Continuous OptimizationDynamic multi-objective heating optimization
Introduction
In this paper we introduce an application of multicriteria optimization from our everyday environment. The problem is to optimize the indoor temperature, i.e., thermal comfort in a residential house. The problem is methodologically quite interesting as decision support is clearly needed due to the system dynamics and the necessity to tradeoff preferences which are costs and comfort over time. The definition of comfort is a complex issue in itself [13]. This paper develops a new goal programming (GP) approach. The dynamics of the problem arises from three factors: the house acts as a heat storage, the price of electricity is time varying and the outdoor temperature changes over the day. The criteria included in the model are the total heating costs, the energy consumed and the living comfort implicitly defined through the levels and variations of hourly indoor temperature. The model is implemented on a spreadsheet application multi-objective heating optimization (MOHO) [18] which is used to illustrate the solutions. A setting of this kind is a realistic one both for small residential and large commercial electricity users. With the introduction of deregulated energy markets [37] the possibilities of a consumer to be offered innovative pricing contracts is increasing. In the old regulated environment there could exist national legislation determining the acceptable types of time varying prices (such as time of use, TOU). Today the situation has changed, at least in the Nordic countries, where the distribution and selling of electricity are separated by law. You can buy electricity from any supplier and not only from your local distributor [19], [37]. There can be brokers who can have different kinds of dynamic pricing policies to offer. Customers are also willing to subscribe to such policies and act reactively in their use of electricity. It is this setting which is of interest in the model presented here. The implementation described remains still a research effort which is not yet available commercially. However, it has successfully been tested with consumers by the utility of Helsinki Energy. There are no technical reasons why a system like this could not be implementable in real life. In fact, the authors do believe that this will be an optional direction for future pricing policies as part of the so-called smart house concept. Environmental issues are also related to the avoidance of demand peaks. They are often met with more polluting reserve generation units. Naturally, policies of this kind become increasingly interesting in larger commercial and community buildings.
Section snippets
Goal programming
GP is a widely used [47] multicriteria method originally presented in 1955 by Charnes and Cooper [9]. The name GP was introduced only later in a book from 1961 [7], where it was described as an extension to linear programming (LP). Today there are new textbooks, e.g., by Ignizio [21], [22]. Some modelling and critical issues of GP are discussed in [41] and more recent developments can be found in [4], [51].
In the multicriteria setting the special characteristic of GP models is the way the
Dynamic multicriteria problems and interval GP
This paper discusses modelling approach needed when dynamics are involved in multicriteria problems and provides a real life example of such problem, namely heating optimization. In particular we study the use of intervals in the definition of the goals. Already in [6], [10] and in the survey paper of Charnes and Cooper [8] the possibility of using goal intervals, i.e., goal sets, was presented. Some related early applications include financial planning [27] and water reservoir management [5].
GPϵ method
In multi-objective analysis one often wants to study the effects of relaxing some goal constraints. This is particularly relevant in dynamic GP where the DM needs to provide goal values for each criterion at each stage. Therefore, we will introduce a method combining the ϵ-constraint method of Haimes [15], [16] and GP in the heating problem. For simplicity, we consider minimization of all the criteria, i.e.,where x=(x1,x2,…,xn) is the n-dimensional vector of decision
Multi-objective heating optimization
The objective of residential heating systems is to keep the indoor temperature within comfortable limits. The traditional control device is a thermostat which keeps the indoor temperature close to the preset level. However, if the price of electricity is time dependent, there is a possibility to save in heating costs by using the house as a heat storage. This leads to a multicriteria problem of maximizing the living comfort and minimizing the heating costs under a given price of electricity,
The spreadsheet application MOHO
The overall setting for the heating is shown in Figs. 4 and 5 shows the interfaces of the related spreadsheet application MOHO. The house parameters consist of the dynamic heat transfer model of the house and the maximum heating power. The variable planning parameters include electricity price for each hour and the outdoor temperatures at five time points.
Before the optimization takes place the DM needs to give his or her preferences. In the first step the DM specifies his indoor temperature
Conclusions
We show how the space heating of a house can be formulated as a dynamic multicriteria optimization problem, and that one can successfully use the spreadsheet as a modelling environment for finding the solution. Instead of directly dealing with the tradeoffs between criteria, we suggest a stepwise procedure. It starts by first minimizing the costs or energy consumption and continues then by respecifying the goal or relaxing the temperature limits. We present a new GPϵ method combining the ϵ
References (56)
- et al.
Optimal economic stabilization policy: Linear goal-interval programming models
Socio-Economic Planning Sciences
(1972) A new goal programming formulation
Omega
(1976)- et al.
Cooperative consumers in a deregulated electricity market – dynamic consumption strategies and price coordination
Energy – The International Journal
(2000) - et al.
Goal programming problems with interval coefficients and target intervals
European Journal of Operational Research
(1991) - et al.
Nonlinear goal programming model for multistage, multiobjective decision problems with application to grouping and loading problem in a flexible manufacturing system
European Journal of Operational Research
(1991) Financial planning using goal programming
Omega
(1980)- et al.
Solving multiple objective quasi-convex goal programming problems by linear programming
International Transactions in Operational Research
(2000) - et al.
Constrained linear quadratic gaussian control with process applications
Automatica
(1984) - et al.
A perspective on the restructuring of the finish electricity market
Energy Policy
(2000) - et al.
Optimal tariff design under consumer self-selection
Energy Economics
(1997)
Preference programming through approximate ratio comparisons
European Journal of Operational Research
Solution of optimal control problems with lumped parameters having single or multiple objectives in fuzzy environment
Fuzzy Sets and Systems
Valuing the future: A MADA example involving nuclear waste storage
Journal of Multi-Criteria Decision Analysis
Existence of efficient solutions for vector maximization problems
Journal of Optimization Theory and Applications
Goal programming with dynamic goals
Journal of Multi-Criteria Decision Analysis
Real-time reservoir operations by goal programming
Journal of Water Resources Planning and Management
Management Models and Industrial Applications of Linear Programming
Goal programming and multiple objective optimization
European Journal of Operational Research
Optimal estimation of executive compensation by linear programming
Management Science
A goal interval programming model for resource allocation in a marine environmental protection program
Journal of Environmental Economics and Management
Saving energy using market-based control
Multiobjective energy generation planning under uncertainty
Transactions of Institute of Industrial Engineers
Thermal Comfort
On a bicriterion formulation of the problems of integrated systems identification and system optimization
IEEE Transactions on Systems, Man, and Cybernetics
Hierarchical Multiobjective Analysis of Large-Scale Systems
Cited by (31)
Dynamic multi-objective optimisation using deep reinforcement learning: benchmark, algorithm and an application to identify vulnerable zones based on water quality
2019, Engineering Applications of Artificial IntelligenceCitation Excerpt :Helbig and Engelbrecht (2014) grouped and classified these applications as follows: Control Problems: The regulation of a lake–river system (Hämäläinen and Mäntysaari, 2001), the optimisation of indoor heating (Hämäläinen and Mäntysaari, 2002), the control of greenhouse system for crops (Ursem et al., 2002). Scheduling problems: Hydro-thermal power scheduling problem (Deb et al., 2007) and the job-shop scheduling problem (Shen and Yao, 2015).
Population-based metaheuristics for continuous boundary-constrained dynamic multi-objective optimisation problems
2014, Swarm and Evolutionary ComputationCitation Excerpt :Numerous real-world DMOO application areas exist, namely Control problems, such as the optimisation of the control of processing plants, e.g. a chemical plant or oil refinery [11,80], regulating a lake-river system that consists of a number of lakes and a river that connects the lakes to the sea [109], the optimisation of indoor heating, i.e. regulating the indoor temperature as efficiently as possible [110], and the control of a greenhouse system for crops [111]. Scheduling problems, including job-shop scheduling and the scheduling of hydro-thermal power [23].
Decentralized operation strategies for an integrated building energy system using a memetic algorithm
2012, European Journal of Operational ResearchCitation Excerpt :As an example, Keeney and Braun (1996) successfully demonstrate pre-cooling of a building can reduce the peaking cooling load, electricity demand and energy cost. Hämäläinen and Mäntysaari (2002) employ dynamic goal programming to study the tradeoff between energy cost, energy consumption and living comfort for the residential house heating system. Braun (2007) and Sun et al. (2006) further develop a heuristic near-optimal control strategy for thermal storage systems with dynamic real-time electric rates.
Modelling renewable supply chain for electricity generation with forest, fossil, and wood-waste fuels
2011, EnergyCitation Excerpt :In this paper I focus on integrated fuel procurement and energy production process and a very essential supporting problem in multiple objective decision-making: How can I optimize a multiple objective model with possibly conflicting decision-making principles (e.g. reducing costs, maximizing revenue and efficiency). Available decision alternatives are assumed to be defined by means of a mathematical model [20–23]. The term dynamic multiple objective linear programming is used to refer to this model.
Technical and economic analysis of electricity generation from forest, fossil, and wood-waste fuels in a Finnish heating plant
2011, EnergyCitation Excerpt :In the present paper, I focus on an integrated forest fuel procurement and energy-production process of a CHP plant, and the resulting problem in multiple-objective decision-making: how it is possible to optimize a multiple-objective model with possibly conflicting decision-making principles (e.g., reducing costs, maximizing revenues). Available decision alternatives are assumed to be defined by means of a mathematical model [20–23]. The term “dynamic multiple-objective linear programming” is used to refer to this model.