Modelling of PV Prosumers using a stationary battery, heat pump, thermal energy storage and electric vehicle for optimizing self-consumption ratio and total cost of energy Dominik Keiner1 and Christian Breyer2 1 Ostbayerische Technische Hochschule Regensburg 2 Lappeenranta University of Technology E-mail:
[email protected]
Motivation & Purpose of Work There is lot of interest in solar photovoltaic (PV) Producer and Consumers (Prosumers) all over the world, as the cost for PV systems are steadily decreasing and by the end of 2020 most residential electricity market segments will have reached grid-parity for solar PV [1] [2]. By optimising the self-consumption ratio (SCR), this advantage can be exploited more. Utilising energy storage technologies, there is a great opportunity for using PV electricity even at times when no energy is produced. The evolution of the global electric car stock reached up to nearly 2 million vehicles within six years from 2010 to 2016 [3]. SCR optimising can also be reached by using battery electric vehicles (BEVs) and charging them with own produced PV electricity. The purpose of this work is finding the least cost PV system designs, the annual total cost of energy and the related SCR, as well as an investigation of demand cover ratios (DCR) and heat cover ratios (HCR).
Main Objectives • To design a least cost energy system. • Optimising the SCR by using as much energy from the own rooftop as possible. • To have an optimal mix of capacities for PV and the stationary battery. • Optimising the SCR by integrating a vehicle-to-home (V2H) BEV. • Investigation of the impact of using different types of BEVs. Input data used • historical weather data for: solar irradiation • synthetic load data for electricity consumption, space heating demand and hot water demand for every region • capex, opex, lifetime for all system components Four scenarios • Two cars: using one normal and one V2H BEV • Only car 1: using one normal BEV • Only car 2: using one V2H BEV • No cars: no BEV usage
Heating System and TES Concept
Methods and Assumptions
PV Prosumer Model
Fig. 1: Structure of the PV prosumer model with all system components as it complies with the full ‘two cars’ scenario.
Based on LUT‘s Energy System Transition model [4] • 8760 hours are analysed • global simulation, represented by 145 regions
Results (Total Cost of Energy)
System components • scanning PV capacity from 1 – 30 kWp in steps of 1 kWp • scanning battery capacity from 1 – 50 kWhcap in steps of 1 kWhcap • 7 kWel heat pump power combined with 800 liter TES; COP = 3.8 for nominal operation and COP = 3 for additional filling • 7 kWel/th heating cartridge power with 200 liter TES; operation with η = 1 Fig. 2: Regions with heat pump and heating cartridge systems.
Feed-in reimbursement
Fig. 2: Annual cost saving potential in 2030 for all regions and scenarios compared to 100% grid supply.
• Only paid for fed-in electricity < 50% of annual generated electricity • 0.02 €/kWh for all regions
Average households • People per household (pph) related to GDP per capita • Linear increase of GDP per capita until 2050 • Population weighted pph for regions with more than one country Fig. 2: Annual cost saving potential in 2050 for all regions and scenarios compared to 100% grid supply.
Fig. 2: TES filling concepts for heat pump systems (800 liter) and heating cartridge systems (200 liter).
Results (Least Cost Systems)
Results (SCR, DCR and HCR)
Fig. 3: Global average least cost system development for all scenarios.
Fig. 4: Global average SCR, DCR and HCR development for all scenarios.
• PV capacities will result in relatively high assets independent on the scenario. • Batteries will reach middle size capacities for scenarios with no V2H BEV and small capacities for scenarios where car 2 is used.
• • • •
The SCR will level off between 50 - 60% It will be possible to reach about 90% DCR Heat can be covered by 80 - 90% No big differences between the scenarios in 2050
Conclusion • SCR optimised residential energy systems are already profitable for most regions in 2015 • Grid-parity is highly dependent on retail electricity prices and independent on the state of the economic development of the regions • High DCRs and HCRs for most regions until 2050 • High annual cost saving potential for all scenarios • SCR optimising very reasonable for residential energy systems • Simultaneous use of V2H and stationary battery has to be re-thought (low value add of battery) • Still high SCR potential but chances for vehicleto-grid (V2G) or residential seasonal storage
References [1] Gerlach A., Werner Ch., Breyer Ch., "Impact of financing costs on global grid-parity dynamics till 2030", 29th European Photovoltaic Solar Energy Conference, 2014. [2] Breyer Ch., Gerlach A., "Global Overview on Grid-Parity", Progress in Photovoltaics: Research and Applications, 21, pp. 121-136, 2013 [3] International Energy Agency (IEA), "Global EV Outlook 2017", June 2017. [4] Breyer Ch., Bogdanov D., Aghahosseini A., Gulagi A., Child M., Oyewo A.S., Farfan J., Sadovskaia K., Vainikka P., 2017. Solar Photovoltaics Demand for the Global Energy Transition in the Power Sector, Progress in Photovoltaics: Research and Applications, forthcoming, oral
7DO.8.1
