Dominion Energy — Residential Usage Analysis

Meter •••• Data: — Loading…

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So Far This Month (kWh)

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Peak Month (kWh)

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Monthly Average (kWh)

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Annual Total (kWh)

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Est. Annual Cost

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Annual CO₂ (metric tons)

Year-over-Year Comparison — Jun–May Billing Year

Light blue = Jun 2024–May 2025 (previous year). Dark blue = Jun 2025–May 2026 (current year). Mirrors Dominion's own portal chart.

All Months — Colour-Coded by Season

Source: Dominion Energy myaccount portal — Usage tab, monthly kWh. Temperature overlay: approximate monthly average °F for Loudoun County, VA.

Monthly Detail

Month	kWh	Days	Avg/Day	Est. Cost	vs Prev Yr
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Usage Context

Peak month—

Lowest month—

Peak-to-low ratio—

Winter avg (Dec–Feb)—

Summer avg (Jun–Aug)—

Shoulder avg (Mar–May, Sep–Nov)—

Primarily heating-dominated. Winter months (Dec–Feb) draw 2–3× more electricity than shoulder months. The geothermal heat pumps are the dominant variable load — their COP of ~3–4 means far less electricity than resistance heating would require.

Rolling 3-Month Average

Rolling 3-month centered average smooths billing cycle noise and reveals the seasonal trend.

Estimated Monthly Cost

Estimate using Dominion Schedule 1 VA rates (2025): $7.58 basic + $0.079/kWh (first 800) + $0.091/kWh (over 800) + $0.042/kWh riders.

Rate Structure — Schedule 1

Basic customer charge$7.58/mo

Energy — first 800 kWh$0.0793/kWh

Energy — over 800 kWh$0.0914/kWh

Fuel adjustment rider$0.0248/kWh

DSM / distribution riders$0.0072/kWh

Transmission rider$0.0095/kWh

Effective bundled rate (avg)—

Note: Rates reflect approximate 2025 Virginia Schedule 1 tariff. Your actual bill may differ based on fuel rider adjustments, local taxes, and billing period length.

Monthly Cost Breakdown

Month	kWh	Basic Charge	Tier-1 Energy	Tier-2 Energy	Riders	Est. Total	¢/kWh eff.
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Tier breakpoints and riders per Dominion Virginia Schedule 1 (2025 approx). Taxes excluded.

Annual Cost Summary

Estimated annual electricity cost—

Monthly avg bill—

Peak month bill—

Low month bill—

Winter premium vs. shoulder—

Cost by Season

Monthly kWh vs. Estimated Monthly Average Temperature

Temperature: approximate monthly means for Loudoun County, VA (NOAA historic normals + 2025–26 estimates). High electricity in winter = geothermal heating demand; moderate summer rise = cooling + dehumidification.

❄ Winter

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avg kWh/month

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est. monthly cost

Dec, Jan, Feb — peak heating load

🌱 Spring

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avg kWh/month

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est. monthly cost

Mar, Apr, May — minimal HVAC

☀ Summer

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avg kWh/month

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est. monthly cost

Jun, Jul, Aug — cooling load

Degree-Day Estimate & Load Decomposition

How to read this: Heating Degree Days (HDD) and Cooling Degree Days (CDD) are standard metrics for HVAC demand. A home's energy use typically tracks linearly with degree days once baseload is subtracted. The slope of kWh vs HDD/CDD reveals your geothermal system's field efficiency.

Estimated baseload (always-on appliances, lights, misc)~1,000–1,200 kWh/mo

Heating-season incremental above baseload—

Cooling-season incremental above baseload—

HDD/CDD estimated using Loudoun County, VA NOAA climate normals (base 65°F). Your actual degree-days may vary slightly.

What would this house consume without geothermal? Two WaterFurnace Series 7 units replaced resistance/gas backup heating and conventional AC. This tab estimates the counterfactual: a similar house with gas furnace (95% AFUE) + central AC (SEER 16) and compares it to the actual geothermal electricity bill.

Actual (Geothermal) vs Counterfactual (Gas + AC)

Counterfactual heating: estimates gas therm consumption using COP difference between geothermal (~3.5 avg) and gas furnace (95% efficiency = COP 0.95). Cooling counterfactual: SEER 16 AC (COP ~4.7) vs geothermal COP ~5+. Gas price assumed $1.40/therm (VA avg 2024). Electricity at blended ~$0.115/kWh.

Annual Savings Estimate

Actual annual electricity cost—

Counterfactual gas + electric cost—

Annual savings (geothermal advantage)—

Geothermal system cost (both units)~$40,000

Simple payback (energy savings only)—

Federal ITC (30%) applied$12,000

Net cost after ITC~$28,000

Adjusted simple payback—

Estimated payback of 8–12 years is typical for 2-unit WaterFurnace installs in VA, factoring the 30% federal tax credit (IRA §25D). Ground loop life exceeds 50 years; heat pump equipment typically 20–25 years.

System Performance Metrics

~3.5

Avg winter heating COP

~5.2

Avg summer cooling COP

67°F

Ground loop EWT (typical)

2×7

Units (WaterFurnace Series 7)

COP values from WaterFurnace Symphony live telemetry (see Symphony Dashboard tab). Ground EWT varies seasonally ~62–72°F at this site depth.

Geothermal vs. Conventional: Carbon Comparison

Geothermal CO₂: actual kWh × VA eGRID factor (0.714 lb/kWh). Gas+AC CO₂: estimated gas combustion (11.7 lb CO₂/therm) + reduced electricity. Does not include upstream methane leakage from gas supply (~2–3% adds 20–30% to effective gas CO₂).

Monthly CO₂ Emissions from Electricity

Virginia eGRID SRVC subregion emission factor: 0.714 lb CO₂/kWh (323 g/kWh). EPA eGRID 2022 data release. Virginia's grid is improving — Dominion's offshore wind (2.6 GW by 2026) and solar buildout are reducing this factor ~3–5% annually.

Annual Carbon Budget

Annual electricity consumption—

VA grid emission factor0.714 lb/kWh (323 g/kWh)

Annual CO₂ from electricity—

Metric tons CO₂e—

Equivalent car-miles driven—

Equivalent gallons of gasoline—

Trees needed to offset (annual)—

Grid Emission Factor Trend (VA)

VA eGRID SRVC factor (lb CO₂/kWh) 2018–2026 estimate. Dominion Energy offshore wind and solar investments drive the decline.

Decarbonization Pathway

Virginia Clean Economy Act (VCEA) mandates Dominion achieve 100% carbon-free electricity by 2045. At current trajectory, the VA grid factor drops to ~0.5 lb/kWh by 2030 and ~0.1 by 2040. Your geothermal system's carbon footprint will shrink automatically as the grid cleans up.

Forecast assumes current usage constant; emission factor declines per VCEA trajectory. Comparison: US residential average ~5 metric tons CO₂/yr from electricity (EIA 2023).

No interval data yet. Upload the Usage_*.xlsx file from the Dominion portal (Usage → Download Data → Excel) to unlock 30-minute interval analysis.

24-Hour Load Profile by Season

Average kW demand at each 30-minute interval, grouped by season. Winter ~5.5 kW overnight = both geothermal units running continuously. Summer ~1.7 kW overnight = your true always-on (appliance) base load.

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Always-On Floor (kW)
Summer overnight — fridges, network, standby

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Geothermal Heat Load (kW)
Winter overnight above base

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Evening Activity Peak (kW)
Avg summer 7–9 PM demand

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Year Peak Demand (kW)
Highest 30-min interval recorded

Estimated Load Decomposition

Stacked avg kW: always-on base + HVAC geothermal + variable (lighting, cooking, EV, entertainment).

Evening Load Ramp — 4 PM to Midnight

Average kW above overnight base (3am floor) during evening hours, by season. Shows lighting + cooking + entertainment combined.

Refrigerator / Freezer Signature

Your summer overnight minimum of ~1.7 kW reveals what never turns off. On mild spring nights (no HVAC), this is your purest always-on baseline — two refrigerators cycling every ~45 min would be visible as 0.1–0.2 kWh bumps in raw 30-minute data.

2-refrigerator pair (typical)0.30–0.45 kW

Network gear (router, NAS, switches)0.15–0.35 kW

Security system + cameras0.05–0.15 kW

A/V & entertainment standby0.05–0.15 kW

Well pump standby / other0.10–0.40 kW

Tip: To isolate your fridges, check your smart panel or clamp-meter on a calm spring night after midnight — you'll see the compressor cycles as 150–200W steps.

Lighting & Human Activity

The 6 PM–9 PM ramp is your clearest lighting + cooking signature. In Spring and Fall — when HVAC is minimal — this bump of ~0.5–0.8 kW above the daytime average represents household activity: overhead lights, range, oven, TV, computers.

In winter this signal is buried under geothermal load, and in summer it blends with AC cycling. Spring and Fall data give the cleanest read on your non-HVAC load.

LED opportunity: Replacing remaining incandescent / halogen fixtures cuts lighting load by 75%. At 2 kWh/day for lighting, that's ~540 kWh/yr saved.

Daily Peak Demand — Full Year

Highest 30-minute kW reading each day. Winter peaks >10 kW = both geothermal stages running simultaneously, possibly with water heater or dryer. Nov 11 peak = 18.6 kW.

Hour-of-Week Heatmap — Average kWh per Hour

Each cell = average kWh consumed during that hour of the week across all recorded days. Dark red = heavy load; dark blue = minimal.

Low

High

Derived from 30-min interval data. 24 hour columns × 7 day-of-week rows. HVAC dominates winter overnight; human activity drives weekday mornings and evenings.

Upload Green Button Data

How to download from Dominion:

Sign in at myaccount.dominionenergy.com
Go to Usage → Download Data
Select Excel (.xlsx) for 30-min interval data (best) — or Green Button XML/CSV
Choose date range (up to 13 months for monthly, or daily/hourly intervals)
Upload the file here — monthly, daily, and interval data are all supported

Click to select or drag & drop a file here

Supports: Dominion Excel (.xlsx), Green Button XML (.xml), Dominion CSV (.csv)

Supported File Formats

Format	Granularity	Source
Dominion Interval Excel ⭐	30-min interval (48/day)	Dominion portal → Download Data → Excel (.xlsx)
Green Button XML	Hourly / 15-min interval	Dominion → Download Data → Green Button
Billing CSV	Monthly	Dominion → Download Data → CSV (billing summary)
Daily CSV	Daily	Dominion → Download Data → Daily usage CSV

Data is stored server-side in data/history/dominion_usage.json. Uploading a new file merges data — it does not replace existing months. To clear all data, delete the JSON file and reload.

Manual Monthly Entry

Month (YYYY-MM)

kWh

Days

Cost ($)

Current Data Store

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