastructures to meet power and H2 demands subject to a variety of operational and policy constraints, considering carbon emissions at the same time. The DOLPHYN model is an extension of the GenX electricity system model and uses much of the same source code for characterizing the electricity system operations and expansion as included in the GenX model (v0.2.0). Periodically, the electricity system representation will be updated as per the latest GenX version. Users looking to study electricity systems alone are encouraged to consider working with GenX rather than DOLPHYN for best functionality and experience.

The developed model can incorporate a wide range of power and H2 technology options, including VRE generation, carbon capture and storage (CCS) applied to power and H2 generation, and truck (gaseous, liquid) and pipelines for H2 transportation. The power systems and H2 supply chain are coupled primarily through electrolysis and power generation technologies fueled by H2, as well as electricity consumption in H2 compression/liquefaction. The key operational constraints of the model include:

supply-demand balance for H2 and electricity at each zone;
inventory balance constraints for stationary storage technologies;
inventory balance constraints related to trucks at a given location (any of the zones and routes, arriving, departing or in transit) and for different states (empty and full), and
linearized unit commitment for conventional thermal power generation technologies and natural gas based H2 production technologies.

The model is designed to be highly flexible and configurable for use in a variety of applications from academic research and technology evaluation to public policy and regulatory analysis and resource planning.

Requirements

DOLPHYN runs on Julia versions above 1.4 series, and a minimum version of JuMP v0.21.x. It is currently setup to use one of the following open-source freely available solvers: A) Clp for linear programming (LP) problems and (B) Cbc for mixed integer linear programming (MILP) problems. We also provide the option to use one of these two commercial solvers: C) Gurobi, and D) CPLEX. Note that using Gurobi and CPLEX requires a valid license on the host machine.

The file julenv.jl in the parent directory lists all of the packages and their versions needed to run DOLPHYN. You can see all of the packages installed in your Julia environment and their version numbers by running pkg> status on the package manager command line in the Jula REPL.

Running an Instance of DOLPHYN

Download or clone the DOLPHYN repository on your machine in a directory named 'DOLPHYN-dev'. Create this new directory in a location where you wish to store the DOLPHYNJulEnv environment.

The Run.jl file in each of the example sub-folders within Example_Systems/ provides an example of how to use DOLPHYN.jl for capacity expansion modeling. Descriptions of each example system is included in the next section. The following are the main steps performed in the Run.jl script:

Establish path to environment setup files and DOLPHYN source files.
Read in model settings genx_settings.yml for electricity sector and other setting files for H2 supply chain from the example directory.
Configure solver settings.
Load the model inputs from the example directory and perform time-domain clustering if required.
Generate a DOLPHYN model instance.
Solve the model.
Write the output files to a specified directory.

To run the model, first navigate to the example directory within DOLPHYN- dev/Example_Systems/{desired-example-directory}:

cd("Example_Systems/{desired-example-directory}")

Next, ensure that your settings in global_model_settings.yml, GenX_settings.yml, hsc_settings are correct. The default settings use the solver Gurobi (Solver: Gurobi), time domain reduced input data (TimeDomainReduction: 1). Other optional policies include minimum capacity requirements, a capacity reserve margin, and more.

Once the settings are confirmed, run the model with the Run.jl script in the example directory:

include("Run.jl")

Once the model has complete, results will be write in the 'Results' directory.

Example Systems

SmallNewEngland: OneZone is a one-year example with hourly resolution representing Massachusetts. A rate-based carbon cap of 50 gCO₂ per kWh is specified in the CO2_cap.csv input file. Expect a run time of ~5 seconds.

SmallNewEngland: ThreeZones is similar to the above example but contains zones representing Massachusetts, Connecticut, and Maine. Expect a run time of ~5 seconds.

2030_CombEC_DETrans is a combined power and hydrogen model for the EU for the year 2030. It contains a power model with hourly resolution, contains zones representing Belgium, Germany, Denmark, France, Great Britain, the Netherlands, Sweden, and Norway. The model also includes a CO2 constraint representing 30% of 2015 power sector CO2 emissions applied to the hydrogen and power sector jointly. Expect a run time of ~8 minutes.

DOLPHYN Team

The model was originally developed by Guannan He while at the MIT Energy Initiative, and is now maintained by a team contributors at MITEI led by Dharik Mallapragada as well as Guannan He's research group at Peking University. Key contributors include Dharik S. Mallapragada, Guannan He, Yuheng Zhang, Youssef Shaker, Jun Wen Law, Nicole Shi and Anna Cybulsky.

grantaguinaldo / DOLPHYN