From the founder
My system and the real savings
I didn't build NRG Sense from a spreadsheet. I run a home battery on Dominion rates here in Charleston, switched my own plan, and watched my bill drop. This is my real setup and the actual numbers.
— Vinh · Charleston, SC
My real setup — tap any photo to enlarge.
Why I built it
Two things pushed me into this: energy bills that climb every year, and living somewhere storms and hurricanes take the power out. A home battery answers both — it's a hedge against rising rates and insurance against the next outage.
My goal is self-reliance — getting as close to off-grid as I can while staying connected, and leaning on the grid only for emergencies. Energy only gets more expensive, so the more of my own power I make and store, the better that bet looks every year.
I had to research all of it myself — the rates, the plan switch, the hardware, the install. NRG Sense is the tool I wish I'd had: an easy way to see why a battery is worth it, what it actually saves, and how to size, buy, and get it installed. I built it to help like-minded folks skip the homework and get straight to honest numbers.
My system
- Storage
- EcoFlow DELTA Pro Ultra + DELTA Pro Ultra X — 2 batteries each (4 × 6.1 ≈ 24.4 kWh)
- Panel
- Smart Home Panel 3 — replaced my main service panel, runs the whole home (32 circuits)
- Rate plan
- Dominion Rate 7 (time-of-use)
- Solar
- Testing a portable 400W panel around the yard
- Layout
- Panel in the laundry room; inverters, batteries & smart inlet box in the garage
My real savings
I switched from Dominion's standard flat rate (Rate 8) to time-of-use (Rate 7) in April, with the battery covering the expensive on-peak window. June was my first full month on it — so here's my normal monthly cost vs. the same usage on my old rate (the honest apples-to-apples):
On Rate 7 + battery
~$190
a normal month · 1,846 kWh
Same usage on Rate 8
~$311
If those 1,846 kWh had stayed on my old rate
≈ $120/month saved — with more expected in peak summer.
And Dominion has more rate changes proposed for July 2026 — as electricity prices climb, switching to time-of-use with a battery system pays off even more.
Straight from my own bills — electricity charges only. My Dominion bill includes gas too, but that's not factored in here. Yours will differ with your usage and rate; that's exactly what the analyzer works out for your home.
What's next for my setup
I'm growing this in stages — battery first, sun next:
- 1.A small ground-mount array (~1.6 kW) to start — panels from Signature Solar at pallet pricing, testing placement in the yard now.
- 2.Then panels on the detached garage.
- 3.When I replace the main roof, go full solar up there — building toward my system’s full ~15.6 kW of solar input, plus ~20% to cover real-world losses.
- 4.And expanding the battery over time, toward the system’s ~90 kWh ceiling.
The goal: run as much of the house on my own sun as I can.
Want to see your numbers?
Run your own Dominion bill through the same honest math.
See what I'd save →