A Solar Dually PVT Driven Direct Expansion Heat Pump One-Year Field Operation Results at Continental Climate

Ci a ion: Sanz, A.; Ma ín, A.J.;
Pe eda, A.; Román, E.; Ibañez, P.;
Fuen e, R. A Sola Dually PVT
D i en Di ec Expansion Hea Pump
One-Yea Field Ope a ion Resul s a
Con inen al Clima e. Ene gies 2022,
15, 3205. h ps://doi.o g/10.3390/
en15093205
Academic Edi o s: Alba Ramos
Cabal, Ma ía He ando and Alessia
A econi
Recei ed: 1 Ap il 2022
Accep ed: 25 Ap il 2022
Published: 27 Ap il 2022
Publishe ’s No e: MDPI s ays neu al
wi h ega d o ju isdic ional claims in
published maps and ins i u ional a il-
ia ions.
Copy igh : © 2022 by he au ho s.
Licensee MDPI, Basel, Swi ze land.
This a icle is an open access a icle
dis ibu ed unde he e ms and
condi ions o he C ea i e Commons
A ibu ion (CC BY) license (h ps://
c ea i ecommons.o g/licenses/by/
4.0/).
ene gies
A icle
A Sola Dually PVT D i en Di ec Expansion Hea Pump
One-Yea Field Ope a ion Resul s a Con inen al Clima e
Asie Sanz 1,2,* , An onio J. Ma ín3, Ainhoa Pe eda 1, Edua do Román1, Ped o Ibañez 1and Raquel Fuen e 2
1TECNALIA, Basque Resea ch and Technology Alliance (BRTA), 48160 De io, Spain;
[email p o ec ed] (A.P.); [email p o ec ed] (E.R.); ped [email p o ec ed] (P.I.)
2Applied Ma hema ics, Facul y o Enginee ing, Uni e si y o he Basque Coun y UPV/EHU,
48013 Bilbao, Spain; [email p o ec ed]
3Ene gy Panel, 14900 Lucena, Spain; ajma in@ene gypanel.es
*Co espondence: asie [email p o ec ed]
Abs ac :
The high ene gy-consuming building sec o needs o mee bo h elec ici y and hea de-
mands. In a nea ly ze o ene gy building scena io, mos o he consumed ene gy would be gene a ed
locally by means o enewable solu ions ha nowadays seem no o p o ide an a ac i e pe o mance
o cos -compe i i eness. Sola -based echnologies end o be he mos p omising ones, bu o high
densely popula ed a eas, he usual pho o ol aic o he mal single app oaches may no be e icien
enough. The cu en wo k is ocused on he analysis o he dual use o he sola esou ce by means
o hyb id PVT collec o s and hei sma combina ion wi h di ec expansion hea pumps h ough
p edic i e con ol s a egies. To ha end, a sys em was de eloped, ins alled in a eal-use single- amily
house a a con inen al clima e o domes ic ho wa e applica ion, ope a ed and moni o ed o one
en i e yea . The a e age day indica o esul s show 83% enewable ene gy sha e, 220% sel -su iciency
a io, 41% hea pump sel -consump ion and 46% o he sola ac ion.
Keywo ds: pho o ol aic- he mal; PVT; PV/T; hea pump; HP; hyb id; sys em; con ol; ield esul s
1. In oduc ion
Global ene gy consump ion is p ojec ed o e u n quickly o p e-pandemic le els [
1
].
The e e ence o 2020 was a ound 600 quad illion B i ish he mal uni s wi h a 50% es-
ima ed inc ease by 2050 d i en by non-OECD economic g ow h and popula ion. The
Eu opean Commission s a es [
2
] ha buildings a e esponsible o 40% o he ene gy con-
sump ion and 36% o CO
2
emissions, and p e ends o educe hei impac h ough di e en
ac ions. Mos o hose buildings need o mee bo h elec ici y and hea demands, o do-
mes ic ho wa e (DHW) and space hea ing/cooling (H&C). In he close, nea ly ze o ene gy
building (nZEB) scena io, mos o he consumed ene gy would need o be gene a ed locally
by means o enewable esou ces. Un o una ely, cu en enewable solu ions seem no o
p o ide an in eg al, simul aneous and local solu ion o his need, ensu ing ene gy supply
gua an ee and cos -compe i i eness.
Howe e , sola ene gy is a ailable all o e he ace o he ea h. Thus, buildings
should y o ake highe alue om e e y beam o ligh eaching hei en elopes. Today,
pho o ol aics (PV), and in he pas , sola he mal (ST) applica ions, a e becoming widely
used o buil en i onmen on-si e gene a ion. Ne e heless, o high densely popula ed
and shadow es ic ed a eas, hese kind o single app oaches a e no enough o sa is y
building ene gy needs. De ailed analysis o sola esou ces in buil en i onmen s shows
ha no only oo s bu also açades should be conside ed wi h highe e iciency sola
con e sion de ices such as PVT [3].
Ha nessing sola ene gy should be a mus o new and e u bished buildings
[4–6]
,
bu when he sun is no shining and ene gy s o es a e emp y, sola base solu ions always
equi e back-up sys ems, which educes hei compe i i eness. The elec ical g id makes
Ene gies 2022,15, 3205. h ps://doi.o g/10.3390/en15093205 h ps://www.mdpi.com/jou nal/ene gies
Ene gies 2022,15, 3205 2 o 23
hings easie o loads, bu he mal needs a e s ill highly ossil uel-dependen in a g ea
pa o Eu ope [
7
]. Howe e , hea pumps (HP) seem a p omising echnology o a educ ion
in building he mal com o - ela ed CO
2
emissions and enable he use o he elec ical in-
as uc u e o use hem as a back-up sou ce [
8
]. The e o e, i sola and HP a e indi idually
sui able o elec ici y and hea gene a ion, me ging hem in a unique hyb id sys em will
enable ob aining e en highe bene i s [
9
–
11
]. Anyway, i is usually ha d o in e -compa e
echnologies and quan i y hose eal bene i s o simply conclude which one shows o e all
g ea e pe o mance. Thus, wi hin he cu en wo k, an expe imen al app oach is p oposed
o shed some ligh on he eal ield pe o mance o such sys ems.
1.1. PVT Dually Coupled HP Technology
The p oposed solu ion is a sola hyb id PVT dually coupled HP. I is a ully in eg a ed
sys em comp ising an unglazed hyb id sola collec o , a di ec expansion sola assis ed HP
(DX-saHP) and an o e all sys em con ol (Figu e 1). The base o he echnology has been
widely s udied be o e by di e en esea ch g oups o compa a i e analysis [
12
,
13
] and
expe imen al s udies [
14
,
15
]. The union o PV and sola he modynamic echnologies in one
collec o enables simul aneous elec ici y and hea gene a ion and in a kind o symbiosis
bo h echnologies wo k op imally wi hou misma ching he o he ’s pe o mance [
16
], as
occu s in con en ional PVT whe e a ade-o be ween he he mal and elec ic pe o mance
is needed. Thus, he dually assis ed HP signi ican ly inc eases he o al annual use o he
sola esou ce while p ima y ene gy consump ion is educed.
Ene gies 2022, 15, x FOR PEER REVIEW 2 o 23
equi e back-up sys ems, which educes hei compe i i eness. The elec ical g id makes
hings easie o loads, bu he mal needs a e s ill highly ossil uel-dependen in a g ea
pa o Eu ope [7]. Howe e , hea pumps (HP) seem a p omising echnology o a educ-
ion in building he mal com o - ela ed CO
2
emissions and enable he use o he elec ical
in as uc u e o use hem as a back-up sou ce [8]. The e o e, i sola and HP a e indi id-
ually sui able o elec ici y and hea gene a ion, me ging hem in a unique hyb id sys em
will enable ob aining e en highe bene i s [9–11]. Anyway, i is usually ha d o in e -com-
pa e echnologies and quan i y hose eal bene i s o simply conclude which one shows
o e all g ea e pe o mance. Thus, wi hin he cu en wo k, an expe imen al app oach is
p oposed o shed some ligh on he eal ield pe o mance o such sys ems.
1.1. PVT Dually Coupled HP Technology
The p oposed solu ion is a sola hyb id PVT dually coupled HP. I is a ully in e-
g a ed sys em comp ising an unglazed hyb id sola collec o , a di ec expansion sola as-
sis ed HP (DX-saHP) and an o e all sys em con ol (Figu e 1). The base o he echnology
has been widely s udied be o e by di e en esea ch g oups o compa a i e analysis
[12,13] and expe imen al s udies [14,15]. The union o PV and sola he modynamic ech-
nologies in one collec o enables simul aneous elec ici y and hea gene a ion and in a
kind o symbiosis bo h echnologies wo k op imally wi hou misma ching he o he ’s pe -
o mance [16], as occu s in con en ional PVT whe e a ade-o be ween he he mal and
elec ic pe o mance is needed. Thus, he dually assis ed HP signi ican ly inc eases he
o al annual use o he sola esou ce while p ima y ene gy consump ion is educed.
(a) (b)
Figu e 1. A ep esen a ion o he PVT dually coupled HP echnology: (a) Physical scheme o main
sys em elemen s; (b) Solu ion squa e iew ollowing IEA p ocedu e [17,18].
1.2. Solu ion Inno a ions
The p oposed solu ion inco po a es inno a ions ocusing on he main c i ical ele-
men s impac ing he en i e sys em’s cos -pe o mance.
1.2.1. PVT Collec o
Deep esea ch has been ca ied ou du ing ecen decades on sola hyb id PVT col-
lec o s [19] and hei in eg a ion a a sys em le el [20]. The las ad ancemen s a e con in-
uously p esen ed [21,22] and u u e ends a e discussed [23,24] by he scien i ic commu-
ni y. In pa allel, a wide se o comme cial p oduc s a e a ailable [25–29], co e ing almos
all di e en ypes o collec o s [30] and applica ions [31], bu he cos is signi ican ly linked
o he he mal e iciency [32,33]. Howe e , o HP-based sys ems he cold side empe a-
u e is no equi ed o be close o he applica ion one. Thus, di ec ly PVT coupled HP
solu ions could bene i om a non-high empe a u e collec o ield he mal ou pu while
Figu e 1.
A ep esen a ion o he PVT dually coupled HP echnology: (
a
) Physical scheme o main
sys em elemen s; (b) Solu ion squa e iew ollowing IEA p ocedu e [17,18].
1.2. Solu ion Inno a ions
The p oposed solu ion inco po a es inno a ions ocusing on he main c i ical elemen s
impac ing he en i e sys em’s cos -pe o mance.
1.2.1. PVT Collec o
Deep esea ch has been ca ied ou du ing ecen decades on sola hyb id PVT collec-
o s [
19
] and hei in eg a ion a a sys em le el [
20
]. The las ad ancemen s a e con inuously
p esen ed [
21
,
22
] and u u e ends a e discussed [
23
,
24
] by he scien i ic communi y. In
pa allel, a wide se o comme cial p oduc s a e a ailable [
25
–
29
], co e ing almos all di e -
en ypes o collec o s [
30
] and applica ions [
31
], bu he cos is signi ican ly linked o he
he mal e iciency [
32
,
33
]. Howe e , o HP-based sys ems he cold side empe a u e is no
equi ed o be close o he applica ion one. Thus, di ec ly PVT coupled HP solu ions could
bene i om a non-high empe a u e collec o ield he mal ou pu while ensu ing p ope
ope a ion [34], e en jus by d i ing he HP wi h PVT he mal con ibu ion [35].
Acco ding o hese p emises, a new PVT collec o has been p oposed (Figu e 2). The
collec o p e ends o be close o a con en ional c-Si PV module in e ms o cos , wi h an
Ene gies 2022,15, 3205 3 o 23
addi ional single esidual hea eco e y uni . This ligh weigh solu ion is manu ac u ed
by means o a di ec ly one-s ep lamina ion on op o a ha d-anodized oll bond he mal
abso be , ha achie es cos compe i i eness while enhancing he hea ans e be ween PV
cells and HP e ige an . To enable u he hea ans e wi h ambien ai [
36
], he collec o
has no ex a backshee , he mal insula ion o any u he mechanical componen s.
Ene gies 2022, 15, x FOR PEER REVIEW 3 o 23
ensu ing p ope ope a ion [34], e en jus by d i ing he HP wi h PVT he mal con ibu-
ion [35].
Acco ding o hese p emises, a new PVT collec o has been p oposed (Figu e 2). The
collec o p e ends o be close o a con en ional c-Si PV module in e ms o cos , wi h an
addi ional single esidual hea eco e y uni . This ligh weigh solu ion is manu ac u ed
by means o a di ec ly one-s ep lamina ion on op o a ha d-anodized oll bond he mal
abso be , ha achie es cos compe i i eness while enhancing he hea ans e be ween
PV cells and HP e ige an . To enable u he hea ans e wi h ambien ai [36], he col-
lec o has no ex a backshee , he mal insula ion o any u he mechanical componen s.
(a) (b)
Figu e 2. The inno a ions in oduced in he PVT sys em unde s udy: (a) The unglazed one-s ep
manu ac u ed PVT collec o ; (b) he o e all con ol sys em implemen ed in a Beagle Bone Boa d.
1.2.2. O e all Sys em Con ol
The sola PVT-based solu ions con olle s ha e been adi ionally le in a second
plane [37,38]. The classical sys ems ha dly equi e high-powe ed ac i e elemen s du ing
ope a ion, whe e excluding elec ic back-up sys ems, he only p esen loads a e he sola
ield ci cula ion pumps. In such con en ional sys ems, he he mal gene a ion is simply
deli e ed o he ank and he elec ical ene gy is injec ed in o he g id [39]. The ecen sel -
consump ion egula ion ad ances a e pushing owa ds mo e complex sys em a chi ec u e
combina ions, whe e PV and ST a e combined wi h HP o o he componen s [9]. These
en i e solu ions mus be con olled in eg ally o ensu ing a p ope global ene gy pe o -
mance, conside ing no only he he mal bu also he elec ical gene a ion [40–42].
Fu he mo e, in an nZEB scena io, he local ene gy gene a ion will no be he only
p oblem o be sol ed. The mal and elec ical ene gy supplies will need o be sma ly han-
dled o sa is y use needs echnically and economically. Howe e , he cu en sola hyb id
solu ion con olle s seem no o be capable o ensu ing he equi ed pe o mance [43,44].
Consequen ly, a new o e all sys em con ol is p esen ed (Figu e 2). The inno a i e
con ol s a egy conside s a day ahead DHW consump ion p edic ion ou ine in eg a ed
in o a high-le el con ol laye ha maximizes he HP ope a ion wi h jus sola esou ces.
Thus, highe sola ac ions and sel -consump ion igu es could be achie ed, op imizing
he o e all sys em pe o mance wi hou a ec ing end-use com o o g id impac .
2. Ma e ials and Me hods
In o de o p o e he p e iously exposed po en ial bene i s, a p o o ype o he p o-
posed solu ion was de eloped, ins alled and ope a ed o one en i e yea in a eal-use
applica ion. The objec i e o he es is double. Fi s , o expe imen ally de e mine he ech-
nical pe o mance o he whole solu ion by means o accu a e moni o ing. Second, o al-
ida e he obus ness o he sys em unde ex eme wo king condi ions.
Figu e 2.
The inno a ions in oduced in he PVT sys em unde s udy: (
a
) The unglazed one-s ep
manu ac u ed PVT collec o ; (b) he o e all con ol sys em implemen ed in a Beagle Bone Boa d.
1.2.2. O e all Sys em Con ol
The sola PVT-based solu ions con olle s ha e been adi ionally le in a second
plane [
37
,
38
]. The classical sys ems ha dly equi e high-powe ed ac i e elemen s du ing
ope a ion, whe e excluding elec ic back-up sys ems, he only p esen loads a e he sola
ield ci cula ion pumps. In such con en ional sys ems, he he mal gene a ion is simply
deli e ed o he ank and he elec ical ene gy is injec ed in o he g id [
39
]. The ecen
sel -consump ion egula ion ad ances a e pushing owa ds mo e complex sys em a chi-
ec u e combina ions, whe e PV and ST a e combined wi h HP o o he componen s [
9
].
These en i e solu ions mus be con olled in eg ally o ensu ing a p ope global ene gy
pe o mance, conside ing no only he he mal bu also he elec ical gene a ion [40–42].
Fu he mo e, in an nZEB scena io, he local ene gy gene a ion will no be he only
p oblem o be sol ed. The mal and elec ical ene gy supplies will need o be sma ly han-
dled o sa is y use needs echnically and economically. Howe e , he cu en sola hyb id
solu ion con olle s seem no o be capable o ensu ing he equi ed pe o mance [43,44].
Consequen ly, a new o e all sys em con ol is p esen ed (Figu e 2). The inno a i e
con ol s a egy conside s a day ahead DHW consump ion p edic ion ou ine in eg a ed
in o a high-le el con ol laye ha maximizes he HP ope a ion wi h jus sola esou ces.
Thus, highe sola ac ions and sel -consump ion igu es could be achie ed, op imizing
he o e all sys em pe o mance wi hou a ec ing end-use com o o g id impac .
2. Ma e ials and Me hods
In o de o p o e he p e iously exposed po en ial bene i s, a p o o ype o he p o-
posed solu ion was de eloped, ins alled and ope a ed o one en i e yea in a eal-use
applica ion. The objec i e o he es is double. Fi s , o expe imen ally de e mine he
echnical pe o mance o he whole solu ion by means o accu a e moni o ing. Second, o
alida e he obus ness o he sys em unde ex eme wo king condi ions.
2.1. Expe imen al Se -Up
2.1.1. Real-Use DHW Applica ion
The demons a o baseline is a single- amily house loca ed a Jablonec nad Nisou,
Czech Republic (Figu e 3). The new solu ion has been ins alled o ully supply ho ap wa e
Ene gies 2022,15, 3205 4 o 23
o a 3-membe amily, eplacing he p e iously exis ing gas boile . Howe e , he boile has
no been emo ed du ing he es pe iod as i s ill co e s space hea ing ene gy needs and
may be punc ually used as a back-up sys em, i needed, du ing he hea y win e season.
Ene gies 2022, 15, x FOR PEER REVIEW 4 o 23
2.1. Expe imen al Se -Up
2.1.1. Real-Use DHW Applica ion
The demons a o baseline is a single- amily house loca ed a Jablonec nad Nisou,
Czech Republic (Figu e 3). The new solu ion has been ins alled o ully supply ho ap
wa e o a 3-membe amily, eplacing he p e iously exis ing gas boile . Howe e , he
boile has no been emo ed du ing he es pe iod as i s ill co e s space hea ing ene gy
needs and may be punc ually used as a back-up sys em, i needed, du ing he hea y win-
e season.
(a) (b)
Figu e 3. The single- amily house conside ed o he es p e ious o he in e en ion, loca ed a
Jablonec nad Nisou (50.7N, 15.1W coo dina es): (a) Ou doo iew o he building sou h oo op and
açade; (b) Indoo oom wi h exis ing boile and u he household appliances.
As pa o a p ein e en ion s udy, he building usage pa e ns ha e been analyzed
acco ding o use ques iona ies. The household accommoda es 2 pe sons du ing wo k-
days and 4 du ing weekends. The daily a e age ho ap wa e consump ion is a ound 200
l, dis ibu ed in ea ly mo ning showe s, sho mid-day cooking/washing, and nigh addi-
ional 10 min showe s. Acco ding o he collec ed in o ma ion, Table 1 shows he es i-
ma ed ene gy equi emen s o be sa is ied.
Table 1. Household expec ed DHW day and mon h ene gy demands, acco ding o his o ical a e -
age maximum/minimum ambien and ap wa e empe a u es.
Mon h T
amb, max
(°C) T
amb, min
(°C) T
ap wa e
(°C) Q
DHW
(kWh
/
Day) * Q
DHW
(kWh) *
Janua y 0.4 −5.4 4 10.672 331
Feb ua y 2.7 −4.0 5 10.440 292
Ma ch 7.7 −1.0 7 9.976 309
Ap il 13.3 2.6 9 9.512 285
May 18.3 7.1 10 9.280 288
June 21.4 10.5 11 9.048 271
July 23.3 11.9 12 8.816 273
Augus 23.0 11.7 11 9.048 280
Sep embe 19.0 8.7 10 9.280 278
Oc obe 13.1 4.3 9 9.512 295
No embe 6.0 0.2 7 9.976 299
Decembe 2.0 −3.3 4 10.672 330
Yea 12.5 3.6 8.3 9.686 3534
* Calcula ed a 50 °C.
Figu e 3.
The single- amily house conside ed o he es p e ious o he in e en ion, loca ed a
Jablonec nad Nisou (50.7N, 15.1W coo dina es): (
a
) Ou doo iew o he building sou h oo op and
açade; (b) Indoo oom wi h exis ing boile and u he household appliances.
As pa o a p ein e en ion s udy, he building usage pa e ns ha e been analyzed
acco ding o use ques iona ies. The household accommoda es 2 pe sons du ing wo kdays
and 4 du ing weekends. The daily a e age ho ap wa e consump ion is a ound
200 L
,
dis ibu ed in ea ly mo ning showe s, sho mid-day cooking/washing, and nigh addi-
ional 10 min showe s. Acco ding o he collec ed in o ma ion, Table 1shows he es ima ed
ene gy equi emen s o be sa is ied.
Table 1.
Household expec ed DHW day and mon h ene gy demands, acco ding o his o ical a e age
maximum/minimum ambien and ap wa e empe a u es.
Mon h Tamb,max (◦C) Tamb,min (◦C) T ap wa e
(◦C)
QDHW
(kWh/Day) *
QDHW
(kWh) *
Janua y 0.4 −5.4 4 10.672 331
Feb ua y 2.7 −4.0 5 10.440 292
Ma ch 7.7 −1.0 7 9.976 309
Ap il 13.3 2.6 9 9.512 285
May 18.3 7.1 10 9.280 288
June 21.4 10.5 11 9.048 271
July 23.3 11.9 12 8.816 273
Augus 23.0 11.7 11 9.048 280
Sep embe 19.0 8.7 10 9.280 278
Oc obe 13.1 4.3 9 9.512 295
No embe 6.0 0.2 7 9.976 299
Decembe 2.0 −3.3 4 10.672 330
Yea 12.5 3.6 8.3 9.686 3534
* Calcula ed a 50 ◦C.
2.1.2. Sys em and Componen s Sizing
The DHW applica ion ha has been chosen o alida ion pu poses de e mines he
s a egy o be used o sys em sizing. Thus, acco ding o he expec ed DHW day demand
and i s consump ion p o ile, he he modynamic bloc comp ising he HP and he he mal
ene gy s o e (TES) is selec ed. T adi ionally, o DX-saHP, he key pa ame e o look a
a his poin is he ime in e al needed o ensu e he en i e ank wa e is hea ed a he
Ene gies 2022,15, 3205 5 o 23
se poin . Usually, a maximum ime is es ablished. Then he HP and TES a e selec ed o
gua an ee ha in he wo s -case scena io he elapsed ime needed o each he se poin is
below he de ined one. Fo he cu en case s udy, a he coldes , lowe sola esou ce and
highe DHW demand mon hs o Janua y and Decembe , wi h a 2.5 kW o hea ou pu HP
and a 200 L TES he elapsed pe iod is 1.65 h.
Howe e , he new solu ion o be es ed p e ends o un mainly on sola esou ces. Fo
his eason, an in e e HP has been selec ed. E en a i s maximum egime, an ou pu o
2.5 kW o hea would be eached, i will egula ly wo k a lowe ope a ion poin s. Thus, a
sligh ly highe TES olume has been selec ed. The inal olume is 300 L, inc easing by 50%
he TES capaci y and enabling us o hea i up du ing sola esou ce a ailabili y pe iods.
Thus, he isk o eaching p ema u e HP s ops due o he maximum TES empe a u e
being educed.
Finally, o he selec ed he modynamic block, he collec ion ield is sized acco ding o
he equi ed cold powe o he HP in he p e iously commen ed win e pe iod wo s -case
scena io. Fo he cu en case s udy, wi h a con en ional DX-saHP sys em, a o al o
2.72 m2
(2 uni s o 1.36 m
2
) o black pain ed oll bond sola he modynamic collec o s would be
enough. Howe e , he new solu ion is based on PVT collec o s and he on laye migh
ha e a lowe hea ans e capaci y. Thus, he selec ed collec ion a ea is inc eased up o
4.8 m
2
(3 uni s o 1.6 m
2
). E en hough 2 uni s migh be enough o he mally un he HP,
he addi ional collec o is supposed o add a plus o he c i ical win e season. To a oid
undesi ed excessi e summe HP suc ion empe a u es, independen blocking al es a e
added o each one o he collec o s. An addi ional PV module is also added in o de o
enable a compa ison o elec ical yields.
The p o o ype key componen s’ main ea u es a e summa ized in Table 2 o he PVT
collec o and PV module, and in Table 3 o he he modynamic block comp ising HP
and TES.
2.1.3. Sys em Ins alla ion
The selec ed sys em has been success ully ins alled in he household (Figu e 4). The
ou doo uni comp ising he sola ield has been ins alled in he same oo op plane, almos
sou h o ien a ion (
−
13
◦
) bu in a high il ing con igu a ion (70
◦
). In e ms o sola esou ces,
he selec ed plane compa ed o he op imal (37
◦
slope and 0
◦
sou h) educes he annual
i adia ion by 12.6% bu s ill o e s an accep able win e pe o mance wi h a 6.3% dec ease
( o Decembe ). Apa om he non-op imal collec ion plane, he e is no any addi ional
signi ican misma ching in he ho izon p o ile ha may a ec he ene gy collec ion.
Ene gies 2022, 15, x FOR PEER REVIEW 6 o 23
Table 3. HP and TES main ea u es.
Fea u es Value
Hea ou pu
340 .. 2500 W
Elec ic consump ion
240 .. 580 W
Comp esso
DJ75F0F-20UB
In e e
PSD101021A
Expansion al e
E2V09USF10
Coe icien o pe o mance
1.4 .. 4.3
Auxilia hea ing esis ance
na
Re ige an
R134A
Volume
300 l
Maximum wo king empe a u e
60
°C *
1
Ope a ing empe a u e ange −5 .. +42 °C
Dimensions (leng h × wid h × heigh ) 2008 × 550 × 601 mm *
2
Maximum wo king p essu e 6 ba
Hea mean ans e
0.025 W/m·K
Ma e ial
S ainless s eel
Isola ion
Injec ed polyu e hane
*
1
Fo HP ope a ion mode. *
2
Including HP.
2.1.3. Sys em Ins alla ion
The selec ed sys em has been success ully ins alled in he household (Figu e 4). The
ou doo uni comp ising he sola ield has been ins alled in he same oo op plane, al-
mos sou h o ien a ion (−13°) bu in a high il ing con igu a ion (70°). In e ms o sola
esou ces, he selec ed plane compa ed o he op imal (37° slope and 0° sou h) educes he
annual i adia ion by 12.6% bu s ill o e s an accep able win e pe o mance wi h a 6.3%
dec ease ( o Decembe ). Apa om he non-op imal collec ion plane, he e is no any
addi ional signi ican misma ching in he ho izon p o ile ha may a ec he ene gy col-
lec ion.
The sola ield composed is o 3 PVT collec o s and he addi ional PV modules (dis-
played on he eas side) ha e been ins alled wi h iden ical ixing solu ions, so no po en ial
he e ogenei y is in oduced. In o de o measu e he po en ial gap in elec ical pe o -
mance, independen maximum powe s o acking ha e been deployed o each one o
he collec o s and modules, based on 2 uni s o he dual inpu mic oin e e APS YC500i.
(a) (b)
Figu e 4. The single- amily house a e he in e en ion: (a) Ou doo iew wi h he PVT/PV uni s
ins alled and unde ope a ion; (b) Indoo oom wi h he HP, TES and moni o ing ins umen a ion.
Figu e 4.
The single- amily house a e he in e en ion: (
a
) Ou doo iew wi h he PVT/PV uni s
ins alled and unde ope a ion; (b) Indoo oom wi h he HP, TES and moni o ing ins umen a ion.

Ene gies 2022,15, 3205 6 o 23
Table 2. PVT collec o and PV module main ea u es.
Fea u es Value
Maximum peak powe 250 W
Maximum powe poin ol age 29.53 V
Maximum powe poin cu en 8.45 A
Open ci cui ol age 37.60 V
Sho ci cui cu en 8.91 A
Cell No mal Ope a ing Tempe a u e 45.0 ±2◦C *1
Sho ci cui cu en empe a u e coe icien 0.04%/◦C
Open ci cui ol age empe a u e coe icien −0.32%/◦C
Maximum powe empe a u e coe icien −0.43%/◦C
Ope a ing empe a u e ange −40 . . . +85 ◦C
Backshee collec ion a ea 1.63 m2*2
Maximum wo king p essu e 10 ba *2
Re ige a ion inpu /ou pu connec o s SAE 1/40 0 /3/800 *2
Dimensions (leng h ×wid h ×heigh ) 1645 ×990 ×40 mm
Weigh (PVT/PV) 30/26 kg
*1Valid only o PV. *2Valid only o PVT.
Table 3. HP and TES main ea u es.
Fea u es Value
Hea ou pu 340 . . . 2500 W
Elec ic consump ion 240 . . . 580 W
Comp esso DJ75F0F-20UB
In e e PSD101021A
Expansion al e E2V09USF10
Coe icien o pe o mance 1.4 . . . 4.3
Auxilia hea ing esis ance na
Re ige an R134A
Volume 300 l
Maximum wo king empe a u e 60 ◦C *1
Ope a ing empe a u e ange −5 . . . +42 ◦C
Dimensions (leng h ×wid h ×heigh ) 2008 ×550 ×601 mm *2
Maximum wo king p essu e 6 ba
Hea mean ans e 0.025 W/m·K
Ma e ial S ainless s eel
Isola ion Injec ed polyu e hane
*1Fo HP ope a ion mode. *2Including HP.
The sola ield composed is o 3 PVT collec o s and he addi ional PV modules (dis-
played on he eas side) ha e been ins alled wi h iden ical ixing solu ions, so no po en ial
he e ogenei y is in oduced. In o de o measu e he po en ial gap in elec ical pe o -
mance, independen maximum powe s o acking ha e been deployed o each one o
he collec o s and modules, based on 2 uni s o he dual inpu mic oin e e APS YC500i.
The e ige an ci cui om he HP o he collec o s has an ini ial common segmen o
7 m in leng h, which is la e di ided in o 3 iden ical pa allel sec ions o 2 m eaching he col-
lec o s, so he di e en ci cui s a e compensa ed. Blocking al es ha e also been included
o enable a po en ial manual disconnec ion o each one o he collec o ’s he mal ou pu s.
The e u n o he ci cui is pe o med in he same way bu wi hou any compensa ion. All
he e ige an pipes a e he mally isola ed wi h a 1cm polye hylene.
The indoo uni has been adap ed o he a ailable oom cons ain s. Thus, he TES
is placed close o he exis ing gas boile , so he ank pipes a e di ec ly connec ed o he
household DHW ci cui .
Ene gies 2022,15, 3205 7 o 23
2.1.4. Ins umen a ion and Da a Acquisi ion
The expe imen al ac i i y equi es accu a e moni o ing o ene gy luxes and u he
ele an bounda y a iables o de e mine he echnical pe o mance o bo h sys em compo-
nen s and he comple e solu ion. Thus, di e en kinds o senso s a e displayed along he
p o o ype (Figu e 5). The mos signi ican a iables o measu e me eo ological condi ions,
ene gy collec ion (sola ield), con e sion (powe elec onics o PV and) HP and s o e (ho
wa e ank) a e summa ized in Table 4.
Ene gies 2022, 15, x FOR PEER REVIEW 7 o 23
The e ige an ci cui om he HP o he collec o s has an ini ial common segmen
o 7 m in leng h, which is la e di ided in o 3 iden ical pa allel sec ions o 2 m eaching
he collec o s, so he di e en ci cui s a e compensa ed. Blocking al es ha e also been
included o enable a po en ial manual disconnec ion o each one o he collec o ’s he mal
ou pu s. The e u n o he ci cui is pe o med in he same way bu wi hou any compen-
sa ion. All he e ige an pipes a e he mally isola ed wi h a 1cm polye hylene.
The indoo uni has been adap ed o he a ailable oom cons ain s. Thus, he TES is
placed close o he exis ing gas boile , so he ank pipes a e di ec ly connec ed o he
household DHW ci cui .
2.1.4. Ins umen a ion and Da a Acquisi ion
The expe imen al ac i i y equi es accu a e moni o ing o ene gy luxes and u he
ele an bounda y a iables o de e mine he echnical pe o mance o bo h sys em com-
ponen s and he comple e solu ion. Thus, di e en kinds o senso s a e displayed along
he p o o ype (Figu e 5). The mos signi ican a iables o measu e me eo ological condi-
ions, ene gy collec ion (sola ield), con e sion (powe elec onics o PV and) HP and
s o e (ho wa e ank) a e summa ized in Table 4.
(a) (b)
Figu e 5. Senso s dis ibu ion in he p o o ype unde es : (a) Local me eo ological condi ions, PVT
collec o s and PV module ope a ion empe a u es; (b) Indoo ins umen a ion in eg a ed in he
on o he HP uni .
The selec ed moni o ing a chi ec u e is based on in-si e measu emen s ha a e im-
media ely ansduced in o Modbus o e RS-485 by he senso s hemsel es. Then he da a
is emo ely eques ed and handled by a da alogge se ice in he same Beagle Bone boa d
whe e he con ol is implemen ed. The 69- a iable moni o ing egis e is ga he ed e e y
minu e and s o ed on a daily basis in cs iles. The con ol and da a logging boa d ha e
an in e ne connec ion by means o a ou e wi h a VPN. A emo e copy o local con en
is c ea ed weekly.
Table 4. A selec ion o he mos signi ican moni o ed a iables, including he ins umen used o
he measu emen and some addi ional ele an in o ma ion.
Ins umen Uni s Desc ip ion Symbol
Range and
Uni s Accu acy
MET calib a ed cell
(A e sa)
2 Global plane o a ay i adiance G
PoA
0 .. 1400 W/m
2
±2.2%
1 Ambien empe a u e
T
amb
−20 .. 100 °C ±0.8 °C
1 Wind speed ws 2 .. 140 km/h ±3% *
1
1 C ys alline silicon PV module
e e ence empe a u e T
PV e
−20 .. 100 °C ±0.8 °C
Figu e 5.
Senso s dis ibu ion in he p o o ype unde es : (
a
) Local me eo ological condi ions, PVT
collec o s and PV module ope a ion empe a u es; (
b
) Indoo ins umen a ion in eg a ed in he on
o he HP uni .
Table 4.
A selec ion o he mos signi ican moni o ed a iables, including he ins umen used o
he measu emen and some addi ional ele an in o ma ion.
Ins umen Uni s Desc ip ion Symbol Range and Uni s Accu acy
MET calib a ed cell
(A e sa)
2Global plane o a ay i adiance GPoA 0 . . . 1400 W/m2±2.2%
1Ambien empe a u e Tamb −20 . . . 100 ◦C±0.8 ◦C
1Wind speed ws 2 . . . 140 km/h ±3% *1
1C ys alline silicon PV module
e e ence empe a u e TPV e −20 . . . 100 ◦C±0.8 ◦C
RTF-100-S4B-5.0-C8 PT100
(Lab acili y)
3
2 a collec o s
and 1 a module
Middle abso be /backshee
empe a u e
TPVT,2
TPVT,3
TPV
−50 . . . 150 ◦C±1%
VMU-E DC ene gy me e
(Ca lo Ga azzi)
4
one pe collec o
Vol age VPVT/PVm,X 0 . . . 400 V ±0.5% *2
Cu en IPVT/PVm,X 0 . . . 20 A ±0.5% *3
Powe PPVT/PVm,X *50 . . . 8 kW ±1%
Ene gy EPVT/PVm,X *5na kWh ±1%
EM110 AC ene gy me e
(Ga lo Ga azzi)
3
G id balance
PV gene a ion
HP consump ion
Ene gy EG id
EPVm
EHP
na kWh ±1% *4
µPC HP con olle
(Ca el) 1
Comp esso ol age VComp na V±1%
Comp esso cu en IComp na A±1%
E apo a ion empe a u e TE a −50 . . . 100 ◦C±1◦C
Suc ion empe a u e TSuc −50 . . . 100 ◦C±1◦C
Discha ge empe a u e TDis −50 . . . 100 ◦C±1◦C
Condensa ion empe a u e TCon −50 . . . 100 ◦C±1◦C
TES load empe a u e TTES,load −50 . . . 100 ◦C±1◦C
TES middle empe a u e TTES,mid −50 . . . 100 ◦C±1◦C
Condense ou le empe a u e TCOu −50 . . . 100 ◦C±1◦C
*
1
The accu acy o wind speed is alid o 15
. . .
140 km/h ange, bu always g ea e han
±
1 km/h. *
2
The
accu acy o DC ol age is alid o 10
. . .
400 V ange. *
3
The accu acy o DC cu en is alid o 0.05
. . .
20 A
ange. *
4
The accu acy o AC ene gy is 1.5% o a ange o 0.25
. . .
0.5 A, acco ding o EN50470-3. *
5
The e m
EPV is le o he o al sola ield elec ical ou pu .
The selec ed moni o ing a chi ec u e is based on in-si e measu emen s ha a e imme-
dia ely ansduced in o Modbus o e RS-485 by he senso s hemsel es. Then he da a is
Ene gies 2022,15, 3205 8 o 23
emo ely eques ed and handled by a da alogge se ice in he same Beagle Bone boa d
whe e he con ol is implemen ed. The 69- a iable moni o ing egis e is ga he ed e e y
minu e and s o ed on a daily basis in cs iles. The con ol and da a logging boa d ha e
an in e ne connec ion by means o a ou e wi h a VPN. A emo e copy o local con en is
c ea ed weekly.
2.2. Da a Analysis, Cleaning and P ocessing
The applied me hodology is essen ially based on he analysis o expe imen al da a.
The moni o ing ac i i y p o ided da ase is pos p ocessed o enable a be e in e p e a ion
and u he discussion.
The ga he ed sys em pe o mance is i s analyzed in de ail. The day-based iles
ha e an au oma ic checking algo i hm. The p ocedu e only enables us o il e en i e day
pe o mance days wi h all da ase a iables in ange. Fu he mo e, all days a e ca e ully
manually analyzed using speci ic imese ies empla es o il e any addi ional e o s. Thus,
days wi h pa ial ope a ion, moni o ed a iable ou lye s o addi ional epo ed phenomena
a e emo ed a his s age. Any kind o gap illing is no conside ed.
The analysis con inues only wi h he alid-day da ase . Fo his selec ion, se e al
in aday pa ame e s and day-agg ega ed ene gy alues a e calcula ed. Addi ionally, day
ep esen a i e key pe o mance indica o s (KPI) a e ob ained.
Finally, day ep esen a i e KPIs a e once mo e agg ega ed in a mon hly-based ap-
p oach. Fo his analysis, he a e age, median o accumula ed alues o day-based KPIs
a e conside ed o mon hly-based pe iods.
2.3. Key Pe o mance Indica o s
The de e mina ion o hese KPIs is pe o med acco ding o he common ag eed p oce-
du e es ablished wi hin di e en Tasks o he In e na ional Ene gy Agency Sola Hea ing
and Cooling p og amme [45].
2.3.1. Sys em Le el
A se o ou main KPIs has been conside ed o cha ac e ize sys em ope a ion. The
enewable ene gy sha e ep esen s he local non- ossil uel po en ial:
RES =Z
.
QHP
PG id,NC
(1)
whe e
QHP
is he HP hea ou pu , which o he cu en DX-saHP solu ion is no di ec ly
measu ed bu calcula ed based on he comp esso manu ac u e da a and moni o ed T
E a
,
TCon and HP con olle comp esso equency.
The sel -su iciency a io shows he eal sola ield ou pu po en ial o co e he HP
elec ic consump ion needs:
SSR =ZPPV
PHP
(2)
whe e
PPV
is he agg ega ed elec ic ou pu o he h ee PVT collec o s and he co espond-
ing one o he PV module.
PHP
is he HP consump ion, which conside s he comp esso
bu also addi ional de ices.
The sel -consump ion a io o de e mine he eal PV ou pu po en ial o co e he HP
elec ic consump ion needs:
SCR =Zmin(PPV,PG id)
PPV
(3)
whe e PG id is he sys em g id consump ion in he scena io o non-PV p oduc ion.
Ene gies 2022,15, 3205 9 o 23
Finally, he sola ac ion, o ob ain he u iliza ion a io o he sola esou ce a he
ene gy collec ion ield:
SF =ZPPV +.
QPVT
4·APVT/PV·GPoA
(4)
whe e
APVT/PV
is he ape u e a ea o he PVT collec o s o PV module, in his case
iden ical.
QPVT
is he PVT collec o ield hea ou pu , which, as in he case o
QHP
, could
no be locally measu ed and has been ob ained as a unc ion o moni o ed T
E a
,T
Con
, HP
equency and manu ac u e es s da a. The ambien gain o PVT collec o s due o below
ambien ope a ion is included in his calcula ion p ocedu e and should be emo ed o
genuine SF ob en ion, bu he e is s ill no con iden p ocedu e o decouple i .
2.3.2. PVT Collec o s
The quan i ica ion o he pe o mance gap be ween he PVT collec o and he e e ence
PV module is he goal o he ollowing wo speci ic KPIs ha a e p oposed. One o hem is
ocusing on he po en ial pe o mance a io inc ease:
∆PRPVT
PV =
∑3
i=1(PRPVTi)
3−PRPV
PRPV
(5)
whe e PRPVTiis calcula ed o each one o he collec o s as ollows:
PRPVTi=ZPPVTi· PVTi
PV
APVT/PV·GPoA
(6)
wi h
PVTi
PV
as he maximum powe poin de ia ion co ec ion be ween each one o he
collec o s and he PV module used as e e ence.
PPVT
is he elec ical ou pu o he 3
PVT collec o - ield. The elec ical cha ac e is ics o each collec o and module ha e been
ob ained wi h an indoo lash es e and in he same way he PRPV:
PRPV =ZPPV
APVT/PV·GPoA
(7)
The second KPI ies o cla i y i he PR de ia ion is co ela ed wi h he expec ed lowe
ope a ion empe a u e o he PVT collec o s [
46
]. Thus, he day’s a e age PVT collec o
empe a u e di e ence wi h he PV module e e ence is calcula ed:
∆TPVT
PV =TPVT −TPV =∑3
i=1TPVTi
3−TPV (8)
whe e TPVT/PV is calcula ed o each one o he collec o s and modules as ollows:
TPVTi/PV =1
N
N
∑
=0
TPVTi/PV (9)
Addi ionally, con en ional con e sion e iciencies a e p oposed. In he case o he PV
module jus conside ing he elec ic ou pu powe :
ηPV =ZPPVm
APV ·GPoA
(10)
whe e
PPVm
is he elec ical ou pu o he PV module, and o he PVT collec o adding he
hea ou come:
ηPVT =ZPPVT·.
QPVT
APVT·GPoA
(11)
Ene gies 2022,15, 3205 16 o 23
Ene gies 2022, 15, x FOR PEER REVIEW 16 o 23
Figu e 13. Mon hly a e age daily mean ene gy magni udes.
Figu e 14. Mon hly a e age daily mean DHW consump ion and he ene gy sou ce.
The en i e yea agg ega ed ene gy by ype is lis ed below:
• 𝐸 = 1050 kWh;
• 𝑄 = 855 kWh;
• 𝐸 = 431 kWh;
• 𝑄 = 1287 kWh;
• 𝐸 = 220 kWh;
3.4. Mon hly A e age Daily KPI Analysis
3.4.1. Sys em Le el
The ou main KPIs selec ed o cha ac e ize en i e sys em pe o mance a e displayed in
Figu e 15 o he a e age day alues. The RES is abo e 60% o he whole pe iod, eaching i s
maximum o 92% o he mon h o May. The SSR shows he expec ed g ea e a iabili y, wi h
a maximum in Augus (470%) and a minimum in Decembe (18%), a ec ed mainly by he
annual ully decoupled DHW ene gy demand and sola esou ce. On he opposi e side, he
ob ained SCR is maximum o he win e pe iod (94% o Decembe ) while is educed o 17%
o he mon h o Augus . The highe alues a e linked o low i adiance and long HP ope a ion
days. Finally, he SF is in he ange o 22–159% o Augus and Decembe , espec i ely. Days
wi h almos no i adia ion bu high PVT he mal ou pu , due o wind and in a ed ene gy
collec ion, leading o abo e 300% alues a e sa u a ed.
0
1
2
3
4
5
6
Jan Feb Ma Ap May Jun Jul Aug Sep Oc No Dec
Ene gy (kWh)
Ep Ehp
Qp Qhp
Egc Egi
Jan Feb Ma Ap May Jun Jul Aug Sep Oc No Dec
-60%
-40%
-20%
0%
20%
40%
60%
80%
100%
-6
-4
-2
0
2
4
6
8
10
Ene gy dis ibu ion (%)
Ene gy (kWw)
Esc Qp Egc Egi Qdhw
Figu e 14. Mon hly a e age daily mean DHW consump ion and he ene gy sou ce.
The en i e yea agg ega ed ene gy by ype is lis ed below:
•EPVac = 1050 kWh;
•QPVT = 855 kWh;
•EHP = 431 kWh;
•QHP = 1287 kWh;
•EGC = 220 kWh;
3.4. Mon hly A e age Daily KPI Analysis
3.4.1. Sys em Le el
The ou main KPIs selec ed o cha ac e ize en i e sys em pe o mance a e displayed in
Figu e 15 o he a e age day alues. The RES is abo e 60% o he whole pe iod, eaching
i s maximum o 92% o he mon h o May. The SSR shows he expec ed g ea e a iabili y,
wi h a maximum in Augus (470%) and a minimum in Decembe (18%), a ec ed mainly by
he annual ully decoupled DHW ene gy demand and sola esou ce. On he opposi e side,
he ob ained SCR is maximum o he win e pe iod (94% o Decembe ) while is educed
o 17% o he mon h o Augus . The highe alues a e linked o low i adiance and long
HP ope a ion days. Finally, he SF is in he ange o 22–159% o Augus and Decembe ,
espec i ely. Days wi h almos no i adia ion bu high PVT he mal ou pu , due o wind
and in a ed ene gy collec ion, leading o abo e 300% alues a e sa u a ed.
Ene gies 2022, 15, x FOR PEER REVIEW 17 o 23
Figu e 15. Mon hly a e age daily mean sys em-le el KPIs.
Fo he en i e yea ’s pe o mance, he ob ained sys em-le el a e age day KPI esul s
a e 83% o RES, 220% o SSR, 41% o SCR and 46% o SF. The same KPIs ob ained o
in eg a ion o he en i e yea a e 86%, 204%, 28.5% and 25.7%. The p e iously commen ed
day and mon h-based esul s a e educed o he en i e pe iod analysis, especially o SCR
and SF. The eason is ha he high ene gy esou ce summe days wi h sho HP ope a ion
a e oo weigh ed in his annual analysis. The high RES is basically based on HP pe o -
mance and enhanced by sola ield con ibu ion. The ob ained SCR shows good unde ly-
ing con ol pe o mance. The ob ained SSR and SF esul s a e huge, bu somehow a i i-
cially boos ed due o summe season high sola esou ce weigh and DX-saHP ambien
hea collec ion, espec i ely.
3.4.2. PVT Collec o Ve sus PV Module
The con e sion e iciency o PVT collec o s is highe han he same size and iden ical
PV echnology modules [30] due o he addi ional he mal ou pu . Howe e , he inal en-
e gy pe o mance usually depends on he applica ion o he PVT ope a ion mean empe -
a u e and on he classical e iciency e sus hea quali y dilemma. The pe iod con e sion
e iciencies de e mined o he es ing pe iod a e shown in Figu e 16. Apa om he cold-
es mon h peaks, due o low esou ce and ambien ene gy collec ion, he es o he win e
mon hs show highe PVT alues wi h a signi ican ly g ea e he mal side con ibu ion.
Howe e , o he high i adia ion and ho mon h o Augus , he PV in luence on e iciency
is la ge han he elec ical one. In annual e ms, he PV con e s 13.9% o inciden sola
ene gy, while PVT eaches 37%.
0
1
2
3
4
5
0.00
0.33
0.66
0.99
1.32
1.65
Jan Feb Ma Ap May Jun Jul Aug Sep Oc No Dec
SSR (pu)
RES, SCR and SF (pu)
RES SSR SCR SF
↑ 0.77 ↑ 1.36
0.0
0.1
0.2
0.3
0.4
Jan Feb Ma Ap May Jun Jul Aug Sep Oc No Dec
E iciency (pu)
E p E p
Figu e 15. Mon hly a e age daily mean sys em-le el KPIs.

Ene gies 2022,15, 3205 17 o 23
Fo he en i e yea ’s pe o mance, he ob ained sys em-le el a e age day KPI esul s
a e 83% o RES, 220% o SSR, 41% o SCR and 46% o SF. The same KPIs ob ained o
in eg a ion o he en i e yea a e 86%, 204%, 28.5% and 25.7%. The p e iously commen ed
day and mon h-based esul s a e educed o he en i e pe iod analysis, especially o
SCR and SF. The eason is ha he high ene gy esou ce summe days wi h sho HP
ope a ion a e oo weigh ed in his annual analysis. The high RES is basically based on
HP pe o mance and enhanced by sola ield con ibu ion. The ob ained SCR shows good
unde lying con ol pe o mance. The ob ained SSR and SF esul s a e huge, bu somehow
a i icially boos ed due o summe season high sola esou ce weigh and DX-saHP ambien
hea collec ion, espec i ely.
3.4.2. PVT Collec o Ve sus PV Module
The con e sion e iciency o PVT collec o s is highe han he same size and iden ical
PV echnology modules [
30
] due o he addi ional he mal ou pu . Howe e , he inal
ene gy pe o mance usually depends on he applica ion o he PVT ope a ion mean em-
pe a u e and on he classical e iciency e sus hea quali y dilemma. The pe iod con e sion
e iciencies de e mined o he es ing pe iod a e shown in Figu e 16. Apa om he coldes
mon h peaks, due o low esou ce and ambien ene gy collec ion, he es o he win e
mon hs show highe PVT alues wi h a signi ican ly g ea e he mal side con ibu ion.
Howe e , o he high i adia ion and ho mon h o Augus , he PV in luence on e iciency
is la ge han he elec ical one. In annual e ms, he PV con e s 13.9% o inciden sola
ene gy, while PVT eaches 37%.
Ene gies 2022, 15, x FOR PEER REVIEW 17 o 23
Figu e 15. Mon hly a e age daily mean sys em-le el KPIs.
Fo he en i e yea ’s pe o mance, he ob ained sys em-le el a e age day KPI esul s
a e 83% o RES, 220% o SSR, 41% o SCR and 46% o SF. The same KPIs ob ained o
in eg a ion o he en i e yea a e 86%, 204%, 28.5% and 25.7%. The p e iously commen ed
day and mon h-based esul s a e educed o he en i e pe iod analysis, especially o SCR
and SF. The eason is ha he high ene gy esou ce summe days wi h sho HP ope a ion
a e oo weigh ed in his annual analysis. The high RES is basically based on HP pe o -
mance and enhanced by sola ield con ibu ion. The ob ained SCR shows good unde ly-
ing con ol pe o mance. The ob ained SSR and SF esul s a e huge, bu somehow a i i-
cially boos ed due o summe season high sola esou ce weigh and DX-saHP ambien
hea collec ion, espec i ely.
3.4.2. PVT Collec o Ve sus PV Module
The con e sion e iciency o PVT collec o s is highe han he same size and iden ical
PV echnology modules [30] due o he addi ional he mal ou pu . Howe e , he inal en-
e gy pe o mance usually depends on he applica ion o he PVT ope a ion mean empe -
a u e and on he classical e iciency e sus hea quali y dilemma. The pe iod con e sion
e iciencies de e mined o he es ing pe iod a e shown in Figu e 16. Apa om he cold-
es mon h peaks, due o low esou ce and ambien ene gy collec ion, he es o he win e
mon hs show highe PVT alues wi h a signi ican ly g ea e he mal side con ibu ion.
Howe e , o he high i adia ion and ho mon h o Augus , he PV in luence on e iciency
is la ge han he elec ical one. In annual e ms, he PV con e s 13.9% o inciden sola
ene gy, while PVT eaches 37%.
0
1
2
3
4
5
0.00
0.33
0.66
0.99
1.32
1.65
Jan Feb Ma Ap May Jun Jul Aug Sep Oc No Dec
SSR (pu)
RES, SCR and SF (pu)
RES SSR SCR SF
↑ 0.77 ↑ 1.36
0.0
0.1
0.2
0.3
0.4
Jan Feb Ma Ap May Jun Jul Aug Sep Oc No Dec
E iciency (pu)
E p E p
Figu e 16. Mon hly a e age daily PV module and PVT collec o con e sion e iciency.
Addi ionally, in he dually d i en DX-saHP es ed solu ion, he PVT collec o is no
equi ed o ope a e a high empe a u es o o e aluable hea and as a esul , he elec ical
ou pu is no educed. Figu e 17 e idences ha he PVT ex ac ed hea educes om
almos 1 o 3.7
◦
C he a e age empe a u e o he PVT collec o abso be e sus PV module
backshee . Due o he cooling, he elec ical PR o he PVT collec o is imp o ed o
almos all he mon hs, excep Janua y and Decembe , a ec ed by hea y collec o on laye
condensa ion and icing. Howe e , acco ding o da ashee alues, he empe a u e educ ion
o 1 K should be aduced in a 0.43% inc ease in he PR, bu he ob ained PR esul s a e no
in consonance, which migh sugges an op imum cooling du ing high i adia ion pe iods.
Finally, he yea base esul concludes wi h a PR inc ease o 4.5%, achie ed no only by he
HP ac i e cooling bu also by be e na u al con ec ion.
Ene gies 2022,15, 3205 18 o 23
Ene gies 2022, 15, x FOR PEER REVIEW 18 o 23
Figu e 16. Mon hly a e age daily PV module and PVT collec o con e sion e iciency.
Addi ionally, in he dually d i en DX-saHP es ed solu ion, he PVT collec o is no
equi ed o ope a e a high empe a u es o o e aluable hea and as a esul , he elec i-
cal ou pu is no educed. Figu e 17 e idences ha he PVT ex ac ed hea educes om
almos 1 o 3.7 °C he a e age empe a u e o he PVT collec o abso be e sus PV mod-
ule backshee . Due o he cooling, he elec ical PR o he PVT collec o is imp o ed o
almos all he mon hs, excep Janua y and Decembe , a ec ed by hea y collec o on
laye condensa ion and icing. Howe e , acco ding o da ashee alues, he empe a u e
educ ion o 1 K should be aduced in a 0.43% inc ease in he PR, bu he ob ained PR
esul s a e no in consonance, which migh sugges an op imum cooling du ing high i a-
dia ion pe iods. Finally, he yea base esul concludes wi h a PR inc ease o 4.5%,
achie ed no only by he HP ac i e cooling bu also by be e na u al con ec ion.
Figu e 17. Mon hly a e age daily PR and ope a ion empe a u e ela ion be ween PVT and PVT.
3.4.3. Hea Pump
The KPI selec ed o de e mine he HP ope a ion is he PF, he con en ional and he
boos ed. Figu e 18 shows he PF oscilla ion be ween 2.3 and 3.4, in acco dance wi h
da ashee anges. Howe e , when he ne g id impo ed ene gy is conside ed he PF is
signi ican ly imp o ed. E en o he win e sols ice, he ob ained alues a e simila , du -
ing he summe pe iod i eaches median alues be ween 20 and 30. Fo he calcula ions,
singula alues wi h null g id consump ion a e no conside ed.
Figu e 18. Mon hly median daily PF pe mon h, o common g id absolu e and ne e sions.
3.4.4. The mal Ene gy S o e
1
10
Jan Feb Ma Ap May Jun Jul Aug Sep Oc No Dec
PF (pu)
PF PFne
Figu e 17. Mon hly a e age daily PR and ope a ion empe a u e ela ion be ween PVT and PVT.
3.4.3. Hea Pump
The KPI selec ed o de e mine he HP ope a ion is he PF, he con en ional and he
boos ed. Figu e 18 shows he PF oscilla ion be ween 2.3 and 3.4, in acco dance wi h
da ashee anges. Howe e , when he ne g id impo ed ene gy is conside ed he PF is
signi ican ly imp o ed. E en o he win e sols ice, he ob ained alues a e simila , du ing
he summe pe iod i eaches median alues be ween 20 and 30. Fo he calcula ions,
singula alues wi h null g id consump ion a e no conside ed.
Ene gies 2022, 15, x FOR PEER REVIEW 18 o 23
Figu e 16. Mon hly a e age daily PV module and PVT collec o con e sion e iciency.
Addi ionally, in he dually d i en DX-saHP es ed solu ion, he PVT collec o is no
equi ed o ope a e a high empe a u es o o e aluable hea and as a esul , he elec i-
cal ou pu is no educed. Figu e 17 e idences ha he PVT ex ac ed hea educes om
almos 1 o 3.7 °C he a e age empe a u e o he PVT collec o abso be e sus PV mod-
ule backshee . Due o he cooling, he elec ical PR o he PVT collec o is imp o ed o
almos all he mon hs, excep Janua y and Decembe , a ec ed by hea y collec o on
laye condensa ion and icing. Howe e , acco ding o da ashee alues, he empe a u e
educ ion o 1 K should be aduced in a 0.43% inc ease in he PR, bu he ob ained PR
esul s a e no in consonance, which migh sugges an op imum cooling du ing high i a-
dia ion pe iods. Finally, he yea base esul concludes wi h a PR inc ease o 4.5%,
achie ed no only by he HP ac i e cooling bu also by be e na u al con ec ion.
Figu e 17. Mon hly a e age daily PR and ope a ion empe a u e ela ion be ween PVT and PVT.
3.4.3. Hea Pump
The KPI selec ed o de e mine he HP ope a ion is he PF, he con en ional and he
boos ed. Figu e 18 shows he PF oscilla ion be ween 2.3 and 3.4, in acco dance wi h
da ashee anges. Howe e , when he ne g id impo ed ene gy is conside ed he PF is
signi ican ly imp o ed. E en o he win e sols ice, he ob ained alues a e simila , du -
ing he summe pe iod i eaches median alues be ween 20 and 30. Fo he calcula ions,
singula alues wi h null g id consump ion a e no conside ed.
Figu e 18. Mon hly median daily PF pe mon h, o common g id absolu e and ne e sions.
3.4.4. The mal Ene gy S o e
1
10
Jan Feb Ma Ap May Jun Jul Aug Sep Oc No Dec
PF (pu)
PF PFne
Figu e 18. Mon hly median daily PF pe mon h, o common g id absolu e and ne e sions.
3.4.4. The mal Ene gy S o e
The TES ope a ion key empe a u e e olu ion indica es he end-use com o o e he
es ing pe iod. Figu e 19 illus a es he TES KPIs. The ank wa e olume is he ep esen-
a i e empe a u e ange
∆TTES50
du ing almos all he pe iod is below 8 K. Howe e , o
some mon hs he minimum day a e age empe a u e is educed beyond desi able alues,
mainly d i en by laxe con olle pa ame e iza ion (Ap il–May), al hough no c i ical poin s
a e eached. The No embe –Janua y pe iod e idences he al eady p e iously commen ed
lowe TES s a e o cha ge, wi h he minimum o Decembe . Fo his scena io, he a e age
DHW load empe a u e is 39.3 ◦C.
The end-use ga he ed expe ience a e he expe imen a ion pe iod concludes com o
le els ha e o e all been achie ed in e ms o DHW se ice empe a u e e en in ha d win e
imes. Only a couple o days wi h punc ual low TES empe a u e in o ma ion shown a HP
display ha e been epo ed, mainly du ing he beginning o he es ing pe iod. Howe e ,
he gas boile ha was le as a po en ial backup has no been connec ed.
Ene gies 2022,15, 3205 19 o 23
Ene gies 2022, 15, x FOR PEER REVIEW 19 o 23
The TES ope a ion key empe a u e e olu ion indica es he end-use com o o e
he es ing pe iod. Figu e 19 illus a es he TES KPIs. The ank wa e olume is he ep e-
sen a i e empe a u e ange ∆𝑇 du ing almos all he pe iod is below 8 K. Howe e ,
o some mon hs he minimum day a e age empe a u e is educed beyond desi able al-
ues, mainly d i en by laxe con olle pa ame e iza ion (Ap il–May), al hough no c i ical
poin s a e eached. The No embe –Janua y pe iod e idences he al eady p e iously com-
men ed lowe TES s a e o cha ge, wi h he minimum o Decembe . Fo his scena io, he
a e age DHW load empe a u e is 39.3 °C.
Figu e 19. Mon hly median daily TES KPIs.
The end-use ga he ed expe ience a e he expe imen a ion pe iod concludes com-
o le els ha e o e all been achie ed in e ms o DHW se ice empe a u e e en in ha d
win e imes. Only a couple o days wi h punc ual low TES empe a u e in o ma ion
shown a HP display ha e been epo ed, mainly du ing he beginning o he es ing pe-
iod. Howe e , he gas boile ha was le as a po en ial backup has no been connec ed.
4. Conclusions
Global ene gy consump ion is es ima ed o be inc eased o e u u e decades, up o
50% by 2050. A he same ime, i is impe a i e o educe g eenhouse gas emissions by
45% by 2030, compa ed o 2010 le els, while eaching ne ze o emissions by 2050. The las
COP26 emphasized he u gency and oppo uni ies o mo ing o a ca bon-neu al econ-
omy. In he mean ime, EU building s ock is esponsible o 40% o he ene gy consump-
ion and 36% o CO2 emissions. Howe e , in he cu en ene gy c isis scena io, he Eu o-
pean Commission seems o ha e a clea oadmap owa d ene gy sec o deca boniza ion.
Mos o hose buildings o be deca bonized need o mee elec ici y and hea de-
mands. In he nZEB scena io, mos o he consumed ene gy would need o be gene a ed
locally by means o enewable solu ions ha nowadays seem no o p o ide an a ac i e
pe o mance o cos -compe i i eness. Sola -based echnologies end o be he mos p om-
ising ones, bu o highly densely popula ed and es ic ed a eas, he usual PV o ST single
app oaches may no be e icien enough.
The cu en wo k is ocused on he expe imen al analysis o he dual use o he sola
esou ce by means o hyb id PVT collec o s and hei sma combina ion wi h di ec ex-
pansion HPs h ough p edic i e con ol s a egies. Fo ha pu pose, a solu ion wi h se -
e al inno a ions in he collec o and in he o e all con ol s a egy was de eloped. A eal-
use single- amily house has been selec ed o hos ing he es a a con inen al clima e (Ja-
blonec nad Nisou, Czeck Republic) o a DHW applica ion o e one-yea o ope a ion.
The sizing o he sys em has been ca ied ou . The sys em comp ising h ee PVT collec o s
and one PV module, dually connec ed o an in e e DX-saHP wi h an o e sized TES and
a p edic i e con ol has been p ope ly ins alled, commissioned and ully accu a ely
25
30
35
40
45
50
Jan Feb Ma Ap May Jun Jul Aug Sep Oc No Dec
Tempe a u e (ºC)
TES.50,max
TES.50,mean
TES.50,min
TES.100,mean
Figu e 19. Mon hly median daily TES KPIs.
4. Conclusions
Global ene gy consump ion is es ima ed o be inc eased o e u u e decades, up o
50% by 2050. A he same ime, i is impe a i e o educe g eenhouse gas emissions by
45% by 2030, compa ed o 2010 le els, while eaching ne ze o emissions by 2050. The las
COP26 emphasized he u gency and oppo uni ies o mo ing o a ca bon-neu al economy.
In he mean ime, EU building s ock is esponsible o 40% o he ene gy consump ion
and 36% o CO
2
emissions. Howe e , in he cu en ene gy c isis scena io, he Eu opean
Commission seems o ha e a clea oadmap owa d ene gy sec o deca boniza ion.
Mos o hose buildings o be deca bonized need o mee elec ici y and hea demands.
In he nZEB scena io, mos o he consumed ene gy would need o be gene a ed locally by
means o enewable solu ions ha nowadays seem no o p o ide an a ac i e pe o mance
o cos -compe i i eness. Sola -based echnologies end o be he mos p omising ones, bu
o highly densely popula ed and es ic ed a eas, he usual PV o ST single app oaches
may no be e icien enough.
The cu en wo k is ocused on he expe imen al analysis o he dual use o he
sola esou ce by means o hyb id PVT collec o s and hei sma combina ion wi h di ec
expansion HPs h ough p edic i e con ol s a egies. Fo ha pu pose, a solu ion wi h
se e al inno a ions in he collec o and in he o e all con ol s a egy was de eloped.
A eal-use single- amily house has been selec ed o hos ing he es a a con inen al
clima e (Jablonec nad Nisou, Czeck Republic) o a DHW applica ion o e one-yea o
ope a ion. The sizing o he sys em has been ca ied ou . The sys em comp ising h ee
PVT collec o s and one PV module, dually connec ed o an in e e DX-saHP wi h an
o e sized TES and a p edic i e con ol has been p ope ly ins alled, commissioned and ully
accu a ely moni o ed. The eco ded da ase has been pos p ocessed acco ding o speci ic
in e na ionally ecognized p ocedu es o PVT plus HP sys ems.
A e one en i e yea o he expe imen al campaign he ob ained sys em-le el a e age
day KPIs show 83% o RES, 220% o SSR, 41% o SCR and 46% o SF. Fo he en i e
pe iod o agg ega ion, he KPIs a e 86% o RES, 204% o SSR, 28.5% o SCR and 25.7%
o SF, due o he impac o common summe ime high ene gy esou ce sho HP ope a ion
days. The high RES is essen ially based on HP pe o mance and enhanced by sola ield
con ibu ion. The ob ained SCR shows good unde lying con ol pe o mance. The ob ained
SSR and SF esul s a e huge, bu somehow a i icially boos ed due o he summe season’s
high sola esou ce and DX-saHP ambien hea collec ion. The o e all good pe o mance
esul s a e endo sed wi h mon hly le el analyses, which show he DHW demand is well
co e ed e en o he mos c i ical mon hs. Fo day-based analysis, a de ailed in aday
pe o mance has been ca ied ou , concluding wi h he alida ion o he sma high-le el
p edic ion-based con olle ha handles he ope a ion o he HP du ing he op imum sola
esou ce and high ambien empe a u e pe iod wi hou impac ing end-use com o .
Ene gies 2022,15, 3205 20 o 23
The end-use expe ience a e one yea o ope a ion was good, wi h no impac on he
DHW usage pa e ns o com o le els. Jus some punc ual ema ks we e epo ed a he
beginning o he es ing pe iod due o he unce ain y caused by no ha ing he TES a
maximum empe a u e. I would be desi able o ha e a de ailed explana ion o end-use s
when hese kinds o sys ems a e eplacing adi ional boile s.
As he main ou come, i can be concluded ha he p oposed solu ion has p o ided
e ec i e and e icien DHW o a amily o one en i e yea . Howe e , he o e sizing o
componen s, mainly o sola collec ion ield and TES, may enhance sys em capabili ies
and ensu e he end-use com o , bu also makes i di icul o succeed in all he KPIs a
he same ime. Fu he simula ion and sensi i i y analysis migh be help ul in o de o
de e mine he equi ed ade-o be ween objec i es o achie e.
5. Pa en s
The PVT collec o es ed in he cu en wo k p esen s di e en in ellec ual p ope y
igh s p o ec ion. The o e all sys em con ol so wa e is also egis e ed.
Au ho Con ibu ions:
Concep ualiza ion, A.S., A.J.M. and E.R.; me hodology, A.S.; so wa e, A.S.
and A.P.; alida ion, A.S., A.J.M. and A.P.; o mal analysis, A.S., A.J.M. and R.F.; in es iga ion, A.S.,
A.J.M. and R.F.; esou ces, A.S. and R.F.; da a cu a ion, A.S., A.P. and R.F.; w i ing—o iginal d a
p epa a ion, A.S.; w i ing— e iew and edi ing, A.S., R.F. and E.R.; isualiza ion, A.S., R.F. and A.P.;
supe ision, A.S. and R.F.; p ojec adminis a ion, A.S., P.I. and E.R.; unding acquisi ion, A.S., P.I.
and E.R. All au ho s ha e ead and ag eed o he published e sion o he manusc ip .
Funding:
This esea ch was unded by EIT InnoEne gy, g an numbe 56_2014_IP127_Handle and
he APC was unded by Fundación TECNALIA Resea ch & Inno a ion.
Da a A ailabili y S a emen : No applicable.
Acknowledgmen s:
We a e g a e ul o Fundación TECNALIA Resea ch & Inno a ion and Ene gy
Panel S.A o ganiza ions o suppo ing he esea ch ac i i ies no co e ed by unding, especially o
hei echnical suppo and o enabling he use o hei own esea ch in as uc u e. To Te mosol,
Vacla and Lenka o hei hospi ali y and willingness o hos he ield demons a o and be ou local
suppo . To he Uni e si y o he Basque Coun y UPV/EHU o i s access o esea ch esou ces. And
inally, o he IEA SHC Task 60 g oup o he aluable disse a ions on PVT.
Con lic s o In e es : The au ho s decla e no con lic o in e es .
Glossa y
APVT/PV ape u e a ea o collec o o module
c-Si c ys alline silicon
DHW domes ic ho wa e
DX-saHP di ec expansion sola assis ed hea pump
EGC g id ne consump ion
EHP hea pump elec ical ene gy
EPVac sola ield elec ical ene gy ou pu
PVT
PV maximum powe de ia ion ac o be ween collec o and e e ence module
GPoA global plane o a ay i adiance
HP hea pump
H&C space hea ing/cooling
IComp comp esso cu en
KPI key pe o mance indica o s
nZEB nea ly ze o ene gy building
OECD O ganisa ion o Economic Co-ope a ion and De elopmen
PR pe o mance a io
PPV sola ield pho o ol aic powe
PPVm e e ence module pho o ol aic powe
Ene gies 2022,15, 3205 21 o 23
PPVT collec o ield pho o ol aic powe
PG id g id powe consump ion
PG id,NC g id ne powe consump ion
PF pe o mance ac o
PR pe o mance a io
PRPVT
PV pe o mance ac o de ia ion be ween collec o and e e ence module
PV pho o ol aic
PVT pho o ol aic- he mal
QHP hea pump hea ou pu
QPVT collec o ield hea ou pu
RES enewable ene gy sha e
SCR sel -consump ion a io
SF sola ac ion
SSR sel -su iciency a io
ST sola he mal
Tamb ambien empe a u e
TCon condensa ion empe a u e
TCOu condense ou le empe a u e
TDis discha ge empe a u e
TES he mal ene gy s o e
TE a e apo a ion empe a u e
TSuc suc ion empe a u e
TTES100 uppe ank, op heigh , empe a u e
TTES50 middle ank, hal heigh , empe a u e
TTES50max middle ank maximum day empe a u e
TTES50min middle ank minimum day empe a u e
TTES50
max
min middle ank day cycle empe a u e del a
TTES,load ank load empe a u e
TTES,mid ank middle empe a u e
TPV e e ence module middle backshee empe a u e
TPVT collec o middle abso be backshee empe a u e
TPVT
PV ope a ion empe a u e de ia ion be ween collec o and e e ence module
VComp comp esso ol age
ws wind speed
ηPV elec ical con e sion e iciency
ηPVT agg ega ed, elec ical and he mal, con e sion e iciency
Re e ences
1. In e na ional Ene gy Ou look 2021. A ailable online: h ps://www.eia.go /ou looks/ieo/ (accessed on 31 Ma ch 2022).
2.
Ene gy E iciency in Buildings. A ailable online: h ps://ec.eu opa.eu/in o/news/ ocus-ene gy-e iciency-buildings-2020-lu -
17_en (accessed on 31 Ma ch 2022).
3.
Yu, G.; Yang, H.; Yan, Z.; Ansah, M.K. A e iew o designs and pe o mance o açade-based building in eg a ed pho o ol aic-
he mal (BIPVT) sys ems. Appl. The m. Eng. 2021,182, 116081. [C ossRe ]
4.
Ene gy Pe o mance o Buildings Di ec i e 2018/844/EU. A ailable online: h ps://eu -lex.eu opa.eu/legal-con en /EN/TXT/
PDF/?u i=CELEX:32018L0844& om=EN (accessed on 31 Ma ch 2022).
5.
Ene gy E iciency Di ec i e 2012/27/EU. A ailable online: h ps://eu -lex.eu opa.eu/legal-con en /EN/TXT/PDF/?u i=CELEX:
32012L0027& om=en (accessed on 31 Ma ch 2022).
6.
Eu opean G een Deal. A ailable online: h ps://ec.eu opa.eu/in o/s a egy/p io i ies-2019-2024/eu opean-g een-deal_en
(accessed on 31 Ma ch 2022).
7. Ela a asan, R.M.; Pugazhendhi, R.; I an, M.; Mihe -Popa, L.; Khan, I.A.; Campana, P.E. S a e-o - he-a sus ainable app oaches
o deepe deca boniza ion in Eu ope—An endowmen o clima e neu al ision. Renew. Sus ain. Ene gy Re .
2022
,159, 112204.
[C ossRe ]
8.
Gau , A.S.; Fi iwi, D.Z.; Cu is, J. Hea pumps and ou low-ca bon u u e: A comp ehensi e e iew. Ene gy Res. Soc. Sci.
2021
,71,
101764. [C ossRe ]
9.
Kamel, R.S.; Fung, A.S.; Dash, P.R.H. Sola sys ems and hei in eg a ion wi h hea pumps: A e iew. Ene gy Build.
2015
,87,
395–412. [C ossRe ]

Ene gies 2022,15, 3205 22 o 23
10. Hado n, J.C. Sola and Hea Pump Sys ems o Residen ial Buildings, 1s ed.; Wiley: Hoboken, NJ, USA, 2015.
11.
Lazza in, R. Hea pumps and sola ene gy: A e iew wi h some insigh s in he u u e. In . J. Re ig.
2020
,116, 146–160. [C ossRe ]
12.
Pei, G.; Ji, J.; Chow, T.-T.; He, H.; Liu, K.; Yi, H. Pe o mance o he pho o ol aic sola -assis ed hea pump sys em wi h and
wi hou glass co e in win e : A compa a i e analysis. P oc. Ins . Mech. Eng. Pa A J. Powe Ene gy
2008
,222, 179–187. [C ossRe ]
13.
Ji, J.; Pei, G.; Chow, T.T.; Liu, K.L.; He, H.F.; Lu, J.P.; Han, C.W. Expe imen al s udy o pho o ol aic sola assis ed hea pump
sys em. Sol. Ene gy 2008,82, 43–52. [C ossRe ]
14.
Sanz, A.; Fuen e, R.; Ma in, A.J. Sola hyb id PVT coupled hea pump sys ems owa ds cos -compe i i e NZEB. In P oceedings
o he Eu oSun 2018, Rappe swil, Swi ze land, 10–13 Sep embe 2018.
15.
Fu, H.D.; Pei, G.; Ji, J.; Long, H.; Zhang, T.; Chow, T.T. Expe imen al s udy o a pho o ol aic sola -assis ed hea -pump/hea -pipe
sys em. Appl. The m. Eng. 2012,40, 343–350. [C ossRe ]
16.
Ji, J.; He, H.; Chow, T.T.; Pei, P.; He, W.; Liu, K. Dis ibu ed dynamic modeling and expe imen al s udy o PV e apo a o in a
PV/T sola -assis ed hea pump. In . J. Hea Mass T ans . 2009,52, 1365–1373. [C ossRe ]
17.
Malenko ic, I.; Pa ish, P.; Eiche , S.; Bony, J.; Ha l, M. IEA SHC Task 44/HPP Annex 38, De ini ion o Main Sys em Bounda ies and
Pe o mance Figu es o Repo ing on SHP Sys ems; A Technical Repo o Sub ask B; IEA SHC: Ceda , MI, USA, 2012.
18. Jonas, D. Visualiza ion o Ene gy Flows in PVT Sys ems; A Technical Repo o Sub ask D; IEA SHC: Ceda , MI, USA, 2020.
19.
Cha alambous, P.G.; Maidmen , G.G.; Kalogi ou, S.A.; Yiakoume i, K. Pho o ol aic he mal (PV/T) collec o s: A e iew. Appl.
The m. Eng. 2007,27, 275–286. [C ossRe ]
20.
Zondag, H.A. Fla -pla e PV-The mal collec o s and sys ems: A e iew. Renew. Sus ain. Ene gy Re .
2008
,12, 891–959. [C ossRe ]
21.
Tyagi, V.V.; Kaushik, S.C.; Tyagi, S.K. Ad ancemen in sola pho o ol aic/ he mal (PV/T) hyb id collec o echnology. Renew.
Sus ain. Ene gy Re . 2012,16, 1383–1398. [C ossRe ]
22.
Daghigh, R.; Ruslan, M.H.; Sopian, K. Ad ances in liquid based pho o ol aic/ he mal (PV/T) collec o s. Renew. Sus ain. Ene gy
Re . 2011,15, 4156–4170. [C ossRe ]
23.
Al-Waeli, A.H.; Sopian, K.; Kazem, H.A.; Chaichan, M.T. Pho o ol aic/The mal (PV/T) sys ems: S a us and u u e p ospec s.
Renew. Sus ain. Ene gy Re . 2017,77, 109–130. [C ossRe ]
24.
Joshi, S.S.; Dhoble, A.S. Pho o ol aic-The mal sys ems (PVT): Technology e iew and u u e ends. Renew. Sus ain. Ene gy Re .
2018,92, 848–882. [C ossRe ]
25.
Ende PVT Glazed Collec o . A ailable online: h ps://ende .com/en/hyb id-sola -panel/ecomesh/ (accessed on 16 Ap il 2022).
26.
Abo a Sola PVT Glazed Collec o . A ailable online: h ps://abo a-sola .com/panel-sola -hib ido/ (accessed on 16 Ap il 2022).
27.
DualSun PVT Glazed/Unglazed Collec o s. A ailable online: h ps://dualsun.com/en/p oduc /hyb id-panel-sp ing/
(accessed on 16 Ap il 2022).
28. B andoni PVT Unglazed Collec o . A ailable online: h p://www.b andonisola e.com/en/p oduc s.php (accessed on 16 Ap il 2022).
29. Sola us C-PVT Glazed Collec o . A ailable online: h ps://sola us.com/p oduc en-p -panelen/ (accessed on 16 Ap il 2022).
30.
Lämmle, M.; He ando, M.; Ryan, G. IEA SHC Task 60, Basic Concep s o PVT Collec o Technologies, Applica ions and Ma ke s;
A Technical Repo o Sub ask D; IEA SHC: Ceda , MI, USA, 2021.
31.
Lämmle, M. Pho o ol aic The mal Hyb id Sola Collec o . A ailable online: h ps://en.wikipedia.o g/wiki/Pho o ol aic_
he mal_hyb id_sola _collec o #ci e_no e-17 (accessed on 16 Ap il 2022).
32.
Beshee , A.; Smy h, M.; Zacha opoulos, A.; Mondol, J.; Pugsley, A. Re iew on ecen app oaches o hyb id PV/T sola echnology.
In . J. Ene gy Res. 2016,40, 2038–2053. [C ossRe ]
33.
He ando, M.; Ramos, A.; Zabala, I. Cos compe i i eness o a no el PVT-based sola combined hea ing and powe sys em:
In luence o economic pa ame e s and inancial incen i es. Ene gy Con e s. Manag. 2018,166, 758–770. [C ossRe ]
34.
Hengel, F.; Heschl, C.; Inschlag, F.; Klana sky, P. Sys em e iciency o p collec o -d i en hea pumps. In . J. The mo luids
2020
,
5–6, 100034. [C ossRe ]
35.
Shao, N.; Ma, L.; Zhang, J. Expe imen al in es iga ion on he pe o mance o di ec -expansion oo -PV/T hea pump sys em.
Ene gy 2020,195, 116959. [C ossRe ]
36.
Simone i, R.; Molina oli, L.; Manzolini, G. Expe imen al pe o mance e alua ion o PV/T panels a nega i e educed empe a-
u es. In P oceedings o he Eu oSun 2018, Rappe swil, Swi ze land, 10–13 Sep embe 2018; pp. 1–10.
37.
Dupey a , P.; Ménézo, C.; Rommel, M.; Henning, H.-M. E icien single glazed la pla e pho o ol aic& he mal hyb id collec o
o domes ic ho wa e sys em. Sol. Ene gy 2011,85, 1457–1468. [C ossRe ]
38.
Siecke , J.; Kusakana, K.; Numbi, B.P. Op imal swi ching con ol o PV/T sys ems wi h ene gy s o age using o ced wa e
ci cula ion: Case o Sou h A ica. J. Ene gy S o age 2018,20, 264–278. [C ossRe ]
39.
Del Amo, A.; Ma ínez-G acia, A.; Bayod-Rújula, A.A.; An oñanzas, J. An inno a i e u ban ene gy sys em cons i u ed by a
pho o ol aic/ he mal hyb id sola ins alla ion: Design, simula ion and moni o ing. Appl. Ene gy 2017,186, 140–151. [C ossRe ]
40.
Le ch, W.; Heinz, A.; Heim a h, R. Di ec use o sola ene gy as hea sou ce o a hea pump in compa ison o a con en ional
pa allel sola ai hea pump sys em. Ene gy Build. 2015,100, 34–42. [C ossRe ]
41.
Poppi, S.; Somme eld , N.; Bales, C.; Madani, H.; Lundq is , P. Techno-economic e iew o sola hea pump sys ems o
esiden ial hea ing applica ions. Renew. Sus ain. Ene gy Re . 2018,81, 22–32. [C ossRe ]
42.
F eeman, T.L.; Mi chell, J.W.; Audi , T.E. Pe o mance o combined sola -hea pump sys ems. Sola Ene gy
1979
,22, 125–135.
[C ossRe ]
Ene gies 2022,15, 3205 23 o 23
43.
Wee a unge, H.; Na silio, G.; de Hoog, J.; Duns all, S.; Halgamuge, S. Model p edic i e con ol o a sola assis ed g ound sou ce
hea pump sys em. Ene gy 2018,152, 974–984. [C ossRe ]
44.
Liu, X.; Pa i osh, P.; Awalgaonka , N.M.; Bilionis, I.; Ka a a, P. Model p edic i e con ol unde o ecas unce ain y o op imal
ope a ion o buildings wi h in eg a ed sola sys ems. Sol. Ene gy 2018,171, 953–970. [C ossRe ]
45.
Zenhäuse n, D.; Gagliano, A.; Jonas, D.; Tina, G.M.; Hado n, J.-C.; Lämmle, M.; He ando, M. IEA SHC Task 60, Key Pe o mance
Indica o s o PVT Sys ems; A Technical Repo o Sub ask D; IEA SHC: Ceda , MI, USA, 2020.
46.
Lämmle, M.; Oli a, A.; He mann, M.; K ame , W. PVT collec o echnologies in sola he mal sys ems: A sys ema ic assessmen
o elec ical and he mal yields wi h he no el cha ac e is ic empe a u e app oach. Sol. Ene gy 2017,155, 867–879. [C ossRe ]
47.
SARAH Sola Radia ion Da a. A ailable online: h ps://join - esea ch-cen e.ec.eu opa.eu/p gis-pho o ol aic-geog aphical-
in o ma ion-sys em/p gis-da a-download/sa ah-sola - adia ion-da a_en (accessed on 31 Ma ch 2022).