Impact

Introduction

A Locational Marginal Emission (LME) is a metric that measures the amount of system carbon emissions equivalent (CO₂e) displaced by 1 MWh of clean energy injected into (or induced by 1 MWh of load with drawn from) the grid at a specific location and a specific point in time. This is very similar to an Locational Marginal Prices (LMP), which measures the system cost avoided by 1 MWh of generation injected into the grid at a specific location and at a specific point in time.

Discover offers the ability to analyze historical emissions metrics for operational wind and solar projects. On the map, wind projects are shown as triangles, and solar projects are shown as squares.

LME data is uploaded to Discover within 14 days of receipt. In ERCOT, there is a three month delay in data (i.e. October data will be available in January). In PJM, data is available each following month (i.e. December data is available in January).

Historical

To access and analyze Historical LME data, navigate to Impact on the left side panel (Historical analysis is the default view when opening Impact for the first time). All historical LME rates are calculated at each individual project node.

Users may choose between As-Generated or ATC (Around The Clock) generation data. Historical data is available from January 2018 onwards. Monthly and hourly data is available to perform analysis on project emissions performance.

When viewing monthly As-Generated LME data, the Project Analysis charts both LME values for both observed generation and periods of modeled generation. Hourly modeled generation is used when observed generation is not available to calculated As-Generated LME values, and denoted by triangles connected with a dashed line. Periods with observed generation are shown as circles connected by a solid line. The time range visible is limited by the period for which LME data at the selected node is available.

For ATC LME data, no generation data is required. Instead, a simple monthly average of LME data is shown at the selected node.

For hourly data, users can plot up to 30 days of data at a given time by selecting the date range filters. From there, dragging and selecting a section of the time series chart below will further specify the time range used in the LME and Generation charts below.

Forecasted

Forecasted LME data is calculated by REsurety’s Weather-Smart Fundamentals Forecasting model in a similar manner to forecasted LMPs. All forecasted LME values, like forecasted LMP values, are calculated at the hub. Hourly hub LME values are paired with hourly project-specific modeled generation to calculated As-Gen LME values. The hub for each project is its default assignment based on its geographic location, which can be found in the Project Characteristics for the project in Discover.

To access and analyze Forecasted LME data, navigate to Impact on the left side panel and select the Fundamentals Forecasting tab.

As-Generated and Around-The-Clock LME types are both available. Depending on availability, forecasts of up to 20 years into the future can be selected.

Note: Currently, Impact only supports the Baseline Scenario and Average p-value to generate analytics for forecasted LMEs. Going forward we will be adding more p-values and power markets scenarios. For more information on the inputs for REsurety’s Fundamentals Forecasts, click here.

Upon selecting a project to analyze, the Project Analysis pane will appear, displaying monthly LME data in chart form. To download the chart content, click on the download button in the top right corner.