Ala Hasan

Ala Hasan
VTT Technical Research Centre of Finland | vtt · Smart Energy and Built Environment

DSc (Tech) Helsinki University of Technology
Academic rank: University Full Professor in Energy in Buildings 2015

About

94
Publications
73,343
Reads
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3,002
Citations
Introduction
Research field: Energy in Buildings and Communities. Professional and research experience in Mechanical Power Engineering since 1982. PhD Helsinki University of Technology 2005, MSc/BSc Baghdad University 1992/1982- Google scholar: https://scholar.google.fi/citations?user=bq-5nKwAAAAJ&hl=en&gmla=AJsN-F526geOcwT70ZS52ay2K7H09h5b8Heh2xPk6BiyLAG1D
Additional affiliations
April 2021 - present
VTT Technical Research Centre of Finland
Position
  • Principal Scientist
January 2013 - April 2021
VTT Technical Research Centre of Finland
Position
  • Senior Scientist
September 1998 - December 2012
Aalto University
Position
  • Senior Researcher

Publications

Publications (94)
Article
Full-text available
The important goal of decarbonization of communities and cities has resulted in the emergence of new concepts and implementations of Net-Zero/Positive-Energy Buildings and Districts (NZPEBD) in recent years [...]
Article
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Buildings consume significant amount of final energy and they emit large amount of CO2 emissions. To address this issue, nearly zero energy buildings is becoming a common in many countries, while research is advancing towards the positive energy building (PEB) target by utilizing renewable energy that can support reducing the emissions from the bui...
Article
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Buildings and the mobility sectors are the two sectors that currently utilize large amount of fossil-based energy. The aim of the paper is to, critically analyse the integration of electric vehicles (EV) energy load with the building’s energy load. The qualitative and quantitative methods are used to analyse the nearly/net zero energy buildings and...
Article
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Exporting generated electricity by on-site renewable energy systems from buildings to the grid is only slightly profitable in many countries. Therefore, it is required to investigate the benefits of sharing generated energy in a microgrid within a community of buildings. Exploiting the benefits of peer-to-peer energy exchange between prosumers in a...
Article
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Many cities and districts have announced that their ultimate goal is to be energy self-sufficient, but there are many technical and economic challenges that are required to be studied. The aim of this study is to find cost-optimal technical solutions for districts with high energy self-sufficiency rates that can cover their electricity demand. Two...
Article
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This paper aims to investigate the effect of fluid flow fragmentation on the hydrothermal performance characteristics of a serpentine mini-channel heat sink (SMCHS) numerically and experimentally. Two novel designs, namely, perpendicular and diagonal, which are related to where the fluid flow is fragmented in the SMCHS, are investigated. The two ne...
Article
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It is important to assess the effectiveness of different energy refurbishment scenarios in the early design stages of apartment buildings. This paper demonstrates the main features of a new tool BIMeaser (BIM Early Stage Energy Scenario - a product of the European Union Horizon 2020 project BIM4EEB), which supports the decision-making process in th...
Article
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On October 29th the workshop corresponding to the mid-term conference of BIM4EEB (Acronym of BIM Based Toolkit for Efficient rEnovation in Buildings, Horizon Project under grant agreement N. 820660 ) project was held during the Sustainable Places 2020 event. The main focus of the workshop was a general introduction of the project combined with vert...
Article
Climate change is the biggest challenge of the present era. Buildings being one of the largest consumers of energy can help address this issue in various ways. The objective of the present study is to simulate and optimize a photovoltaic-based energy system integrated with onsite battery and electric vehicles for a demo site in Belgium in the Centr...
Article
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A new method for the optimization of seasonal energy storage is presented and applied in a case study. The optimization method uses an interval halving approach to solve computationally demanding mixed integer linear programming (MILP) problems with both integer and non-integer operation variables (variables that vary from time step to time step in...
Article
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Interactive energy sharing networks with centralised coordinated energy management between buildings and vehicles can increase eco-economics viability, while tracking battery degradations is critical to the assessment of techno-economic performance and energy flexibility. In this study, a mathematical model was developed to characterise the cycling...
Chapter
In this paper, simulations of the performance of a building that has different energy flexibility sources is conducted. The building is a simulated single-family house located in Helsinki-Finland. The building’s energy system components include on-site energy generation from renewable energy (PV panels, solar thermal collector and a small wind turb...
Conference Paper
This paper describes the implementation of an energy management system (EMS) onto a semi-virtual nearly zero-energy building emulator. The emulator platform consists of a physical part for energy production (PV panels, micro-wind turbine), storage (electrical battery and hot water tank) and conversion (ground-source heat pump and electric heater)...
Article
Solar and wind energy are the significant renewable energy sources that can be used to tackle the climate change issue. The aim of the study is to design and compare different architectures of community-level energy systems, in order to find a positive energy community in cold climate. The design proposed is a centralized solar district heating net...
Conference Paper
Full-text available
The aim of this paper is to describe the development of an energy-matching assessment tool that can be used to study different innovate energy concepts in new districts based on existing distribution infrastructure (district heating and cooling). The objective is to demonstrate carbon free energy concepts based on renewable energy sources. District...
Article
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A focal point of ongoing research is matching the energy demand in the built environment to the energy supply from onsite generation, to maximize the self-consumption, and from the energy grids, to lower energy costs and reduce peak loads on the system. Energy flexibility addresses this task by modulating the energy demand in a building according t...
Article
This article presents a new energy management system (EMS) for a variety of energy flexibility conversion, routing and storage options in buildings. The EMS uses an efficient nonlinear optimization-based model-predictive control (MPC) method, which achieves low computational complexity by utilizing successive linear programming (SLP) for continuous...
Article
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The complexity of finding solutions to reach energy sustainability in the built environment poses a significant challenge. Therefore, there is interest in adequate management of the generation, conversion, storage, use and exchange of heat and electricity. The novelty of this study exists in presenting and comparing multiobjective optimizations for...
Article
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This paper describes the composition and operation of a semi-virtual energy system and building emulator designed for studying hybrid grid interactions of a modern nearly-zero energy building. The system consists of a real part for energy production (PV panels and micro-wind turbine), storage (batteries and hot water storage tanks) and conversion (...
Article
A key element to reach sustainability in the built environment is reducing the need to compromise between performance and cost-optimality. Particularly, conversion and/or exchange of surplus energy from on-site generation components can offer opportunities to increase the overall system profitability and enhance its performance. This study addresse...
Conference Paper
This paper describes the composition and operation of a semi-virtual energy system and building emulator. The research is part of a joint project between VTT Technical Research Centre of Finland and Aalto University funded by the Academy of Finland. The system consists of a real part of energy production (PV panels, micro-wind turbine and solar the...
Article
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Surplus energy can be a recurrent phenomenon in zero-energy buildings (ZEBs) with onsite generation systems, usually resulting in the export of excess electricity. Yet, converting electricity into heat and exporting it could improve the overall energy balance. This study analyses the energy and exergy performance of a Finnish nearly zero-energy bui...
Article
Energy planning and management in the built environment should not limit their scope to reaching zero-energy or nearly zero-energy balances: they should aim for cost optimality as well. Only then can environmental and economic sustainability be attained. In this study, a set of energy systems that include exchange with electrical and heating grids...
Conference Paper
By the end of 2020, all new buildings must be nearly zero energy as instructed by the European Commission. In southern Finland, a demonstration project building tries to reach the zero energy level by minimizing energy demand and integrating photovoltaic panels, solar thermal collectors, and a ground source heat pump. An analysis of measured data h...
Conference Paper
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This paper reports first results of our work in using simulation-based optimization in automatic generation of building shapes considering multiple objectives, variables and constrains. An optimization problem is presented for finding the optimum geometry solutions for an office building that has a basic cross-shape. The problem is solved as a two-...
Article
VTT, The Technical Research Centre of Finland Ltd (www.vtt research.com) is a multidisciplinary application-oriented research organization. VTT carries out research and innovations that support the development of smart cities in many different ways. The focus of this paper is to explore the role of energy in buildings in the smart city. Because 40%...
Conference Paper
All new buildings in the EU are to be nearly zero-energy buildings (nZEB) by the end of 2020. Energy efficiency, reduced demand, and onsite renewable energy systems, are key characteristics of nZEBs; when this features are combined, the generation from the supply systems may exceed the energy demand of the building. Such has been the case in the ze...
Conference Paper
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The cost of locally installed renewable electrical and thermal systems in residential buildings is dropping rapidly and it has become increasingly common to invest in multiple-energy technologies such as PV, wind turbines and heat pumps. With the higher number of options, it is feasible to include more intelligent systems than basic low-level contr...
Article
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A net zero energy building (NZEB) is a grid connected building that exports as much energy as it imports over a predefined period of time based on a certain balance metric. Energy matching defines how much the building load covered with its own generation, as well as the interplay with the surrounding grids. This study aims to investigate the energ...
Article
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Solar electricity is growing very popular in the world, but it has some problems in matching of generation and demand both in hourly and seasonal levels. In northern latitudes the problem is especially significant, as the difference between solar availability in winter and summer is very large. Cooling needs do not increase electricity demand in su...
Chapter
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This chapter presents implementations of simulation-based optimization by giving two examples for finding optimum values of design/decision parameters in the building envelope, building heating/cooling systems, and energy systems. In addition, the features of the multi-objective building performance optimization program (MOBO®) are presented. MOBO...
Article
The cost-optimal solutions for a new office building in Finland are obtained. The EBPD comparative framework methodology is followed. Biomass CHPs with high overall efficiency and low P/H ratio are economically viable. Biomass CCHPs do not have economic or environmental benefits over biomass CHPs. Extending the cost-optimal solutions by PV system y...
Conference Paper
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Nowadays, we can come across different concepts related to Zero-Energy Buildings. Despite having common perspectives for reducing the environmental impacts, the methods and specific targets are different in different concepts. This paper reviews the terminology and calculation methods used in the two concepts of Net-Zero Energy Buildings (NZEB) and...
Conference Paper
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The economic viability of using small-scale biomass-based co-generation heat and power (CHP) as a heating system for an office building, in Helsinki, Finland, using the Energy Performance of Building Directive (EBPD) comparative framework methodology is the aim of this study. Seven heating/cooling energy generation system package (H/C-EGSP) consist...
Conference Paper
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In this study, four different small scale biomass-based cogeneration heat and power (CHP) technologies along with three conventional energy generation systems serving an office building in Helsinki, Finland are investigated to find the local cost-optimal solutions for minimum energy performance for each as well as the global cost optimal solution....
Chapter
Full-text available
Building performance optimization (BPO) paired with building performance simulation (BPS) is a promising solution for evaluating many different design options and obtaining the optimal or near-optimal solution for a given objective or combination of objectives while complying with constraints. This chapter discusses major obstacles to BPO in the bu...
Article
Recently, the extended matching indices for electrical and thermal energy were defined for different types of energy use and conversion based on two basic matching indices: on-site energy fraction (OEF), which is the load proportion covered by the on-site generated energy, and on-site energy matching (OEM), which is the on-site generated energy pro...
Conference Paper
Full-text available
On-site energy management is one of the key strategies toward improving energy efficiency and reducing CO 2 emissions in the building sector. The Japanese energy supply situation has changed drastically before and after the nuclear power plant accident in 2011 because the power plants operation has been restricted considering safety. Since the ener...
Technical Report
Full-text available
MOBO optimization software manual
Conference Paper
Full-text available
We think that there is a need for a new building optimization tool that should be a generic freeware and can fill the shortages recognised in available tools. MOBO (Multi-Objective Building Optimization) is a generic freeware able to handle single and multi-objective optimization problems with continuous and discrete variables and constraint functi...
Conference Paper
Full-text available
The HVAC research group at Aalto University (former Helsinki University of Technology) has been developing combined use of building simulation and optimisation since the beginning of this millennium. The first trials were simple single-objective problems but soon the approach was changed into multi-objective. From the beginning, the goal has been t...
Conference Paper
Full-text available
The building sector is responsible of some 40% of the total energy consumption in the world. Cooling energy is an important part of the energy needed in buildings and is increasing as a result of the higher levels of indoor air conditions and the global warming problem. In order to contribute in making a sustainable built environment and mitigate t...
Article
In order to meet EU objective of nearly zero-energy building, mismatch problem is an inevitable side effect, which requires suitable criteria to quantitatively evaluate the problem. There are two commonly used basic indices for matching analysis: on-site energy fraction (OEF) and on-site energy matching (OEM). OEF indicates the proportion of the lo...
Conference Paper
Full-text available
This paper introduces a new software developed for building performance optimization. MOBO is a generic freeware able to handle single and multiobjective optimization problems with continuous and discrete variables and constraint functions. It can be coupled to many external (simulation) programs. It has a library of different types of algorithms (...
Article
The objective of this paper is to close the scientific gap that there is a lack of comprehensive matching analysis for the increasingly complicated on-site hybrid energy systems with a continuously decreased annual primary energy consumption/equivalent CO2 emission. Thus, a thorough matching analysis is conducted for the on-site hybrid systems of t...
Article
This paper conducts analyses and proposes solutions for reducing mismatch between renewable energy (RE) production and electrical demand from a 150 m2 single-family house. The RE options are photovoltaic (PV) and micro-wind turbine. This paper mainly focuses on the situation when grid feed-in is not available, but a brief economic analysis with gri...
Article
Finding cost-optimal solutions towards Nearly-Zero-Energy Buildings (nZEBs) in accordance with European Energy Performance of Buildings Directive (EPBD-Recast 2010) is a challenging task. It requires exploring a huge number of possible combinations of energy-saving measures (ESMs) and energy-supply systems including renewable energy sources (RES),...
Conference Paper
Full-text available
Finding cost-optimal solutions for nearly-zero energy buildings (nZEB) according to the new recast of the European Energy Performance of Buildings Directive EPBD- recast 2010 is a challenging task that requires exploring numerous possible combinations of energy-saving and energy-supply measures. Multiobjective simulation-based optimisation can be e...
Article
The objective of this paper is to study a method to achieve sub-wet bulb temperature by indirect evaporative cooling of air (without using a vapor compression machine). For this purpose, an analytical model is developed based on the effectiveness-NTU method (ε-NTU). The main idea for achieving a sub-wet bulb temperature by indirect evaporative cool...
Article
Full-text available
The new recast of the Energy Performance of Buildings Directive (EPBD) calls for all new buildings to be nearly zero energy buildings by the end of 2020. Besides, there are many evolving new definitions of Net Zero Energy Building (NZEB) that need to be fulfilled. To achieve the above mentioned targets is quite challenging. In this paper the author...
Article
Recently adaptive thermal-comfort criteria have been introduced in the international indoor-climate standards to reduce the heating/cooling energy requirements. In 2008, the Finnish Society of Indoor Air Quality (FiSIAQ) developed the national adaptive thermal-comfort criteria of Finland. The current study evaluates the impact of the Finnish Criter...
Conference Paper
Full-text available
In 2008, the Finnish Society of Indoor Air Quality (FiSIAQ) has introduced new criteria for the thermal comfort classes (S1, S2, and S3). The criteria stipulate adaptive model based on 24 houraverage outdoor air temperature. The maintenance of particular comfort level is linked to energy consumption and consequent energy cost. The current study use...
Article
Recently adaptive thermal-comfort criteria have been introduced in the international indoor-climate standards to reduce the heating/cooling energy requirements. In 2008, the Finnish Society of Indoor Air Quality (FiSIAQ) developed the national adaptive thermal-comfort criteria of Finland. The current study evaluates the impact of the Finnish Criter...
Article
Modern buildings and their HVAC systems are required to be not only energy-efficient but also produce fewer economical and environmental impacts while adhering to an ever-increasing demand for better environment. Research shows that building regulations which depend mainly on building envelope requirements do not guarantee the best environmental an...
Conference Paper
This paper presents a method for automatic simulation-based optimisation with search techniques for single and multi-objective designs of combined buildings and energy systems. An example is presented here with various design variables: types of the building (a standard house, a low energy house and a passive house), HVAC system (equipment sizes an...
Article
Indirect evaporative cooling is a sustainable method for cooling of air. The main constraint that limits the wide use of evaporative coolers is the ultimate temperature of the process, which is the wet bulb temperature of ambient air. In this paper, a method is presented to produce air at a sub-wet bulb temperature by indirect evaporative cooling,...