Institut für ZukunftsEnergieSysteme an der Hochschule für Technik und Wirtschaft HTW
Feasibility Study for a Mobile Latent Heat Storage in Belgium
Horst Altgeld Ralf Cavelius Institut für ZukunftsEnergiesysteme (IZES) www.izes.de 1
Technical / Economic dependencies Heat Storages may have to fulfill either of the following demands: - overcome time dependent mismatches of heat availability and heat demand example: varying solar INPUT requires buffer storage - overcome misfits between local heat generation and demand through transport systems example: CHP systems at remote locations (e.g. farms) may require gas/hot water pipelines or transportable storages 2
Photos of the Biogas Installations on a Farm
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Application Considered: Biogas Production / CHPP on a Farm Assumptions: Farm generates surplus heat in the CHPP units analyses of in situ heat utilisation have shown no good options heat transportation in storage tanks is considered as an extra option storage tank availability and up to date costs are assumed as given Goal: Assessment of economic viability of transporting heat in a container to external users 4
Key Figures of the Farm: Biomass Inputs: Cows, bulls (total): ~ 480 Æ 5 -10 t/d
Corn: ~50-60 ha Cofermentation feed:
Æ 5 -10 t/d Æ2 -10 m³/d
Biogas- Plant: 2 Cogeneration units – each: 80 kW el, 105 kW th
2 Digesters:
- Volume: ~770m³ each
Internal Heat sinks (supply by local heat grid):
digester: 30 kW summer, >60 kW winter Heating/Warmwater:2 houses – in winter 2 x ~35kW Æ5 % of avail.energy Dairy production ~95 kW max - short peaks Æ6,5 % of avail.energy Heat grid thermal losses: 3.5 kW max Æ < 1% of avail.energy
5
Yearly Energy- Balance (actual situation)
865000
Surplus Heat
~59%
Total Heat Production: ~1.460.000 kWh/a (~ 1.100.000 kWhel/a)
Sankey 400000
Digesters Heat ~28%
75000
Houses ~5% Dairy,... ~7%
120000
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Simulation results Production, consumption, surplus heat HEAT PRODUCTION
HEAT CONSUMPTION (internal) Average heat and energy consumption (monthly repartition)
Average heat and energy production (monthly repartition)
Heat energy consumption Heat power consumption
Heat energy production [kWh] Heat power [kW]
200,0
140.000,0
200,0
140.000,0
175,0
120.000,0
175,0
120.000,0
60.000,0
Heat energy [kWh]
80.000,0 100,0 75,0 40.000,0 50,0 20.000,0
25,0 0,0 february
march
april
mai
june
july
august
september
october
100.000,0
125,0 80.000,0 100,0 60.000,0 75,0 40.000,0
50,0
20.000,0
25,0
0,0 january
0,0
november december
0,0 january
february
march
april
Month
mai
june
july
august
september october
november december
Month
146 m³ Diesel Oil/yr
SURPLUS HEAT Average surplus heat power and surplus energy (monthly repartition) 7000h/a: summer and winter 19h/d surplus heat energy [kWh] surplus heat power [kW]
200,0
140.000,0
175,0
120.000,0
150,0
126 m³ Diesel Oil/yr
100.000,0
125,0 80.000,0 100,0 60.000,0
Heat energy consumption [kWh]
Heat power [kW]
Heat power [kW]
100.000,0 125,0
150,0
75,0 40.000,0 50,0 20.000,0
25,0 0,0
0,0 january
february
march
april
mai
june
july Month
august
september
october
november december
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Heat energy consumption [kWh]
Heat power consumption [kW]
150,0
Simulation results Surplus heat (actual situation) Average heat production and surplus heat Average surplus power: yearly average: 101 kW Internal Heat Sinks (digesters, houses, dairy)
winter: 83 kW
summer: 119 kW
Average heat power cogeneration units (Ptot)
Average surplus heat = heat power - digester heat - heat houses and warmater - heat dairy (Ptot - Pdig - Phouses -
200 Heat production
Surplus Heat heat produced
180
160 Surplus Heat
Average Heat Power [kW]
140
surplus heat
120
100
local heat sinks
80
Internal Heat sinks Digester, Houses, Dairy
60
40
20
0 0
1000
2000
3000
4000
5000
6000
7000
8000
hours
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Search for External Heat-Sinks H eat valorisation applications for decentralised biogas p lants Intern al V alorisation D ry ing G rass / H ay
G rains, seed s, cereals
B iofertilizer pro duction
H eating Farm – buildings (housing, stables… )
G reen houses
C ooling Cooling of farm ing products (m ilk, cheese, m eat, ...)
E xternal V alorisation Pro cesses, others
D ryin g
D istillery/ brew ery
W ood drying - technical - w ood chips - pellets - others
G rains, seeds, cereals B iofertilizer production
H eating B uildings - heat netw ork - tourist/vac ation building -
Sw im m ing pool,…
C o oling cooling of foodw arehouses (m ilk, cheese, m eat, frozen foods ...)
Storage heat storage w ith phase change m aterials
G reen hou ses
M edicinal plants S ew age sludge
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Feasibilty studies for different heat valorisation applications Internal heat sinks Internal (local) heat network Production of cold External heat sinks Wood drying Hygienisation External heat network Heat transport (Container) to customers like homes for elderly people, swimming pools, ....
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Feasibility study: External heat network (district heating system) Æ Distance village-Biogas plant too large (~ 2.500m )
Heat network Biogas plant - Attert Total deliverables heat per year Distance biogas plant - town
Æ Heat network becomes only interesting for a heat delivery of >1.400 MWh/a - not realistic! (compensation of annual costs by heat sales only)
Total Invest-Costs Annual Costs
Æ Better economic situation for heat sales of 800 MWh/a only possible when utilising „green certificates“ no positive effect for the overall economic balance of the biogas plant
800 MWh/a 2500 m 1.000.000,00 € 75.000,00 €/a
Annual Revenues consumption spec. Revenues Certificats verts 590 90,000 €/CV Heat sales 800 MWh/a 40 €/MWh Total Annual Revenues
53.100,00 €/a 32.000,00 €/a 85.100,00 €/a
INCOME
10.100,00 €/a
10.000
Yearly balances (€ / a)
0 0
200
400
600
800
1000
1200
1400
Heat sales 1600 (MWh/a)
-10.000
-20.000
-30.000
-40.000
Heat sales: 30 €/MWh 40 €/MWh 50 €/MWh 60 €/MWh
-50.000
-60.000
-70.000
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Feasibility study: Heat transport Heat sinks: Households Village, home for elderly (container discharging)
Transport
Heat source: Biogas plant (container loading)
farm
12 Container with phase - change material
Transportable Latent Heat Storage / Container
Phase Change Material: e.g, Sodium Acetate Melting Point: 58 °C Storage capacity: 2,5 MWh Recommended Charging Power: 250 kW Recommended Discharging Power: 125 kW Charging Time : ~ 10 hrs Discharging Time: ~ 20 hrs Heat Source Temp.: min. 75 °C Weight of Container: ~ 26 t Manufacturer of Container: Alfred Schneider
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Heat transport / Container– Economical analysis Æ Heat transportation only interesting for high heat-demand (> 500MWh/a) and short distances to possible heat sinks Æ Heat transport generates no relevant positive balance, but creates additional value added work for the farmer (transportation costs: ~25.000€/a) ÆDiesel consumption for transports counteracts the number of assigned „green certificates“
Heat Transfer (prices incl. TVA) Total transfered heat per year Drivercosts to discharching point Total Invest-Costs Annual Costs Annual Revenues consumption spec. Revenues Certificats verts 423 90,000 €/CV Heat sales 600 MWh/a 0,020 €/kWh Total Annual Revenues INCOME
Revenues / year [€/a]
Yearly revenues depending on: heat transport costs, distance to discharching point, heat transfer quantity, certificats verts (heat sales price fixed - 20 €/MWh)
20.000 € 15.000 € 10.000 € 5.000 € 0€ -5.000 €100 -10.000 € -15.000 € -20.000 € -25.000 € -30.000 € -35.000 € -40.000 € -45.000 € -50.000 € -55.000 €
600 MWh/a 5 km 146.000,00 € 46.930,79 €/a
38.080,00 €/a 12.000,00 €/a 50.080,00 €/a 3.149,21 €/a
Invest costs: 146.000€ Revenues: Heat sales: 20 €/MWh Certificats verts: 90 €/CV
40 km
200
300
400
500
600
700
800
900
30 km 20 km 10 km 5 km
14 Heat transport [MWh/a]
Economic Sensitivity Analysis- Base Case Invest
Revenues / year [€/a]
Yearly revenues depending on: heat transport costs, distance to discharching point, heat transfer quantity, certificats verts (heat sales price fixed - 20 €/MWh)
20.000 € 15.000 € 10.000 € 5.000 € 0€ -5.000 €100 -10.000 € -15.000 € -20.000 € -25.000 € -30.000 € -35.000 € -40.000 € -45.000 € -50.000 € -55.000 €
Invest costs: 146.000€ Revenues: Heat sales: 20 €/MWh Certificats verts: 90 €/CV
40 km
200
300
400
500
600
700
800
900
30 km 20 km 10 km 5 km
Heat transport [MWh/a]
15
Economic Sensitivity Analysis - Invest ~75%
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Revenues in Germany worse than in Belgium
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Simulation results (actual situation) Simulation results (base-case-scenario) Gas yield 589.000 m3/a 1.630 m3/d 1.630 m3/d
Total gas production Winter Summer Diesel consumption Total consumption
23.570 l/a Electrical Energy
Total electricity production
~ 322 households
1.147.000 kWh/a Heat Energy
Total heat production 1.484.000 kWh/a Heat – digester needs 407.000 kWh/a Heat – network needs (houses, local needs 193.000 kWh/a warmwater, dairy) Surplus Heat Surplus Heat 884.000 kWh/a Running Time of cogeneration units Total running time (for 2 units)
~ 14.338 h/a
~ 40 households
Runtime per CHP-unit: 18 ~7.000h/a