Q2. What is the role of thermoeconomics in the economic assessment of MES?
While deterministic techniques are widespread in the operational and planning economic assessment of MES, in recent years also probabilistic or stochastic assessment models are emerging.
Q3. What is the way to assess MES planning flexibility?
As for the case of Monte Carlo approaches in real options models, multi-stage stochastic programming techniques based on scenarios appear to be more suitable to assess MES planning flexibility than numerical approaches borrowed from financial mathematics owing to the possibility of using generic stochastic processes and scenarios.
Q4. What is the idea of increasing interest in creating district energy microgrids?
In fact, an idea of increasing interest is to deploy the heat rejected from small scale thermal generators to supply local communities so as to create district energy Microgrids with DMG and controllable multi-energy loads.
Q5. What is the main reason why real options are used in DMG planning?
More specifically, real options, whereby financial option models are applied to engineering (“real”) problems and capture the value from exercising the option – that is, investing in the plant – at a later stage, have indeed also been applied to DMG planning under uncertainty, and again particularly for CHP systems.
Q6. How many efforts are there to support the integration of renewable energy resources into the power system?
There are significant efforts worldwide at multiple levels, from research to policy initiatives, to support the integration of renewable electricity resources into the power system and particularly by deploying innovative concepts such as the Smart Grid.
Q7. What are the main concepts for integrating distributed energy resources into power system operation and planning?
Given the small- and even micro-scale level of many DMG systems (for instance, micro-CHP generators installed in individual houses), a number of general aggregation concepts have been put forward for integration of distributed energy resources into power system operation and planning [60], most noticeably, Microgrids [61] and virtual power plants (VPP) [62][63].
Q8. Why is the uncertainty problem more difficult?
This is mainly in response to increasing degrees of uncertainty introduced for instance by market operation and larger volumes of intermittent RES in many countries, so that the investment problem, in particular, becomes more challenging.
Q9. What is the role of the emission balance models in determining the environmental impact of a power?
While these emission balance models are extremely useful to represent boundary impacts and in particular for regulatory purposes based on emissions rather than pollutant concentration, the actual environmental impact lies somewhere in between and would need a pollutant dispersion analysis conducted with dedicated tools that allow drawing pollutant concentration maps, as for instance illustrated in [131][132].
Q10. What is the definition of a spark-spread model?
Such spark-spread models can effectively be used for profit-oriented operational decision making in a real-time market framework through heuristic approaches that do not require formulation and solution of a full optimization problem.
Q11. What are the main types of indicators used for a regulatory context?
The FESR and similar types of indicators and relevant pitfalls when used for applications in regulatory contexts in different countries are for instance extensively discussed in [107], and the paper [108] has recently carried out a comprehensive analysis of the requirements to comply with the cogeneration directives and guidelines of the European Union.
Q12. What is the role of thermoeconomics in the economic analysis of MES?
Exergy-based operational and planning assessmentConsideration of exergetic aspects into the economic analysis of MES for planning purposes has also been discussed in several publications through the thermoeconomic theory.
Q13. What is the key aspect to a cleaner and affordable energy system?
In this outlook, a key aspect to evolve towards a cleaner and affordable energy system is to better understand and develop integrated or multienergy systems (MES), whereby electricity, heat, cooling, fuels, transport, and so on optimally interact with each other at various levels (for instance, within a district, or a city, or at a country level).
Q14. What are the main objectives of this work?
In particular, specific objectives of this work refer to critically discussing concepts, approaches, and analysis tools that have been proposed to deal with multi-energy systems, as well as evaluation methodologies and performance metrics that are capable to properly capture costs and benefits (from an energy, environmental, and techno-economic perspective) that are relating to various types of MES.
Q15. What are some examples of how energy systems interact?
For instance, electricity, heat/cooling and gas networks interact in many cases through various distributed technologies such as combined heat and power (CHP), electric heat pumps (EHPs), air conditioning devices, trigeneration of electricity heat and cooling, and so on [2][3].
Q16. What is the main reason for the analysis of energy indicators?
In particular, energy indicators are being considered more and more from a regulatory point of view to boost the utilization of MES, and hence a critical analysis of them proves to be fundamental.