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Building services installationSustainable retrofitting of buildings- Sub module 3
Districtheating
• Towards lowertemperature on primary side
New demands to secondary side
Prerequisits• Low flow temperature • Low return temperature• Potential to add local produced
heat from renewable energy sources and heat recovery
Solutions• Decentral hot water preparation• Larger radiators and convectors• Mixing loop/shunt
Connecting district heating directly to central heating system
Distribution pipes in basementRoom heating, supplyRoom heating, return
District heating connection in basement, block 13
Outdoor temperaturesensor
Energy meter
Simple solution for add-on of local energy sourceDistribution pipes in basement
District heating connection in basement, block 14 and 15
Energy meter
Heat pump
Buffer tank
Outdoor temperature sensor
Hot water is produced in the individual apartments. (Micro heat exchanger)
Connection to roomheaters
Flatstation
Floor heating
Room temperature thermostat
Return flow temperature thermostat
Possible shuntPossible shunt
Energy and waterflow are connected to BMS
Regulation valves are dynamic
Principal diagram for connection of room heating and waterheating in each apartment for Trigeparken block 13-15
Optimized flatstation (Instantaneous water heater) from Danfoss
• Advantages• designed for low temperature DH• insulated to lowest heat loss in market• superefficient heat exchanger HEX• cold HEX under idle load esave
TM
• integrated differential pressure control• no circulation of hot water max 4 l vol.in pipes• stainless steel• no limestone fouling• no legionella• 32,3 kW DHW
Low temperature district heating system – pros and cons
Advantages• Heat loss is reduced leading to
significant economical savings for district heating company and perhaps district heating customer
• If the heat is produced on a combined heat and power plant (CHP), the electrical efficiency will be improved
Disadvantages• Old district heating pipes might need
to be changed• Heaters in houses might not have
sufficient capacity when using lower temperatures in the central heating system.
Ventilation and heat recovery – Växjö, Sweden
• New balanced ventilation• Heat recovery
Supplyair
Exhaustair
Ventilation unit
Appartement
Attic
Ventilation and heat recovery
Ventilation and heat recovery – Växjö, sweden
Calculated savings ≈ 40 – 4 = 36 kWh/m2 (≈90%)
Before renovation:
Ventilation princip for Trigeparken.
Fresh air is distributedto each room throughducts
Exhaust air is led to the roof through verticalducts in technical shafts
Fresh air intake from facade
Ventilation unit with heat recovery and fans
All ducts are insulated with 50 mm to avoid risk of condensation and heat loss
Air is extracted from bathroom and kitchen
Most important specifications for ventilation system in Trigeparken• Max. pressure loss for ducts: 0.8 Pa/m• Max. electricity consumption (SFP) for complete ventilation system: 0.8 kJ/m³
• Heat recovery of min 86% (Temperature efficiency)• To save electricity, the heat recovery unit will be bypassed when outdoor
temperature is above 17 ˚C• Air flow is demand controlled through humidity sensors.
• Alarms are triggered, when filters are congested. • Demand controlled ventilation can save up to 30% on electricity consumption for
fans. In the Swedish dwelling project Isbanan in Helsingborg, electricity savings have been measured to 0.6 kWh/m²/year and heat savings to 0.13 kWh/m²/year
Central vs. decentral ventilation
• Lower electricity consumption with decentral ventilation• Decentral ventilation requires more ventilation units, which normally will require more
maintenance• With decentral ventilation, the users can have the possibility of controlling their own ventilation
unit• Troubleshooting can be more time demanding with decentral ventilation, as there are more
ventilation units, which might require access to the apartments• Yearly access to apartments can also be an advantage.
Waste water heat recovery – Växjö,Sweden
Heat exchanger – polymericmaterial
Waste water heat recovery - heat exchanger
Non-corrosive
Standard –couplings
Low weight
Evertech-heat exchangerPatented design withpolymeric material
Waste water heat recovery – ”special house”, Växjö, Sweden
Waste water to sewer ; + 6°C
Waste water from appartments ; + 21°C;
3300 m3/year
Waste water heat recovery system
Alabastern area, Växjö39 appartments
17 MWh electric energy
76 MWh thermal energy
Calculated savings ≈ 45 – 31 = 14 kWh/m2 (≈ 30%)
Waste water heat recovery – System in Trigeparken, Aarhus
Heat exchanger
Terrain
Sewage water
Existing drain pipe
Pump (must be able cope with diapers, tissues, toilet paperetc)
Clamp for placement of sensors
Layer of coated Leca for insulation against the cold soil
Closed circuit with an water/glycol mixture connected to heat pump placed in installations room. Temperaturset around 5/10 oC
Heat pump
Hot watertank
Heat pump cools the closed circuit and transfer the extracted heat to the hot water tank
2.5 m
Waste water heat recovery – System in Trigeparken, Aarhus
New collecting well for collecting sewage water is placed on existing drainpipe
Existing drain pipes
Waste water heat recovery – simulation results• The waste water heat recovery system is expected to cover about
75% of the heat needed for hot tap water consumption• COP is expected to be 4,3• Heat pumps are in the range of 7 - 10 kW pr. unit• Each heat pump recover from 27 – 36 appartments pr. unit
Waste water heat recovery – Existing system in Aarhus
Drain pipeleading sewagewater to well
Pipe med pump (submerged in the sewagewater) pumpingsewage wateraway from well
Heat exchanger
Waste water heat recovery – Existing system in Aarhus
Domestic hot water – Alabastern, Växjö, Sweden
Individual monitoring!
Domestic hot waterVäxjö, Sweden
Before NYD20:
After:
The integrated total system – Växjö, Sweden
• The integrated total system• The control system
• Monitoring• etc.
Lithium Balance Battery Systems approach
BMS
BESS Rack
BESS controller
Energy Asset
Control
Grid Support
Cloud EMS
Cloud BMS
Forecasts
1. Functionally safe BMS thatallows advanced diagnostics
2. Certified and costcompetitive BESS rack
3. Time charge/discharge and reduce inverter power loss to reduce energy costs
5. Enable DSO remote control
6. Use price, weather and load forecasts to time charge/discharge and reduce energy costs
7. Remote and advancedbattery diagnostics to optimise battery life and reduce service costs
Market trends for batteries
Reference :BATTERY STORAGE FOR RENEWABLES: MARKET STATUS AND TECHNOLOGY OUTLOOK 2015, http://www.irena.org/documentdownloads/publications/irena_battery_storage_report_2015.pdf
Reference : ees Europe: Falling prices boost energy storage, PV Europe, 15/5/2017, http://www.pveurope.eu/News/Energy-Storage/ees-Europe-Falling-prices-boost-energy-storage
• Big potential market for large battery energy storage systems
• Capacity increase by a factor 14 expected worldwide the next 7 years
• Residential: 35% price decrease in 3 years, 20% price decrease the next 2 years
Battery systems for PV – Denmark vs. Sweden
• Increased self-consumption gives better economy for PV system owners
• Relevant for private owners, housing associations and businesses
• With a PV Battery System the self-consumption increases from approximately ~30% to 80%
Battery systems for PV - Maximized self consumption
Sunny day • Morning: battery is rapidly
charged in the morning and hereafter PV power is exported
• Evening: stored power is gradually released so import/export is balanced at almost zero
Lower electricity prices
• Example on avg. electricity price for a Danish housing association:
• Calculation model by COWI developed in Elforsk-project ”Boligejendomme med CO2 neutralt elforbrug”
kr/kWhGrid only: 2,25Grid + PV: 1,75Grid + PV + Battery: 1,62
Battery Systems implementation for READY
• 43kWh battery rack• Space for 5 racks
• 50kW ABB inverter• Space for an
additional inverter
• Low power free cooling system
• Alarm system
Advanced testing and control
• The Controller:• Controls up to 32 BESS Racks• Manages charge/discharge • Controls other energy assets such as
heat pumps and EV chargers to reduce energy cost at the site
• Facilitates remote DSO control• Partnership with ABB • The inverter is the main source of energy
loss• 60% of the time the battery inverter is in
standby mode• 30% of the power loss is due to standby• Developed new inverter SW that allows
LiBAL BESS Controller to manage the inverter for more intelligent standby aggregation
PVT module from Racell
PV = PhotoVoltaic (Solar cells) for electricity production
T = Thermal for heat production
Cross section of PVT modules
How much of the solar energy (1000 W/m²) can be converted to usable power?
Existing commercial products and systems only (rough numbers):
PV cell Heat Collector
electricity heat energy
15 - 20% 50-80%
170 W/m² 650 W/m2
Example of installation
PVT modules – placement in Trigeparken
286 m2 PVT modules on the roof of block 12
217 m2 PVT modules on the roof of block 11
217 m² PVT modules on the roofof block 11
oooo
oo
56 m2 PV modules on the roof of gable of block 12
PVT module system for Ringgaarden
PVT simulations on system performancePVT modules for heat pump. Performance as a function of the PVT area. Valid for one block.
PVT area 220 110 m²
Solar thermal energy to the system 34.842 33.767 kWh/yearElectricity production 29.863 16.208 kWh/year
Thermal production per m² PVT 158 307 kWh/m²/yearElectricity production per m² PVT 136 147 kWh/m²/year
BalanceDemand for hot tap water 47.700 47.700 kWh/yearCirculation loss 6.000 6.000 kWh/yearHeat from heat pump 36.100 36.600 kWh/yearDistrict heating 11.000 12.500 kWh/yearCOP 4,1 4,0
Performance at full load from PV part
PVT modules – simulation results
• The heatpump and PVT module can cover 75% of the heat needed for domestichot water demand
• The PVT module can – in combination with the battery – cover 100% of the electricity demand for the heat pump. The rest of the electricity produced will beused by the common facilities (lights, clothes washing etc.)
SummaryBuilding services installation - heat• Both central and decentral heat distribution is used in Ringgaarden• Waste water heat recovery/PVT modules with heat pump can cover
about 75% of the heat needed for domestic hot water• Low temperature heating can be implemented without changing the
radiators and convectors• District heating temperature can be lowered from 80 to 60 °C
SummaryBuilding services installation - electricity• In Denmark, as much electricity as possible produced by PV should be
used for self consumption• Without batteries, 70% of the electricity produced will be sold to the
grid• With the batteries, 20% of the electricity produced will be sold to the
grid• Demand controlled ventilation can save up to 30% on electricity
consumption
ContactsMorten [email protected]
Ph. 5640 7187 / 4176 7187
Reto Hummelshø[email protected]
Ph. 5640 2766 / 2964 7160
Stefan [email protected]+46 709 890181
