Energy self-sufficiency, grid demand variability and consumer costs: Integrating solar PV, Stirling engine CHP and battery storage
Author(s)
Balcombe, P
Rigby, D
Azapagic, A
Type
Journal Article
Abstract
Global uptake of solar PV has risen significantly over the past four years, motivated by increased economic feasibility and the desire for electricity self-sufficiency. However, significant uptake of solar PV could cause grid balancing issues. A system comprising Stirling engine combined heat and power, solar PV and battery storage (SECHP-PV-battery) may further improve self-sufficiency, satisfying both heat and electricity demand as well as mitigating potential negative grid effects. This paper presents the results of a simulation of 30 households with different energy demand profiles using this system, in order to determine: the degree of household electricity self-sufficiency achieved; resultant grid demand profiles; and the consumer economic costs and benefits. The results indicate that, even though PV and SECHP collectively produced 30% more electricity than the average demand of 3300. kWh/yr, households still had to import 28% of their electricity demand from the grid with a 6. kWh battery. This work shows that SECHP is much more effective in increasing self-sufficiency than PV, with the households consuming on average 49% of electricity generated (not including battery contribution), compared to 28% for PV. The addition of a 6. kWh battery to PV and SECHP improves the grid demand profile by 28% in terms of grid demand ramp-up requirement and 40% for ramp-downs. However, the variability of the grid demand profile is still greater than for the conventional system comprising a standard gas boiler and electricity from the grid. These moderate improvements must be weighed against the consumer cost: with current incentives, the system is only financially beneficial for households with high electricity demand (<4300. kWh/yr). A capital grant of 24% of the installed cost of the whole micro-generation system is required to make the system financially viable for households with an average electricity demand (3300. kWh/yr).
Date Issued
2015-06-23
Date Acceptance
2015-06-09
Citation
Applied Energy, 2015, 155, pp.393-408
ISSN
0306-2619
Publisher
Elsevier
Start Page
393
End Page
408
Journal / Book Title
Applied Energy
Volume
155
Copyright Statement
© 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC-BY license (http://creativecommons.org/licenses/by/4.0/)
Subjects
Energy
09 Engineering
14 Economics
Publication Status
Published