Evaluating Costs and Benefits of a Smart

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Nov 21, 2013 (3 years and 9 months ago)

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Evaluating Costs
and
Benefits
of a
Smart

Polygeneration

Microgrid

Project
in a
University
Campus

Stefano Bracco*,
Federico Delfino
**, Fabio Pampararo**, Michela Robba***
and Mansueto Rossi**


University of Genoa
-

ITALY

*Dept. of Mechanical, Energy, Management & Transportation Engineering

**Dept. of Electrical, Naval & ICT Engineering

***Dept. of Informatics, Bioengineering, Robotics & Systems Engineering

federico.delfino@unige.it

Outline

of the
presentation


The Savona Campus: a
research

&
teaching

facility

of the
University

of Genoa


The Smart
Polygeneration

Microgrid

(SPM)
project


The Smart Energy Building (SEB)
project



Economic

&
Environmental

Analysis

o
Reduction

of
annual

energy

operating

costs

o
Reduction

of
CO
2

emissions


Conclusions


The Savona Campus: a R&T facility of the University of Genoa


50,000 square meters


courses from the Faculties
of Engineering, Medicine,
and Media Sciences


laboratories, research
centers and private
companies (several
operating in the
environment &energy
field)


library, residences,
canteen, café, etc…

The Smart
Polygeneration

Microgrid

(SPM) Project


Special
project

in the
energy

sector

funded

by the
Italian

Ministry of Education,
University and Research (amount 2.4 M

)


SPM is a 3
-
phase low voltage (400 V line
-
to
-
line) “intelligent” distribution system
running inside Savona Campus and connecting:


2
m
䍈C

G慳aT畲扩u攠
⠹㕫(攬eㄷ〠
歗瑨
⤠晥f批湡n畲慬u条猻


1 PV field (80
kWp
);


3 CSP equipped with
Stirling

engines (3
kWe
; 9
kWth
);


1 absorption chiller
(H
2
O/
LiBr
) with
a storage tank;


1 electrical storage: NaNiCl
2

batteries (100 kWh)


2 PEV charging stations.



The Smart
Polygeneration

Microgrid

(SPM) Project



SPM
one
-
line

diagram
:

-

400 V distribution system
(ring network, 500m long)

-
five

switchboards


The Smart
Polygeneration

Microgrid

(SPM) Project



SPM planning,
supervision &
control

system


RTU
TM 1703 ACP
planning
& management
supervision
& control
field data acquisitions &
local automation
IEC 61850
SICAM
DEMS
The Smart
Polygeneration

Microgrid

(SPM) Project



SPM

ICT
infrastructure


The Smart Polygeneration Microgrid (SPM) Project

Main goals
:



to

build

a

R&D

facility

test
-
bed

for

both

renewable

and

fossil

energy

sources




to

promote

joint

scientific

programs

among

University,

industrial

companies

and

distribution

network

operators



Day
-
ahead

production

scheduling

of

dispatchable

sources

and

storage

exploiting

renewables

forecast

and

optimization

techniques



to

optimize

thermal

&

electrical

energy

consumptions,

minimizing

the

CO
2

emissions,

annual

operating

costs

and

primary

energy

use

of

the

whole

University

Campus


The Smart Energy Building (SEB) Project


Special
project

in the
energy

efficiency

sector

funded

by the
Italian

Ministry for
Environment (amount 3.0 M

)


SEB is an environmentally sustainable building connected to the SPM, equipped by
renewable power plants and characterized by energy efficiency measures:


Geothermal

heat

pump



PV
plant

on the
roof

(20
kWp
)


Micro
wind

turbine (
horizontal

axis
, 3 kW)


High performance
thermal

insulation



materials

for building
applications


Ventilated

facades



SPM & SEB inside the Savona
Campus
of

the
University

of

Genoa




SEB
is

an


active

load

of

the SPM







SEB
is

an
energy

“PROSUMER”

Storage
-
related

research

activity



SPM OPTIMAL SCHEDULING


DEMS

uses

o
costs
and revenues
functions;

o
forecast of electric and thermal energy demand;

o
operative constraints (equipment ratings, maximum power ramp, etc.);

o
forecast of the
renewable units production
by resorting to weather services and
historical records



to compute a scheduling for
dispatchable

sources including storage, which
minimizes the daily energy costs. The optimization process has a time
-
horizon of 1 day
(
typical
of a day
-
ahead energy market session), subdivided in 15 minutes time
-
intervals.
The optimization method is based on
linear programming.



This research line results
at the storage level
in an automatic production shifting
application

Storage
-
related

research

activity




Storage state of
charge

variation

on
a
typical

winter

day

Production from
dispatchable

sources


PV Production &
Demands


Economic & Environmental Analysis


Two different scenarios are considered



AS
-
IS

Without SPM & SEB

TO
-
BE

With SPM & SEB



Electrical Energy


→ National Grid + SPM + SEB



Thermal Energy


→ 2 boilers + SPM + SEB



Electrical Energy


→ National Grid



Thermal Energy


→ 2 boilers (gas,1000 kWth)

AS
-
IS scenario: energy consumptions and operating costs



Including

also

maintenance

cost

TO BE scenario: share
of

electricity

and
heat

generation




ELECTRICITY

˜ 37% delivered by
SPM and SEB
generation units

HEAT

˜ 25% delivered by
SPM and SEB
generation units



SPM / SEB
energy

consumption

and production



Assumptions
:


-
winter operation for
m
䝔猬

㈰〰桯畲猠慴⁲a瑥搠灯p敲


-
absorption chiller turned off




Calculation

of

the total
operating

costs

for

the 2
scenarios



_ _
T AS IS AS IS pp AS IS pp m AS IS
C EEC e TEC TES C
   
    


_ _ _ _
_ _ _
_
65,30

T TO BE el Grid pp th Boiler pp m TO BE
el SPM el SEB f f k
f k
k C C
C E e E TES C
E E e M p
 


     
    

where
:


_ _ _ _ _
el Grid AS IS el EHP el SPM el SEB el SEB
E EEC E E E E
  
    
_ _ _
th Boiler AS IS th SPM th SEB
E TEC E E

  
and
C
m

and
p
f

being

respectively

the
maintenance

cost

and the
natural

gas price
for

the
m
GTs


;
M
f_
k

=

m
3

natural gas used by
each
m
GT



Calculation

of

the total
operating

costs

for

the 2
scenarios



where
:



e
f
-
n

= 0.465 tCO
2
/
MWh
el

(the emission factor of the Italian electrical mix);




η
el_Grid

=0.9 (national electrical grid efficiency);



e
f
-
NG

= 1.961∙10
-
3

tCO
2
/m
3

(natural gas emission factor);



O
f

= 0.995 (natural gas oxidation factor);



LHV
=9.7∙10
-
3
MWh
pe
/m
3

(natural gas lower heating value).



Calculation

of

the CO
2

emissions

for

the 2
scenarios



2_
_
f n f NG f
AS IS AS IS AS IS
el Grid Boiler
e e O
CO EEC TEC
LHV
 
 
  

   

_
2_ _ _
65,30
_
+
f n th Boliler
TO BE el Grid f NG f f k
k C C
el Grid Boiler
e E
CO E e O M
LHV
 

 

 
    
 

 

Calculation of the CO
2

emissions for the 2 scenarios


Economic & Environmental Analysis


Economic and environmental benefits provided by the system SPM + SEB
can be
further increased by:




using the
m
GTs in trigeneration asset (resorting to the absorption chiller) in order to
cool the library of the Savona Campus (now cooled by means of an electrical heat
pump) during summer months (+ 600 working hours for the
m
GTs with respect to the
examined case)

Conclusions




The “
Sustainable Energy
” R&D infrastructures under construction at the Savona
Campus of the University of Genoa have been described and the main research
lines that can be investigated by means of their use have been outlined




An approach has been presented to assess the Campus operating costs, CO
2

emissions and primary energy saving on a yearly time
-
scale




It has been shown that the Smart
Polygneration

Microgrid

(SPM) and the Smart
Energy Building (SEB) contribute to increase the overall energy efficiency of the
Campus, lowering its environmental impact




It should be underlined that the revenues obtained by the improved energy
performances of the whole Campus can be then employed to financially support
research activities and to yearly upgrade the two pilot plants SPM + SEB