Outage Simulation: Battery ONLY vs. Battery + Fuel Cell

Overview

• Key priorities for homeowners considering investing in energy solutions are resilience, comfort and savings. These desired outcomes translate directly into system requirements to both reliably keep the lights on during grid outages that are increasing in frequency & duration, and to minimize utility bills through self-consumption & VPP monetization when the grid is expensive & stressed.
• Modern, unified home energy solutions need to reliably deliver against all three of these key outcomes without forcing homeowners to make uncomfortable compromises between safety & comfort for their families and their wallet. They are holistically designed, fully integrated and optimized battery-first, grid-interactive & supportive systems with intelligent home load control and firm on-site generation capabilities by combining intermittent solar with on-demand fuel cell.
• Designing, deploying & maintaining these next-generation energy solutions represents a strategic opportunity for the traditional solar & storage installers and standby generator dealers, as well as progressive electrical and HVAC contractors, to evolve into home energy solutions contractors and become the trusted whole home energy advisors to the homeowner.

How to Use This Tool

The "Home Energy Resilience Estimator" is a sales tool that enables a home energy advisor during a consultation, to help a homeowner visualize & dynamically experience the benefits of a home energy system where all key components work synergistically together to deliver desired outcomes without compromises, even during worst-case scenarios.

1. Make parameter selections in the YOUR HOME PROFILE section to closely reflect the specific home profile you are simulating and set GRID OUTAGE DURATION to the number of days for which the homeowner wants to be sure they are protected. Any parameter changes are instantly reflected.
2. The tool fundamentally compares the performance of a Battery ONLY system with that of a Battery + Fuel Cell system. In EQUIPMENT BASELINE, the tool uses the "highest seasonal electricity use" (kWh) of the YOUR HOME PROFILE and determines required battery and fuel cell units, which can be applied to System 1 – Battery ONLY and System 2 – Battery + Fuel Cell model as a starting point.
3. Increase or decrease GRID OUTAGE DURATION and adjust equipment choices and parameters (battery | fuel cell | solar | load control) to see how different equipment permutations change the energy resilience profile of the model home.

Design Considerations

Off-grid design best practices follow a fairly standardized order: Home Load first, then Solar, then Battery Storage, and lastly Generator, as backstop.

1. Home Load assessment comes first. Determining accurate kWh/day consumption is critical. An underestimated load profile can cascade into undersized batteries and excessive generator runs. Optimizing load efficiency is almost always cheaper than adding generation capacity.
2. Solar is sized to the worst month. An off-grid system should be sized for the worst month of the year, because sizing for annual averages means overproducing in summer and running deficits in winter, which defeats the purpose of grid independence.
3. Battery Storage capacity is set by "days of autonomy". How many consecutive days must the system run on stored energy with zero solar recharge. The standard formula is daily load in kWh multiplied by the number of days of autonomy, determining the total storage capacity needed.
4. Generators are sized as backup insurance, not a primary source. The job of the generator is covering the gap during extended low-solar stretches, to let the battery storage + solar combination use a shorter, more economical autonomy target than a system without backup.