Training & Tutorials — Utility Forecasting

Utility tutorials for forecasting DER deployment and reviewing forecast results.

Forecasting Overview

Gridtwin forecasting predicts where, when, and how DERs are most likely to be developed — and what their interconnection will cost — before projects are built. Standardized data and models turn a multi-month effort into a repeatable, configurable run.

• Rank millions of potential projects on their economics (20-year IRR)
• Simulate year-over-year deployment against real network constraints
• See per-substation and per-feeder MW and the upgrades they trigger
• Slice results by site, year, feeder/substation, and cost

Steps

1. Confirm objectives for the forecast
2. Identify datasets and assumptions
3. Run parcel processing, then the solar forecast
4. Interpret results and sanity-check against assumptions

Step 1: Gather and Standardize Data

Gridtwin ships the standard layers, so a forecast can run with minimal input; the utility supplies the territory-specific layers that define real capacity, costs, and economics.

• Standard layers from Gridtwin — parcels, land cover (NLCD), elevation (USGS DEM), and solar resource
• Utility-specific layers — network data and ratings, hosting capacity, interconnection cost catalogs, and financial parameters
• Environmental, conservation, and cultural exclusion layers
• Uploads live in the shared file library — filtered by state, utility, and layer type, and reused across reports and forecasts

Steps

1. Review the standard datasets for your territory
2. Upload utility-specific inputs to the file library
3. Validate schemas and geographies
4. Point reports at the correct datasets

Step 2: Parcel Processing — Characterize and Price Every Site

The Parcel Processing & Creation report turns every parcel in the territory into a characterized, priced candidate site — the foundation the forecast ranks on.

• Land use → buildable area, with exclusions and setbacks clipped out
• Terrain → slope and aspect; solar resource → capacity factor
• Sizing → MW potential from the buildable area
• Network → nearest feeder and substation, with distances and hosting capacity
• Interconnection → cost to connect, priced from the cost catalog
• Economics → a 20-year IRR and NPV for every parcel

Steps

1. Run the Parcel Processing & Creation report
2. Choose the parcel source, project type, and allowed land uses
3. Layer in environmental, wetland, and brownfield exclusions
4. Review the resulting candidate dataset

Step 3: Build and Rank the Candidate Pool

Before deployment is simulated, the candidate pool is filtered and ranked into a merit order against the live network.

• Filter on project size, slope, coverage, distances, interconnection cost, and a minimum 20-year IRR
• Drop parcels too close to existing solar
• Re-price every surviving candidate against the current network
• Rank descending by interconnection-adjusted IRR — the merit order

Steps

1. Set viability thresholds and filters
2. Gridtwin ranks the pool by 20-year IRR

Step 4: Forecast Deployment Over Time

The forecast connects projects one at a time, in merit order, while the network state updates around them — each connection changes what the next selection sees.

• Apply annual MW deployment targets, processed in ascending years
• Connect the best site and draw down its feeder and substation hosting capacity
• Re-price and re-rank same-substation neighbors after every connection
• Schedule triggered upgrades — their added capacity unlocks in a later year
• Continue until each year's target is met; a year can underfill if capacity runs out

Steps

1. Set annual MW targets across the deployment horizon
2. Tune substation and feeder expansion behavior
3. Run the Solar Forecast report
4. Review the deployment timeline

Modeling Network Constraints

Detailed feeder and substation models keep the forecast honest about grid limitations. Interconnection costs in a forecast are transparent screening estimates priced from cost catalogs — a heuristic, not a full power-flow study.

• Automatic routing of new service lines
• Feeder and substation capacity gates what can connect, and when
• Two capacity registers — capacity available now, and capacity a scheduled upgrade unlocks later
• Configurable upgrade increments and delays for substations and feeders
• Multi-utility (joint) forecasts — one merit order across territories, each parcel priced with its own utility's catalog

Steps

1. Review feeder and substation limits and fallbacks
2. Configure upgrade triggers, increments, and delays
3. Validate sample scenarios

Technologies Covered in Forecasts

Gridtwin forecasting models support the DER technologies relevant to distribution utilities, each at an appropriate spatial scale.

• Ground-mount solar — parcel-based IRR
• Canopy and commercial rooftop solar — IRR per site
• Residential rooftop solar — propensity models
• Public and residential EV charging — propensity models

Steps

1. Select the technologies in scope
2. Confirm spatial resolution needs
3. Prepare technology-specific inputs

Forecast Outputs and Reports

A completed forecast produces three output files, plus charts and maps in the report viewer — everything exportable for planning and regulatory use.

• forecast.csv — every forecasted project with its year, order, IRR, and cost
• substation_data.csv — sited MW and scheduled upgrades per substation
• feeder_data.csv — per-feeder sited MW and remaining capacity
• Charts and maps in the report viewer for review and sharing

Steps

1. Open results in the report viewer
2. Export the output files
3. Share results with stakeholders