Smart IoT Devices to Control & Balance Home Energy Ecosystem for Grid Backup
Objective: Smart automated control and balance of home energy ecosystem to maximize renewable energy usage thereby reducing utility grid-buy for backup. Yearly grid-buy for 2018 & 2019 was reduced by 92.5% from 14.5MWh/year to 1.17MWh/year for a 3 year pay back and island nano-grid mode of operation. Resilient 100% electrification of the home saves lives during and after disasters from hurricanes, earthquakes, wildfires, tornedos and floods when lifesaving medical equipment requires power 24/7.
Methods: 20+ smart IoT devices are used throughput the home providing smart home security, smart home environmental control and smart home appliance control. Other smart IoT devices are used to monitor and control home energy demand for HEMS (home energy management system) and for local weather forecasting. With the right data analytics we identified the top 6 household appliances with the highest energy demand spikes. We also developed a new smart control box for total home energy ecosystem control and balance to maximize multiple renewable energy sources used in off-grid or grid-tie modes of operation. Grid electricity is used only as backup on rainy/cloudy days.
Results: Smart home with multiple smart IoT devices for home automation was made resilient to any power blackouts by using a smart controller to balance the total home energy ecosystem. Smart weather forecasting using sky-cam, local satellite and radar imagery for micro-climate and time of day, we prioritized which renewable energy source to use for lowest cost of electricity. Summertime air conditioner uses 60% of energy, hot water 21%, refrigerator/freezer 10%, pool pump 4% and others 5%. Wintertime hot water uses 50%, refrigerator/freezer 24%, pool pump 10%, clothes dryer 6% and others 10%. On sunny summer (s) and winter (w) days, 100% of daily home energy needs (s=70.6kWh, w=53.6kWh) was achieved with: 1) solar-PV s=41.7kWh (59.1%), w=22.1kWh (41.2%), 2) battery discharge s=12.9kWh (18.3%), w=14.6kWh (27.2%), 3) hot/cold thermal storage equivalent s=16kWh (22.6%), w=16kWh (29.8%) and 4) grid-buy s=0.0kWh (0%), w=0.9kWh (1.7%) for 92.5% off-grid mode of operation. On the 7.5% rainy summer and winter days, grid-tie mode of operation was used for backup. 100% of daily home energy needs (s=44.9kWh, w=57.9kWh) was achieved with: 1) solar-PV s=21.1kWh (46.9%), w=15.5kWh (26.7%), 2) battery discharge s=12.9kWh (28.7%), w=15.0kWh (25.9%), 3) hot/cold thermal storage equivalent s=0kWh (0%), w=0kWh (0%) and 4) grid-buy s=10.9kWh (24.3%), w=27.4kWh (47.3%) for 7.5% grid-tie mode of operation.
Conclusion: Smart home control box for total home energy ecosystem control and balance allowed off-grid mode of operation 92.5% of the time in 2018 & 2019 using grid-tie for backup. Use of smart IoT devices is critical for data analytics and local weather micro-climate time of day forecasting for lowest cost of electricity, island nano-grid and 3.1 year pay back.