Load Matching, Grid Interaction, and Advanced Control - Modeling, Design, and Optimization of Net-Zero Energy Buildings - page 308

Fig. 6.6 Load match ( f load, T ) and grid interaction ( f grid, T ) indices for the
Solar XXI Building in Portugal (Voss et al. , 2010). The load match index,
similar to the load cover factor, is defined as

The capacity factor , as formulated in Verbruggen et al. (2011) shows the
total energy exchange with the grid divided by the exchange that would
have occurred at nominal connection capacity. It provides a measure of the
utilization of the grid connection. The capacity factor is defined as

(6.7)

where E des is the nominal (or design) capacity of the “energy exporting”
system (e.g., the nominal installed capacity between the building and the
grid) and T is the time period between τ 1 and τ 2 .

Category III . This category contains load matching indicators that require
information beyond on-site load and generation. For example, the
mismatchcompensationfactor (MMCF) is the quotient between the on-site
generation capacity providing annual energy balance and the capacity that
compensates economically for the mismatch (i.e., the capacity that makes
total generated electricity worth as much as demanded electricity on an
annual basis). As defined in Lund, Marszal, and Heiselberg (2011)

(6.8)

The MMCF requires information about electricity pricing. An MMCF<1
means that the system that compensates for the mismatch is smaller than
the system giving a net-zero energy balance because generated electricity
is, on average, worth more than demanded electricity (Lund, Marszal, and
Heiselberg, 2011).
A similar index is the market matching indicator, proposed in Widén and
Wäckelgård (2010b). The market matching indicator shows the difference
between the market values of delivered and bought energy, respectively
and

, with a cost :