SUPPLYING RENEWABLE ZERO-EMISSION HEAT

Transcription

1 SUPPLYING RENEWABLE ZERO-EMISSION HEAT

2 Foreword & Introduction Birger Lauersen President of Euroheat & Power To meet the EU energy and climate challenges, there is a compelling case for a hierarchy for measures: reduce, recycle and replace: Firstly, reduce energy consumption through higher efficiency throughout the energy chain, secondly, recycle energy that otherwise would be wasted, and finally, replace fossil fuels with more benign sources. Climate protection is a collective task requiring collective solutions that are future-proof and provide citizens with flexible, near- and long-term affordable comfort. District heating and cooling responds to this challenge by extending the advantages of renewable heat supply from individual buildings to eco-districts or even cities. The combination with solar thermal technologies, though not widespread yet, is without any doubt a promising new development bringing us closer not only to a low-carbon but also more resource-efficient energy future. The project 'SDH - Solar District Heating in Europe', co-financed by the EU s Intelligent Energy for Europe programme, provides us with an excellent platform to support the exchange of know-how and experience with innovative district heating and cooling technologies. Take a look at the materials produced, take part in the activities become a frontrunner! 2

3 Success Factors in Solar District Heating District heating and solar heating have got increased interest all over Europe in recent years. Block and district heating is one major approach to increase the overall energy efficiency in urban areas, either by refurbishment of existing systems or by the introduction of new systems in existing or new building establishments. Solar heat is available in principle anywhere all over Europe. The development is supported by increased incentives in the form of EU directives, local and regional support policies together with improved competiveness in the local heating markets. The result is that more than 125 plants with more than 500 m² of solar collectors have been put into operation since the mid 90 s. Out of these about 40 plants have a nominal thermal power of 1 MW th and a major part of the plants are connected in existing or new block and district heating schemes. Twenty years of operational experience, plant technology and know-how are available and since the mid of the last decade there is an increased interest in the commercial operation of solar district heating, mainly by utilities but also from local authorities and the housing sector. A prevailing success factor of the realised plants presented in this publication is the involvement of one or several local actors with interest and knowledge to develop and demonstrate the new technologies, being a local city government, a local utility, a local manufacturer or a combination of those. The SDH Project Solar district heating plants are usually operated by utilities or local heat suppliers. They are the key actors for solar district heating. Therefore, five national district heating associations (or groups) from Austria, Czech Republic, Denmark, Germany, Italy and the European roof association Euroheat & Power joined with acknowledged experts on the field of large-scale solar heating plants for the project SDH Solar District Heating in Europe. The project actions follow a comprehensive approach for a market introduction of solar district heating, contributing to a development to its full long term potential, which experts estimate at 5 10 % of district heat from solar and an annual solar heat production of PJ. In the project the partners analyze the market conditions and barriers leading to recommendations to policy and support scheme decision makers. District heating experts and industries together at one table with experts and industries of the solar thermal sector elaborate industry standards and guidelines for SDH, necessary for commercial activities on this sector. Capacity on the supply side is built up by training and support structures. Targeted dissemination activities will motivate and support new market actors in more European countries to start activities on this field. The SDH Project is supported by 3

4 Solar District Heating more than 125 solar heating and cooling plants larger than 500 m 2 / 350 kw th overseas Large-scale solar heating systems were introduced in the late 70 s by the interest to develop solar heating systems with seasonal storage. Sweden had a leading role in the early demonstrations together with The Netherlands and Denmark. In the 90 s the interest in large-scale solar heating increased in Germany and Austria and more than 125 new plants with more than 500 m² of solar collectors have been put into operation since the mid 90 s. Out of these about 40 plants have a nominal design power of 1 MW th or more. The total installed collector area amounts to about m² (~170 MW th ). Applications The majority of the large-scale solar heating plants supply heat to residential buildings in block and district heating systems. Typical operating temperatures range from low 30 C to high around 100 C. Two thirds of these plants are connected to existing buildings, especially in Sweden, Denmark and Austria. German plants are mainly applied in new residential building areas. Most of the plants have roof-integrated or roof-mounted solar collectors while several plants in Sweden and Denmark have ground-mounted collector arrays. A large part of the plants in Sweden and Austria are built in connection to wood fuel fired heating plants. A couple of large-scale solar heating plants are industrial applications or solar cooling plants. 4

5 Kungälv, SE The Swedish large-scale solar heating plants are used by district heating and housing companies, mainly for existing building areas, using both ground mounted collector arrays and roof-integrated or mounted collectors. The oldest plant still in operation dates from Marstal, DK The Danish large-scale solar heating plants are used in small district heating systems and all collectors are ground-mounted. Neckarsulm, DE The German large-scale solar heating plants are mainly applied in new residential building areas using roof-integrated or roof-mounted collectors. Some of the large projects have so called pre-fabricated solar roofs. Integrating Solar into District Heating District heating is an infrastructure where heat is distributed in pipe networks by circulating heated water. The water delivers heat via substations to connected buildings and is returned to the main heating plant where it is heated again. Solar heat can be integrated into the system either by a central or a distributed plant. Central solar district heating plant: The solar collectors deliver heat to a main heating central. With large seasonal heat stores the solar heating plant can contribute more than 50 % to the total heat demand. Distributed solar district heating plant: The solar collectors are placed at suitable locations and connected directly to the district heating primary circuit on site. Often these plants utilise the district heating network as a storage. 5

6 Denmark & Austria In Denmark solar district heating became feasible against high prices of fossil fuels. Key advantages are the very low operation costs of solar plants leading to an almost fix heat price for an operation period of 25 years. Leo Holm, CEO of Marstal Fjernvarme and Chairman of the Danish Solar Utility Group and Per Kristensen, CEO of Brædstrup Fjernvarme Solar Heat in CHP Plants in Denmark Fossil based Combined Heat and Power (CHP) dominates electricity generation and the heat supply in urban areas in Denmark. The recent strong development in wind power in Denmark has created a situation where in periods with good wind conditions it is less feasible to operate the CHP and more feasible to operate boilers to supply the required district heat. Relatively high district heat costs and a strong local solar collector industry caused the idea to implement large solar heating plants in connection to existing or new short-term storages in CHP plants. The Danish large-scale solar heating plants are used in small district heating systems and all collectors are ground mounted. A breakthrough was the development of a number of solar district heating plants initiated by Marstal Fjernvarme in the late 1990 s. The recent development is initiated by Brædstrup Fjernvarme and followed by several district heating utilities in cooperation with Dansk Fjernvarme, the Danish District Heating Association. The above described development has resulted in seven new plants with solar collector arrays from to m² (3.5 to 7 MW th nominal power) put into operation since 2006 and several more are planned. Solar heat costs are of the order of 4 Eurocent/kWh without subsidies. The Brædstrup Solar District Heating Plant Brædstrup Fjernvarme installed the first plant combining solar thermal with CHP. Owner Brædstrup Fjernvarme Solar collector area 8000 m² Storage type 2000 m³ steel tank Heat output 3.4 GWh/a Heat load 42 GWh/a Solar contribution 8 % More Information about solar district heating in Denmark: 6

7 All of our solar district heating plants have been realized for economical reasons. We reach feasibility, whenever the local solar radiation availability, the energy price pattern and the profile of our customer fit together. Christian Holter, CEO of S.O.L.I.D, Austria, Graz ESCO develops Solar Heat in Austria The implementation of solar heating requires a major investment while the operation costs are very low. One prerequisite to make the investment is that the plant owner judges the risk in a favourable way. As most utilities and building owners lack experience from solar heating the risk is judged to be too large, even if the long term economic feasibility looks interesting. One way to overcome this problem is to create an Energy Service Company (ESCO) that makes the investment, operates the plant and sells the heat to a housing facility owner or to a district heating utility. The main driver behind the solar ESCO development is the local company S.O.L.I.D. The development has led to a number of realised solar heating plants in Austria, especially four large plants in the district heating system in Graz. Solar heat costs are of the order of 6-8 Eurocent/kWh without subsidies. Solar District Heating Plant Wasserwerk Andritz At Wasserwerk Andritz, Graz ground mounted collectors are used for domestic hot water and room heating of an office building and for feed-in into the city district heating grid. Owner nahwaerme.at Energiecontracting GmbH Solar collector area 3855 m² Storage type 65 m³ water buffer tank Heat output 1.6 GWh/a 7

8 Germany & Sweden Solar district heating may become powerful especially with the realisation of new, stand-alone networks. It is also a potential, complementary component of new systems for heat generation, based on biological primary energy resources. Big hot water storage tanks enable the combined usage with the cogeneration of heat and power. Werner Lutsch, CEO of the German Heat and Power Association AGFW Demonstration of seasonal heat storage in Germany A major challenge to increase the potential use of solar heat is the possibility to store heat from the summer to the heating season in order to cover a larger part of typical loads in district heating systems. Within a comprehensive national R&D program eleven solar district heating plants with seasonal storage have been realised since the mid 1990 s. The German plants are mainly applied in new residential building areas using roof-integrated collectors and reaching solar fractions of 50 % of the total heat demand for hot water and space heating. Four different types of seasonal storage have been demonstrated: - Tank thermal energy storage (TTES) - Pit thermal energy storage (PTES) - Borehole thermal energy storage (BTES) - Aquifer thermal energy storage (ATES) Tank thermal energy storage (TTES) (60 to 80 kwh/m³) Borehole thermal energy storage (BTES) (15 to 30 kwh/m³) Pit thermal energy storage (PTES) (60 to 80 kwh/m³) Aquifer thermal energy storage (ATES) (30 to 40 kwh/m³) Further information on solar district heating and seasonal heat storage in Germany: Solare Nahwärme Ackermannbogen in München, Germany In a new residential building area in Munich a tank storage has been integrated into the solar assisted district heating network. The solar collectors are roof-integrated on the surrounding multifamily buildings. Owner Stadtwerke München GmbH Solar collector area 2921 m² Storage type 5700 m³ concrete tank Heat output 1.0 GWh/a Heat load 2.3 GWh/a Solar contribution 45 % 8

9 Distributed solar collector arrays, e.g. on buildings in district heating systems, make it posssible to trade green heat in pipe grids as green electicity is traded in the electric grids. Jan-Olof Dalenbäck, Professor in Building Services Engineering, Energy and Environment, Chalmers University of Technology Net-Metering of Solar Heat in Sweden The Swedish large-scale solar heating plants are used by district heating and housing companies, mainly for existing building areas, using both ground mounted collector arrays and roof-integrated collectors. An increased number of building owners connected to district heating have expressed an interest to use solar collectors on their buildings. One way to use solar thermal is to connect the solar heating system in the district heating main circuit, use the district heating system as buffer storage and develop a netmetering contract with the district heating provider. This feed-in integration was pioneered by the municipal service buildings owner and the district heating provider in Malmö (E.ON, former Sydkraft) and has now resulted in a number of systems in other cities. The development of a prefabricated solar district heating substation in cooperation with an established system component company has been a major facilitator in the projects. Solar heat costs are of the order of 7 Eurocent/kWh without subsidies. The Vislanda Solar Plant integrated into the Local Distict Heating System In Vislanda a roof-integrated solar collector field that is connected to the district heating network via a prefabricated sub-station has been installed on a multi-family building. The housing association has a net-metering contract with the district heat supplier. Owner Allbohus Fastighets AB Solar collector area 350 m² Storage type none Heat output 140 MWh/a (expected) Heat load of building 150 MWh/a 9

10 Italy & Czech Republic - New Markets in Learning Countries The diversification and the use of local energy sources is of utmost importance for utilities operating district heating grids. Among these sources, solar thermal is undoubtedly for Italy one of the most interesting and promising options. Franco Buscaroli, Head of the Integrated District Heating Working Group in AIRU First Solar District Heating Initiatives in Italy Thanks to the participation the Italian District Heating Association (AIRU) and the energy consultant Ambiente Italia in the SDH project, Italian market actors are planning for the first solar thermal plants connected to district heating networks. The multiutility Gruppo Hera, Bologna is planning the extension of its district heating grid in Ferrara through a renewable energy hub including geothermal and about 2 MW th of solar thermal collectors. The local utility Geo Energy Service, operating in Tuscany, is assessing the feasibility of two solar thermal plants for integration into existing geothermal steam powered district heating grids. District Heating meets Solar Thermal in Czech Republic The association for District Heating of the Czech Republic (ADHCR) together with the energy consultant City- Plan organize workshops and conferences for district heating stakeholders within the SDH project. There are already today a couple of smaller pilot plants in the Czech Republic. Some providers of smaller district heating grids start activities focused on possibilities of integrating large solar collector arrays into their systems. A higher probability of realization of new plants is connected to the district heating systems owned by municipal utilities, due to the conditions of Czech subsidy programs. Solar Air-conditioning at Hotel Duo in Prague The solar plant of the Hotel Duo in Prague is used as main heat source for the cooling absorption unit of the hotel air-conditioning system. The remaining 40 % are backed-up by the district heating system. Surplus of solar heat is used for domestic water heating. The Collector field consists of 282 evacuated tube collectors. The rated output of the absorption unit is 560 kw. Owner Solar collector area Storage type Heat output Solar contribution Hotel Duo 536 m² ETC 4000 l steel tank 270 MWh/a 60 % of the cooling load 10

11 The SDH Project offers Information and Support for district heat suppliers, utilities and contractors component suppliers, service providers, professionals local communities, housing and industry enterprises policy makers and support scheme managers Get in direct contact with Europe s most experienced operators of solar district heating systems, experts and professionals. Benefit from the project products, services and events you find on the project website. Support for New Actions in the Field of Solar District Heating The SDH Project partners provide you with numerous valuable informations and services which support you in your initiative for solar district heating. You can either contact the SDH help desks operated by the participating district heating associations or visit the project website. Information and Training If you subscribe to the periodic newsletter of the SDH project, you will stay informed about related news and recent publications. Download from the website updated analyses reports on projects and markets as well as technical SDH guidelines for the realisation of plants. As professional you can benefit from the plant excursions and trainings organised in the frame of the project. Reference Projects Benefit from more than twenty years of operational experience, proven plant technology and expert know-how. Best practice plants and lessons learned are presented in an exhaustive plant data base on the project website. Experienced Business Partners The data base of experienced market actors created in the SDH project will help you when you are seeking for an experienced planner or supplier or when you wish to exchange know-how with an experienced operator of a solar district heating plant. Use our events for networking. 11

12 The SDH Project Project Partners Solites, Steinbeis Research Institute for Solar and Sustainable Thermal Energy Systems Germany (project coordinator) AGFW, German Heat and Power Association Energie Graz - Austria S.O.L.I.D. Company for Installation of Solar and Design - Austria Marstal District Heating Denmark PlanEnergi - Denmark AIRU, Italian District Heating Association Ambiente Italia - Italy Association for District Heating of the Czech Republic CityPlan Czech Republic Euroheat & Power - Belgium CIT Energy Management Sweden Imprint Edited by: Thomas Pauschinger, Solites - Steinbeis Research Institute for Solar and Sustainable Thermal Energy Systems Meitnerstr. 8, Stuttgart, Germany, info@solites.de, Base text for this brochure: Success Factors in Solar District Heating, Jan-Olof Dalenbäck, CIT Energy Management AB,, 12/2010 Layout: Holger Bischoff, AGFW-Projekt-GmbH Image sources: Arcon, Stadtwerke Crailsheim, Euroheat&Power, Dalenbäck, Kungälv Energi AB, Marstal District Heating, Solites, Braedstrup District Heating, S.O.L.I.D, Armatec, Albohus Fastihets AB Stuttgart, June 2011 Supported by: Disclaimer: The sole responsibility for the content of this publication lies with the authors. It does not necessarily reflect the opinion of the European Union. Neither the EACI nor the European Commission are responsible for any use that may be made of the information contained therein.