Energy Independence and freedom form GHG emissions, which we call net-zero is a pledge many countries, industries and some individuals have undertaken. However, the path to achieve these is far from clear. From the choices of technologies to incentives and policies, how to approach the net-zero transition is a problem of multi objective optimisation. While the above approaches are attempted feverishly or sheepishly by many, a question to ponder is if we are approaching this transition the wrong way. Air, water, heating, cooling and electricity form five principal utilities, along with material streams and human resources to deliver any of the goods or services in the modern society. Would it then be prudent to approach decarbonisation and net-zero transition by handling it utility wise?
For instance, water, a commonly used and mis-used resource contributes to around 10-12% of the global GHG emission. Similarly, compressed air contributes to around 2% of the global GHG emission. Among the energy steams, heating and cooling contribute to nearly 50% of the overall energy demand including electricity. While these are based on utilities, decarbonisation efforts are often focused on specific industrial sectors by denoting them under categories like “hard to abate” or “transportation” or “agriculture” etc. By such classification, we quickly jump to solutions that may often be unviable economically or even sustainable. It is very clear that for the energy transition to be successful, it certainly needs to make economic sense. We could look at an alternative framework, by focusing on the five principal utilities or the new panchabutas: Air, Water, Heating, Cooling and Electricity and attempt to decarbonise them along with handling the material circularity. This will also allow us to develop a realistic, time-bound approach to net-zero and such timebound actions are necessary as the globally committed timelines are not very far-off.
Let’s explore the new panchabuta framework with an example. If we want to imagine a net-zero dairy processing plant, we start with the utilities. The requirements are heating for pasteurisation, cleaning-in-place, spray drying and sometimes ultra-high temperature (UHT) processing. Similarly, cooling is needed for pasteurisation, storage and transportation. Coal/fossil fuel or biomass-based boilers are used for generating the above heat and chillers that run on electricity from the grid provide the cooling. Significant water is also used in processing contributing up to 6 kg CO2e for every m3 of water used. The obvious decarbonisation approach would be to use more RE by integrating roof top or other RE sources. But that is only a partial solution and does not address all other emission sources. In this case, the panchabuta approach would be as follows:
- Heating could be decarbonised by switching to RE based sources.
- But before we attempt to do that, it begs to ask if we really need to burn fuels, even if it is biomass, which some may consider as RE.
- A careful look at the temperature needed in the process reveal that it can be satisfied by low grade heat sources such as solar thermal or heat pumps.
- Heat pumps also provide the additional benefit by providing cooling as a byproduct and hence decarbonising the same.
- Water could similarly be decarbonised by complete processing of wastewater within the plant reducing the carbon footprint by over 30-40 times.
- Switching to RE with battery storage, once such optimisations are planned will completely decarbonise dairy processing, that too economically.
A question one may ask is what about sectors like cement, where there are process linked CO2 emissions as well?
Here again, we would take the same approach as above to address heating, electricity and looking at enhancing efficiency to such an extent that we are only left with GHG emissions that we absolutely must deal with and could be possible to handle economically and sustainably.
Industry, agriculture, transportation and human settlements/habitation roughly contributes in equal measure to the global CO2 emission, and we see the common thread that links all these are the five utilities used in different measures. Net-zero and thereby sustainability is embedded in the embodied footprint of these resources. Even human beings, we could argue are over 80% fossil energy. About 200 years ago, they would have been predominantly renewable. Such is the embodied footprint in all the resources we consume currently, that addressing sustainability or even net-zero goals is not meaningful if we frame it into narrow sector or process specific problems. The new panchabuta framework provides an approach to develop a roadmap to net-zero in a time bound manner by focusing on the roots of the problem.
Who knows, India may be net zero even by 2047, when we celebrate our 100th year of independence! Jai Hind!
Author – Prof Satyanarayanan Seshadri
