The project has already resolved several scientific challenges.
1. Although the concept of ‘the feasibility of climate mitigation’ has been widely used in both policy and scientific literature, how to define and systematically assess it in the context of climate scenarios has been contested. MANIFEST has proposed a rigorous definition and a systematic way to assess feasibility that can be used across a wide range of climate actions. We have pioneered a new tool known as a feasibility space which we have tested on a number of energy transition actions such as coal phase-out, renewable energy growth, and CCS deployment.
2. Measuring the speed of growth of still expanding technologies is a challenging scientific problem which scholars have struggled with since the the 1950s. The challenge has always been how to measure growth of a new technology in a way which accounts for the dynamic and non-linear nature of technological growth yet is robust and comparable. In MANIFEST, we designed a metric which measures the maximum speed of growth by fitting a series of S-curve models to identify the timing and level when technology growth peaks. In contrast to other commonly-used metrics in the field, this measure of growth is stable overtime and also robust to different assumptions about future developments.
3. Building on our development of a robust metric for measuring the growth speed of expanding technologies, we developed a method for creating probabilistic global projections for solar and wind power (
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4501704(öffnet in neuem Fenster)). Today, projections for the future of solar and wind power are primarily based on energy system models (ESMs) and integrated assessment models (IAMs). These models depict solar and wind growth due to falling costs and increasing returns, however, renewable growth is also shaped by countervailing forces such as public opposition and incumbent resistance. In MANIFEST, we have developed an empirically-grounded probabilistic model which accounts for both drivers from increasing returns and countervailing forces from for example public opposition. We are validating our model on other technologies and plan to use it to evaluate the new generation of scenarios published since MANIFEST began as well as the tripling of renewables target announced at COP28.
4. Using our new method for measuring the growth of expanding technologies, we measured the growth in the 60 largest countries in the world representing about 95% of the world's electricity supply and found that in about half of these countries, growth is no longer accelerating. Nevertheless, we have identified a number of policies in Europe introduced after the war in Ukraine which aim to re-accelerate wind power. We are working on understanding the advantages and disadvantages of these policies to accelerate the growth of renewable energies.
5. Using our method for measuring the growth of expanding technologies, we have shown that solar and wind power grow slower in latecomer countries than they grow in pioneering countries. Our hypothesis is that the same factors which delay the introduction of these technologies prevent solar and wind from growing faster in latecomer countries. We are now testing this hypothesis to see if it holds across technology types and to better understand the mechanisms shaping technology diffusion in new markets.
6. We developed a systematic method to identify the end of the formative phase and incorporate it into measuring and predicting technological growth. Technological growth during the formative phase is notoriously volatile and is shaped by distinctly different mechanisms than the mechanisms which shape growth once a technology has take-off. Most analysis of future technological deployment does not distinguish between formative and post-formative phase data. We are testing our approach in order to extend this analysis to additional technologies.
7. We developed a method to estimate the future deployment of emerging technologies which are not yet commercial. Understanding the potential growth of such technologies is key to understanding the feasibility of climate targets since meeting them likely implies significant deployment of these technologies like hydrogen, carbon capture and storage (CCS), and negative emission technologies. Yet there is a tremendous amount of uncertainty for these technologies despite extensive policy support. We narrow this uncertainty by developing a three-stage method which considers: the history of industry plans for CCS and their potential failure in the near-term (5-10 years), near-exponential historical acceleration of technology deployment at low market penetration levels (10-20 years), and long-term market expansion. We thus measure feasible deployment levels of emerging policy-driven technologies throughout the century to meet climate targets.
