Scenario analysis of accelerated coal phase-out by 2030: A study on the European power system based on the EUCO27 scenario using the METIS model

The present report is a hands-on exercise by the European Commission's Joint Research Centre (JRC) using the METIS model (Artelys, 2017). The area covered by the analysis extends to the 28 EU member states plus Norway, Switzerland and the Western Balkans. The model is used on two variations of the European Commission EUCO27 scenario built to simulate the impacts of an accelerated coal phase-out policy unfolding during the next decade. One of the first results is that the simulated coal-fired capacity retirement will lead to conditions of lacking adequacy in certain areas. The two new scenarios restore adequacy by expanding the European power system in two opposing directions. The first is an expansion-as-usual scenario, based on new thermal peaking capacity. The second represents a scenario, where additional optimally placed renewable capacity, coupled with interconnection upgrades and limited storage, appear equally effective in restoring adequacy to the affected regions.JRC.C.7-Knowledge for the Energy Unio

Measurable events indexed by trees

A tree $T$ is said to be homogeneous if it is uniquely rooted and there exists an integer $b\geq 2$, called the branching number of $T$, such that every $t\in T$ has exactly $b$ immediate successors. We study the behavior of measurable events in probability spaces indexed by homogeneous trees. Precisely, we show that for every integer $b\geq 2$ and every integer $n\geq 1$ there exists an integer $q(b,n)$ with the following property. If $T$ is a homogeneous tree with branching number $b$ and $\{A_t:t\in T\}$ is a family of measurable events in a probability space $(\Omega,\Sigma,\mu)$ satisfying $\mu(A_t)\geq\epsilon>0$ for every $t\in T$, then for every $0<\theta<\epsilon$ there exists a strong subtree $S$ of $T$ of infinite height such that for every non-empty finite subset $F$ of $S$ of cardinality $n$ we have \mu\Big(\bigcap_{t\in F} A_t\Big) \meg \theta^{q(b,n)}. In fact, we can take $q(b,n)= \big((2^b-1)^{2n-1}-1\big)\cdot(2^b-2)^{-1}$. A finite version of this result is also obtained.Comment: 37 page

A density version of the Carlson--Simpson theorem

We prove a density version of the Carlson--Simpson Theorem. Specifically we show the following. For every integer $k\geq 2$ and every set $A$ of words over $k$ satisfying $$\limsup_{n\to\infty} \frac{|A\cap [k]^n|}{k^n}>0$$ there exist a word $c$ over $k$ and a sequence $(w_n)$ of left variable words over $k$ such that the set $$\{c\}\cup \big\{c^{\smallfrown}w_0(a_0)^{\smallfrown}...^{\smallfrown}w_n(a_n) : n\in\mathbb{N} \ \text{ and } \ a_0,...,a_n\in [k]\big\}$$ is contained in $A$. While the result is infinite-dimensional its proof is based on an appropriate finite and quantitative version, also obtained in the paper.Comment: 73 pages, no figure

The Joint Research Centre Power Plant Database (JRC-PPDB): A European Power Plant Database for energy modelling

The current document reports on the creation of a power plant database which by combining input from different sources aims to become the most comprehensive source of information on powerplants currently available to serve the energy modelling activities within the European Commission. The database, called JRC-PPDB is hosted online on a MySQL server in Petten. The JRC-PPDB has been designed at a conceptual level for automatic updating to the highest extent possible.JRC.C.7-Knowledge for the Energy Unio

Dense subsets of products of finite trees

We prove a "uniform" version of the finite density Halpern-L\"{a}uchli Theorem. Specifically, we say that a tree $T$ is homogeneous if it is uniquely rooted and there is an integer $b\geq 2$, called the branching number of $T$, such that every $t\in T$ has exactly $b$ immediate successors. We show the following. For every integer $d\geq 1$, every $b_1,...,b_d\in\mathbb{N}$ with $b_i\geq 2$ for all $i\in\{1,...,d\}$, every integer k\meg 1 and every real $0<\epsilon\leq 1$ there exists an integer $N$ with the following property. If $(T_1,...,T_d)$ are homogeneous trees such that the branching number of $T_i$ is $b_i$ for all $i\in\{1,...,d\}$, $L$ is a finite subset of $\mathbb{N}$ of cardinality at least $N$ and $D$ is a subset of the level product of $(T_1,...,T_d)$ satisfying $$|D\cap \big(T_1(n)\times ...\times T_d(n)\big)| \geq \epsilon |T_1(n)\times ...\times T_d(n)|$$ for every $n\in L$, then there exist strong subtrees $(S_1,...,S_d)$ of $(T_1,...,T_d)$ of height $k$ and with common level set such that the level product of $(S_1,...,S_d)$ is contained in $D$. The least integer $N$ with this property will be denoted by $UDHL(b_1,...,b_d|k,\epsilon)$. The main point is that the result is independent of the position of the finite set $L$. The proof is based on a density increment strategy and gives explicit upper bounds for the numbers $UDHL(b_1,...,b_d|k,\epsilon)$.Comment: 36 pages, no figures; International Mathematics Research Notices, to appea

The Virtual Block Interface: A Flexible Alternative to the Conventional Virtual Memory Framework

Computers continue to diversify with respect to system designs, emerging memory technologies, and application memory demands. Unfortunately, continually adapting the conventional virtual memory framework to each possible system configuration is challenging, and often results in performance loss or requires non-trivial workarounds. To address these challenges, we propose a new virtual memory framework, the Virtual Block Interface (VBI). We design VBI based on the key idea that delegating memory management duties to hardware can reduce the overheads and software complexity associated with virtual memory. VBI introduces a set of variable-sized virtual blocks (VBs) to applications. Each VB is a contiguous region of the globally-visible VBI address space, and an application can allocate each semantically meaningful unit of information (e.g., a data structure) in a separate VB. VBI decouples access protection from memory allocation and address translation. While the OS controls which programs have access to which VBs, dedicated hardware in the memory controller manages the physical memory allocation and address translation of the VBs. This approach enables several architectural optimizations to (1) efficiently and flexibly cater to different and increasingly diverse system configurations, and (2) eliminate key inefficiencies of conventional virtual memory. We demonstrate the benefits of VBI with two important use cases: (1) reducing the overheads of address translation (for both native execution and virtual machine environments), as VBI reduces the number of translation requests and associated memory accesses; and (2) two heterogeneous main memory architectures, where VBI increases the effectiveness of managing fast memory regions. For both cases, VBI significanttly improves performance over conventional virtual memory

Assessment of underlying capacity mechanism studies for Greece

The increased electricity production from variable sources in the EU combined with the overall decline in demand in recent years, have raised concerns about the security of electricity supply, in general, and in particular about generation adequacy and flexibility, prompting some Member States to consider new public interventions, the so-called capacity remuneration mechanisms. This work presents a review of the underlying capacity mechanism studies for Greece based on European best practices to highlight the latest developments and current trends.JRC.C.3-Energy Security, Distribution and Market

Virtuoso: An Open-Source, Comprehensive and Modular Simulation Framework for Virtual Memory Research

Virtual memory is a cornerstone of modern computing systems.Introduced as one of the earliest instances of hardware-software co-design, VM facilitates programmer-transparent memory man agement, data sharing, process isolation and memory protection. Evaluating the efficiency of various virtual memory (VM) designs is crucial (i) given their significant impact on the system, including the CPU caches, the main memory, and the storage device and (ii) given that different system architectures might benefit from various VM techniques. Such an evaluation is not straightforward, as it heavily hinges on modeling the interplay between different VM techniques and the interactions of VM with the system architecture. Modern simulators, however, struggle to keep up with the rapid VM research developments, lacking the capability to model a wide range of contemporary VM techniques and their interactions. To this end, we present Virtuoso, an open-source, comprehensive and modular simulation framework that models various VM designs to establish a common ground for virtual memory research. We demonstrate the versatility and the potential of Virtuoso with four new case studies. Virtuoso is freely open-source and can be found at https://github.com/CMU-SAFARI/Virtuoso

Turkey's Energy Strategic Planning in the Eastern Mediterranean: Business Planning – Challenges – Adjustments

This paper attempts to describe Turkey's energy strategy, through an approach of its strategic position, energy needs and policies. This analysis presents a modern approach to strategic analysis that concerns a country, as it uses models of international policy, business and energy analysis, which are mainly utilized in business sector of trade and energy. The combination of these models leads to a better and in-depth understanding of the Turkish political and economic reality, which determines the development and evolution of the Turkish energy strategy