Economic Systems Analysis of small scale CHP

Transcription

1 Economic Systems Analysis of small scale CHP Prof. Dr. Georg Erdmann Chair Energy Systems Berlin University of Technology Forum International d'urbistique 2006 "Développement urbain durable, gestion des ressources et services urbains«lausanne, Septembre 2006

2 Profile of the chair Energy systems Founded in 1995 at the Berlin University of Technology. Interdisciplinary research and consulting on innovations (technologies, regulation) and markets energy market liberalization (prices, regulation, demand) energy storage and control energy risk analysis (portfolio management, real options,..) Spin off: recent projects and mandates on hydrogen and fuel cells EU project Hyfleet:Cute Passenger vehicle industry (mobile fuel cell and fuel market; hydrogen infrastructure) power distribution companies (small stationary cogeneration appliances, business case for CHP under deregulation)

3 Questions addressed in our research How a mass market of CHP systems < 20 kw may look like, if costs would allow market entry? What is the market potential for such technologies (as a function of relevant parameters such as power demand, size of the heat sink, and energy tariffs)? What would be the quantitative impacts of a CHP mass market on the incumbent regional and urban fuel and the power suppliers? Does small scale CHP offer business opportunities for regional and urban power and gas companies?

4 Total fuel efficiency of gas fired CHP 58% 51% CO 2 - free electricity power (CCGT) 38% heat (condensing boiler) 100%

5 Load duration curve of a heat sink hourly heat demand [kw] h/a

6 Specific investments of gas fired CHP [Schmitz, Koch (1996) Kraft-Wärme-Kopplung. Düsseldorf: VDI-Verlag] investments [EUR/kW] electric capacity (kw)

7 Dilemma of small scale CHP 8000 full load hours [h/a] break even 5000 Small scale CHP electric capacity [kw]

8 Potential niche for stationary fuel cells 4'000 investments [EUR/kW] 3'000 gas motor block heating station 2'000 fuel cell 1' Electric load (kw)

9 Heat sinks in residential buildings,027frequency,021,014 Weibull Distribution! $ 1!! % T $ " & % % T $ " & & f ( T ) = )' ( ) exp $ ' ( # * # + ' * # + ( * + β = 1,39 (shape) η = 50'134 (scale) γ = 3'304 (location),007,000 heat demand [kwh/a] heat capacity [kw] 37'500 75' ' '

10 Methodology We model the operation of CHP systems on the basis of 15 minute power load profiles of individual buildings. From the results we derive synthetic functions describing the structure of CHP power output (and natural gas input) as a function of a number of specific properties of individual buildings. Based on a statistical distribution of residential buildings we calculate the relevant market shares by using the Monte Carlo simulation of a model with the synthetic functions. The impact of decentralized CHP on the revenues of local gas and electricity companies is calculated and analyzed. Our methodology can be adapted to different populations of buildings, CHP support schemes, energy prices etc.

11 Marginal power and heat costs c power = p gas " MinÖSt ( / ) H H #! u o el gas c heat = p gas " MinÖSt ( / ) H H #! gas u o total p gas MinÖSt gas H u H o η el η total natural gas price (energy rate) natural gas tax credit (mineral fuel tax credit) lower heating value of natural gas upper heating value of natural gas electric efficiency of the fuel cell system total fuel efficiency of the fuel cell system (0,75 η total 0,95)

12 100% Fuel efficiencies of small scale CHP systems fuel efficiency [source: Bokämper 2002] SOFC total 80% PEMFC total 60% 40% PEMFC electr 20% SOFC electr 0% 0% 20% 40% 60% 80% 100% Fuel cell load (% of maximum rated power)

13 Determining the CHP operation If the marginal heat costs c heat > ( p + p )! c einsp zusatz power SKZ p einsp p zusatz electricity fed-in tariff additional subsidy for fed-in electricity (0,0511 ct/kwh bonus) SKZ power to heat factor (we assume SKZ = 0.7) then the heat oriented operation of the CHP system is selected. Otherwise the power oriented operation of the CHP-system is applied (as far as the produced heat can be used or stored).

14 Power oriented CHP operation [simulation of a 4 kw el -CHP-system] electric load [kw] :00 2:00 4:00 6:00 8:00 10:00 12:00 14:00 16:00 18:00 20:00 hour of the day

15 Retail energy prices [Source: BMWI 2006] 50 natrual gas [Ct/m 3 ] heating oil [EUR/100 l] electricity [Ct/kWh]

16 Fed-in electricity price [Source: EEX 2006] EUR/MWh

17 Sample output of a single simulation annual energy costs [EUR/a] 2'000 1'600 1' maintenance burner capital costs burner net annual fuel costs net annual electricity costs 0 Conventional system FC system

18 Costs of the FC system as compared to the natural gas system [Output of a MC simulation] relative frequency 0, % 1,0 1,2 0,8 annual costs FC system / natural gas system 1,4

19 Conclusions and Outlook Residential building sector is a potential mass market for small scale decentralized CHP systems. Crucial variables for the CHP competitiveness are power to heat demand power to fuel energy prices. Electricity taxes (!) and power grid unreliability represent incentives to small scale decentralized CHP systems. Once small scale CHP systems become competitive (compared to conventional heating systems), revenues of regional energy companies may come under pressure. An appropriate response could be reserve power tariffs for customers with CHP virtual power plant contracting

20 Thank you for your attention Tel: +49 (030) Fax: +49 (030)