Article: Surana, K and S.M. Jordan. 2019. The climate mitigation opportunity behind global power transmission and distribution. Nature Climate Change, 9, 660-665. https://doi.org/10.1038/s41558-019-0544-3
Climate mitigation planning is inadequate without acknowledging the need for an overhaul of our global power infrastructure. As it stands, the power sector is responsible for around a third of total carbon emissions worldwide, and these emissions continue to rise at a terrifying rate.
One of the key climate goals outlined in the Paris Agreement is the reduction of carbon dioxide emissions, which are largely produced by power generation via fossil fuels – currently the leading source of electric power globally. However, a new study asks us to consider the emissions that result not just from the generation of power, but from its transmission and distribution through our power grids. In other words, how are CO2 emissions affected by inefficiency losses as electricity courses the grid to reach our cities and towns?
The life cycle of electric power is more complex than we give it credit for
Drs. Kavita Surana from the University of Maryland and Sarah M. Jordaan from Johns Hopkins University argue that a significant portion of electric power is generated solely to compensate for losses in its delivery – that is, its transmission and distribution (T&D) – see Figure 1. There is enormous potential to reduce these T&D losses globally, which could cut global carbon emissions substantially while paving a path towards efficient and sustainable renewable power grids. The researchers sought to find out just how much opportunity lay in reducing these losses alone.
But out of the 162 countries that have submitted climate mitigation plans to the World Bank (known as INDCs – intended nationally determined contributions) as part of the Paris Agreement, only 32 have mentioned plans to reduce T&D loss. In this study, Drs. Surana and Jordaan analyzed the limitations to our knowledge that may prevent policymakers from producing more expansive climate mitigation strategies – particularly ones that address emissions from T&D loss.
Where is the lost power going?
The task of estimating global electric power lost in transit is made more difficult by the fact that it varies drastically from country to country, and in some cases, within a single country. Just where are these losses coming from, and where does the lost power go?
To glean an answer, the researchers characterized T&D losses in two ways. First, they defined physical inefficiencies of power grids due to aging infrastructure – old wires, for example – as technical losses. Next, they defined regulatory inefficiencies resulting in power consumption without financial compensation – such as fraud, meter tampering, and stealing – as non-technical losses, which can alter demand for electric power and thus its consumption patterns. These losses can be estimated (with uncertainty) from data for power generated, consumed, and paid for within each country.
The proportion of technical to non-technical losses helps inform us of region-specific (rather than global) needs to lower emissions from T&D losses. For example, countries experiencing war and conflict, such as Haiti, Iraq, and Pakistan, suffer from some of the highest T&D losses in the world due to widespread destruction of their infrastructure. Without the resources to repair and reconstruct, these countries suffer from highly inefficient power grids and thus higher emissions that are not simple to address.
Calculating opportunities for carbon emissions reduction
With data available from previous studies and institutions such as the International Energy Agency (IEA), World Bank, and National Renewable Energy Laboratory (NREL), the researchers estimated T&D losses in 2016 for 142 countries. Emissions factors – values that relate an activity (like electricity generation and delivery) to a quantity of CO2 emitted – were calculated for each country’s generation technology or fuel source.
While this study notes that a global mean T&D loss has been estimated at about 5% of total power generated, their results indicate that India’s losses add up to a whopping 19% while Singapore – the most efficient distributor of electric power in the world – is estimated at just 2%. The United States falls around 6% while countries ravaged by war and other extreme circumstances – like Iraq, the Democratic Republic of Congo, and Sudan, to name a few – average 24%.
While countries with high T&D losses – such as developing nations like India – stand to gain the most from improving the efficiency of their power grids, the study suggests that global-scale reductions in T&D losses can have globally significant impacts on carbon emissions. They estimate that up to the equivalent of 544 million metric tons of CO2 emissions per year (MtCO2e/yr) can be prevented by reducing both technical and non-technical T&D losses of each country to reflect the global average of 5%. Assuming a typical passenger car emits 4.6 MtCO2e/yr, that’s the yearly emissions of about 118 million cars!
Global priorities for climate mitigation
Within the full life cycle of electric power – from mining and drilling for fossil fuels, to power generation, to delivery – the majority of emissions undoubtedly come from the actual power plants where these fuels are burned and turned into electricity. Consequently, we know that reducing T&D losses can only go so far. Decarbonization – the transition to renewable power generation – is the most important thing the power sector could do to mitigate climate change.
The researchers suggest that strengthening grid infrastructure may offer multiple benefits regardless, including optimized power grids that are more reliable and durable than existing ones. As climate change and climate-affected conflict increasingly threaten our aging power infrastructure, optimization may start to become a necessity.
I’m a PhD student at the University of Rhode Island’s Graduate School of Oceanography. I use a small-scale computer model to study how physical features like surface waves at the air-sea interface produce friction for the wind that can limit momentum, energy, gas, and heat exchange between the ocean and atmosphere. In the future, I hope to learn more about the role waves play in different parts of the world as weather and climate patterns evolve. Also, I love to write.