ANDERS DYRELUND, RAMBOLL INTEGRATION OF WIND AND SOLAR IN THE SMART ENERGY SYSTEM
HERE IS SOMETHING MAGIC, THE HIDDEN BACKBONE OF THE LIVEABLE IT USES A CITY LOT OF ELECTRICITY, IF THE WIND IS BLOWING AND THE ELECTRICITY PRICE IS LOW IT DOES NOT USE ELECTRICITY OR IT EVEN PRODUCES ELECTRICITY, IF THE WIND IS NOT BLOWING AND THE PRICE IS HIGH WHAT CAN IT BE?
IT IS AN INTEGRATED SMART ENERGY SYSTEM WITH THERMAL STORAGES LIKE A VIRTUAL BATTERY
MAIN COMPONENT OF THE SMART ENERGY SYSTEM TO INTEGRATE WIND AND SOLAR Interconnected grids with storages International power grid, Nordpool market, with some hydro storage National natural gas grid with gas storage City-wide district heating grids with thermal storages Local district cooling grids with thermal storages Buildings with Low-temperature heating and High-temperature cooling Conversion technologies (interconnecting the grids) CHP plants Heat pumps for co-generation of heating and cooling Electric boilers Absorption heat pumps P2GAS
THE THERMAL VIRTUAL ELECTRICITY STORAGE (BATTERY) Source: Paul-Frederik Bach The baseline Small heat pumps without storage og gas boiler back-up Can-not adjust consumption to the fluctuations of the wind The virtual electricity storage DH&C grids Large heat pumps, which can be interrupted Electric boilers, operates only at low price CHP plants, operates only at high price Hot and cold water storage, daily and seasonal
Investment EUR1000/MWh storage COST OF HEAT STORAGE TANKS AND PITS 10 9 8 7 6 Heat storage tank 160 C Heat storage tank 95 C Heat storage pit 85 C 5 4 3 2 1 0 0 2,000 4,000 6,000 8,000 10,000 12,000 Capacity in MWh storage
THE SIMPLE HEAT STORAGE TANKS PRESSURELESS AND DIRECT CONNECTION All CHP plants have heat storage tanks in Denmark Optimize operation of the CHP plant > 8 max load hours Can integrate surplus heat from waste, solar, wind etc. Optimize the operation of the DH system Maintain the pressure Provide peak capacity the coldest day Fynsværket power plant, Odense 70,000 m 3 Direct connection Maximum temp 95 o C. 90/40 Storage capacity, 3,6 GWh, e.g. 300 MW in 12 hours
ADVANCED HIGH TEMPERATURE HEAT STORAGE TANKS PRESSURIZED AND PRESSURE SECTIONED Temperature above 100 o C can be necessary due to consumer needs (poor heating installations), But - the larger temperature - the larger investment. Pressure sectioning can be necessary due to the pressure level in the DH grid and due to necessary pressure variations at the location Pressure sectioning increase costs, but is cheaper and more efficient than a heat exchanger connection Avedøre CHP plant, Copenhagen 2 x 24,000 m 3 Maximal temp 120 o C actual temp. 105/50 Pressure diff: 10 Bar Storage capacity 2,400 MWh, e.g. 300 MW in 8 hours
HEAT STORAGE PITS PRESSURELESS AND SECTIONED BY HEAT EXCHANGER Heat storage pit, an innovative combination of: Landfills for establishing liners to a water proof pit Heat storage tank for diffusers Off shore technology for diffusers and pipes A floating cover (newly developed) Impossible to avoid oxygen in the water, therefore sectioned by heat exchanger Maximal temp 85 o C Storing weekly or monthly fluctuations The driver for this development in Denmark has been to increase share of solar heat up to 60%
HEAT STORAGE PITS PRESSURELESS AND SECTIONED BY HEAT EXCHANGER Test plants with subsidy 10,000 m 3 Test plant in 2010 in Marstal 70,000 m 3 Full-scale test plant 2012 in Marstal 62,000 m 3 Full-scale test plant 2014 in Dronninglund Commercially, without subsidy, new floating cover 125,000 m 3 Gram district heating 2015 200,000 m 3 in Vojens district heating 2015 70,000 m 3 in Toftlund district heating 2017 150,000 m 3 in Løgumkloster district heating 2017/18 Several more in the pipeline, may be 100 in 2025
ECONOMY OF SCALE FOR HOT WATER STORAGES EUR/MWH HEAT STORAGE CAPACITY One family house, 0.16 m 3 300,000 Large building, 4 m 3 40,000 DH tank, 160 C 7,000 DH tank, < 95 C 4,000 Storage pit, 150,000 m 3 800 Pit alone, 100,000-200,000 m 3 500 Marginal extension of the pit 200 Sources: Henrik Lund and Ramboll
CHILLED WATER STORAGES, REDUCING THE DAILY COOLING PEAKS Steel tank, district heating technology Concrete chamber, water supply technology, e.g. under new road in Carlsberg city Cold water storage, heat storage pit technology Ground source cooling (ATES)
A CASE INSPIRED BY GRAM DISTRICT HEATING Electricity prices 1-21 January 2016: DK east Strong wind in 10 days followed by 10 days without any wind Baseline 1,000 individual heat pumps, COP=3 in total 13 MW heat Average uncontrolled production in January 5 MW heat District heating, one automatic control centre District heating annual heat production: 30,000 MWh heat Average heat production 1-21 January: 5 MW heat Peak capacity 10 MW heat Heat pump capacity, COP=3 3 MW heat Electric boiler capacity 5 MW heat Gas CHP 4.5 MW elec / 5 MW heat Volume of large heat storage pit, 125,000 m3 Objective: minimize heat production cost e.g. with Mentor Planner or EnergyPro
Heat production cost, Euro/MWh THE VARIABLE COST OF HEAT PRODUCTION DEPENDS ON ELECTRICITY PRICES, (EXCLUDING TAXES) 120 100 80 60 40 20 Heat pump Elec. Boiler Gas CHP Gas boiler 0-20 0 20 40 60 80 100 Electricity price, Euro/MWh
1 14 27 40 53 66 79 92 105 118 131 144 157 170 183 196 209 222 235 248 261 274 287 300 313 326 339 352 365 378 391 404 417 430 443 456 469 482 495 THE ELECTRICITY CONSUMPTION FOR DH RESPONDS TO THE ELECTRICITY PRICES 250 200 150 100 Electricity price Euro/MWh 50 0 Electricity consumption 100kWh/h -50-100
1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181 193 205 217 229 241 253 265 277 289 301 313 325 337 349 361 373 385 397 409 421 433 445 457 469 481 493 DH MINUS 1,7 MW ELEC SMALL HEAT PUMPS IT S LIKE A VIRTUAL BATTERY 250 200 150 Electricity price Euro/MWh 100 50 0 Electricity consumption compared to individual heat pump 100kWh/h -50-100
1 22 43 64 85 106 127 148 169 190 211 232 253 274 295 316 337 358 379 400 421 442 463 484 THE HEAT STORAGE BEHIND THE VIRTUAL BATTERY FOR THIS PERIOD 350 MWH STORAGE IS NEEDED 40 35 30 25 20 15 10 Heat production MWh Stored heat 10 MWh 5 0
LARGE-SCALE SOLAR HEATING WITH SEASONAL STORAGE PIT The solar heat occupies the storage from mid April to end of September Free storage capacity from 0 to 8,000 MWh the rest of the year Only 350 MWh was needed in this case The storage capacity could be designed to include storage of surplus wind in the summer period
FOR MORE INFORMATION, SEE CASE 2 IN REPORT FROM EU JRC Main conclusion: Consumers empowerment basis for efficient development to the benefit of the consumers Gas CHP engine operates in the Nordpool market Gram DH has gradually replaced gas boilers with largescale solar heat, electric boiler, surplus heat and heat pump Large-scale solar heating has been the driver for developing seasonnal heat storage pit The large heat storage opens for integration of wind
DH&C IS A COST EFFECTIVE ALTERNATIVE TO INDIVIDUAL HEAT PUMPS AND CHILLERS RESPOND AS A BATTERY
NEW URBAN DEVELOPMENT AN OPPORTUNITY FOR STARTING THE DEVELOPMENT OF DH&C New city district Heating Cooling Buildings no 1600 80 Floor area m2 660000 470000 Building level capacity MW 14 13 Annual consumption MWh 27000 15000 Optimized DH&C to the district DH DC Length og network and branch lines km 35 10 DH storage tank, rough estimate m3 7000 DC storage tank m3 3500 Capacity demand to network MW 12,0 11,0 Capacity leveling of storage MW 3,0 Ground source cooling MW 3,0 Gas boiler for peak MW 5,0 Total installed heat pump for DH&C MW 7,0 5,0 Total installed capacity MW 12,0 11,0 Necessary electric capacity MW 2 Total COP for cogen of DH&C MW/MW (7+5)/2 = 6
INVESTMENTS IN BASELINE AND DH&C ARE ALMOST THE SAME IN OTHER WORDS - THE VIRTUAL BATTERY IS FREE Investment in base line Heating Cooling Total Individual heat pumps / schillers mio.euro 20 19 39 Investment in DH&C system DH DC DH&C DH&C networks mio.euro 20,0 7,9 27,9 DH&C storages mio.euro 1,6 0,8 2,4 DH&C boiler / ground source cooling mio.euro 0,7 1,1 1,7 DH&C heat pump for DH&C mio.euro 5,5 5,5 Total DH&C mio.euro 37
THANK YOU FOR YOUR ATTENTION ANDERS DYRELUND AD@RAMBOLL.COM RAMBOLL