Real-time data can help to track and reduce emissions from electricity sector

Power generation is currently the largest source of CO₂ emissions globally with fossil fuel use such as coal and gas still featuring heavily in power mixes around the world. But the power sector also represents the greatest opportunity to reduce emissions on both the supply and demand side of the global energy system. By integrating larger shares of renewables and electrifying end-use sectors, the world can gradually transition away from fossil fuel use on the way to meeting its climate goals.

Most climate mitigation scenarios include some degree of electrification of end-use sectors, which leads to a substantial increase in the share of electricity in final energy consumption. As such, it is important to consider how electricity generation, particularly from low emissions sources, and electrification may contribute to decarbonisation goals and overall emissions reduction benefits.

Electricity grids are sensitive to a variety of factors, including:

1. supply and demand shocks such as wars, pandemics and extreme weather events
2. predictable variations like intra-day, monthly and seasonal weather changes
3. evolving policy settings, including but not limited to reform or repeal of climate and energy policy measures.

The IEA has leveraged real-time data from the IEA Real-Time Electricity Tracker alongside granular electricity generation data included in the IEA World Energy Balances to develop real-time data for tracking CO₂ emissions associated with the electricity grids with hourly and daily resolutions. Such data provides the opportunity to track emissions with a higher temporal resolution compared to monthly and yearly emission factors derived from statistics. For details corresponding to the underlying methodology, please refer to the documentation file.

Access to such timely emissions data can help shape effective policy measures to incentivise shifting demand to times when penetration of low emissions sources in the electricity mix is high. This flexibility can reduce the emissions footprint of electricity generation and is expected to be increasingly important as grids integrate larger shares of variable power generation. Additionally, the disclosure requirements of greenhouse gas (GHG) emissions by the private sector have increased significantly and will continue to do so in the coming years. Access to high quality real-time grid intensity factors for tracking the footprint corresponding to electricity consumption may better incentivise load management and procurement strategies that could support decarbonisation of grids. 

Real-time CO₂ intensity data means the impact of disruptions such as extreme weather events on electricity grids can be monitored. This information may provide valuable insight for strengthening the resilience and flexibility of power generation systems.

As an example, earlier this year, Colombia's hydro reservoirs hit a record low of 30% in April. As hydro availability dwindled, CO₂ intensity rose steadily, surpassing 300 gCO₂/kWh by the end of the month. However, due to heavy rainfall, the grid intensity quickly dropped back to below 100 gCO₂/kWh in early May.

Additionally, seasonality, weekly and intra-day variations are important characteristics of electricity supply/demand and influence the emissions footprint of electricity grids. The supply and consumption patterns are dependent on multiple factors such as the production mix, electricity/fuel prices, periodic activities and weather variables. Hence, it is valuable to compare CO₂ intensity of electricity grids across times of day, seasons and countries. By analysing the average intensity for each hour over a month, clear patterns emerge. 

In Germany, CO₂ intensity fluctuates between 100 and 350 gCO₂/kWh, where the upper bound is influenced by the continued reliance on coal and natural gas in the electricity mix, particularly during fall and winter when the demand is higher. However, thanks to higher penetration of solar and wind power, the spring and summer months show a noticeable dip in CO₂ intensity around midday.

South Africa’s electricity generation is dominated by coal, with renewables accounting for around 8%. As a result, the country’s intensity remains relatively stable throughout the year, reaching approximately 1 000 gCO₂/kWh at night and dropping to around 800 gCO₂/kWh between 8 a.m. and 7 p.m. when solar output increases.

In Costa Rica, 70% of electricity generation comes from hydropower. The wet season, lasting from May to mid-November, sees low CO₂ intensity in the range of 15-100 gCO₂/kWh, with a peak occurring in the early afternoon when thermal generation increases. However, during the dry season, as rainfall becomes scarce, CO₂ intensity rises. The daily intensity curve during the dry season contrasts sharply with that of the wet season, with higher values at night (when hydro production is lower) compared to the daytime.

This example of Germany, South Africa and Costa Rica during the current year illustrates the significant variations in emissions intensity of electricity grids throughout the day, across seasons and among countries. The IEA Real-Time Electricity Tracker allows users to explore different years and countries independently, displaying not only CO₂ intensities, but also the corresponding emissions data broken down by fuel type. 

As shown above, the real-time emissions data helps improve our understanding of how various patterns and disruptions effect the emissions footprint of electricity grids. Policy makers may leverage such information to introduce price signals and tariffs which would incentivise load shifting, hence reducing the climate impact of electricity consumption.

Additionally, high quality real-time grid intensity factors enable tracking emissions which are closely correlated with physical delivery of electricity to consumers. An increasing number of organisations have pledged emissions reduction targets to demonstrate their efforts to reduce the climate impact of their operations. Hence, the disclosure of GHG emissions has increased significantly in recent years. This type of reporting will continue to increase as more mandatory disclosure requirements come into effect. Electricity consumption is a major contributor to the organisational footprint across different activity sectors. At present, most corporate footprint measuring, and clean electricity procurement practices, are guided by the accounting framework set out in the Greenhouse Gas Protocol (GHG Protocol).

The GHG Protocol sets two different approaches for estimating the GHG footprint corresponding to consumption of purchased electricity. However, detailed in a recent survey feedback, experts express concern regarding risk of discrepancies between attributed and actual emissions reduction claims under the current framework. The location-based method, which calculates the emissions based on a yearly average intensity of the power grid in a specific geographical region, may not reflect an accurate estimate of system emissions, and thus a fair allocation of reduction commitments. Similarly, the market-based approach, which relies on emission intensities based on contractual instruments, could underestimate the actual emissions. As suggested by the experts, this problem arises as emissions intensity of the delivered electricity to the point of consumption may not match the corresponding procurement contract and result in misreporting. Access to real-time data on intensity of electricity grids, if complemented by geographical granularity, may enable reporting emissions which are closely correlated with physical delivery of electricity. Such granular tracking requirements may better incentivise load management and procurement strategies that may accelerate grid decarbonisation.

However, real-time electricity data may not currently capture the entire scope of generation data for a given country. This is because this data is typically derived from the information published by transmission system operators (TSOs). Hence, the data does not always include all generation from small scale/distributed sources nor generation from auto-producers. As a result, real-time grid carbon intensities are not always well-suited for reporting purposes. This constraint highlights the importance of having access to all-encompassing real-time generation information to enhance the suitability of this data for climate disclosure requirements. The IEA Emissions Factors database currently publishes annual average intensities of the national grids which may be used for location-based reporting under the GHG Protocol.

It should be also noted that the real-time grid intensity data developed by the IEA are production-based factors and do not consider the impact of cross-border trade. The IEA will look at developing consumption-based intensities in a near future by considering cross-border flows to obtain a closer estimate of intensity at the point of consumption.