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Project Title:

Zero energy house with hydrogen storage in Freiburg

Ref.No.: 56

Project Type and Category:

Hydrogen demonstration

Project Duration:

Planning: 4/1989 Construction: 1990 – 1992, Operation 1993-now

Project Participants:

Fraunhofer Institut für Solare Energiesysteme

Sponsor:

BMBF, State of Baden-Würtemberg

Project Budget and
Funding:

Conception, Construction, Operation 5,8 Mio DM (from BMBF 89 - 95), Construction costs 3,6 Mio DM

Project Description and Objectives:

At the Fraunhofer Institute for Solar Energy Systems the concept of the 'Self-sufficient Solar House 2000' was developed over several years, built from Sept. 1991 to Oct. 1992 in Freiburg, Germany. It takes into account solar architecture priciples, thermal collectors, transparent insulation, photovoltaics, battery storage, hydrogen storage and an electricity and hydrogen application system. It provides all energy needs from solar radiation.
The energy supply strategy of this concept supposes direct electricity use during sunshine. Excess energy is stored in a lead-acid battery system. As soon as this system is charged completely, hydrogen and oxygen are produced in a membrane pressure electrolysis unit at a level of 3 MPa and stored in gas cylinders. The hydrogen storage is a seasonal storage with a cycling period of one year. During wintertime the hydrogen is converted to electricity by a pem fuel cell system or to high temperature heat in a catalytic cooker with 4 diffusion burners and in a catalytic air-heater with a two step diffusion burner. The battery buffers electric peak-demand which cannot be covered by the fuel cell. The catalytic cooker replaces the electric one when the sun is not shining. The oven is operated electrically.
The daily energy consumption is assumed to be in the order of 3 kWh and the overall efficiency of the storage system is calculated to be about 70%.
The solar hydrogen system exists of the following components:
- Solar generator: 84 Siemens M 50 modules with 36 monocrystalline silicon cells each covering 30 m2 with a total output of 4.2 kWp,
- Battery bank: 48 lead acid batteries with 200 Ah at 2 V each, delivering a system voltage of 48 V and a design capacity of 19.2 kWh,
- Auxiliary Batteries: 11 lead acid batteries with 75 Ah at 2 V each, delivering a system voltage of 22 V and a design capacity of 1.65 kWh (for the process control system),
- Inverter: sinus-type with a design rating of 3 kW,
- Electrolyzer: 30 cell membrane electrolyzer by FhG-ISE with a design capacity of 2 kW, a operating pressure of up to 3 MPa at a current of up to 90 A, an operating temperature of 80°C and a hydrogen/ oxygen production capacity of 1.2 m3/h respectively 0.6 m3/h,
- Fuel cell system: 14 cell alkaline fuel cell unit operated with 30% KOH, with Ni gas diffusion electrodes, operating temperature of 70°C and design output of 0.5 kW, (presently the system has been replaced by a PEMFC unit)
- Gas storages: Hydrogen: 15 m3, 3 MPa, 1436 kWh energy content. Oxygen: 7.5 m3, 3 MPa,
- Cooking Stove: 4 catalytic diffusion burners with 2.6, 1.7, 1.7 and 1.0 kW design output (FhG-ISE development)
- Electric baking oven with 230 VAC supply,
- Air-Heater: 2 step catalytic diffusion burner of 0.5/ 1.5 kW power rating built into the air supply duct, automatic ignition (FhG-ISE development)
The solar thermal collector system for the production of hot water consists of selective absorbers, type 'BEIKO', with a cermet cover achieving an absorption degree of 0.93 and an emissivity of 0.09, of a 1000 l water stratification storage, a flat plate heat exchanger for the collector circuit and the fuel cell excess heat circuit and 24 V circulation pumps with variable flow rates.
The air ventilation system has a design capacity of 200 m3/h providing an exchange rate of 0.7. The fresh air enters into a system of tubes burried 4 m deep in the earth, by passing through the tubes the air is pre-heated, then it passes a heat exchanger (recovery factor 0.85) recovering the heat contained in the used air and finally the air is heated to its required final temperature by the hydrogen powered air-heater. In 1997, the house was again connected with the public electricity and gas grid since the funding for the scientific monitoring ran out.

Technical Goals:

Independend energy supply of a solar house with energy storage. Operating this house under the climatic conditions of Germany.

Project Status

House is still operating

Preliminary or Final Results:

See description

Related Reference Papers and Other Publications:

-      BINE -Infoblatt Nr.18 /Dez. 1994 ISSN 0937-8367
W. Stahl, A. Goetzberger, K. Voss: Das Energieautarke Solarhaus: Mit der Sonne wohnen; Verlag C.F. Müllre, Heidelberg 1997, ISBN 3-7880-7513-9
K. Voss (Hrsg.): Konzeption und Bau eines energieautarken Solarhauses; Schlußbericht zum BMBF Projekt; Fraunhofer IRB Verlag 1997 ISBN 3-8167-4610-1

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Project Title: Zero energy house with hydrogen storage in Freiburg		Ref.No.: 56
Project Type and Category:	Hydrogen demonstration
Project Duration:	Planning: 4/1989 Construction: 1990 – 1992, Operation 1993-now
Project Participants:	Fraunhofer Institut für Solare Energiesysteme
Sponsor:	BMBF, State of Baden-Würtemberg
Project Budget and Funding:	Conception, Construction, Operation 5,8 Mio DM (from BMBF 89 - 95), Construction costs 3,6 Mio DM
Project Description and Objectives:	At the Fraunhofer Institute for Solar Energy Systems the concept of the 'Self-sufficient Solar House 2000' was developed over several years, built from Sept. 1991 to Oct. 1992 in Freiburg, Germany. It takes into account solar architecture priciples, thermal collectors, transparent insulation, photovoltaics, battery storage, hydrogen storage and an electricity and hydrogen application system. It provides all energy needs from solar radiation. The energy supply strategy of this concept supposes direct electricity use during sunshine. Excess energy is stored in a lead-acid battery system. As soon as this system is charged completely, hydrogen and oxygen are produced in a membrane pressure electrolysis unit at a level of 3 MPa and stored in gas cylinders. The hydrogen storage is a seasonal storage with a cycling period of one year. During wintertime the hydrogen is converted to electricity by a pem fuel cell system or to high temperature heat in a catalytic cooker with 4 diffusion burners and in a catalytic air-heater with a two step diffusion burner. The battery buffers electric peak-demand which cannot be covered by the fuel cell. The catalytic cooker replaces the electric one when the sun is not shining. The oven is operated electrically. The daily energy consumption is assumed to be in the order of 3 kWh and the overall efficiency of the storage system is calculated to be about 70%. The solar hydrogen system exists of the following components: - Solar generator: 84 Siemens M 50 modules with 36 monocrystalline silicon cells each covering 30 m2 with a total output of 4.2 kWp, - Battery bank: 48 lead acid batteries with 200 Ah at 2 V each, delivering a system voltage of 48 V and a design capacity of 19.2 kWh, - Auxiliary Batteries: 11 lead acid batteries with 75 Ah at 2 V each, delivering a system voltage of 22 V and a design capacity of 1.65 kWh (for the process control system), - Inverter: sinus-type with a design rating of 3 kW, - Electrolyzer: 30 cell membrane electrolyzer by FhG-ISE with a design capacity of 2 kW, a operating pressure of up to 3 MPa at a current of up to 90 A, an operating temperature of 80°C and a hydrogen/ oxygen production capacity of 1.2 m3/h respectively 0.6 m3/h, - Fuel cell system: 14 cell alkaline fuel cell unit operated with 30% KOH, with Ni gas diffusion electrodes, operating temperature of 70°C and design output of 0.5 kW, (presently the system has been replaced by a PEMFC unit) - Gas storages: Hydrogen: 15 m3, 3 MPa, 1436 kWh energy content. Oxygen: 7.5 m3, 3 MPa, - Cooking Stove: 4 catalytic diffusion burners with 2.6, 1.7, 1.7 and 1.0 kW design output (FhG-ISE development) - Electric baking oven with 230 VAC supply, - Air-Heater: 2 step catalytic diffusion burner of 0.5/ 1.5 kW power rating built into the air supply duct, automatic ignition (FhG-ISE development) The solar thermal collector system for the production of hot water consists of selective absorbers, type 'BEIKO', with a cermet cover achieving an absorption degree of 0.93 and an emissivity of 0.09, of a 1000 l water stratification storage, a flat plate heat exchanger for the collector circuit and the fuel cell excess heat circuit and 24 V circulation pumps with variable flow rates. The air ventilation system has a design capacity of 200 m3/h providing an exchange rate of 0.7. The fresh air enters into a system of tubes burried 4 m deep in the earth, by passing through the tubes the air is pre-heated, then it passes a heat exchanger (recovery factor 0.85) recovering the heat contained in the used air and finally the air is heated to its required final temperature by the hydrogen powered air-heater. In 1997, the house was again connected with the public electricity and gas grid since the funding for the scientific monitoring ran out.
Technical Goals:	Independend energy supply of a solar house with energy storage. Operating this house under the climatic conditions of Germany.
Project Status	House is still operating
Preliminary or Final Results:	See description
Related Reference Papers and Other Publications:	- BINE -Infoblatt Nr.18 /Dez. 1994 ISSN 0937-8367 W. Stahl, A. Goetzberger, K. Voss: Das Energieautarke Solarhaus: Mit der Sonne wohnen; Verlag C.F. Müllre, Heidelberg 1997, ISBN 3-7880-7513-9 K. Voss (Hrsg.): Konzeption und Bau eines energieautarken Solarhauses; Schlußbericht zum BMBF Projekt; Fraunhofer IRB Verlag 1997 ISBN 3-8167-4610-1