6 - Bales - Small and Larger Scale Solar Thermal for Norther Climtes1

Small and larger scale

Solar Thermal

for northern climates

Chris Bales

Solar Energy Research Center SERC, Högskolan Dalarna

Midnight Sun Seminar 2012, 23rd Aug 2012

Contents

• Background

• Fundamentals

• System types for northern climates

• Current research and the future


My background…

• Born in Kenya (50 km from equator)

• Married to someone born 50 km from Arctic Circle

• Educated in England

• Engineering degree in electrical sciences

• 5 years at British Antarctic Survey

• Weather observer and technician

• 2 years at New Zealand Meteorological Service

• Working with climate databases

• 20 years at Högskolan Dalarna

• Started as technician….now associate professor

• Specialist in solar thermal, heat storage, system

simulations

• Mostly international projects


Campus Lugnet

Humanities and Media

Studies

Health and Social

Studies

2 600 students

Campus

Framtidsdalen

Technology and

Business Studies

1 900 students

Bergsskolan Filipstad

@ Web-Based

Distance Education

Falun

Borlänge

Högskolan Dalarna


Student Numbers 2010

• 18 000 students

• 7 256 full-time students

• 11 800 distance students

• 1141 degrees conferred

Now over half the students

are distance students

Midnight Sun Seminar 2012, 23rd Aug 2012 6

SERC – Solar Energy Research Center

• Founded 1984, grown steadily since

• 23 staff engaged in R&D and education:

4 Professors (part-time), 9 PhD, 8 PhD

students,

(in process recruiting 1 more professor)

technician, 1-3 trainees, guest researchers

• Multidisciplinary research: technology and social sciences

• Variety of educational programmes

• Research turnover >1,5 M€/year

www.serc.se

Energy and environmental technology

http://www.serc.se/


SERC –Research Areas

Solar and biomass heating systems

Solar thermal systems and thermal storage

Solution vessel

Water vessel

Reactor

Condensor /

Evaporator

• Conversion of electrically heated

homes

• Development of solar and biomass

heating systems

• Lab and field measurements

• Modeling and simulation

• Minimising primary energy use and

harmful emissions

• Advanced thermal storage

• Chemical heat pumps

• Solar heating and cooling

• Seasonal storage of heat


SERC –Research Areas

Energy use and societal processes

Small scale electricity generation

Social anthropology+Political

science+Technology

• Conversion of heating systems

• Installers and other market players

• Home owners choice of heating system

• Implementation of national energy policy

• PV grid connected systems

• PV/wind hybrid stand-alone systems

• Small scale cogeneration

Energy and buildings

• Passive houses of Massive wood

• Thermal storage in buildings

• Steel claddings for reduced heating and

cooling demand (Prelaq Energy)


SERC –Education

• One year International Master program

in solar engineering – ESES (European

Solar Engineering School) www.eses.org

• Collaboration in 2 year solar and

biomass technician programme

• 2 year energy technician programme

(start 2008)

• Responsible for solar specialisation of

KTH’s 2 year master program

• Participation in development of ”nordic”

master in biomass and solar

(värmeekom)

http://www.eses.org/


Källa: PVGIS © European Communities, 2001-2006

Solar Radiation in Europe

kWh/m2/a %

Pori 1129 100

Hamburg 1104 98

Graz 1321 117

Sevilla 1947 172

Irradiation on an optimally tilted plane [kWh/m2/a]


0

50

100

150

200

250

Jan

Feb Mar

Apr

May

Jun

Jul

Aug

Sep O

ctNov

Dec

Mo

nth

ly irr

ad

iati

on

[kW

h/m

2]

Pori

Hamburg

Graz

Sevilla

Irradiation Potential

The uneven yearly distribution of

irradiation presents a problem in the

Nordic Countries:

Data: European Comission PVGIS, http://re.jrc.ec.europa.eu/pvgis/

Irradiation on an optimally tilted plane.

The energy demand is highest when

available irradiation is lowest.

For solar fractions > ~25% we

need seasonal storage of energy

from summer to winter (space heating+DHW systems)


The solar thermal ”pinch”

0

5 0 0

1 0 0 0

1 5 0 0

2 0 0 0

2 5 0 0

3 0 0 0

Ja n F e b M a r A p r M a y Ju n Ju l A u g S e p O c t N o v D e c

(kW h )

E xcess irrad ia tion E xcess consum p tion

Usab le so la r ene rgy Irrad ia tion

To ta l consum p tion

3 0 0 0

2 5 0 0

2 0 0 0

1 5 0 0

1 0 0 0

5 0 0

0

1

2

3

1


Don’t forget – radiation varies from year to year!

Data for horisontal radiation – lower for higher latitudes

+/- 10% !!


Temperature Important with Solar Thermal !

Figure: Lennart Molin


Classification of systems

• Classification by use (load)

• DHW systems

• Combisystems

• Pool systems

• Process heat

• Solar cooling

• ….

• Domestic systems

• Multifamily houses

• District heating (large scale)

Traditional Scandinavian market:

domestic solar combisystems


Pumped Solar Combisystem

Source: Solenetek AB

Auxiliar heat from:

Biomass boiler/stove

Electricity

Heat pump

Gas/oil boiler

….


Small systems bought , larger systems custom built

• Small systems sized and installed by salesman/installer

• Buyer often gets quotes from several suppliers, but not

always

• Often ”standard” packages even though some

customisation is possible

• Larger systems designed by engineers

• Every system unique

• Engineers size system (simulation tools) and then do

detailed design

• Owner often not same as user

• Greater requirements on documentation and professionalism

• Often requirement for public call for tenders


Trends: Full integration – or greater flexibility

More integration + System optimisation

+ Quicker installation

+ Smaller risk for faulty installation

+ Uses less space

- Less flexibility

- Everything must be bought at one time

Flexible systems + Can easily be changed

over time

+ Not everything has to be bought at same time

+ Not dependent on just one supplier

- More difficult to optimise (several different controllers)

- Greater risk for faulty installation

- Uses more space


Integrated DHW systems

Standard size (60 x 60 cm) for tank unit

Figures: Vaillant GmBH


Integrated boiler and tank

Oil or gas boiler in tank

(Germany – Solvis)

Source: Stocksbro energi(biosolpanna)

Pellet boiler in tank -

biosolpannan (Sweden –

Stocksbro energi).


Solar and biomass logical for Scandinavia

• Most popular form of system

• Many advantages

• Much work been done with them

• Building regulations a hinder in Sweden

• Retrofit the biggest market


Handbook with all latest research results

• In Swedish – suitable for both consultants and installers

Tomas Persson

Researcher at SERC

[email protected]

Lars Andrén

Author, chairman Swedish

solar energy association

[email protected]

mailto:[email protected]



Are building regulations a barrier for solar + biomass?

Biomass

η=80%

Heat load

max

13 000 kWh

110 kWh/m2 55 kWh/m2 55 kWh/m2

District heat

η=100%

Heat load

max

16 500 kWh

110 kWh/m2

Exhaust air heat

pump

Heat load

max

20 000 kWh

Ground heat

pump

COP=3

Heat load

max

25 000 kWh

Bought energy limited by

building regulations !

Different for electricity

Electrically

heated houses Other heat source

90 kWh/m2

13 500 kWh 10 800 kWh


Costs for different heating systems….

Kiruna, standardhus

0 5000 10000 15000 20000 25000 30000 35000 40000

Passiv+Sol+FTX

Pellet

Pellet+FTX

Pellet+Sol+FTX

FVP

FVP kond.

FVP kond+Sol

FVP+JV

BV

BV+FTX

Fjärrvärme

Fjärrvärme+FTX

Kapitalkostnad Underhållskostnad Energikostnad

For houses being built now


Small scale solar and pellet system


Pellet stove and solar hot

water system separately

– suitable for houses with

electrical panel heaters

Combined system for

houses with water

distribution system


24 134

19 669 19 768 19 263 18 822 17 990 17 62715 750

305

1 012 350 397 387376 440

383

0

2 481 4 0223 789 3 978

3 932 4 604

4 176

0

5 000

10 000

15 000

20 000

25 000

Referens

(63%)

73% 79% 80% 82% 86% 87% 97%

Systemeffektivitet, köpt energi

Årl

ig e

nerg

itill

förs

el (k

Wh)

Sol

El

Pellets

Last

16 200 kWh/år

A B C ED F G

Solar and pellet systems – much better than pellet only


Turn boiler/stove off during the summer


Also best for oil and gas

boilers


Solar and heat pump – many systems !!

• 70 commercial systems found in EU

• Many different designs


Common Features for the two Technologies

• Both solar collectors and heat pumps

use electricity to make „free“ energy

available for hot water and space heat

• Both have decreasing efficiency with

increasing supply temperature

• Both have relatively high capital costs

and lower running costs compared to

conventional heating systems

• Both use thermal storage in systems

• The „free“ resource varies with the

seasons

HP


Several Unanswered Questions !

• How can the systems be compared ?

• Which systems are good ?

• How can they be tested ?

• Can they be cost effective ?…….

IEA-SHC Task 44 will try to answer these !

EU project MacSheep is trying to develop better systems


Quelle

: W

agner

& C

Oo

462 kWth; 660 m²

Multifamily houses – renovation key


Solar and district heat

• Centralised large systems

• Decentralised that feed into network

• Decentralised that take out heat from network

• Not very common apart from Denmark boom


Large Centralised systems

Källa: www.solar-district-heating.eu

• Often ground mounted collectors

• Sweden and Denmark leaders

• Germany and Austria also (new system in Lilleström)

• Normally relatively low solar fraction

• Scale effects reduce costs


Large Systems 2009

Källa: J-O Dalenbäck


Example Strandby (DK) - 2008

• 8.000 m2 Arcon collector (18% solar fraction)

• 2x1.500 m3 steel tanks

• Natural gas CHP (+ abs. Heat pump)

Källa: www.solar-district-heating.eu


Strandby - costs

Källa: www.solar-district-heating.eu – success factors

• 2.900 kr/m2 incl. all costs

• 2.350 kr/m2 after subsidies

http://www.solar-district-heating.eu/






Decentralise feeding grid – example (2009)

• Vislanda – Alvesta energi

• 350 m2 in large roof integrated modules (~10% solar fraction)

• Prefabricated connection unit








Vislanda (2)


• 2.450 kr/m2 after subsidies and ”roof replacement” costs

• Same as Danish larger system

• Economy dependent on what utility pays!








Decentralised – replaces bought energy

• Simple to add to existing houses with district heating

• Utilities often not positive to it


• But replaces bought energy


Danish Large Scale Systems



Demonstration System – multisource RE

Seasonal solar storage in combination with other heat sources – mostly heat pump

www.iea.shc.org/task45


Current Research and the Future

Solar thermal;

278

Buildings and cities; 126

PV & PV

systems; 91

Solar Thermal Power; 56

Radiation &

resource forecasting; 64

Other; 148

ISES World Congress 2011 Papers

Collectors and PVT; 51

Storage; 41

Solar

cooling; 40

Testing and simulation; 40

Industrial

applications; 27

Domestic hot

water systems; 22

Solar + heat pump; 21

Other; 36

Solar Thermal Papers


Solar Collectors

• ”High” temperature (100 – 200°C) collectors for solar cooling or process heat

• IEA-SHC task in preparation

• + old www.iea-shc.org/task33

• Polymer collectors for domestic applications

• www.iea-shc.org/task39

Source : Aventa, Norway

Source : PSE, Germany

http://www.iea-shc.org/task33







Storage

• The dream of seasonal storage on smaller scale

• Material and process development

• Closed and open systems

• Basic and applied research

www.iea-shc.org/task42

• Three new EU projects on seasonal storage

Source: J. van Berkel




Thank you for your attention

[email protected]

www.serc.se


http://www.serc.se/

Documents

6 - Bales - Small and Larger Scale Solar Thermal for Norther Climtes1