⚠️ This article describes the smart charging feature. This feature is currently only available to a small, selected group of test users. After this test period, smart charging will become available to everyone.
We believe you should be able to use a home battery worry-free, even if you are not a technical expert. Whether you only want to store your own solar power, help out the power grid in your neighborhood, or save money with a dynamic contract: the P1 Meter or kWh Meter on your main connection controls your Plug-In Battery fully automatically based on what your home needs at that moment.
Because every home is different, you can choose from three charging strategies. In the app, go to Settings > Devices > Plug-In Battery > Charging strategy.
Option 1: Net zero.
What is the Net zero strategy?
In the Net zero strategy, you use as much of your own solar power as possible. If you produce more electricity than you consume at that moment, the battery charges. Do you use more electricity than you produce? Then the battery discharges.
In practice, it works like this:
Do you consume 154 watts more than you produce? The Plug-In Battery delivers 154 watts.
Do you produce 182 watts more than you consume? The Plug-In Battery charges with 182 watts.
If your production or consumption changes, the Plug-In Battery switches extremely fast (±3 seconds) to get back to net zero. With this strategy, you continuously strive for a grid connection that is as close to zero as possible.
When do I choose the Net zero strategy?
Choose Net zero if a predictable performance of the Plug-In Battery is important to you. The battery reacts immediately to changes in production or consumption, without considering your predicted production and consumption later in the day. Do you value sustainability or want to save extra with a dynamic energy contract? Then consider smart charging with option 2 or 3.
Option 2: Smart and grid-friendly.
What is the smart and grid-friendly strategy?
The 'smart and grid-friendly' charging strategy constantly looks ahead. Based on your current and predicted consumption, the expected production, and the local weather forecast, charging or discharging is shifted to the best times. This helps prevent 'gridlocks' on the power grid (grid congestion) in your neighborhood, reducing the risk of grid outages and solar panel shutdowns.
The battery still aims for net zero, but delays charging to lower the daily solar peak and saves this energy for the times with the highest electricity demand in your neighborhood.
In summary, this means:
Charging is shifted to times with the most solar power in the neighborhood.
Discharging occurs when the demand for electricity in your neighborhood is highest, such as the morning and early evening.
For more information, read the chapter How does smart charging work?.
When do I choose the smart and grid-friendly strategy?
With 'smart and grid-friendly', you help stabilize the power grid in your neighborhood and make better use of sustainable energy. This charging strategy helps ensure that solar panels in your neighborhood shutdown less often due to excessive grid load.
Option 3: Smart with dynamic tariffs.
The 'smart with dynamic tariffs' charging strategy is specifically for users with a dynamic energy contract. This strategy is fundamentally similar to 'smart and grid-friendly', but is optimized for maximum savings with a dynamic contract.
Charging is shifted to the times when electricity prices are lowest, and the stored energy is used as much as possible during the times when electricity prices are highest.
When the export rate does not differ enough from the maximum consumption costs later in the day, the battery will not charge. This is because charging would not be cost-effective due to inverter efficiency (losses during charging and discharging) and battery depreciation.
Additionally, with this strategy, your Plug-In Battery charges from the grid at favorable times when little to no solar production is expected. This way, you can benefit from low electricity prices even without sunshine. This also takes into account inverter efficiency and a purchasing surcharge on top of the dynamic tariff rate. The battery only charges from the grid when the price difference is large enough. This accounts for the impact of the extra cycles this feature adds, weighed against the average lifespan of the battery.
Good to know: the 'smart and grid-friendly' and 'smart with dynamic tariffs' strategies learn from previous measurements. Actual consumption or weather can always vary. However, on average, smart charging is more sustainable and cost-effective (with a dynamic tariff) than the 'Net zero' strategy or complex manual control.
Other charging methods.
Manually charge to full once
With the 'Manually charge to full once' option, you charge your Plug-In Battery to 100% once. This is useful for testing your battery. When you enable this feature, the battery temporarily ignores the chosen charging strategy until it is full.
Charge for storage
For optimal lifespan and reliable operation, we recommend always leaving your Plug-In Battery connected. If a battery is not used for too long, it will slowly discharge, just like a car battery. As a result, the battery may fail to start up after an extended period.
Are you temporarily not going to use the battery, for example, due to renovations or moving? Then always use the charge for storage option first. This prepares the battery for an extended period without power. Go to Settings > Devices > Plug-In Battery > Options ··· (top right) > Charge for storage (60%).
Manual via API
For technically advanced users, it is possible to control the Plug-In Battery via the local API of the P1 Meter. This allows you to integrate the Plug-In Battery into your own smart home automations. This charging strategy becomes visible in the app as soon as the battery is controlled via the P1 Meter API.
If you choose smart charging ('predictive') via the API, 'Smart and grid-friendly' is used by default. Do you prefer the dynamic tariff variant of smart charging? Select 'Smart with dynamic tariffs' once directly in the HomeWizard app. This choice will then be remembered when you switch charging strategies using the API.
How does smart charging work?
With the 'smart and grid-friendly' and 'smart with dynamic tariffs' charging strategies, the Plug-In Battery does not just react to your current production or consumption. The system continuously creates a schedule to charge and discharge at the best times to maintain net zero. This ensures a stable power grid and cost savings if you have a dynamic energy contract. We collectively call these charging strategies smart charging.
The core of smart charging
Smart predictions: smart charging learns from your past electricity consumption and solar panel production. This creates an energy profile of your home. If there is a major change in consumption or production, such as from an EV charger, heat pump, or more solar panels, it takes a few weeks for smart charging to adapt to the new situation.
Weather forecast: the local weather forecast is continuously monitored. This forecast is used to predict how much electricity your solar panels will produce.
Electricity prices: smart charging looks at current electricity prices as an indication of grid demand. With the 'smart with dynamic tariffs' charging strategy, you can set whether you have a contract based on hourly or 15-minute prices. This optimizes the charging schedule for your situation.
A tailored plan: smartly combining your consumption, production, the weather forecast, and electricity prices creates a schedule. This schedule becomes more accurate when your solar panels are also connected, via an inverter integration, kWh Meter, or Energy Socket.
Continuous adjustment: what if the weather deviates from the forecast or you unexpectedly turn on a high-power appliance? No worries. The schedule is updated every 15 minutes based on what is actually happening in your home at that moment.
What does this mean in practice?
Smart charging makes smart decisions throughout the day:
Optimizing solar hours: is a lot of sun expected this afternoon? Then charging is postponed until the afternoon. This way, you charge when there is a surplus of solar power in the neighborhood.
Supporting the grid: is a peak in electricity demand expected in your neighborhood? Then the battery stores the power to avoid or reduce grid usage during that busy time.
Looking ahead to tomorrow: is there lots of sun today, but not tomorrow (when there will be high demand)? Then the battery saves today's energy for tomorrow or even the day after.
Smart response to consumption: are you temporarily using a lot of electricity (for example, with an oven or EV charger) when there is plenty of energy available (and the electricity price is low)? Then the battery can wait to discharge. Is the grid busy? Then the battery will discharge.
Smart pausing to save: with the 'smart with dynamic tariffs' charging strategy, charging can temporarily pause in the morning or late afternoon. This happens if it is more profitable to export power than to store it in the battery, or if the prediction is that you won't be able to empty the battery before tomorrow. You then save by exporting electricity and leaving room for tomorrow's lower electricity prices.
Frequently asked questions.
Do I need Energy+?
No, you do not need Energy+ or any other subscription to use these smart charging strategies for your HomeWizard Plug-In Battery. However, solar panel measurements via a kWh Meter or an integration via Energy+ will improve the accuracy of smart charging.
Does it matter which energy supplier I am with?
No, all strategies work independently of your energy supplier.
What does 'Early Access' mean?
Over the past year, we have worked hard on these innovative charging strategies. We have now made smart charging available as 'Early Access' so you can start using it, while we continue to fine-tune the software to the vast diversity of homes and situations in practice. Together with as many users as possible, we make the feature a bit smarter every day. This is how we build the future of affordable and sustainable energy together.
How much extra do I save with 'smart with dynamic tariffs' compared to Net zero?
Savings depend on your situation. The major difference is that a schedule is continuously created for the best moments to charge and discharge, rather than just reacting to the current situation. With a dynamic contract, the algorithm anticipates price differences by charging during the cheapest times and discharging during expensive peaks.
Do the benefits of 'smart with dynamic tariffs' outweigh the extra cycles for the battery?
Yes. Although smart charging uses the battery more actively, the extra savings outweigh the minimal wear and tear from the additional cycles the battery goes through.
Does smart charging take my electric car, heat pump, or other large appliances into account?
Yes. Smart charging adjusts every 15 minutes based on your current electricity consumption. The system constantly weighs whether it is more sustainable or cost-effective to discharge the battery at that moment. This ensures that the energy from your battery is always used at the most favorable time, even during extended periods of high power usage.
It is sometimes thought that charging a car from a battery results in more energy loss because the power is converted twice: once in the battery and once in the car. While this is technically correct, you do not suffer more loss when charging the car from a battery. Regardless of whether you use the power in the battery for your appliances or your car, the loss is the same. The same goes for the car: whether it charges from the grid or from a battery, the loss is the same.
What if the weather forecast is completely wrong?
Smart charging uses the local weather forecast to plan ahead. Smart charging continuously checks whether the actual situation in your home still aligns with that schedule. If the weather deviates or you unexpectedly consume more or less power, the schedule is adjusted based on the current status of your battery and consumption. Of course, the weather and your consumption can differ from predictions. Still, on average, smart charging is more sustainable and cost-effective (with a dynamic tariff) than the Net zero strategy or complex manual control.
Can I see what the battery is going to do with smart charging in the HomeWizard app?
In the today view of the Plug-In Battery graph, next to your current charge line, you will see a dotted line showing the expected current charge later in the day. This shows you, for example, why your battery is not charging now, even though the sun is shining: it has been calculated that doing so later in the day is more favorable, and the battery will still get fully charged. This expectation is continuously adjusted based on your consumption and expected production.
What happens if the internet goes down?
With any charging strategy, your Plug-In Battery is controlled by your P1 Meter or kWh Meter on the main connection. The Net zero strategy does not require an internet connection for control. Smart charging, however, does need an internet connection to create schedules. If the internet connection is lost, the last created schedule will still run for a few hours. If the internet outage lasts longer, the battery is automatically controlled according to the Net zero strategy. Without an internet connection, the battery status in the app will not be updated either.
Since I started using the smart charging strategy, my Plug-In Battery sometimes charges at 8 or 9 watts for a longer period. Why is that?
With smart charging, the battery switches on and off more frequently throughout the day. Therefore, the internal inverter remains switched on if the schedule indicates that the battery may need to kick in quickly.
The displayed consumption of a few watts is therefore not the battery charging; it is simply the standby consumption of the inverter 'standing by' to jump into action immediately. When the schedule indicates that the battery is not needed for a longer period, the inverter automatically turns off completely to save power.