Abstract
This report uses the GREEN Grid project research data to analyse a variety of residential household appliances and their contribution to peak demand under several scenarios. Although the data does not derive from a representative sample of households, we demonstrate that identifiable heating contributes ~ 21% to residential peak (17:00-21:00) demand in winter with Hot Water at ~ 17%, Lighting at 14% and Ovens at 7% while non-identified appliances contribute ~ 40%. These percentage contributions are generally similar at both regional network and sample co-incident peaks and across seasons although total power demand varies by season according to the appliance. Thus ‘Others’, heating and lighting are substantially lower in summer and whilst further research is clearly needed to unpack ‘Other’ demand, this suggests heating may be a major component.
Our results also show that simple mean (or median) values or single indicators such as average load factors mask considerable variation both within and between households. Overall we conclude that future work should focus on collecting data from a larger and representative sample of New Zealand households, ensuring that appliances are identified on circuits (especially electric heaters) and that both inter and intra-household heterogeneity should be adequately represented in analytic results.