Stressed Grid Substations - Case Study
Extreme weather, variable PV and wind, and aging infrastructure are straining grids. Stressed substations, particularly those at the grid’s edge, present especially difficult and costly challenges. At times, they can be overwhelmed by too much power on the grid, e.g., from too much PV or wind. At other times aging infrastructure coupled with the often widely variable demand they serve outstrips a substation’s ability to provide reliable electricity.
OUR SOLUTION
HeatStorE™: a hybrid long-duration battery and spinning reserve
247Solar’s HeatStorE™ operates almost exactly like electric batteries but also provides spinning reserves at substation scale. HeatStorE stores excess electricity from the grid or renewables as heat and converts that heat to electricity on demand for 9 hours or more on a single charge. As a spinning reserve, HeatStorE burns a local fuel to produce power whenever needed even when storage is depleted.
Benefits include:
- Increased grid reliability and reduced costs
- 24/7 fully-dispatchable standby power
- Spinning reserves to meet fluctuating demand
- Load shifting of 8 hours or more
- Increased substation resiliency
EXAMPLE
A stressed edge-of-grid substation in Australia faces a dilemma serving a remote community. A conventional upgrade will be too costly.
- Grid owners must either cut the connection and spend a considerable amount on PV, wind, batteries, gensets, and fuel to enable the community to generate its own power and achieve self-sufficiency or
- Grid owners can add HeatStorE to the substation and continue serving the community.
EXAMPLE COMPARISON
1. Cut the connection, community self-sufficiency
- CAPEX, annualized: PV, wind, batteries, 2 MW gensets: (0.8) USD million
- O&M/yr: (0.5) • Fuel/yr: (2.6) USD million
- Annual revenue to system owner: (1.5) USD million
- Annual Net: (2.4) USD million
2. Add HeatStorE and continue serving the community
- CAPEX, annualized: 2 MW HeatStorE: (0.5) USD million
- O&M/yr: (0.7) USD million
- Fuel/yr: (0.6) USD million
- Annual revenue to system owner: (1.5) USD millions
- Annual Net: (0.3) USD million
