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The total electrical and thermal consumption of both the houses and the aquaponic greenhouse facility (modelled from the data in Tables 15.1 and 15.2) is shown in Table 15.3. The aquaponic greenhouse facility is responsible for 38.3% of power consumption and 51.4% of heat consumption. The power demand for an aquaponics facility integrated in a residential microgrid is therefore slightly over one-third of the total local energy demand, given that all of the residential energy and vegetable/fish production is done locally. The heat demand comprises roughly 50% of the total heat demand, which can be attributed for a large part to the distillation unit running on high-temperature water.
As can be seen in Figs. 15.4 and 15.6, the Smarthoods energy system is capable of balancing production and demand most of the time. The total share of imported electricity from the grid is 4.62% for the reference case. At times, a slight imbalance of power can be observed, which can be attributed to suboptimal control for the current version of the model for the most part. The CHP, for instance, switches from an on- to off-state multiple times over the course of several hours, resulting in an overproduction of electricity. Such behaviour will not occur for a more optimised control system, since the CHP can be ramped down in coordination with the heat pump in order to deliver the precise amount of electricity and heat needed.
The system is highly flexible as a result of the CHP and the aquaponics facility with its flexible lighting and pumps, and high thermal buffering capacity, as well as the
Table 15.3 Electrical and thermal load for different aspects of the microgrid
table thead tr class="header" th/th th Residential /th th Aquaponic facility /th /tr /thead tbody tr class="odd" tdElectrical average demand/td td 17.2 kW /td td 10.2 kW /td /tr tr class="even" tdElectrical peak demand/td td 47.6 kWsubp/sub /td td 15.2 kWsubp/sub /td /tr tr class="odd" thElectrical total demand/th th 143.2 MWh/year /th th 89.2 MWh/year /th /tr tr class="even" tdThermal average demand/td td 37.1 kW /td td 39.3 kW /td /tr tr class="odd" tdThermal peak demand/td td 148.4 kW /td td 121.2 kW /td /tr tr class="even" thThermal total demand/th th 325.0 MWhsubth/sub/year /th th 344.2 MWhsubth/sub/year /th /tr /tbody /table
Fig. 15.6 Time-series graphical diagrams for the power (top-left) and heat (bottom-left) energy balances (in W) of the Smarthood system. Storage capacity (in kWh) is indicated on the right side for power (top-right) and heat (bottom-right). The x-axis represents number of hours since the start of the year. The black line represents the imbalance of energy
battery, and the hydrogen system. The aquaponic system, especially, greatly increases the overall flexibility of the system, as it can function for a wide range of energy input, as can be derived from Table 15.4. As a result of this flexibility, the system manages to achieve near total (95.38%) power self-sufficiency and 100% heat self-sufficiency.