Tasks of the planner

Transcription

1 Players in the planning process of a solar system Architect Subsidy donor Consultation, supervision User Client Planner Information, orders Consultation, planning, supervision Installer Offer, installation, maintenance 1 Project development IDEA 1 Basic evaluation 2 Preliminary planning 3 Blueprint planning 4 Approval planning 5 Implementation planning 6/7 Tender, placing 8 Construction supervision 9 Supervision of the object Tasks of the planner Concept, feasibility study Compilation of data Cost framework System alternatives Estimation of costs Examination of support measures Detailed planning Detailed estimation of costs Authorisation, if necessary Static certificate Practicable planning Detailed graph Calculation of costs Preparation of technical specifications Participation in placing Evaluation of offers Coordination of works Time and cost schedule Technical control Documentation Trouble shooting Source: HOAI 2-1-

2 Identification of the basic conditions Estimation/compilation of consumption data Are the consumption data confirmed by measurements? Have the losses been taken into consideration? Are the consumption profiles (year, week, day profile) known? Have vacation times been taken into consideration? Energy savings at the object (insulation, renovation, economic armatures, )? Is it possible to minimise boiler and circulation losses? Is an exchange of the boiler or a refitting planned? Are changes in the user structure imminent (modification, enlargement, )? What is the life cycle of the designated roofages? Are static expertises necessary? Is there enough space for the placement of storages and system technology? Is the insertion of storages through existing openings possible? Determine ceiling height, tilting degree Are shadowless spaces available? First clarification of the cable rooting Source: ITW 3 Energetic overall concept Losses Registration of the whole energy demand in the building Energetic examination of the building stock Examination of all energy supply devices Heat Climate Hot water Ventilation Saving potentials of building equipment and systems User Consumption profile Fossil fuels Renewable energies 4-2-

3 Available technologies and possibilities of supply Gas Solar thermal Pellets CHP Heating oil Heat pump Criterion Ecology Investment Operational costs Maintenance Evaluation % % % % Gas (Reference) Gas and Solar Pellets and Solar Gas and CHP Pellets, Solar, CHP Heating oil ++ very good + good o satisfying - bad -- very bad Heat pump Photos: Kienast, Lauerer, Paradigma, target GmbH (2), Wibbing 5 Synergetic effects at renovation and boiler exchange Are renovation works for the building pending? Renovation of the roofage Exchange / renovation of the boiler plant Renewal of the heat / hot water distribution network Change-over of the heating system to another energy source In these cases synergy effects can be used: Economisation of the roofing Installation of fixing elements without harming the roof panel later on Use of the scaffolds and the elevators Entitlement to adequate support programmes Reduction of energy need and losses Application of shared control and measurement technique 6-3-

4 Possible saving effects Need of fossil fuels [kwh/qm inhabited surface] current situation -x % integrated energy concept optimised combination of costs and saved energy e.g. roof insulation, windows, solar thermal systems, CHP, PV, Electricity (Primary energy) Losses Hot water Heating Source: Ambiente Italia 7 Factors of success Which factors are necessary for the evaluation of a solar system s success? always hot water high water temperature visibly installed collector surface minor losses fuel economy 8-4-

5 Definition of the terms Efficiency Utilisation level consider connection! Fraction Fuel economy Coefficient of performance Capacity utilisation 9 Utilisation level Q sun system limit Q losses Q coll. Q solar Qboiler Qcirc. Q consumption Utilisation level of collector loop System s utilisation level η coll. = Q coll. / Q sun η sys. = Q solar / Q sun 10-5-

6 Share of coverage Q sun system limit Q losses Q consumption Q coll. Q solar Q boiler Q circ. Solar fraction Tapped fraction f solar = Q solar / (Q solar + Q boiler ) f tapped = Q solar / (Q solar + Q consumption ) f solar = Q solar / (Q consumption + Q circ. + Q losses ) 11 Fuel consumption with solar system Domestic hot water production in a multi-family building (60 accommodation units, A = 50 m 2, V St. = 2,500 l) Hot water storage 52 MWh/a 1,100 kwh/(m 2 a) L = 15 m Sys = 0.42 Q Sys = 22.5 MW/a Heating boiler b = 0.85 Q L,rt 44.2 MWh/a Q L,St MWh/a required heat output: Q = l/d 365 d/a 1.16 kwh/(l K) 35 K = 66.7 MWh/a Source: Ambiente Italia 12-6-

7 Coefficient of performance (COP) The coefficient of performance (COP) describes the ratio of the utility heat provided by the solar system to the electrical energy needed for pumps, control and actuator. Solar system output COP = Sum of auxiliary electrical energy Foto: Stadtwerke Karlsruhe 13 Capacity utilisation Typical values for capacity utilisation large systems medium systems small systems big dimensioning small dimensioning capacity utilisation in l/m² collector surface The capacity utilisation of a solar hot water system describes the ratio of the daily need of hot water to the collector surface: capacity utilisation = need of hot water / collector surface [l/(d m²)] only useful for systems for pure domestic hot water heating it is important to indicate the temperature level (normally 60 C) 14-7-

8 Hot water consumption of different institutions Hospitals Homes for the aged Halls of residence Vacation homes Large residential buildings 1 or 2-family houses Schools can approach 0 during vacation periods in vacation periods around Hot water consumption (60 C) per person at full occupancy and day [l/(p d)] Summer Other times Dots mark the mean value Source: BINE/Solarpraxis 15 Normalisation of consumption for the off-peak period Hot water demand, normalised for off-peak period 1,6 1,4 1,2 1,0 0,8 0,6 0,4 0,2 0,0 Measuring period Mean during 6 weeks summer r off-peak period =1 (or 100%) Example Measuring period : 9. April 21. Mai (6 weeks) Measured: 9 m 3 /d Correction value for measurement: 1.38 Consumption for dimensioning: 6.5 m 3 /d Beginning days of the week Source: BINE/Solarpraxis 16-8-

9 Development of the hot water demand in a building 7 Consumption [m³] Trend Implementation of an economy measure Economisation Time [years] 17 Connections: fraction, capacity utilisation, utilisation level Fraction Heat price Surplus Collector surface Inlet & return flow temperature Specific investment costs Utilisation level Consumption Capacity utilisation Production Coefficient of performance 18-9-

10 Influence of capacity utilisation on important characteristic values Collector surface [m²] C: Costs solar heat [ /kwh] U C F C: Costs of usable solar heat (sloping roof) U: Utilisation level of the solar system F: Fraction used by tapped hot water Capacity utilisation [l/(d m²)] Consumption and connection to consumer fixed; system size variable; optimised system with very good flat plate collectors; place with medium irradiation Source: BINE / Solarpraxis 19 Influence of over dimensioning, surplus Hot water demand and irradiation offer for different collector surfaces Surplus Irradiation offer [kwh] Growth of solar utility energy Hot water demand Jan Feb Mar Apr Mai Jun Jul Aug Sep Oct Nov Dec In case of enlargement of the collector surface the surplus is growing faster than the utility energy

11 Influence of tap water temperature and return flow temperature For a bath a maximum temperature of about 36 C is needed, for a shower about 40 C. As the storage temperature is normally higher, the consumer adds cold water at the extraction point. A large part of the tap volume uses the cold water pipe. The increase of the temperature in the standby storage reduces the storage output, as more cold water is added because of the higher outlet temperature. The storage output is decisive for the heat output of the solar system. Low return flow temperatures increase the efficiency of the collector. Production and fraction increase, the heat price sinks. 21 Result of deviation of the presumed consumption Collector surface [m²] C: Costs solar heat [ /kwh] U C F C: Costs of usable solar heat (sloping roof) U: Utilisation level of the solar system F: Fraction used by tapped hot water Capacity utilisation [l/(d m²)] effective operating point at 30 % less consumption effective operating point at 30 % higher consumption planned dimensioning with 60 l/(d m²) Source: BINE / Solarpraxis, M. Schnauss

12 Advantages of a layered storage tank high inlet temperature early attainment of the hot tap water temperature high efficiency avoidance of unnecessary backup heating cold return flow 23 Frequent errors concerning system dimensioning wrong estimation of consumption no or insufficient consumption measurement no or insufficient consideration of (summer) off-peak periods insufficient consideration of temperature level of the effective storage output missing overall concept insufficient consideration of possible savings (in the conventional system) RESULT: over dimensioning minor output high heat price bad amortisation Source: ZfS

13 Functional and solar heat gain test (I) Reasons for an output and performance control and for guaranteed solar output breakdown of collector system is detected very late, as the conventional backup heating is assuring the supply badly working systems create safety and trust in the technique in the eyes of the investor promotional measure market stimulation demand of the subsidy donor Procedure use of control devices acceptance control with mobile data acquisition contractual arrangement Source: R. Tepe 25 Functional and solar heat gain test (II) Devices for the output and performance control Calorific meter Registration of the pump run time by time meter Input-Output-Controller Control unit with integrated functional and solar heat gain test Mobile acceptance data acquisition Source: R. Tepe

14 Guaranteed solar gain Approach towards Guaranteed solar gain contractual arrangement in sales contract stipulation of guaranteed gain on the basis of simulation calculations in case of less gain detected: - installer/planner can retouch - installer/planner refunds output deficit Source: R. Tepe