Off-grid load monitoring is the difference between knowing you are losing battery capacity overnight and knowing exactly which appliance in the guest room is stealing it, and the difference between oversizing your solar array to compensate for a drain you could have fixed with a $10 mechanical timer. You have the Victron SmartShunt installed and calibrated as covered in our SmartShunt vs BMS guide. You know exactly how many amp-hours are leaving the battery bank. But the SmartShunt tells you the total flow it does not tell you where the flow went. Off-grid load monitoring at the circuit level tells you where it went. Before you understand the off-grid load monitoring standard, you need to know how much solar power you actually need. The ghost load drain you discover through off-grid load monitoring may change your solar sizing calculation entirely.
Off-Grid Load Monitoring: The Ghost Load Problem
What a ghost load is: A ghost load is the standby power draw of a modern electronic device that is switched off but not unplugged. Every device with an instant-on startup, such as televisions, streaming devices, gaming consoles, smart appliances, and satellite routers, maintains an internal power supply in standby mode. This standby power supply responds to remote control signals, maintains clock synchronization, checks for software updates, and enables the instant-on startup that consumers expect. The standby current is typically 1-5 watts per device. Individually invisible. Collectively devastating in an off-grid system.
The ghost load mathematics: A single OLED television in standby: 2.5W. A satellite internet router running 24 hours: 18W. A smart coffee maker with a display: 4W. A gaming console in standby: 15W. A cable or satellite receiver in standby: 25W. A total of 64.5 watts is being drawn continuously 24 hours per day, 365 days per year. At 64.5W continuous: daily ghost load = 64.5W × 24h = 1,548Wh = 1.55kWh per day. On a 5kWh usable battery bank, this is 31% of total capacity consumed by devices that are switched off. That is the vampire in the Fortress.
Why the inverter screen cannot identify ghost loads: The Victron MultiPlus-II display shows total AC output watts, the sum of all loads currently running. It does not show individual circuit breakdown. When you look at the inverter display at 2 am and see 65 watts, you cannot tell whether that is the refrigerator cycling, the internet router, the TV on standby, or all three simultaneously. Off-grid load monitoring at the circuit level is the only tool that answers this question.
I was doing an off-grid load-monitoring audit at a Rockwood cabin last autumn. The owner had been losing approximately 15% of their battery bank overnight with no obvious explanation. All the lights in the microwave are off. No large appliances are running. I installed the Emporia Vue CT clamps on their AC panel breakers and ran the overnight monitoring. The data showed three consistent ghost loads: the satellite internet router drawing 21W continuously, the OLED living room TV drawing 18W in standby, and a smart coffee maker drawing 29W with its illuminated display clock. Combined: 68W × 8 hours overnight = 544Wh = 10.9% of a 5kWh battery bank gone every night to devices that were switched off. As covered in our SmartShunt vs BMS guide, the SmartShunt had been accurately reporting the drain the off-grid load monitoring audit revealed who was responsible.
The CT Clamp Installation -How Off-Grid Load Monitoring Works
What a current transformer is: A current transformer CT clamp is a split-core inductive sensor that clips around a single wire and measures the AC current flowing through it without breaking the circuit. The Emporia Vue uses CT clamps on every individual breaker circuit in the AC panel, one CT clamp per hot wire on each breaker, plus two whole-home CT clamps on the main service entry conductors. The CT clamps feed current readings to the Emporia Vue hub, which calculates watt-hours per circuit and uploads the data to the Emporia cloud app in real time.
The installation procedure: The Emporia Vue installs inside the AC load panel, with the panel cover removed. The CT clamps clip around each breaker’s hot wire inside the panel. No wires are cut. No circuits are interrupted. The hub mounts inside or adjacent to the panel and connects to the home WiFi network. The Emporia app shows real-time watt readings for each individual circuit and historical watt-hour data for any time period. The off-grid load monitoring data is accessible on a phone in the living room, in the equipment room, or remotely through the app.
The whole-home CT clamp calibration: The two whole-home CT clamps on the main service entry conductors provide the total AC consumption reference the same total that the Victron SmartShunt measures on the DC side. When the Emporia Vue whole-home reading and the SmartShunt DC reading are reconciled, accounting for the inverter’s conversion efficiency (typically 90-95% for the MultiPlus-II at light loads), the AC/DC synergy check confirms thatthe off-grid load monitoring system is reading correctly.
The AC/DC Synergy – Finding Inverter Efficiency Loss
What the AC/DC synergy check reveals: The SmartShunt measures DC amp-hours leaving the battery bank. The Emporia Vue measures AC watt-hours consumed by the loads. At 93% inverter efficiency: AC watt-hours consumed = DC watt-hours drawn × 0.93. If the Emporia Vue shows 500Wh consumed and the SmartShunt shows 600Wh drawn, the difference is 100Wh -500Wh ÷ 600Wh = 83% effective efficiency. The MultiPlus-II at light loads should achieve 90-95%. An 83% result indicates either a degraded inverter component. This is the off-grid load monitoring AC/DC synergy diagnostic that no other monitoring method provides.
Why the numbers never perfectly match: The SmartShunt measures all DC loads, AC loads through the inverter, plus any direct DC loads connected to the battery bank. If there are DC loads, such as 12V lighting, a DC refrigerator, and USB chargers, their consumption appears in the SmartShunt reading but not in the Emporia Vue AC reading. The reconciliation must account for all DC direct loads separately. As covered in our SmartShunt SOC Calibration guide, the energy flow diagram shows the DC-to-AC conversion efficiency in real time.
The Ghost Load Elimination Protocol
Step 1 – The phantom search: With the off-grid load monitoring data visible turn off every switch in the house lights, appliances, everything with a physical power button. Observe the Emporia Vue whole-home reading. Any remaining load above 5W is a ghost load a device drawing power despite being switched off. The whole-home CT reading identifies the total ghost load. The individual circuit readings identify which circuits contain the ghost loads.
Step 2 – Circuit isolation: For each circuit showing ghost load current switch off the breaker for that circuit and observe whether the whole-home reading drops by the expected amount. A circuit breaker that eliminates 20W of ghost load when switched off contains the vampire. Restore the breaker and use the individual circuit data to identify the specific device — the circuit data shows whether the load is constant (router, always-on device) or intermittent (TV standby with compressor cycling).
Step 3 – The mechanical timer kill switch: For ghost loads that cannot be permanently unplugged, such as routers, satellite receivers, and smart hubs, a mechanical outlet timer eliminates the overnight draw without disrupting the device’s function. Set the timer to cut power during sleep hours, 11 pm to 6 am, which is the standard for most Fortress builds. The device loses power, reboots when power returns at 6 am, and is fully operational within 2-3 minutes. The off-grid load monitoring data confirms that the elimination of the circuit should show zero draw during the timer-off period.
I showed a Guelph client the before-and-after of the mechanical timer protocol on their three ghost-load devices: the satellite router, the OLED TV, and the smart coffee maker, all set to mechanical outlet timers that cut power from 11 pm to 6 am. The next morning, the SmartShunt time-to-go display showed the overnight drain had dropped from 15% to 3.8% of the battery bank. The client looked at the SmartShunt display and said, “I just found 11% of my battery bank.” That is 550 Wh, enough for an hour of microwave cooking or three hours of LED lighting, recovered from devices that were switched off. The off-grid load monitoring data had made the invisible visible as the baseline for future efficiency monitoring.
Off-Grid Load Monitoring vs Battery Monitoring – The Complete Picture
What the SmartShunt tells you: The SmartShunt measures total DC current flow every amp-hour leaving and entering the battery bank. It tells you how much energy you have, how fast you are using it, and how long until the bank reaches low voltage cutoff. It does not tell you which AC circuit is consuming the energy. As covered in our SmartShunt vs BMS guide the SmartShunt is the fuel gauge. The off-grid load monitoring system is the engine diagnostic it tells you which cylinder is misfiring.
What the Emporia Vue tells you: The Emporia Vue tells you which circuit is drawing power, how much it is drawing, and when it draws it. It tells you the fridge compressor cycles for 8 minutes every 45 minutes and draws 180W during each cycle. It tells you the well pump draws 1,200W for 90 seconds every time a tap opens. It tells you the satellite router draws 21W every minute of every hour of every day. This is the off-grid load monitoring data that transforms a Fortress from a system you monitor to a system you manage.
The combined monitoring standard: A complete Fortress monitoring installation includes both the DC-side SmartShunt and the AC-side off-grid load monitoring system. The SmartShunt answers: how much energy do I have? The Emporia Vue answers: where did my energy go? Together they provide complete visibility into the energy metabolism of the Fortress the data that makes intelligent load management possible and ghost load elimination permanent.
Quick Reference – Off-Grid Load Monitoring Ghost Load Targets
| Device | Typical Standby Draw | Daily Ghost Load | Annual kWh Waste | Timer Elimination |
|---|---|---|---|---|
| Satellite/cable receiver | 20-25W | 480-600Wh | 175-219kWh | Yes — 11pm-6am |
| OLED television | 1.5-3W | 36-72Wh | 13-26kWh | Yes — 11pm-6am |
| Internet router | 8-25W | 192-600Wh | 70-219kWh | Yes — 11pm-6am |
| Smart coffee maker | 1-5W | 24-120Wh | 9-44kWh | Yes — 11pm-6am |
| Gaming console | 10-20W | 240-480Wh | 88-175kWh | Yes — 11pm-6am |
| Total typical home | 50-80W | 1,200-1,920Wh | 438-701kWh | Timer protocol |
Pro Tip: Run the off-grid load monitoring phantom search quarterly not just at commissioning. Ghost loads change as devices are added, replaced, or updated. A new smart TV, a WiFi mesh node, a second router each addition increases the standby draw invisibly. The quarterly phantom search takes 10 minutes: close the Emporia app, switch off every device in the house, observe the whole-home reading. Zero should be the target. Anything above 5W is a new ghost that joined the Fortress since the last audit. As covered in our Solar System Labeling guide label every mechanical timer in the system – GHOST LOAD TIMER – 11PM-6AM so the Next Guy knows why the router goes offline at night and does not disable the timer thinking it is a fault.
The Verdict
Off-grid load monitoring is the diagnostic tool that finds the vampire the device stealing 15% of your battery bank while you sleep.
Three steps to complete the ghost load audit today:
- Install CT clamps on every breaker in the AC panel Emporia Vue or equivalent get circuit-level data before drawing any conclusions about battery drain
- Run the phantom search everything off, whole-home reading observed any draw above 5W is a ghost that needs a mechanical timer or a permanent unplug
- Compare SmartShunt DC draw with Emporia Vue AC consumption the reconciliation confirms inverter efficiency and identifies any DC direct loads not accounted for in the AC reading
You can’t manage what you don’t measure. Hunt the ghosts. Keep the batteries full.
Disclosure: This article contains affiliate links. If you buy through them, GridFree Guide earns a small commission at no extra cost to you.
Questions? Drop them below.