A Perspective on Heating Technology

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1 A Perspective on Heating Technology Heat driven heat pumps the future of domestic heating? Bob Critoph Director, i-stute University of Warwick UKLPG Annual Conference 6th October 2014

2 Context Introduction to technologies Market potential in the short term Barriers to development Market potential in the longer term

3 Context The UK is committed to a reduction in greenhouse gas emissions of 80% by 2050 across all sectors The Carbon Plan: Delivering our low carbon future. Presented to Parliament pursuant to Sections 12 and 14 of the Climate Change Act 2008 Amended 2nd December 2011

4 Context The UK is committed to a reduction in greenhouse gas emissions of 80% by 2050 across all sectors Building a low-carbon economy The UK s contribution to tackling climate change. The First Report of the Committee on Climate Change December 2008 London: TSO. ISBN

5 Context In 2011, RCUK initiated a call to fund up to six interdisciplinary Centres in End Use Energy Demand. Each Centre would be funded for five years initially with a nominal budget of 5M. i-stute was awarded one of the centres and funding commenced from April 2013 its distinctive feature is concentration on heating and cooling.

6 Why heating and cooling? 47% of fossil fuels in the UK are burnt for low temperature heating purposes (25% of CO 2 emissions) 16% of electricity in the UK used to provide cooling - Worldwide it represents 10% of greenhouse gas emissions Energy Consumption by end use 2012 Other 14% Transport 39% Heat 47% Provisional data for 2012 (DECC)

7 Energy Consumption by end use 2012 Other 14% Transport 39% Heat 47% i-stute coverage in red Heat Use by Sector Industry 24% Service 19% Domestic 57% Provisional data for 2012 (DECC)

8 High temperature process 6% Heat use by purpose Low temperature process 9% Drying/seperatio n 3% Electricity 15% solid fuel 3% Bioenergy & Waste Heat sold 2% 2% Cooking/caterin g 5% Water heating 14% Space heating 63% Oil 7% Gas 71% Breakdown by fuel of total heat use i-stute coverage in red The largest component is in space and water heating What do we plan to do about it?

9 Projects in Space Heating Task Compact chemical heat store Compact latent heat energy storage Advanced electric heat pump Next generation gas powered heat pump Heat emitter study

10 Projects in Space Heating Task Compact chemical heat store Compact latent heat energy storage Advanced electric heat pump Next generation gas powered heat pump Heat emitter study

11 Limitations of the energy infrastructure why the future will not be renewable electricity and electric heat pumps UK heat & electricity hourly demand variability Design point for heat delivery system?? Peak electricity demand will exceed electrical grid capacity in future Design point for electricity delivery system Source: Energy Technologies Institute, 2012

12 00:00 02:00 04:00 06:00 08:00 10:00 12:00 14:00 16:00 18:00 20:00 22:00 Consumption (kwh/6min) Domestic Heat pumps cannot economically provide the high powers (25kW) required for instantaneous hot water production Grid limitations prevent even close to 100% of instantaneous demand heat pumps. GWh/d In excess of 3 times the peak capacity needed? 35-40million heat pumps? GWe Days Other Air/Ground heat Heat Pump Electric load Power Source: S. Marland, National grid, Why hybrids and gas heat pumps?, GasTech seminar 19 th March x Electricity distribution network capacity needed? Rewire +250,000km in years? in 20 Peak Network Electricity (with Fast Charge) Time of Day Source: S. Marland, National grid, Why hybrids and gas heat pumps?, GasTech seminar 19 th March _GG 2050_ER

13 What ways are there of addressing the problem?

14 1) Hybrids Hybrid electric heat pump/gas boilers have been suggested as one solution but as the housing stock thermal performance improves, DHW provision will become a larger fraction of the total load. Source: E. Sutherland, Bosch, Bosch Hybrid, GasTech seminar 19 th March 2012

15 1) Hybrids Hybrid electric heat pump/gas boilers have been suggested as one solution but as the housing stock thermal performance improves, DHW provision will become a larger fraction of the total load. 3kw Air to Water Heat Pump Gas Condensing Combi Boiler Source: Cliff Jones, Itho UK, GasTech seminar 19 th March 2012

16 2. Compact chemical/latent heat store Another approach to the problem heat storage Advanced compact heat stores can smooth out the diurnal peaks on the grid. They are part of a complex solution that involves hybrids, gas fired heat pumps and perhaps other technologies. Latent heat energy storage (short term) Chemical heat store (long term) A nearer to market interim solution to the challenge A phase change latent heat energy storage approach. Energy density is several times greater than water but subject to parasitic heat loss over time. This project will develop and test a prototype system scalable to meet 2-4 hours of maximum winter space and water heating load. Objective is to develop a POC chemical thermal energy storage and delivery system with an energy density of at least five times that of a comparable water store able to deliver all of its heat at a temperature of 65 C. Challenges are materials selection, reactor and system design, instantaneous effectiveness, long term system performance. Good for trimming peak loads over a day, important but not enough!

17 3. Gas heat pumps Another option is the gas fired heat pump three domestic, many commercial products on or near market:

18 Technologies Engines

19

20

21 Technologies Engines Sorption Absorption Adsorption

22 Absorption Adsorption Performance similar in principle Refrigerants similar: Water Ammonia Methanol

23 Absorption Adsorption How do they work???

24 Electric heat pump Heat to radiators 3 kw 1 kw (e) Electrically driven compressor High pressure gas Low pressure gas Liquid COP = 3 Heat out. Electricity in Heat from outside air 2 kw

25 Electric heat pump Heat to radiators 3 kw 1 kw (e) Motor Compressor High pressure gas Low pressure gas Liquid COP Heat out. = 3 Electricity in Heat from outside air 2 kw

26 Gas engine heat pump = 1.5 kw Heat to radiators 0.9 kw 1 kw gas Gas engine 0.3 kw work Compressor High pressure gas Low pressure gas Liquid COP Heat out. = 1.5 Heat (gas) in Heat from outside air 0.6 kw

27 Gas engine heat pump COP Heat out. = 1.5 Heat (gas) in Wins on fuel cost Wins on CO 2 emissions Maintenance, noise etc rule out domestic applications

28 Absorption heat pump 1 kw gas 4) Heat solution to drive out gas at high pressure 3) Pump ammonia solution to high pressure 2) Low pressure ammonia gas dissolves in water High pressure gas Low pressure gas COP Heat out. = 1.3 Heat (gas) in 1.3 kw Liquid Heat to radiators 5) Gas condenses to liquid at high pressure 1) Low pressure ammonia liquid boils in evaporator Heat from outside air 0.3 kw

29 Absorption heat pump 1 kw gas 4) Heat solution to drive out gas at high pressure 6) Weak solution throttled back to low pressure to absorb more gas 2) Low pressure ammonia gas dissolves in water High pressure gas Low pressure gas COP Heat out. = 1.3 Heat (gas) in 1.3 kw Liquid Heat to radiators 5) Gas condenses to liquid at high pressure 1) Low pressure ammonia liquid boils in evaporator Heat from outside air 0.3 kw

30 Absorption heat pump 1.3 kw 1 kw gas Heat to radiators WHAT IS IN THE BOX IS A HEAT DRIVEN COMPRESSOR High pressure gas Low pressure gas Liquid COP Heat out. = 1.3 Heat (gas) in Heat from outside air 0.3 kw

31 Adsorption heat pump

32 Adsorption heat pump Initial State: 170º C Ambient Temperature Low pressure High concentration 40º C Pressure 40º C 0º C

33 Adsorption heat pump Process 1 170º C Carbon bed is heated, ammonia is driven off and pressure increases until 40º C Pressure 40º C 0º C Heat Input

34 Adsorption heat pump Process 2 starts 170º C The saturation pressure is reached and ammonia condenses in the right hand vessel at ambient temperature. 40º C Pressure 40º C 0º C Heat Input

35 Adsorption heat pump Process 2 continues 170º C More ammonia is driven out from the carbon and condensed in the right hand vessel 40º C Pressure 40º C 0º C Heat to water Heat Input

36 Adsorption heat pump Process 3 170º C The carbon is cooled, the concentration increases and the pressure drops. 40º C Pressure 40º C 0º C Heat to water

37 Adsorption heat pump Process 4 170º C The carbon is cooled towards ambient and the concentration increases. Ammonia boils in the right hand vessel giving the refrigerating effect. 40º C Pressure 40º C 0º C Heat to water Heat from outside air

38 Adsorption heat pump 170º C End of Process 4: The system is returned to the starting condition 40º C Pressure 40º C The net effect is just the same as in a liquid adsorption system but this is a batch process rather than continuous as a user or as a specifier or as an installer you do not care about the difference! 0º C

39 Existing and near market products: Vaillant Technical data of zeotherm VAS 106/4 Rated heat output range Heating 1,5-10 kw Rated heat output range d.h.w. 4,2-12,5 kw Adjustable flow temperature C Recommended max. flow temperature HC < 40 C El. power consumption max. 100 W Appliance width 772 mm Appliance height incl. flue outlet mm Appliance depth 718 mm Transport weight (without casing) 160 kg Operating weight 175 kg Integrated controller zeolite module > no moving parts / no maintenance

40 Existing and near market products: Vaillant system: Water refrigerant, zeolite adsorbent heat pump,solar collector, water storage tank Only intended for use with underfloor heating systems with Maximum output temperature of 40 C Claimed reduction of annual energy use of 18% compared with a condensing boiler. Initial system sale price was around 16,000.

41 Existing and near market products: Robur Ammonia water absorption Air, water and ground source options DHW at 65 C (gross COP 1.24) 38 kw to radiators (supply temperature 50 C) COP of 1.52 (gross), 1.38 (net). Saving of about 40% in gas consumption compared to a condensing boiler. Single module 854(w) x 1256(d) x 1281(h). 18kW unit, is under development. The product is badged by BDR Thermea and Bosch 40kW unit is c. 12,000.

42 Existing and near market products:

43 Existing and near market products:

44 Existing and near market products: Sorption Energy Change in product concept over time of project: 1.5 m 0.5 m 0.4 m Where has the rest of the hardware gone?

45 Existing and near market products: Sorption Energy Fits into standard wall-mounted casing Adsorbent Beds (Generators) Box-for-box exchange for old boiler Key competitive advantage other gas-fired heat pumps too large for wall mount Retrofit market >90% of annual sales

46 Other wacky ideas etc Boost Heat Cooll ThermoLift. One of these types of heat pump will eventually win out over the gas boiler we just do not know which one yet! But this is not just about being green, we need to be commercial what are the markets, what are the barriers???

47 Units (millions) Market potential in the short term Competing with gas boilers rather than electric heat pumps World domestic boiler market Others Italy South Korea UK Year UK market largest in world at c. 1.5 M units p.a. 1.1 M are distress purchases in private houses

48 Market potential in the short term Competing with gas boilers rather than electric heat pumps What influences consumer choice? Regulation

49 Market potential in the short term Competing with gas boilers rather than electric heat pumps What influences consumer choice? Installer Familiarity with boiler (installed them before, received training from manufacturer, accredited installer) Easy and quick to install (weight/ fittings). Must be a one man fit. Good back-up support from manufacturer should there be a problem e.g. spares available Performance/ reliability (if the boiler breaks down it will be under warranty (2 years generally) from the manufacturer, but the installer will be called back). Incentives: manufacturers sometimes give vouchers to installers for each boiler installed.

50 Market potential in the short term Competing with gas boilers rather than electric heat pumps What influences consumer choice? Customer Capital cost (can be important if an unplanned / distressed purchase). [Note that RHI might mitigate additional capital cost] Performance. If anything other than simple condensing boiler is suggested then payback likely to be important. Base point is a standard condensing gas boiler ( 1800+VAT, incl installation). Pay back in three years for mass market Availability of finance to cover capital cost can help influence decision Physical size/ noise Advertising/ brand: There has been some but limited brand building Recommendation from friend

51 Barriers to development Specifier/Installer training Consumer Behaviour Capital cost Safety Noise Life/reliability How can we make heat pumps desirable???

52 Market potential in the longer term The limitations of the energy infrastructure 2010 UK heat & electricity hourly demand variability Design point for heat delivery system?? Peak electricity demand will exceed electrical grid capacity in future Design point for electricity delivery system Source: Energy Technologies Institute, 2012

53 Market potential in the longer term Figure 56, National Grid, Future Energy Scenarios 2012

54 Market potential in the longer term UK Housing Stock Time Dense urban 22% Suburban 59% Rural 19% The Future of Heating: Meeting the challenge, DECC, March 2013

55 Thank you for your attention Any questions?