Course Swh

7/28/2019 Course Swh

1/18

Clean Energy Project Analysis Course

Minister of Natural Resources Canada 20012004.

Photo Credit: NRCan

Solar Water HeatingProject Analysis

Glazed Flat Plate Collectors, Ontario, Canada


2/18


Objectives

Review basics ofSolar Water Heating (SWH) systems

Illustrate key considerations forSWH project analysis

Introduce RETScreen SWH Project Model


3/18


Domestic Hot Water

Process Heat

Swimming PoolHeating

but also Increased hot water

storage

Extended swimmingseason (pool heating)

What do SWH systems provide?

Photo Credit: Vadim Belotserkovsky

Conference Centre, Bethel, Lesotho

Housing Development, Kungsbacka, Sweden

Photo Credit: Alpo Winberg/ Solar Energy Association of Sweden


4/18


Components of SWH Systems

Photo Credit: NRCan


5/18


Unglazed Solar Collectors

Low cost

Low temperature

Rugged

Lightweight

Seasonal pool

heating Low pressure

Poor performance in cold or windy weather

Photo Credit: NRCan


6/18


Glazed Flat Plate Solar Collectors

Moderate cost

Higher temperature

operation

Can operate atmains water

pressure

Heavier and morefragile

Photo Credit: NRCan


7/18 Minister of Natural Resources Canada 20012004.

Evacuated Tube Collectors

Higher cost

No convection losses

High temperature

Cold climates

Fragile

Installationcan be morecomplicated

Snow is less ofa problem

Photo Credit: NRCan

Photo Credit: Nautilus

Tube Developed and Manufactured in China



Solar Water Heating in VariousClimates

For a domestic solar water heating system with 6 m2 of glazedcollector, a demand of 300 L/day of hot water at 60C and 300 L ofstorage, the solar fraction is:

21% in Troms, Norway (70N)

40% in Yellowknife, Canada (62N)

32% in Warsaw, Poland (52N)

51% in Harbin, China (46N)

67% in Sacramento, USA (39N)

39% in Tokyo, Japan (36N)

78% in Marrakech, Morocco (32N)

75% in Beer-Sheva, Israel (31N)

81% in Matam, Senegal (16N)

59% in Puerto Limn, Costa Rica (10N)

59% in Jakarta, Indonesia (6S)

86% in Huancayo, Peru (12S)

69% in Harare, Zimbabwe (18S)

65% in Sydney, Australia (34S)

39% in Punta Arenas, Chile (53S)



Examples of SWH System Costsand Benefits

Glazed year-round system(w/storage)

La Paz, Bolivia

2.2 GJ/m2

$400/m2

Evacuated tube year-roundsystem

(w/storage)

Copenhagen, Denmark

1.8 GJ/m2

$1,000/m2

0

10

20

30

40

50

60

70

80

90

100

5 15 25 35 45

Cost of energy ($/GJ)

Annual

Savings($/m2)

G

as@$

0.1

5/m3

G

as@$

0.5

0/m3

Electric

ity@$

0.0

5/kWh

Electric

ity@$

0.1

5/kWh

Unglazed summer-only swimming pool

Montreal, Canada

1.5 GJ/m2

$150/m2



Solar Water Heating ProjectConsiderations

Factors for successful projects:

Large demand for hot water to reduce importance of fixed costs

High energy costs (e.g. natural gas not available)

No reliable conventional energy supply

Strong environmental interest by building owner/operator

Daytime hot water loads require less storage

Lower cost, seasonal systems can be financially preferable tohigher-cost year-round systems

Maintenance similar to any plumbing system, but operator mustbe committed to timely maintenance and repairs



Examples: Australia, Botswana and Sweden

Domestic Hot Water Systems

On-grid, need a committed homeowner

Can have long payback when energy prices are low

Systems provide 20 to 80% of hot water

Off-grid or where the energy supply is unreliable

Photo Credit: Marie Andrn, Solar Energy Association of Sweden Photo Credit: Vadim Belotserkovsky

Photo Credit: The Australian Greenhouse Office

Thermosiphon System, Australia

House for Medical Staff in Rural Area, BotswanaHomes, Malm, Sweden



Examples: USA and Canada

Swimming Pool Systems

Low-cost unglazed collectors Summer pools in cold climates

Extend the season in warm climates

For summer use on a year-round pool in coldclimates

Can have 1 to 5-year paybacks

Glazed collectors for heat year-round

Filtration system serves as pump

Photo Credit: NRCan

Photo Credit: Aquatherm Industries/ NREL Pix

Pool system, Canada

Community Pool System, Ontario, Canada



Examples: Greece and CanadaCommercial/Industrial Hot Water Systems

Hotels/motels, apartments and office buildings

Health centres & hospitals

Car washes, laundromats, restaurants

Sport facilities, schools, shower facilities

Aquaculture, other small industry

Photo Credit: NRCanPhoto Credit: Regional Energy Agency of Crete/ISES

Hotel, Agio Nikolaos, Crete Aquaculture Operation, British Columbia, Canada



RETScreenSolar Water HeatingProject Model

World-wide analysis of energy production, life-cycle costs andgreenhouse gas emissions reductions

Glazed, unglazed, and evacuated tube

Indoor and outdoor swimming pools(w/ or w/o cover)

Service hot water systems(w/ and w/o storage)

Only 12 points of data for RETScreen

vs. 8,760 for hourly simulation models

Currently not covered: Changes in service hot water daily loads

Stand-alone service hot water

Systems w/o storage havinghigh solar fractions

Sun tracking, concentrator & integrated solar collectors



See e-Textbook

Clean Energy Project Analysis:RETScreen Engineering and Cases

Solar Water Heating Project Analysis Chapter

RETScreenSWH Energy Calculation



Example Validation of theRETScreen SWH Project Model

RETScreen compared to:

WATSUN for domestichot water system in Toronto,Canada:

500

1000

1500

2000

2500

3000

500 1000 1500 2000 2500 3000

Measured annual solar energy delivered (kWh)

RETScreenpredictedannuals

olarenergydelivered

(kWh)

ENERPOOL for 48-m2 summerpool in Montreal, Canada

Energy required to within 2%

Monitored data from a1,200 m2 summer pool inMhringen, Germany

Energy required to within 3%and solar energy production towithin 14%

RETScreen vs. monitored datafrom 10 domestic hot watersystems in Guelph, Canada

RETScreen WATSUN Diff.

Incident radiation (GJ) 24.34 24.79 -1.8%

Load (GJ) 19.64 19.73 -0.5%

Energy delivered (GJ) 8.02 8.01 0.1%

Pump run time (h) 1,874 1,800 4.1%



Conclusions

Unglazed, glazed and evacuated tube collectors provide hot water formany uses in any climate

Significant hot water demand, high energy costs, and strongcommitment on part of owner/operator are important factors in success

RETScreen calculates:

Service hot water load and swimming pool load

Performance of solar swimming pool and service hot water systems with or without

storage RETScreen is an annual analysis with monthly resource calculation that

can achieve accuracy comparable to hourly simulation models

RETScreen can provide significant preliminary feasibility study costsavings


18/18 Mi i f N l R C d 2001 2004

Questions?

Solar Water Heating Project Analysis Module

RETScreen International Clean Energy Project Analysis Course

www.retscreen.netFor further information please visit the RETScreen Website at

Documents

Course Swh