Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Counter-intuitive behaviour of energy system models under CO2 caps and
  prices   The mitigation of climate change requires a fundamental transition of the
energy system. Affordability, reliability and the reduction of greenhouse gas
emissions constitute central but often conflicting targets for this energy
transition. Against this context, we reveal limitations and counter-intuitive
results in the model-based optimization of energy systems, which are often
applied for policy advice. When system costs are minimized in the presence of a
CO2 cap, efficiency gains free a part of the CO2 cap, allowing cheap
technologies to replace expensive low-emission technologies. Even more striking
results are observed in a setup where emissions are minimized in the presence
of a budget constraint. Increasing CO2 prices can oust clean, but expensive
technologies out of the system, and eventually lead to higher emissions. These
effects robustly occur in models of different scope and complexity. Hence,
extreme care is necessary in the application of energy system optimization
models to avoid misleading policy advice.

29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
5
The categories of this paper are: gr-qc
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an