IEA Solar Heating and Cooling Programm - NachhaltigWirtschaften.at

IEA SHC Task 38
Monitoring Procedure
Usually the heat acquired by the solar collectors is stored in buffer tanks before being used.
In some cases the hot buffer is shared with the heat backup system and it represents the
only connection point between the heat sources and the load (Figure 3-1).
Q_sol
E1
Collector field
E2
Q1
Hot storage
Q1S
Q2S
E3
Back up heat source
(conventionally powered
or RES or waste heat…)
Figure 3-1 Connection between the heat back-up system and the solar collectors: shared hot
storage
This means that:
Q 2D _ fossil =
0
[ ] kWh th
Eq. 23
[ ]
Q 2D _ RES = 0 kWh th
Eq. 24
Q2 _ total sum
= Q2S_ fossil + Q2D _ fossil + Q2S _ RES + Q2D _ RES
= Q2S_ fossil + Q2S _ RES = Q2S
Eq. 25
In these cases, as the output of the storage includes both the input from solar and back-up
system, the storage solar fraction, defined as the ratio between the heat collected by the
solar collectors and the heat produced by the backup system, is calculated according to:
17 99% draft Version