Balancing distributor and customer benefits of battery storage co-located with solar PV

by Elizabeth L Ratnam

Institution: University of Newcastle
Year: 2016
Keywords: renewable energy; photovoltaics; electricity; fossil fuel; battery storage; solar power; power flow
Posted: 02/05/2017
Record ID: 2069316
Full text PDF: http://hdl.handle.net/1959.13/1312195


Research Doctorate - Doctor of Philosophy (PhD) In recent years, a rapid and dramatic increase in electrical power generation from renewable energy sources has been observed in many countries. Rapid increases in grid-connected small-scale solar photovoltaics (PV) have been driven by government incentives and renewable energy rebates, including residential feed-in tariffs and the financial policy of net metering. However, new challenges arise in balancing the generation of electricity with variable demand at all times as traditional fossil fuel-fired generators are retired and replaced with intermittent renewable electricity sources. This thesis looks at ways to balance distributor and customer benefits of battery storage co-located with solar PV, with a view to facilitating continual increases in grid-connected solar PV. Two issues that arise when accommodating significant residential-scale PV generation are addressed: the first is reverse power flow that leads to considerable voltage rise; the second corresponds to peak loads that occur infrequently, but potentially lead to the need for costly network augmentation when PV generation is unavailable. The benefits associated with addressing these two distributor issues are balanced with the benefit of scheduling battery storage to improve operational savings that accrue to customers. Conventional approaches to managing peak loads and reverse power flows in distribution networks vary from country-to-country, since they are often driven by government policies and regulation. In the Australian context, the first part of the thesis introduces typical costs associated with the design and operation of electrical networks to assess the economic viability of large-scale energy storage. We also introduce a publicly available dataset consisting of load and rooftop PV generation for 300 de-identified Australian residential customers in a distribution network. All simulation-based results in the thesis incorporate data from this publicly available dataset. The second part of the thesis considers potential savings that accrue to residential customers that co-locate battery storage with solar PV. We address reverse power flow and peak-loads coincident with peak pricing periods where the residential customer designs battery charge and discharge schedules. This leads us to a constrained optimization-based problem that we formulate as a quadratic program. The third part of the thesis focuses on coordinated approaches to charge and discharge residential battery storage. Emphasis is given to the management of bi-directional power flows in a distribution grid, and the maintenance of supply voltages within prescribed limits. This has motivated a novel approach to Adaptive-Receding Horizon Optimization (A-RHO). We implement our A-RHO approach in a GridLAB-D model of an Australian distribution network to assess the distributor beneits. Advisors/Committee Members: University of Newcastle. Faculty of Engineering & Built Environment, School of Engineering.