SmartSheffield #20 - Dr. Pierre Drezet: "Time-shifting Domestic Electricity Consumption for Greener and Cheaper Supply"

Pierre is a Director and Smart-IoT systems engineer at inx, and in this talk he discusses the potential for using hot water for energy storage in order to timeshift energy consumption to smooth out grid demand and better utilise energy from renewables.

For more, please visit: inx

These slides were presented at SmartSheffield#20 on July 11th 2022 - please see the Event Website for videos of all the talks and to sign up to receive notification of future events.

Many thanks to Arup for hosting, as well as our regular sponsors: Pitch-In Project and Sheffield Digital.

Transcript

1. ERGY Time-Shifting Electricity Consumption Options for the here and now
2. Outline Why Timeshift Energy? What time shifting is most useful? What can be done?
3. Problems with electricity… - Electrons are not all born equal - Binge consumption
4. GRID Carbon Intensity ERGY × 5 80gCO 2 /kWh 2 ( ~ ×2)
5. Dynamic Time-of-Use Costs ERGY × 5 Octopus Energy Agile pricing dropped below 2p ~80 hours/year in 2021 …but regular usage drives user cost and net carbon emissions every day
6. Trends and Annual Variations ERGY
7. Time-shifting consumption : - Could reduce costs every day for consumers - Provides more sink/dump for generators How can it be done?
8. Where could & should we store energy? GRID Scale Storage. • Pumped Hydroelectric ◦ Large but limited • Compressed Air Energy Storage (CAES) ◦ Low efficiency and geographic scale • Green Hydrogen ◦ Low efficiency / contentious • Batteries ◦ Flow Batteries - Materials issues ◦ Cell Batteries - limited capacity
9. 1 Grid Storage …is growing slowly Many potential technologies but not many efficient technologies that scale to GRID level requirements css.umich.edu/publications/factsheets/energy/us-grid-energy-storage-factsheet
10. UK Pumped Hydroelectric UK’s largest energy storage is pumped hydroelectric: ~30 GWh capacity. Total domestic energy consumption (All Fuels) : 1,200GWh/day ~2.5% UK Pumped Hydro: 30GWh (Max) — Domestic Consumption: 1,200 GWh/day UK Domestic & other consumption data Here
11. Domestic Energy Storage Availability Domestic Storage Possibilities • House Batteries ◦ Limited capacity ◦ OK in non-electrically heated homes • Electric Vehicles ◦ Larger capacity by 2030 ◦ Limited duty (battery longevity) • Domestic Hot water ◦ Large legacy installation ◦ Low/zero duty limits ◦ Lossy over 24+ hours • Domestic Central Heating ◦ Heat pumps require peak electricity. ◦ Low energy storage capability ◦ Off-peak direct heating options.
12. The easy options Assuming -All hot water-based systems converted to high temperature water thermal storage -All projected EV sales in next 8 years allow 50% charge/discharge depths for 30 days/year. ~37% EV storage (30days/year duty ): 11GWh 1% Hot Water (13M*150l cyl.): 104GWh 12% Central Heating (9M*250l cyl. ): 284GWh 24% — Domestic Consumption: 1,200 GWh/day UK Domestic & other consumption data Here
13. W h at’er you like? css.umich.edu/publications/factsheets/energy/us-grid-energy-storage-factsheet An unloved thermal storage deity? • 5+ times more “sensible heat” energy per kg/°C than other (non-gas) materials • Ubiquitous, low maintenance and environmentally friendly. • Is a bit tricky at 100°C (!) ◦ Rarely heated above 65C in domestic environments, but can be. At higher operating temperatures (up to ~95C), SMART water-based thermal storage compares well with other domestic heat-battery technologies such as phase change, chemical or high temperature ceramic heaters.
14. Reality Challenges • Dynamic Time of Use Tariffs are not wide-spread (or competitive) • Safety components for high temperature hot water are expensive • Lobbying plumbers, specifiers, architects & home owners is not easy • Low peng quotient of water cylinders
15. End of presentation Smart energy community site: inxergy.com
16. Spare Slides
17. Curtailment can still happen in 2022 ERGY
18. Smart digital high temp. IoT Control HVAC & Industrial IoT Domestic OEM Components System OEMs: boards, modules & brandable apps
19. Smart ToU Tariff • Accurate continuous usage estimation • Usage trend estimation & analysis • Generalised DToU & solar storage optimiser • Multi-channel control (exploiting stratification) • APIs for device and data integrations Home #2 Raw Usage Home #1 Raw Usage
20. Smart Solar Diverter Optimiser • Keeping storage capacity high for solar by keeping temperatures low when not needed • Provides nearly free hot water for family when the sun is shining and sufficient supply when it’s not. Not smart Smart consumption based optimisation Large Reheats after usage Frequent heating before solar input and user demand More free hot water: Infrequent grid heating when solar is available Minimal grid heating when solar is absent. OEM configurable high temperature limits to suite cylinder safety specifications and maximise capacity
21. Thanks for listening