Energy source: Energy source is the primary energy input to the system. It can be any energy source prior to the conversion to the desired energy form. In the case of a building, thermal demands are heat at an immediately functional temperature level.
that the losers are neither the end-users nor the society.
As the saying goes: You lose some, and you win some. The winnings from having no distribution loss are that no heat is lost between the heat source and the end-users, and there is no need for insulation. Having no insulation further means a cheaper distribution system (at least in theory). Potential loss- es from having “no losses” could, on the other hand, be lost opportunities and secondary inefficiencies. As lost opportunities can be too many to count, one should focus on those who are likely to be most important, such as: • Ability to use alternative energy sources capable of gener- ating heat at immediately useful temperature levels, such as waste heat from industry, power production, or any oth- er new types of energy sources that may be discovered in the local area - Operating uninsulated pipe network at higher than the ambient temperature would lead to significant distribu- tion losses • Ability to use more energy and cost-efficient large-scale centralized heat plants • Avoidance of upgrading or specifying unnecessarily strong power distribution grid - As thermal demand is a vast majority of building energy demands, there is a high risk that the heating demand in an individualized electrified heating system would be defining the power connection capacities • Ability to have long-term decoupling of the thermal de- mand and thermal generation - Long-term decoupling can only be achieved via central thermal storage capable of fulfilling thermal demands at immediately functional temperature levels 5G claim: Uninsulated pipe network is cheaper While saving investment costs by using uninsulated pipe is certainly an interesting point. It also deserves a closer look: One needs to consider the system design conditions, par- ticularly the expected temperature difference between the supply and return flow, as this will define the required pipe diameters of the distribution network. In that respect, two main factors can negatively influence the design of ambient loop systems. • The ambient temperature heat sources tend to cool down during the heating season. • The higher the heat pump efficiency, the smaller the tem- perature difference is across the evaporator, e.g., the cool- ing of the heat source. Both points lead to squeezing the system temperature difference and lead to the need for large pipe dimensions. In the perspective of potential cooling demands being used for regenerating the heat supply in the 5G system it should be considered that during the heating season the likelihood of
Heat plant: Heat plant is the conversion technology used to convert the energy source to the desired temperature level.
With these definitions in place, we can make a clear distinc- tion between the 4 th generation and the 5 th generation: • The 4 th and 1 st to 3 rd generations rely on centralized heat plants to convert the energy source to heat at immediately useful temperature levels for the end-user. • The 5 th generation is taking a different approach, which is to deliver the energy source to the end-user, which uses his heat plant to convert that energy source to heat at an immediately useful temperature level. For the 4 th generation, the form/type of the applied primary energy source and central heat plants are not restricted. For the 5 th generation, the primary energy source is low-quality heat at too low levels for direct utilization, mainly ambient heat sources, and the heating plant is a building level / end- user heat pump. This individualization of the temperature upgrading of am- bient sources provides the fundamental difference between the 5 th generation and the prior generations. It provides the platform to compare the 5 th generation to the 4 th generation. From a technical point of view, the moving of the heating plant from a central location towards the end-user has some benefits, for example: • Distribution heat losses may become insignificant, even irrelevant, as no energy has been spent on upgrading the input energy, ambient heat, to useful temperature levels. • With no distribution losses, pipe insulation becomes irrel- evant, which in theory will lead to a cheaper distribution network. • The heat plants (end-user heat pumps) can be adapted to the temperature requirement of each end-user, in theory leading to better heat generation efficiency. • Possibility to integrate cooling into the same system by enabling the end-user heat pumps to operate in a cooling mode and deliver the waste heat into the distribution grid. From the outset, these are quite promising benefits, at least at first glance. Since everything is subjected to local conditions, and even from the viewer's standpoint, it is perhaps a good idea to look into these benefits from a broader perspective. 5G claim: No distribution loss is the best First, nobody likes losses, except for parents losing games to their happy and smiling kids (which is technically a win in the bigger picture). Now, if no one likes losses, why should we bother with a closer look at the lossless distribution? If there are winners, there are also losers. We just need to make sure
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