This knowledge base article explains how RapidLCA accounts for grid electricity.
It is anticipated that only a small number of experienced users will need this information. Good prior knowledge would be an understanding of National Greenhouse Gas Reporting standards and the “EN15978 Sustainability of construction works – Assessment of environmental performance of buildings – Calculation method”.
RapidLCA (and the underlying eToolLCD software) aligns with EN15978 for accounting for grid electricity impacts. The key requirements from this standard as they relate to electricity impacts are:
- All significant impacts should be accounted for (meeting the study cut of rules)
- Must avoid double counting of impacts and benefits associated with energy production
- Building integrated equipment is included in scope, off site equipment is not in scope even if commissioned by the building developers as part of the scope of the building development.
- The data quality requirements relevant to the electricity and grid inventory must be satisfied
The LCI data that RapidLCA relies on is AusLCI which draws the grid inventory data from the NGERs factors. It is important to note that the purpose of AusLCI data and NGERS data is quite different. NGERs data is meant to determining national greenhouse gas accounts and the factors are established explicitly to avoid double counting of these national emissions. The factors are aggregated (eg single figure) and there is very limited granularity of the underlying processes and assumptions etc. AusLCI however is meant for Life Cycle Assessment purposes and provides data in a very granular and holistic form. Each year the NGERs factors are released the AusLCI grid factors are reconciled against these factors, in addition to generation source information from the market operators to update the AusLCI inventory data.
Because AusLCI is using NGERS factors the grid impacts are provided per state/region (as per NGERS). So a building in Canberra for example will be using the NSW / ACT Grid figures from NGERS.
Green Power and Off-site Renewables
Credits and impacts associated with green power purchase agreements and off-site renewable plants (i.e. not integrated into the building) are not accounted for in the scope of the study in accordance with EN15978. The reasons for this are detailed in this eToolLCD support post.
Notwithstanding EN15978, Green Power and offsite renewable plant investments should be encouraged, they are very important aspects of the low carbon future. To model “what if” scenarios users can add equivalent solar generation to their design. Note that this should not be the design “Submitted” but can be useful for understanding the affect on your building footprint.