Density matters: Carbon Neutral Potential

Today, the World is facing the most important environmental challenge in the whole of humanity: Climate change. It is known that, this it is mainly driven by carbon emissions and with the building sector contributing to up to 40% of the total emissions. In this regard, some of the main questions raised by people at Transsolar are: where are we and what could we do more than what we are already doing to limit global warming? This results to discussions around the topic of Carbon Neutrality during the project days, trying to find a uniform approach to address Carbon Neutrality in projects and how to communicate its meaning to clients.

Looking around to the rest of the world, different approaches and definitions of Carbon Neutrality already existing were compared. In the search to come out with our own definition and framework, it was thought that maybe a definition is not needed, but instead defining what is the potential for Carbon Neutrality is important, and as well as how to communicate this potential to clients.

Therefore, the whole discussion was flipped from Carbon Neutrality onsite definition to Carbon Neutrality onsite potential. To understand Carbon Neutrality onsite Potential, the focus was put on how much a building can do to be "Carbon Neutral" onsite. From a similar perspective, one of the most relevant question raised was: “what is the density(height) of a low energy building to be Carbon Neutral onsite based on a certain program (residential, school, office etc.), in a certain climate and considering what carbon balance (operational energy, plug loads, embodied carbon)?”

Here starts the sensitivity analysis, trying to answer these questions for different climate zones in the World. The main takeaways from the sensitivity analysis are summarized in the following points:
• To achieve Carbon Neutrality onsite, the height of the building will vary based on the carbon balance (operational energy, plug loads, materials) and climate.
• If embodied carbon of materials is included in the carbon balance, there is only a slight difference in number of floors between wood and concrete construction for some climates (such as Stuttgart) compared to the others such as Pune.
• The orientation of the building offers an extra advantage (height of building) in climate with high solar radiation (closer to the equator).

To keep the bigger picture in mind, the question about the impact of buildings on climate change is still to be addressed. However, this study provides some insights to understand the potentials and limitations of achieving Carbon Neutrality onsite in different parts of the World.

final documentation >

Mentors: Clara Bondi, Tommaso Bitossi

Francis Fotsing – Cameroon

Francis Fotsing – Cameroon

Francis holds a master’s degree in Energy Engineering from the Pan African University Institute of Water and Energy Sciences (PAUWES) in Algeria. He was project manager of the JUA JAMII Team for the Solar Decathlon Africa in Morocco. His work experience reaches from projects in the field of energy efficiency, renewable energy, sustainable building, HVAC systems, oil and gas, and waste management.