The view of Kornelis Blok

Professor of Energy Systems Analysis Kornelis Blok (Faculty of Technology Policy and Management), who also contributes to IPCC reports on climate mitigation, is chairman of the TU Delft Energy Initiative. The world’s entire energy system is to be overhauled in 20-30 years’ time. How will we do that?

Today, the final energy use consists of 20% electricity and 80% fuels and heat. The electricity is produced globally by two-thirds from fossil sources. Fuels and heat are to a much larger extend based on fossil sources, say up to 90%.

In the EU, where we now see a stable energy use, energy efficiency improvement could lead to a reduction of the energy consumption. On a global scale the situation would be  different. Because of the much stronger increase in population and economic growth, energy efficiency improvement could still lead to a stabilisation of global energy use.

One of the important by-products of energy efficiency is electrification. We see in most long-term low-carbon scenarios that the share of electricity increases a lot. Where it is now 20%, it will probably go to 40-50% in the long run. In most scenarios solar energy and wind energy are most important. That has to do with the fact that the cost of these two sources has gone down substantially over the last ten years. But others like hydropower, nuclear energy and fossil fuels with carbon capture and storage will play a role as well.

The large share of solar and wind will also lead to challenges for the electricity system. One of them is the larger flexibility that is required. Production of solar and wind normally does not match with the demand for electricity. So, we need flexibility that can be achieved in many ways. For example, through grid expansion, which makes international exchange easier. Demand response also increases the grid’s flexibility, as do short-term and long-term storage.

Having said that, we also need fuels and heat. It is possible to supply low-temperature heat, say up to 100 degrees or so, from geothermal sources or from solar sources. That can solve part of the heat and fuels requirement. But we also need fuels for high-temperature applications in industry and transportation. We basically have three important categories to supply these: bioenergy, fossil fuels with carbon capture and storage, and hydrogen or other new fuels. Hydrogen can be produced in two ways: green hydrogen from renewable electricity and blue hydrogen from fossil fuels in combination with carbon capture and storage. With hydrogen we can also produce various other substance like ammonia and ethylene.

Developments in fuel and heat are typically in a less advanced stage than the transition in the electricity sector. Green fuels are also typically more expensive. Where solar and wind have become quite affordable, most of these new fuels and resources are still substantially more expensive than their fossil alternatives.

Overall, the challenge of the energy transition is huge because the world needs to accomplish this in a period of 20-30 years. That is a very short time to completely redevelop the energy system.”  

In the MOOC Designing a climate neutral world Professor Kornelis Blok will focus on designing a climate neutral world. Participants will learn about climate change strategies and are given basic tools used for evaluation alternative options for mitigating greenhouse gas emissions. See online-learning.tudelft.nl.

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