Institut für Gebäude- und Solartechnik Prof. Dr.-Ing. M. Norbert Fisch Mühlenpfordtstraße 23 D-38106 Braunschweig PV2Heat: Development of a vacuum insulated high temperature solid storage combined with PV Prof. Dr.-Ing. M.N. Fisch Dipl.-Ing. Mani Zargari Institut für Gebäude- und Solartechnik Prof. Dr.-Ing. M.N. Fisch Dialogplattform Power to Heat 5. + 6. Mai 2015 Technische Universität Braunschweig
Content 1. PV in the Power Market: Challenges and Solution Approach 2. Technique of a High-Temperature-Solid-Storage (HTFS) 3. System Integration of a HTFS 4. System Comparison 5. About the Research Project May 7, 2015 Hochtemperaturspeicher Seite 2
PV in the Power Market Oversupply of PV-Power Turn down of convential power plants (grey) for renewables Price for power collapses at the spot market Cut-off of renewable power plants from the grid in future May 7, 2015 Hochtemperaturspeicher Seite 3
Power [GW] PV in the Power Market PV-Gain and Demand 140 Installed Power and Demand 120 100 80 60 40 Other Renew. Wind PV 20 0 Demand 2014 2018 2024 Renewable Midterm Prognosis of the German network operators 2014 (EEG Mittelfristprognose 2014) May 7, 2015 Hochtemperaturspeicher Seite 4
PV in the Power Market Options for Flexibilization DMS P2H Flexible Renewables Flexibel Conventionals Power Storage BEE-Studie Möglichkeiten zum Ausgleich fluktuierender Einspeisungen aus Erneuerbaren Energien 2013 im Auftrag BEE, Lichtblick und Enercon, ausgeführt von BET Büro für Energiewirtschaft und technische Planung GmbH May 7, 2015 Hochtemperaturspeicher Seite 5
PV in the Power Market HTFS shifts PV-Power to the demand HTFS Heat Demand PV -Oversupply PV-Power Jan Feb Mrz Apr Mai Jun Jul Aug Sep Okt Nov Dez HTFS connects the power-market and heat-market Oversupply of PV-Power is transformed to heat and shifted to the time of demnad May 7, 2015 Hochtemperaturspeicher Seite 6
HTFS: Technique HTFS in the Energy-Market 90 C Heat exchanger combined with vacuum super insulation - Maghemite (iron ore) and heating rods 50 C to 750 C 30 C Advantages: High-efficient Maintaince-free Cycle resistant Avoids network supply of PV-power May 7, 2015 Hochtemperaturspeicher Seite 7
HTFS: Technique State of the Art: Night Storage Heater Core Fe 2 O 3, ρ = 3900 kg/m³ / Maghamit, Magnetit Heating Rods Durability depends on the operating temperature (750 C: 10.000 h) Operating temperature limited to 750 C Insulation 20 mm mikroporous material (Aerogel, Pyrotherm λ=0,03-0,05 W/(m*K) / 20 C 750 C) Outer Shell: ventilated air-layer May 7, 2015 Hochtemperaturspeicher Seite 8
HTFS: Technique State of the Art: VSI-Hot Water Storage Storage Media Water, oil (up to 250 C) Vacuum Insulation Perlite, opacifer, vacuum < 0,1 mbar Parameters Cooling rate 0,0026 K/(d*K) (conventional storage 0,0095 (K/d*K)) Thermal transition coefficient: 1/R=0,04 W/(m²*K) Costs 5m³ - Storage: 16.000 EUR May 7, 2015 Hochtemperaturspeicher Seite 9
HTFS: Technique Comparison of Storage Medias c [kj/kgk] ρ [kg/m³] s [J/cm³K] Costs [ /t] Costs [ /(J/K)] Brick 0,84 2000 1,7 150 179 Concrete 0,88 2300 2,0 52 59 Fire-Brick 1,00 2000 2,0 390 390 Ceramics 1,00 2500 2,5 200 / 1500* 200 / 1500* Water 4,18 1000 2,4 0 0 Iron Ore Fe 2 O 3 0,92 3900 3,5 300 163 *Bulk-Material/ Stones May 7, 2015 Hochtemperaturspeicher Seite 10
HTFS: Technique Comparison of Insulation Techniques T [ C] Λ [W/mK] Costs [ /m³] Cost [ /Storage Tank]* Pyrogel (Aspen/Stadur) 200 600 0,028 0,089 1.000 12.000 Microtherm Panele (Night Storage) 229 750 0,032 0,053 3.600 43.000 Vakuum-Super- Insulation 100 400 0,009 0,02 150 750 *Insulation Material for Heat Transfer Coeffcient of. 0,05 W/m²K, Costs only for insulation material, net price May 7, 2015 Hochtemperaturspeicher Seite 11
System-Integration Integration in a Residential Building Simulation Studie System Parameters: PV-Generator: 10 kwp 4 Persons Heat Demand (Water + Heating) 60 kwh/(m²*a) HTFS: 18t / 5m³ May 7, 2015 Hochtemperaturspeicher Seite 12
HTFS_Temp. [ C] System-Integration Integration in a Residential Building Simulation Studie 800 HTFS HTFS mit with und and ohne without Speicherverlust Heat-Loss Energy Balance: 700 Total solar gain 9.400 kwh/a Own use of solar power 1.200 kwh/a Own use of PV-heat with the HTFS: 600 500 400 300 200 100 Mit Speicherverlust Ohne Speicherverlust 8.200 kwh/a 0 01 02 03 04 05 06 07 08 09 10 11 12 Monat May 7, 2015 Hochtemperaturspeicher Seite 13
System-Comparison Reference System Reference System: PV 6 kwp ST 40 m² Residential building (research project Future:Solar) Wärmeversorgung Solar-thermal plant 40 m² Seasonal hot water Storage 10m³ Wechselrichter Gas/ Gasbrennwertkessel Gas boiler (condensing) PV-generator 6 m² High solar fraction in the heat supply Stromnetz Saisonaler WW-Speicher 10m³ Haushaltsstrom May 7, 2015 Hochtemperaturspeicher Seite 14
Energiemenge [kwh/mt.] Energiemenge [kwh/mt.] System-Comparison Solar Fraction Reference (Future Solar_Combi System) ST + LZWS + GT + PV ST: 40 m²; PV: 6 kwp; LZWS: 10m³/10t HTFS (HTFS) PV + HTFS PV: 10 kwp; HTFS: 5m³/18t Heat Wärmebedarf Demand Heat Wärmebedarf Demand 1.800 1.600 1.400 1.200 1.000 800 600 400 200 0 Solarthermie Gas-Brennwertkessel Jan Feb Mrz Apr Mai Jun Jul Aug Sep Okt Nov Dez 1.800 1.600 1.400 1.200 1.000 800 600 400 200 0 HTWS (PV) Netzstrom Jan Feb Mrz Apr Mai Jun Jul Aug Sep Okt Nov Dez May 7, 2015 Hochtemperaturspeicher Seite 15
System-Comparison Heat Production Price EFH (VAR 1_100%_Future Solar) ST + LZWS + GT + PV ST: 40 m²; PV: 6 kwp; LZWS: 10m³/10t Solar Fraction (Heat) 75% Investment Costs* 47.000 EUR Costs per Year 2.700 EUR/a Heat Production Price 0,35 EUR/kWh EFH (HTfS) PV + HTFS PV: 10 kwp; HTFS: 5m³/18t Solar Fraction (Heat) 90% (estimated) Investment Costs 42.000 EUR Costs per Year 3.000 EUR/a Heat Production Price 0,38 EUR/kWh (for 90% solar fraction) *All net prices for Heat Supply only May 7, 2015 Hochtemperaturspeicher Seite 16
Heat Costs /kwh System-Comparison Heat Production Price and Solar Fraction Heat Costs and Solar Fraction 1,60 1,40 1,20 1,00 ST + vacuum super insulated seasonal hot water storage 0,80 0,60 0,40 0,20 ST district heating + seasonal hot water storage PV + HTFS 0,00 0 10 20 30 40 50 60 70 80 90 Solar Fraction[%] Heat costs escalate with increasing solar fraction May 7, 2015 Hochtemperaturspeicher Seite 17
Research Project Milestones Applied Research Project HTFS: Tasks 1. System analysis and -development with plant simulation 2. Design and construction of an prototype of an HTFS (with CFD/FEM) 3. Realized prototype at laboratory of the IGS at TU Braunschweig and test Operation 4. Analysis and optimization, analysis of effects of a HTFS on the grid 5. Preparing for series production May 7, 2015 Hochtemperaturspeicher Seite 18
Research Project Project Partners May 7, 2015 Hochtemperaturspeicher Seite 19