Methodology

Every impact number TotalView returns is produced by one consistent method: a consequential, marginal-displacement model paired with full ReCiPe 2016 lifecycle impact assessment. This page explains what that means and why the results hold up to scrutiny.

Consequential, not average

When a solar or wind project adds 1 MWh to the grid, some fossil generator reduces output by roughly 1 MWh. The marginal fuel is the one that actually responds — not the average grid mix. This distinction is the whole ballgame: coal produces roughly 10× the human-health impact per MWh of natural gas, so which fuel backs off determines the real benefit.

TotalView answers the consequential question — what did the grid do differently because this project ran? — rather than assigning a project its share of an average grid.

Step 1 — Determine the marginal fuel mix

TotalView trains an independent model for each grid zone — covering US balancing authorities, European bidding zones, and Great Britain — using publicly available hourly generation data:

Region	Source	Window
US	EIA-930 hourly generation by fuel	2019–present
Europe	ENTSO-E Transparency Platform	2019–present
UK	Elexon BMRS half-hourly generation	2019–present

Each zone’s model learns how generation by fuel type responds to changes in net demand, using hourly features such as net load, ramp rate, time of day and season, interchange, and relative fuel prices. It is a physics-informed model: training enforces grid constraints — energy balance, plant capacity limits, and ramp-rate limits — so it cannot produce physically impossible dispatch. The output is an hourly marginal share for each fuel that varies by hour, season, and market conditions (evening peaks tend to be gas-heavy; overnight hours carry more coal).

Step 2 — Calculate displaced generation

For every hour of the project’s generation profile, displacement is computed per fuel:

displaced_fuel[hour] = project_generation[hour] × marginal_share_fuel[hour]

Hourly displacement is capped at the flexible generation actually available for each fuel — you cannot displace more coal than is running above its baseload minimum. Annual figures are the sum across all 8,760 hours.

Step 3 — Cross-zone displacement

When a project sits in a zone with little or no fossil generation (e.g. hydro- heavy Nordic zones, the Pacific Northwest), displacement is attributed to neighboring zones using measured cross-border power flows — EIA bilateral interchange (US), ENTSO-E physical flows (Europe), and BMRS interconnector flows (UK). Each neighbor is evaluated with its own marginal model and its own regional impact factors.

Step 4 — Transmission-congestion adjustment

In hours when a project’s zone is transmission-constrained, less of the otherwise-marginal fossil generation can actually be backed off — the binding line means the operator backs off something closer instead. TotalView applies an hourly congestion factor (derived from LMP congestion components in US ISOs, and from zonal price spreads and interconnector saturation in the EU/UK) that scales the per-hour displacement. The project’s metered energy delivered is unchanged; only the displacement credited is reduced for those hours. The adjustment is applied identically to metered (existing) and modeled (future) profiles.

Step 5 — Lifecycle impact assessment

Displaced generation is converted to environmental impact using ecoinvent v3.11 characterization factors with the ReCiPe 2016 (Hierarchist) method across 18 impact categories. Results roll up to three endpoint damage categories:

Endpoint	Unit	What it measures
Human health	DALYs	Years of healthy life lost (air pollution, toxicity, climate)
Ecosystem quality	PDFs	Fractional species loss integrated over area × time (land use, ecotoxicity, acidification)
Resource scarcity	USD	Economic cost of depleting non-renewable resources

The manufacturing footprint of the project itself (panels, turbines, balance of system) is computed from technology-specific ecoinvent activities and netted out:

Net impact = fossil-displacement benefit − project infrastructure impact

This is why TotalView reports full lifecycle impact, not a single carbon number — every result spans all 18 ReCiPe categories.

Step 6 — Hourly attribution

Because displacement is resolved hourly, each hour’s impact reflects the fuel actually displaced that hour — a midday hour displacing coal can carry several times the health benefit of an evening hour displacing gas. This enables time-of-generation impact accounting and hour-level attribution for PPAs.

Validation

Results are checked four ways: against directly observed hour-over-hour generation changes in the training data; against prior production outputs for the same projects; against known dispatch characteristics (e.g. coal-heavy MISO, gas-dominated Great Britain); and by backtesting model predictions against observed grid changes when large renewable projects came online.

How results are reported

All TotalView impact results are computed under this single consequential standard. The API returns these results directly through the Impacts & Time Series endpoints — there is no methodology to select or configure.

Next steps

• Impacts & Time Series — retrieve the results this model produces
• LCIA Results — interpret DALYs / PDFs / USD
• ReCiPe Impact Categories — every midpoint and endpoint TotalView reports, defined
• API Reference — exact query params and response schemas