At the heart of a solar + storage system is a battery, but that heart can’t beat without its brain — the software layer telling it how to operate. For your customers, regardless of battery manufacturer, the software brain is driven by three possible value streams.
- Peak demand shaving. This is a commercial project value.
- Time of use (TOU). Discharging on-peak and recharging off-peak.
- Self-consumption. Pairing storage with solar and setting it to not export to the grid.
Deciding which value stream to choose might be easy, but determining just how much value is in that stream is complex. During the Solar Business Boot Camp presenter Adam Gerza, COO of Energy Toolbase, will be showing attendees how to accurately model and analyze the economics of solar and energy storage projects.
“It’s a math problem; there’s a best answer,” Gerza said. “So, how much is your storage project saving in dollar terms? We’re quantifying savings and trying to optimize them.”
An examples of how crucial this value modeling is from Hawaii:
The net metering 2.0 tariffs in Hawaii are extreme but demonstrate where self-supply is a valuable option because if you export solar to the grid you get zero return for that production.
So, take two neighbors with identical load profiles (1,000 kWh a month; 12,000 kWh a year), with the only difference being time of use. A 6-kW DC rated PV system would produce a 79 percent offset for both homes. One home is peaking midday, between 10:30 a.m. and 2 p.m. The other home peaks in the evening. Overlaying time of use profiles reveals the midday home is only exporting about 29 percent of its energy to the grid, whereas the night owl is exporting 61 percent.
“What did that just do to the value of solar? During the day it is 19.5 cents; at night, the value collapses to 10 cents,” Gerza notes.
Hawaii PV + storage
Say you have a house (10 kW DC system, producing 15,000 kWh, 87 percent offset) exporting 50 percent of its PV production to the grid, where, again, you get nothing in return for it. After specifying a 14-kWh, 7-kW, two-hour battery, that export number goes down to 24 percent.
“There’s still a lot exporting from this,” Gerza says. “This is a function of running out of capacity. So, think about what’s happening. The system stored and prevented exports but then ran out of space. So, trial and error. If we want to get to 100 percent, we have to size up.”
That’s just a taste of the deep dive into solar + storage proposals that Adam will be presenting on Day 2 of the Solar Business Boot Camp. Be sure to head here to register today and be the go-to solar contractor for storage projects in your area.