SOLAR THERMAL IN MAJOR RENOVATIONS AND PROTECTED URBAN AREAS

Transcription

1 SOLAR THERMAL IN MAJOR RENOVATIONS AND PROTECTED URBAN AREAS TRANSFER GUIDELINE ON TECHNICAL ISSUES DRAFT

2 1 Dani Gonzalez Verdiana Russo Aiguasol Sistemes avançats d Energia Solar Tèrmica Deliverable: WP 3: Task 3.2: Deliverable 3.2: Adaptation & Transfer Adaptation and transfer to implementation instruments Transfer guidelines Legal Disclaimer: The sole responsibility for the content of this publication lies with the authors. It does not necessarily reflect the opinion of the funding authorities. Neither the authors nor the funding authorities are responsible for any use that may be made of the information contained therein.

3 TABLE OF CONTENTS 2 TABLE OF CONTENTS 1. Introduction Identification of barriers and opportunities Opportunities Decision tree for technical solution Technical solution tools Centralized collector field and backup system (DHW) Collective solar field and accumulation with individual backup system (DHW) Collective solar field with individual accumulation and backup system (DHW) Individual solar thermal system (DHW) Centralized systems for DHW and heating STS Integration with DH network Activities... 9

4 3 1. INTRODUCTION This document is a technical help for municipalities when evaluating the possibility of implementing solar thermal energy in a district or in a protected area of the city. The aim is to show how communities, energy agencies and municipalities in general can improve the situation for installing solar thermal systems and not necessarily act as investor themselves. To do this, they have to be capable to understand the principal aspects associated with the process of decision of the proper solar thermal system. This is important to understand what the technical possibilities for a proposed intervention are or to propose an intervention. They also need to have the basic technical knowledge to demonstrate its feasibility in the group of competent delegations dealing with the management of the areas of the city, the realization of the urban planning, the propose of competitions in the sector of the urban rehabilitation, and in general with all that activities that can include the installation of a STS in the buildings of a district. As a technical help, this guide includes: A catalog of barriers and opportunities to consider in the feasibility analysis of an intervention of STS in existing residential buildings and/or protected buildings. A decision tree that gives to the municipalities all the viable technical solutions for STS implementation in a district. You have to use this tool for every typology of building of the district. Based on these results, you can choose what the best intervention proposal for the district is. A description of the scheme of every technical solution proposed as result of the decision tree. A proposal of activities to diffuse technical information on solar thermal systems and to keep up to date the principal actors of the decision process and of the executive projects. 2. IDENTIFICATION OF BARRIERS AND OPPORTUNITIES Before entering the process of decision making on the type of technical solution to install, you should know very clearly what are the possible barriers that may hinder your choice, and what the opportunities that may give them strength The principal barriers that affect the decision process are: Architectural limitations for protection causes: it refers to the reservations made by heritage conservator (eg. Special colors of the frame that implicates higher costs, impossibility to change the exterior aspect of the building facade, ). Complex intervention if not promoted in a refurbishment plan. Lack of available surface for the collector field (ex. roofs are also occupied by other installations).

5 4 Complexity of volumes distribution in flat roofs that causes shadows and reduction of profitable surface. Orientation of the roof. Lack of space for technical area (storage, interchange of heat, ), collective and/or individual. Structure problems for accumulation weight Opportunities The principal opportunities for the solar thermal installation are: Other available alternative sources with respect to solar energy: possibility to combine other available sources with the solar thermal system (eg. Geothermal). The district or the building are included in a plan of renovation (eg. of the roofs). Set STS adoption as an option when promoting specific intervention works, such as replace of the old heating system, requalification of the water or gas distribution net in the building or the roof cover requalification, installing elevators etc. Existence of a rehabilitation plan for the specifics intervention works listed above. Special funds for buildings renovation. Solar Thermal Ordinance the obligation to use hot water that is heated by solar collectors. Existence of a district heating net. Proximity to the storage of a district heating net.

6 3. DECISION TREE FOR TECHNICAL SOLUTION 5

7 6 4. TECHNICAL SOLUTION TOOLS 4.1. Centralized collector field and backup system (DHW) Scheme + Description Potentials opportunities - Unique control for all the building: better control - Integrated business models with proper monitoring systems that are user friendly interface with ESCO models; - There is no risk of collectors overheating or freezing. - It favors architectural integration - Centralized accumulation axpects to be studied (e.g. need to recalculate the structure of the building) - Need of an extensive technical room; - The economic viability depends on the full occupation of all the apartments otherwise the maintenance costs rise. - Difficult to install if the existing installation is not centralized - Tenants do not realize if there is a problem in the STS - Problems if not all the tenants want a STS 4.2. Collective solar field and accumulation with individual backup system (DHW) Scheme + Description Potentials opportunities - Monitoring system for the energy distribution facilitates the billing; - Tenants major awareness of the functioning of the system: they can detect problems - It favors architectural integration - Centralized accumulation axpects to be studied (e.g. need to recalculate the structure of the building) - Each dwelling s back up system billing will depend on the inhabitants behaviour and according to it some may benefit more from the STS; - Need to install both of centralized and individual monitoring system to facilitate the detection of problems; - Need of an extensive technical room; - The economic viability depends on the full occupation of all the apartments otherwise the maintenance costs rise. - Each dweller should be aware of his backup system bill in order to perceive fails in the system and communicate these to the maintenance team; - Difficult to install if the existing installation is not - Problems if not all the tenants want a STS centralized

8 Collective solar field with individual accumulation and backup system (DHW) Scheme + Description Potentials opportunities - Integrated solutions for energy accumulation and back-up system; - Monitoring system for the energy distribution facilitates the billing to each apartment; - Tenants major awareness of the functioning of the system: they can detect problems - The installation in existing buildings is perfectly compatible with an intervention at the water or gas distribution systems; - It favors architectural integration - Structure does not need to be recalculated for acumulation (it depends on the age and the conditions of the building) - Requires more storage space both for the individual inertia deposits and backup system;high maintenance costs; Maintenance to the whole system: centralized field and individual systems; Substantial damage in case of serious sinister of the accumulators. - Each dweller has to monitor its in-house installation (in the case of individual accumulation and back up) to detect problems in early stages and communicate it to the maintenance team; - Problems if not all the tenants want a STS centralized 4.4. Individual solar thermal system (DHW) Scheme + Description Potentials opportunities - Complete solution per apartment. It can be installed for one apartment only, if the other tenants do not want a STS; - Easier to detect problems in each apartment; - Easier to install if the inclusion of the STS is decided at a late stage; - Easily approved for single family houses; - System s maintenance requires easy access to the roof cover to each solar collector. If problems arise with the deposit it s more difficult to substitute; - Each tenant having its own maintenance company, instead of a unique one to control all the systems, including the energy distribution network, can be more complex and expensive; - Lack of architectural integration passes a negative image of STS.

9 Centralized systems for DHW and heating Scheme + Description Potentials opportunities - The STS can be easily integrated into an existing system; - Optimization of the system to maximize the solar gains and take advantageous of the lower temperatures required for the space heating; - In existing buildings this system is compatible with the substitution of heating systems and boilers; - It favors architectural integration - Complex installation, especially in existing buildings; - Requires the pre-existence of the space heating network in each dwelling; - Maintenance costs; - Users should be aware of the system functionalities and best practices in its management; - The economic viability much depends on the full occupation of all the apartments otherwise the maintenance costs rise. - Centralized accumulation axpects to be studied (e.g. need to recalculate the structure of the building) - Need of an extensive technical room; - Difficult to install if the existing installation is not centralized - Tenants do not realize if there is a problem in the STS - Problems if not all the tenants want a STS 4.6. STS Integration with DH network Scheme + Description heating plant districtheating network Central solar DH plant Source: Solites Potentials opportunities - Performance improvement (stability of the demand) - Less investment costs (shared equipment) - Operation improvements (reduction of operation costs) - Simple integration with seasonal storage - Possibility to integrate other efficient technologies - Possibility of reducing seasonality with the integration of the cold demand higher solar contribution Multifield (central+distributed) solar DH plant; Source: Solites - In the case without seasonal storage the management model is more difficult than the cases with the storage - In the case without seasonal storage the network has to be a bit overdimensioned, so it is possible to have greater losses

10 9 5. ACTIVITIES Various activities can be organized and carried out to promote the diffusion of new integration solutions for STS in existing districts and the knowledge of existing technical solutions: Organization of events To encourage and foster the diffusion of knowledge and new solutions it is important for municipalities to organize events inviting architects, engineers, manufacturers, researchers. New products and integration concepts are the result of a joined effort between these actors. Publicize pilot experiences throw conferences, information days Publicize positive experiences of architectural integration Workshops Workshops can be organized with installers and manufacturers to discuss the different STS technical solution in building renovations. It could be useful to unify different experiences, identify barriers and opportunities and use them as a new basis of discussion of the problem. The outcome information of these workshops should be sent to the participant and should be publicized towards information channels (e.g. articles in magazines, seminars, energy agency website, etc...). Diffusion of articles on scientific magazines