Project · Solar Surplus Control for Plug-In Devices
Use Excess Solar Power for Plug-In Devices
When your solar PV system produces more electricity than your home consumes, ecoMain can detect the surplus and enecess HEMS can automatically switch on ecoPlug. Use more of your own solar energy to charge portable power stations, e-bike batteries, and other suitable plug-in devices during sunny hours.
The Problem: Solar Surplus Is Often Exported Instead of Used
Solar production changes throughout the day. Around midday, a PV system may generate more electricity than the home consumes. If no suitable load is running at that moment, the excess power may be exported to the grid.
At the same time, many small devices do not need to be charged immediately. Portable power stations, e-bike batteries, garden tool batteries, dehumidifiers, and other plug-in loads can often wait until solar energy is available.
The challenge is knowing when excess solar energy is available and switching on the right device at the right time without checking an app all day.
What You Gain
By combining ecoMain, ecoPlug, and enecess HEMS, solar households can make better use of excess PV energy without manually switching devices on and off.
Run flexible plug-in loads when solar surplus is available instead of exporting all of the extra energy.
Let HEMS decide when ecoPlug should switch on or off based on configured thresholds.
Direct excess solar energy to portable power stations, e-bike batteries, or other chargers.
Use multiple ecoPlugs and decide which device should run first when surplus power is limited.
ecoPlug can monitor the energy consumption of the connected device.
Start with one ecoPlug and add more flexible loads as your solar use case grows.
The enecess Solution
The enecess system combines energy monitoring, smart plug control, and HEMS software.
ecoMain monitors the home's energy flow, including grid import/export, solar PV generation, and selected circuits. ecoPlug controls and measures plug-in devices. enecess HEMS uses the monitoring data to determine when enough excess solar energy is available and can automatically switch ecoPlug on or off according to the configured strategy.
This article focuses on plug-in devices that can be safely switched on or off through ecoPlug, not large fixed installations or loads that require continuous power modulation.
How It Works
Solar Surplus Control Flow
| Condition | System Action | Customer Result |
|---|---|---|
| Solar surplus is above the configured threshold | enecess HEMS switches ecoPlug on | The connected device starts charging or operating |
| Solar surplus falls below the threshold | enecess HEMS switches ecoPlug off | The system helps avoid charging from the grid |
| Multiple ecoPlugs are configured | HEMS follows the load priority order | Higher-priority devices can run first |
| The connected device consumes energy | ecoPlug measures device-level power and energy | You can see how much energy the device has consumed |
Product Roles in This Project
This application works because the system separates monitoring, decision-making, and switching. ecoMain provides the energy data, enecess HEMS applies the automation logic, and ecoPlug controls the plug-in device.
Example: Charging a Portable Power Station with Excess Solar Power
In this example, a portable power station charger is connected to ecoPlug. During the day, ecoMain monitors energy flow at the main circuit and detects whether the home is importing power from the grid or exporting excess PV power.
When the available solar surplus is above the configured threshold, enecess HEMS switches ecoPlug on and charging of the portable power station begins. If the solar surplus falls below the threshold, the system can switch ecoPlug off to help avoid drawing grid power for charging.
When multiple ecoPlugs are used, one device can be assigned a higher priority than another. For example, a portable power station for backup power can run before a lower-priority e-bike charger when surplus power is limited.
ecoMain monitors the main energy flow and detects whether the home is importing from or exporting to the grid.
ecoPlug automatically switches the connected plug-in load according to the configured solar surplus strategy.
A portable power station or similar flexible device can be charged when enough excess PV energy is available.
The enecess App helps users understand energy flow and confirm whether surplus energy is being used.
Other Suitable Plug-In Devices
The same control logic can be used for other plug-in devices, as long as the device is suitable for automatic on/off control through a smart plug and does not exceed ecoPlug's rated power.
Charge during sunny hours and keep stored energy available for later use.
Shift charging to periods when excess PV power is available.
Charge garden tools and other battery-powered devices using more self-generated energy.
Run flexible household loads automatically when solar energy would otherwise be exported.
Use only if the device is within ecoPlug's rated power range and is safe for automatic switching.
Schedule or start operation during periods of excess PV power if the pump is suitable for smart plug control.
When This Setup Works Best
This setup is especially useful when:
- Your solar PV system often exports electricity during the day
- Exported electricity is worth less than imported electricity
- You have flexible plug-in loads that can run during sunny hours
- You want to increase PV self-consumption without manual switching
- You prefer an app-based solution instead of building custom automations
Limitations and Safety Notes
ecoPlug should only be used with devices that are within its rated current and power range. Do not use automatic switching for devices that require supervised operation, have special startup requirements, or may be damaged by repeated on/off switching.
For portable power stations and battery chargers, always follow the manufacturer's instructions. The enecess system controls AC power through ecoPlug; it does not directly control the internal battery management system of the connected device.
If a load requires continuous power modulation rather than simple on/off control, a smart plug may not be the best solution. Dedicated controllers or devices with adjustable power control may be more suitable.
FAQ
Can I charge a portable power station only when solar surplus is available?
Yes. With ecoMain monitoring the home's energy flow and ecoPlug controlling the charger, enecess HEMS can switch charging on when excess solar power is available and switch it off when surplus power drops.
Can I use this for an e-bike charger?
Yes, if the e-bike charger is suitable for smart plug control and does not exceed ecoPlug's rated power.
Does this require Home Assistant?
No. This scenario can be managed through enecess HEMS and the enecess App. Advanced users can also integrate enecess devices with open platforms where supported.
Can I connect multiple ecoPlugs?
Yes. Multiple ecoPlugs can be used for different devices, and load priority can be configured based on the available solar surplus.
Will this prevent all grid import?
Not necessarily. The goal is to increase PV self-consumption. Actual grid import depends on solar production, household load, device power, threshold settings, and response time.
Can I use ecoPlug for an EV charger, heat pump, or water heater?
This article focuses on smaller plug-in devices. EV chargers, heat pumps, water heaters, and other high-power or professional loads should be evaluated separately for rated power, installation requirements, and manufacturer safety instructions.
Where to Find the Detailed Setup Steps
This project article is intended to explain the use case, customer benefits, and system boundaries. Detailed app configuration steps should be provided in a separate setup guide so buyers and support users can follow the exact workflow without making this page too long.
Recommended guide title: How to Set Up Solar Surplus Control for Plug-In Devices with ecoMain and ecoPlug
Recommended location: /pages/support/solar-surplus-plug-in-control-setup
Link to the setup guide from this project page and link back to this use case page from the guide. This keeps the SEO page focused while still giving existing customers a clear implementation path.
Build Your Solar Surplus Control Setup for Plug-In Devices
ecoMain and ecoPlug help solar households automatically use more of their own PV energy. Start by monitoring grid import/export with ecoMain, then add ecoPlug to control flexible plug-in loads such as portable power stations, e-bike chargers, and other suitable devices.