Michel Bernier, ing., Ph.D. Professeur titulaire Département de génie mécanique

THERMAL ENERGY STORAGE IN BUILDINGS

1

PLAN

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Energy consumption and power demand

Diurnal thermal energy storage in buildings

Electric hot water tanks

High temperature compact storage

Seasonal thermal energy storage in a community

Drake Landing solar community

Summary

ENERGY CONSUMPTION IN BUILDINGS

3

0

20

40

60

80

100

120

China UnitedStates

USBuildings

Russia India Japan Canada Germany Brazil Korea,South

France

Primary energy consumption (Quadrillion Btu) 2011

[1]

ENERGY CONSUMPTION IN QUÉBEC

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Total electric energy consumption = 186 TWh

Industrial [POURCENTAGE]

Commercial [POURCENTAGE]

Space heating 21%

DHW [POURCENTAGE]

Appliances 6% Residential

[POURCENTAGE]

Electric energy consumption by sector in Québec - 2011

[2]

YEARLY POWER DEMAND

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Cold climate with high penetration of electric space heating

0 2 4 6 8 10 12 14 16 18 20 22 24

Hour [h]

Grid p

ow

er

MW

POWER DEMAND - PEAK WINTER DAY IN QUÉBEC

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[3]

≈ 39000 MW

Residential space Heating (≈ 11000 MW)

Domestic hot water (≈ 2000 MW)

SUMMARY

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Space heating and DHW for residential buildings in Québec: • ≈ 1/4 of the total annual electric energy

consumption • ≈ 1/3 of the power demand at peak conditions

Great potential for power and energy savings using thermal energy storage

ELECTRIC HOT WATER TANKS

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Typical Québec family: -Daily water consumption: ≈ 250 liters/day -Daily energy consumption: ≈ 15 kWh -Annual energy consumption: ≈ 5000 kWh

ELECTRIC HOT WATER TANKS

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[3]

ELECTRIC HOT WATER TANKS

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Ideal for load shifting [5]

HIGH TEMPERATURE COMPACT STORAGE

Ceramic bricks at 500°C

Electric heating elements

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Developed by researchers at Hydro-Québec’s research lab (LTE) [6]

HIGH TEMPERATURE COMPACT STORAGE

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Measured data at the Price building in Quebec city [6]

SEASONAL THERMAL ENERGY STORAGE

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Space heating needs and solar availability are not in sync

SEASONAL THERMAL ENERGY STORAGE

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The best example is in Canada !

Drake Landing Solar Community [7]

SEASONAL THERMAL ENERGY STORAGE

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Auxiliary heating

Borehole Thermal Energy Storage (BTES)

SEASONAL THERMAL ENERGY STORAGE

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Measured temperatures in the borehole storage [8]

SEASONAL THERMAL ENERGY STORAGE

17 Solar fraction of ≈ 95% for space heating !

SUMMARY

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• Buildings use a substantial amount of energy. • Buildings in Québec require a significant

amount of power at peak conditions.

• Solutions exists to reduce the energy/power impact of buildings:

Electric hot water tanks Compact high temperature storage Seasonal storage in boreholes

ACKNOWLEDGMENTS

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• Past, current, and future graduate students.

• Prof. Baliga.

•

•

REFERENCES

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1. Based on a presentation made by Ellen Franconi (from RMI) at the 2011 IBPSA world conference and US Energy Information Administration (www.eia.gov).

2. www.mern.gouv.qc.ca/energie/statistiques.

3. Based on a profile presented by : Laperrière, A. Three elements electric water heater. 2011 ACEEE Hot Water Forum.

4. Atabaki, N., Bernier, M. 2005. A Semi-empirical model for residential electric hot water tanks, ASHRAE Transactions, vol. 111, Part 1, pp.159-168.

5. Bouthillier, P., Bernier, M. 1995. A new model to simulate the thermal performance of electric water heaters, Canadian Electrical Association - Technical conference - Electricity '95, Vancouver, Canada, 20 pages.

6. Moreau, A. Le chauffage électrique hors-pointe avec accumulation thermique - résultats de l’édifice Price de Québec, Infobec, Novembre 2003.

7. www.dlsc.ca

8. Sibbit, B., McClenahan, D., Djebbar, R., Thornto, J., Wong, B., Carriere, J., Kokko, J. 2012. The Performance of a High Solar Fraction Seasonal Storage District Heating System – Five years of Operation. Energy Procedia, 30: pp. 856-865.