Optimizing 100%‐renewable grids through shifting residential water‐heater load

Abstract

Summary A low‐carbon electricity supply for Australia was simulated, and the installed capacity of the electrical grid was optimized by shifting the electricity demand of residential electric water heaters (EWHs). The load‐shifting potential of Australia was estimated for each hour of the simulation period using a nationwide aggregate EWH load model on a 90 × 110 raster grid. The electricity demand of water heaters was shifted from periods of low renewable resource and high demand to periods of high renewable resource and low demand, enabling us to effectively reduce the installed capacity requirements of a 100%‐renewable electricity grid. It was found that by shifting the EWH load by just 1 hour, the electricity demand of Australia could be met using purely renewable electricity at an installed capacity of 145 GW with a capacity factor of 30%, an electricity spillage of 20%, and a generation cost of 15.2 ¢/kWh. A breakdown of the primary energy sources used in our scenario is as follows: 43% wind, 29% concentrated solar thermal power, and 20% utility photovoltaic. Sensitivity analysis suggested that further reduction in installed capacity is possible by increasing the load‐shifting duration as well as the volume and insulation level of the EWH tank.

Using temperature sensitivity to estimate shiftable electricity demand

“…Other kinds of flexible loads, besides those that we can identify statistically, are likely shiftable using demand-side thermal storage. Water heating might be the easiest current use of electricity that is shiftable ( Buescher et al., 2015 ; Passenberg et al., 2016 ; Ali et al., 2019 ). Although some water-heating demand may be captured by our estimates, the timing of water-heating demand tends to be more closely associated with use, not with ambient temperature, and thus less estimable in this manner.…”

Using Temperature Sensitivity to Estimate Shiftable Electricity Demand: Implications for power system investments and climate change

“…5 For example, the Energy Information Administration reports that HVAC systems comprise 26% of use from both residential and commercial sectors while attributing 72% of total load to these sectors, implying a total HVAC share of about Other kinds of flexible loads, besides those that we can identify statistically, are likely shiftable using demand-side thermal storage. Water heating might be the easiest current use of electricity that is shiftable (22)(23)(24)(25). While some water-heating demand may be captured by our estimates, the timing of water-heating demand tends to be more closely associated with use, not with ambient temperature, and thus less estimable in this manner.…”

A review of 100% renewable energy scenarios on islands

“…Most studies are in hourly resolution, while only six articles describe a transition (Aboumahboub et al, 2020;Hong et al, 2014;Howard et al, 2018;Mason et al, 2010Mason et al, , 2013Turner et al, 2013), and the other 21 articles are overnight studies. Most articles are limited to the power sector, but two articles cover the power and heat sector (Ali et al, 2019;Kharel & Shabani, 2018).…”