In order to utilize alternative energy sources which are available at times when energy is not needed energy storage is required. An other reason for energy storage is to reduce the size of energy production equipment. The storage enables energy production at all times. When the energy demand is smaller than the rate of production energy is stored, whereas when the demand is larger than the rate of production energy will be withdrawn from the storage.

Storage of thermal energy can be performed by sensible heat storage, e.g. heating a material to a higher temperature at loading and cooling it down at deloading. Water is a common material for sensible heat storage at temperatures between 5 and 100 °C.

An other way of storing thermal energy is the utilization of the latent heat of a phase change materials. Usually the heat of melting is utilized. The heat of melting is 80 to 100 times larger than the heat required for heating a material one degree.The use of liquid -vapor phase change further increases the energy density.

The use of chemical reactions for thermal energy storage expands the temperature range for storage and also increases the possible energy density in the storage.

The scope of the work undertaken in this annex includes thermal energy storage by solid-solid, solid-liquid, liquid -vapor and solid-vapor phase transfer, for instance melting/solidification, crystallization/solubilization, vaporization/liquifaction and solid sorption processes as well as by chemical reactions.

The difficulties in using phase change materials for energy storage are

1. to find a suitable material for the required temperature range
2. mass and heat transfer limitations
3. reversibility of the phase change
4. system integration

2. Objectives

The objectives of this Task are to overcome technical and market barriers for introduction of long- (seasonal) or short-term phase change and chemical reaction thermal energy storage for energy savings and for reduction of peak demand of energy in buildings, agricultural and industrial applications. Specifically this will be achieved by

1. the demonstration of thermal energy storage with phase change materials in building materials
2. the demonstration of thermal energy storage with phase change materials or chemical reactions for cold and heat storage for comfort cooling
3. the demonstration of thermal energy storage with phase change materials or chemical reactions for long and short term storage in the food sector
4. the demonstration of thermal energy storage with phase change materials or chemical reactions for applications in industrial processes.

3. Means

The participants shall share the coordinated work necessary to carry out this Task. The objectives shall be achieved by:

1. Collecting, in their countries, data relevant for the use of energy storage with phase change materials or chemical reactions in the building, the agricultural and the industrial sector.
2. Collecting, in their countries, data on ongoing projects on energy storage with phase change materials or chemical reactions in the building, the agricultural and the industrial sector.
3. Performing case studies and initiating demonstration projects on thermal energy storage with phase change materials or chemical reactions in the building, the agricultural and the industrial sector.

4. Results

The results of this Task shall be:

1. Periodic documents and interim progress reports on the results achieved under the Programme of Work;
2. A final report describing the work carried out under this Task. The final report should restate the scope and objectives of the Annex, its findings, documentation of case studies and demonstration projects, documentation of national RD & D projects, a summary of workshops, expert meetings, guidelines and recommendations for future application oriented R & D projects;
3. Information database on a www site on Internet as specified in the Programme of Work;
4. Documentation and results from the performed case studies and demonstration projects. Moreover, recommendations for future case studies shall be given by priority by the participants.

5. Time schedule

This Annex shall commence 1st January, 1998 and remain in force until 31st of December 2000. It may be extended by agreement of two or more Participants, acting in the Executive Committee, and taking into account any recommendations of the Agency's Committee on Energy Research and Technology concerning the term of this Annex. Extensions shall apply only to those Participants who agree to the extension or who notify the IEA Secretariat of their decision to continue to participate.

6. Specific obligations and responsibilities of the participants

In addition to the obligations enumerated in Article 7 of this agreement

1. Each participant shall provide the Operating Agent with detailed reports on the results of the work carried out.
2. Each participant shall collect, assess and report to the Operating Agent data on ongoing projects in the field of thermal energy storage in phase changing materials and on other data relevant for the use of thermal energy storage in phase changing materials and chemical reactions.
3. Each participant shall participate in the editing and review of draft reports on the Task.

7. Specific obligations and responsibilities of the operating agent

In addition to the obligations enumerated in Articles 4 and 7 of this agreement the Operating Agent shall:

1. Prepare and distribute the results mentioned in paragraph 4 above
2. At the request of the Executive Committee organize workshops, seminars, conferences and other meetings
3. Prepare the detailed program of work for the Task in consultation with the participants and submit the program of work for approval to the Executive Committee
4. Propose and maintain a methodology and a format for the submission of information on data relevant for the use of thermal energy storage in phase change materials and on ongoing projects in the same fields which are collected by the participants as described in paragraph 3 (1) and (2) above
5. Provide the semi-annually, periodic reports to the Executive Committee on the progress and the results of the work performed under the program of work
6. Provide to the Executive Committee within six month after completion of all work under the Task a final report for its approval and transmittal to the Agency
7. In coordination with the participants use its best effort to avoid duplication with activities of other related programs and projects implemented by or under the auspices of the Agency or by other competent bodies
8. Provide the participants with the necessary guidelines for the work they carry out assuring minimum duplication effort
9. Coordinate the efforts of all participants and ensure the flow of information in the Task
10. Perform such additional services and actions as may be decided by the Executive Committee acting by unanimity

8. Funding

1. Semi-annual meetings. The semi-annual meetings pursuant to paragraph 3 above shall be hosted in turn by the several participants. The cost of organizing and hosting meetings shall be borne by the host participants.
2. Publications. The cost of publishing the reports and summary assessments described in paragraph 4 above shall be met by the Operating Agent.
3. Individual financial obligations. Each participant shall bear all the costs it incurs in carrying out the Task activities, including reporting and travel expenses.
4. Task-Sharing requirements. The level of the effort to perform the work specified in this Annex is estimated at 0.5 person-years per year for the Operating Agent, 4 additional person-months for each participant in the first year that the annex is in force, and in additional 3 person-month per year for each participant during the remainder of the term of the annex.

9. Operating Agent

The Swedish Council for Building Research, acting through the department of chemical engineering and technology at the Royal Institute of Technology is designated as Operating Agent

10. Information and Intellectual Property

1. Executive Committee's Powers

   The publication, distribution, handling, protection and ownership of information and intellectual property arising from this Annex shall be determined by the executive Committee, acting by unanimity, in conformity with this Annex.

2. Right to publish.

   Subject only to copyright restriction described in paragraph 10(i) below, the Participants shall have the right to publish all information arising from this Task, except proprietary information, as defined in paragraph 10(3) below.

3. Proprietary information.

   The Participants and the Operating Agent shall take all necessary measures in accordance with this paragraph, the laws of their respective countries and international law to protect the proprietary information provided to, or arising from this Task. For the purpose of this Annex, proprietary information shall mean information of a confidential nature such as trade secrets and know-how (for example computer programmes, design procedures and techniques, chemical composition of materials or working media, manufacturing methods, processes or treatments) which is appropriately marked provided that such information:

   1. Is not generally known or publicly available from other sources;
   2. has not previously been made available by its owner(s) to others without obligation concerning its confidentiality;
   3. Is not already in the possession of the recipient Participant(s) without obligation concerning its confidentiality;

   It shall be the responsibility of each Participant supplying such proprietary information and of the Operating Agent for developing proprietary information to identify each information as proprietary and to ensure that it is appropriately marked.

4. Production of Relevant information by Governments.

   The Operating Agent should encourage governments of all Agency Participating Countries to make available or identify to the Operating Agent all published or otherwise freely available information known to them that is relevant to the Task.

5. Production of relevant information by Participants.

   Each Participant agrees to provide to the Operating Agent all previously available information and information developed independently of the Task which can assist or is needed by the Operating Agent to carry out its function in this Task, which is freely at the disposal of the Participant and the transmission of which is not subject to nay contractual and/or legal limitations under the following conditions:

   1. If no substantial cost is incurred by the Participant in making such information available at no cost to the Task therefor;
   2. If substantial costs must be incurred by the Participant to make such information available at such charges to the Task as shall be agreed between the Operating Agent and the Participant with the approval of the Executive Committee;
6. Use of confidential information.

   If a Participant has access to confidential information which would be useful to the Operating Agent in carrying out the studies, assessments, analyses or evaluations called for in this Task, such information may be communicated to the Operating Agent but shall not become part of any report or other form of documentation issued as part of this Task, nor shall it be communicated to the Participants except as may be agreed between the Operating Agent and The Participant who supplies such information.

7. Acquisition of Information for the Task.

   Each Participant shall inform the Operating Agent of the existence of information that can be of value to the Task but which is not freely available and each Participant shall endeavour to make such information available to the Task under reasonable conditions in which event the Executive Committee may, acting by unanimity, decide to acquire each information.

8. Reports on work performed under the Task.

   The Operating Agent shall provide reports on all work performed under the Task and the result thereof including studies, assessments, analyses, evaluations and other documentation but excluding proprietary information in accordance with paragraph 10(c) above.

9. Copyright.

   The Operating Agent, or each Participant for its own result, may take appropriate measures necessary to protect copyrightable material generated under this Task. Copyrights obtained shall be the property of the Operating Agent, for the benefit of the Participants provided, however, that Participants may reproduce and distribute material, but shall not publish it with a view of profit, except as otherwise provided by the Executive Committee.

10. Authors.

    Each Participant shall, without prejudice to any rights of authors under its national laws, take necessary steps to provide the co-operation from its authors required to carry out the provisions of this paragraph. Each Participant shall assume the responsibility to pay awards or compensation required to be paid to its employees according to the laws of the country.

11. Participants in this Task

Participants in this task are Bulgaria, Canada, Finland, Germany, Japan, Poland, Sweden and Turkey. Further members could be Australia, China, the Nederlands, United Kingdom and USA.

Source: Chemical Engineering and Technology, Royal Institute of Technology Last updated: 2000-06-15 webmaster@ket.kth.se