PV2Heat: Development of a vacuum insulated high ... · Technique of a High-Temperature-Solid-Storage (HTFS) 3. System Integration of a HTFS 4. System Comparison 5. About the Research

Institut für Gebäude- und Solartechnik Prof. Dr.-Ing. M. Norbert Fisch

Mühlenpfordtstraße 23 D-38106 Braunschweig

www.tu-braunschweig.de/igs

PV2Heat: Development of a vacuum insulated

high temperature solid storage combined with

PV

Prof. Dr.-Ing. M.N. Fisch

Dipl.-Ing. Mani Zargari

Institut für Gebäude- und Solartechnik

Prof. Dr.-Ing. M.N. Fisch

Technische Universität Braunschweig

Dialogplattform Power to Heat

5. + 6. Mai 2015

www.tu-braunschweig.de/igs May 7, 2015 | Hochtemperaturspeicher| Seite 2

1. PV in the Power Market: Challenges and Solution Approach

2. Technique of a High-Temperature-Solid-Storage (HTFS)

3. System Integration of a HTFS

4. System Comparison

5. About the Research Project

Content


•Turn down of convential power plants (grey) for renewables

•Price for power collapses at the spot market

•Cut-off of renewable power plants from the grid in future

Oversupply of PV-Power PV in the Power Market


0

20

40

60

80

100

120

140

Demand 2014 2018 2024

Po

wer

[GW

]Installed Power and Demand

Other Renew.

Wind

PV

PV-Gain and Demand PV in the Power Market

Renewable – Midterm – Prognosis of the German network operators 2014 (EEG Mittelfristprognose 2014)


BEE-Studie „Möglichkeiten zum Ausgleich fluktuierender Einspeisungen aus Erneuerbaren Energien“ 2013 im

Auftrag BEE, Lichtblick und Enercon, ausgeführt von BET Büro für Energiewirtschaft und technische Planung

GmbH

Options for Flexibilization PV in the Power Market

DMS

P2H

Flexible Renewables

Flexibel Conventionals

Power Storage


HTFS shifts PV-Power to the demand PV in the Power Market

Jan Feb Mrz Apr Mai Jun Jul Aug Sep Okt Nov Dez

PV -Oversupply

PV-Power

HTFS

Heat Demand

HTFS connects the power-Market and heat-Market

Oversupply of PV-Power is transformed to heat and shifted to the time of demnad


Advantages:

-

Heat exchanger

combined with

vacuum super

insulation

Maghemite (iron

ore) and heating

rods

50°C to 750°C

•High-efficient

•Maintaince-free

•Cycle resistant

•Avoids network supply of PV-power

HTFS in the Energy-Market

30°C

90°C

HTFS: Technique


Core

• Fe2O3 , ρ = 3900 kg/m³ / Maghamit , „Magnetit“

Heating Rods

•Durability depends on the operating temperature

(750°C: 10.000 h)

•Operating temperature limited to 750°C

Insulation

• 20 mm mikroporous material (Aerogel, Pyrotherm®

λ=0,03 - 0,05 W/(m*K) / 20°C – 750°C)

•Outer Shell: ventilated air-layer

:

State of the Art: Night Storage Heater HTFS: Technique


Storage Media

• Water, oil (up to 250°C)

Vacuum Insulation

• Perlite, opacifer, vacuum < 0,1 mbar

Parameters

• Cooling rate

0,0026 K/(d*K) (conventional storage 0,0095 (K/d*K))

•Thermal transition coefficient:

1/R=0,04 W/(m²*K)

Costs

• 5m³ - Storage: 16.000 EUR

:

State of the Art: VSI-Hot Water Storage HTFS: Technique


c

[kJ/kgK]

ρ

[kg/m³]

s

[J/cm³K]

Costs

[€/t]

Costs

[€/(J/K)]

Brick 0,84 2000 1,7 150 179

Concrete 0,88 2300 2,0 52 59

Fire-Brick 1,00 2000 2,0 390 390

Ceramics 1,00 2500 2,5 200 / 1500* 200 / 1500*

Water 4,18 1000 2,4 0 0

Iron Ore

Fe2O3

0,92 3900 3,5 300 163

*Bulk-Material/ Stones

Comparison of Storage Medias HTFS: Technique


*Insulation Material for Heat Transfer Coeffcient of. 0,05 W/m²K, Costs only for insulation material, net price

T

[°C]

Λ

[W/mK]

Costs

[€/m³]

Cost

[€/Storage Tank]*

Pyrogel

(Aspen/Stadur)

200

600

0,028

0,089

1.000 12.000

Microtherm Panele

(Night Storage)

229

750

0,032

0,053

3.600 43.000

Vakuum-Super-

Insulation

100

400

0,009

0,02

150

750

Comparison of Insulation Techniques HTFS: Technique


Simulation Studie

System Parameters:

•PV-Generator: 10 kWp

•4 Persons

•Heat Demand (Water + Heating)

60 kWh/(m²*a)

•HTFS: 18t / 5m³

Integration in a Residential Building System-Integration


0

100

200

300

400

500

600

700

800

01 02 03 04 05 06 07 08 09 10 11 12

HTF

S_Te

mp

. [°

C]

Monat

HTFS mit und ohne Speicherverlust

Mit Speicherverlust

Ohne Speicherverlust

Integration in a Residential Building System-Integration

Simulation Studie

Energy Balance:

•Total solar gain

9.400 kWh/a

•Own use of solar power

1.200 kWh/a

•Own use of PV-heat with the HTFS:

8.200 kWh/a

HTFS with and without Heat-Loss


Reference System:

•Residential building (research

project Future:Solar)

•Solar-thermal plant 40 m²

•Seasonal hot water Storage

10m³

•Gas boiler (condensing)

•PV-generator 6 m²

•High solar fraction in the heat

supply

System-Comparison

PV 6 kWp ST 40 m²

Wärmeversorgung

Stromnetz

Gas/

Gasbrennwertkessel

Wechselrichter

Haushaltsstrom

Saisonaler

WW-Speicher

10m³

Reference System


Solar Fraction

Reference

(Future Solar_Combi System)

ST + LZWS + GT + PV

ST: 40 m²; PV: 6 kWp; LZWS: 10m³/10t

HTFS

(HTFS)

PV + HTFS

PV: 10 kWp; HTFS: 5m³/18t

0

200

400

600

800

1.000

1.200

1.400

1.600

1.800


Ene

rgie

me

nge

[kW

h/M

t.]

Solarthermie

Gas-Brennwertkessel

Wärmebedarf

System-Comparison

0

200

400

600

800

1.000

1.200

1.400

1.600

1.800


Ene

rgie

me

nge

[kW

h/M

t.]

HTWS (PV)

Netzstrom

WärmebedarfHeat Demand Heat Demand


Heat Production Price

EFH (VAR 1_100%_Future Solar)

ST + LZWS + GT + PV

ST: 40 m²; PV: 6 kWp; LZWS: 10m³/10t

EFH (HTfS)

PV + HTFS

PV: 10 kWp; HTFS: 5m³/18t

Solar Fraction (Heat)

75%

Solar Fraction (Heat)

90% (estimated)

Investment Costs*

47.000 EUR

Investment Costs

42.000 EUR

Costs per Year

2.700 EUR/a

Costs per Year

3.000 EUR/a


0,35 EUR/kWh


0,38 EUR/kWh (for 90% solar fraction)

System-Comparison

*All net prices for Heat Supply only


Heat Production Price and Solar Fraction System-Comparison

Heat costs escalate with increasing solar fraction

BINE

0,00

0,20

0,40

0,60

0,80

1,00

1,20

1,40

1,60

0 10 20 30 40 50 60 70 80 90

He

at C

ost

s €

/kW

h

Solar Fraction[%]

Heat Costs and Solar Fraction

ST district heating +

seasonal hot water

storage

ST + vacuum super

insulated seasonal

hot water storage

PV + HTFS


Milestones

Applied Research Project HTFS: Tasks

1. System analysis and -development with plant simulation

2. Design and construction of an prototype of an HTFS (with CFD/FEM)

3. Realized prototype at laboratory of the IGS at TU Braunschweig and test

Operation

4. Analysis and optimization, analysis of effects of a HTFS on the grid

5. Preparing for series production

Research Project


Project Partners Research Project

Documents

PV2Heat: Development of a vacuum insulated high ... · Technique of a High-Temperature-Solid-Storage (HTFS) 3. System Integration of a HTFS 4. System Comparison 5. About the Research