The Tigo EI Battery (US) Sizing Tool is for grid-tied residential systems and is divided into two sections:
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Click HERE to watch the tutorial video.
The Load Entry area is the starting point for the tool. This section has editable fields related to the loads (i.e., appliances, devices, etc.) that will be backed up when the grid goes down. The area is further divided into three tiers, each higher tier representing larger loads requiring more power and battery capacity to run.
Each load requires the following information:
Item- The name of the load. Although there are common prefilled cells, you may change the names to match your specific profile. You may also include the load by selecting YES or NO on the drop-down menu to the right of the row.
Rating (W)- the amount of power the load requires to operate. This is found on the device nameplate or online. Many websites provide power ratings for common household appliances and devices. Although this is not an exhaustive list, this website provides a substantial amount of information: https://generatorist.com/power-consumption-of-household-appliances
# - the number of devices
Hours- how many hours per day the device will operate
Power- the updated power requirements based on Rating * Number of devices. This is automatically updated.
Energy (Wh)- how much energy the load(s) consumes (Power x Hours)
The most important thing you can do in this section is relay its contents to the customer openly and honestly. Managing customer expectations is as important as sizing and designing the system. Poor expectation management results in a poorly performing system and negative customer feedback.
The Tier 1, 2, and 3 Totals at the bottom of the Load Entry section are the first to look at.
Total Power - 6053 W (6 kW)
This represents the worst-case scenario- all of the loads in the list are running simultaneously. This scenario is plausible but not probable. Total power also represents the minimum size of the Tigo Inverter. For example, if the total power from all Tiers equals 8kW, then you would need the Tigo 11.4kW inverter and at least two Tigo Batteries IF all the loads ran simultaneously. More on this when discussing another part of the Load Analysis section.
Total Watt Hours - 33,370 Wh (33.37 kWh)
This value represents the amount of energy consumed during a 24-hour period. It is based on the number of loads, the power requirements of the loads, and how long the loads will run. If the homeowner adds more loads or runs them longer than the entered values, the amount of capacity and the amount of time the battery will last will go down.
Total watt hours provide an estimation of the minimum Tigo Battery size. For example, if the total from all three tiers is 18kWh (18,000 watt hours), the minimum battery size must be 20 kWh since the Tigo Battery is sold in 10 kWh increments.
It is time to analyze the Inverter and Battery data under the Load Analysis header.
Battery Power and Energy Available
This section is informational and displays the continuous system power rating regarding the Tigo inverter and the number of batteries in the system. This chart assumes the loads are running on battery power only, and there is no available PV to support the loads.
Each Tigo Battery can supply up to 5000W of continuous power, but the output depends on the size of the Tigo hybrid inverter. For example, the Tigo 3.8kW with one Battery will only supply 3000W even though there is a max output of 5000W from the battery. It is analogous to oversizing a PV inverter. You can connect 7kW of PV to a 5kW inverter, but that inverter will only produce 5kW.
Max PV Capacity shows the 200% oversizing limit. Breaker Space indicates the breaker size for the applicable inverter.
Backup: Power and Energy
This table reflects the percentage of power the system can provide based on the total watts calculated earlier. A value in green represents greater than 100% of the power supplied by the system. A value in red will be less than 100%. If ALL loads run simultaneously, the Tigo system will only supply that fraction.
Backup Energy Available
This part of the tool is the spotlight data since it is the one thing customers wish to know, “How long will this system last?”
This deliverable shows the maximum number of hours per day the system will run on backup power. It assumes all loads will run for the times entered in the tool. A value greater than 24 hours generally means the system can run in a perpetual backup mode. This is highly dependent upon the local weather conditions since the fall and winter months have less available sunlight for battery charging.
Backup time, or autonomy, demands the most amount of customer expectation management since there are so many assumptions in the calculations. We don’t want the customers to become discouraged when they see a backup time of 10 hours! Again, these values assume the worst-case scenario and may not be reflective of real-world operation.
There are a few things the customer can do to extend their backup time:
- Add more solar. This ensures plenty of daytime solar available to power the loads and to charge the batteries. However, if the design fills up the roof with solar modules, then this is not a viable option.
- Add more batteries. This is usually a budget concern since the batteries are typically the most expensive part of the system. Additionally, if the sizing tool maxes out the number of batteries per system, then more capacity will necessitate a separate ESS to accommodate.
- Reduce loads! This is the cheapest solution but requires the most discipline. This does not mean they must remove loads from the list, but instead better manage the consumption of those loads during an outage.
The great equalizer for any energy storage system is a generator. The Tigo 200A Automatic Transfer Switch with generator Support can accommodate this addition. A generator can supplement both the power and energy requirements in the sizing tool. If the homeowner has enough fuel, the generator can power larger loads and charge the batteries when there isn’t enough sunlight for the PV array to accommodate.
To know more about battery sizing and customer expectation management, please check out the Amazon best seller, The Battery Powered Home.
If you have any questions about the Tigo Sizing Tool, please contact our Sales Engineering Team.