If you have solar panels and an electric vehicle — or are planning to get both — the myenergi Zappi is almost certainly the EV charger you have heard recommended most often. And for good reason. The Zappi is the only mainstream home EV charger specifically designed to work in harmony with solar generation, allowing you to charge your car using surplus solar electricity rather than grid power. In this review, we examine whether the Zappi lives up to its reputation, and whether it is the right choice for your home.
Why the Zappi Is Designed for Solar Homes
Most home EV chargers are simple devices: you plug in your car and it charges at the maximum available rate, drawing power from the grid. The Zappi is fundamentally different. It is designed to monitor your home's solar generation in real time and dynamically adjust the charging rate to match your surplus solar output. Instead of exporting that surplus to the grid at a low SEG rate, the Zappi diverts it directly into your car's battery at no additional cost.
This concept — known as solar divert or solar-matched charging — is the Zappi's defining feature. For a home with 4-6kWp of solar panels, the Zappi can deliver a substantial portion of your annual EV charging from free solar electricity, dramatically reducing your transport fuel costs.
Three Charging Modes Explained
The Zappi offers three distinct charging modes, each suited to different situations:
- Fast Mode: Charges at the full available rate (up to 7kW on single-phase or 22kW on three-phase), drawing power from the grid as needed. This is identical in behaviour to a standard dumb charger and is useful when you need to charge quickly regardless of solar generation.
- Eco Mode: The Zappi blends solar generation with grid power to maintain a minimum charge rate (1.4kW minimum for most vehicles). As solar generation fluctuates throughout the day, the Zappi automatically adjusts the balance between solar and grid power. This mode ensures your car always charges, but prioritises solar energy where available.
- Eco+ Mode: The Zappi charges exclusively using surplus solar electricity. If solar generation drops below the minimum threshold (around 1.4kW), charging pauses rather than drawing from the grid. This mode delivers the lowest possible charging cost — effectively free — but requires patience on cloudy days.
Switching between modes is straightforward using the Zappi's physical dial or the myenergi app.
Key Specifications
The Zappi is available in two power variants. The standard single-phase unit provides up to 7kW of charging power, sufficient to add around 25-30 miles of range per hour for most EVs. A three-phase version delivers up to 22kW, adding 75-80 miles per hour, and is more suitable for properties with three-phase electricity supplies or commercial applications. Both versions use a Type 2 universal connector, compatible with all modern electric vehicles and plug-in hybrids sold in the UK and Europe.
The Zappi has an IP65 weatherproof rating, making it suitable for outdoor installation, and it comes in tethered (cable attached) or untethered (socket) configurations. The tethered version is more convenient for daily use; the untethered version is preferable if you charge multiple vehicles with different connectors.
The myenergi App
The myenergi app is available for iOS and Android and provides real-time monitoring of your Zappi's charging activity alongside your solar generation, home consumption, grid import, and grid export. The dashboard gives you an instant picture of where your home's energy is coming from and where it is going, making it easy to optimise your charging schedule.
The app also allows you to set boost targets (charge to a specific level by a specific time), configure scheduled charging to take advantage of off-peak electricity tariffs like Octopus Go, and review historical charging data. Over-the-air firmware updates are delivered automatically. The app is generally well-regarded, though some users report occasional connectivity issues that are usually resolved by restarting the hub.
Integration With GivEnergy and Tesla Powerwall Batteries
The Zappi integrates naturally with home battery storage systems, though the interaction requires some thought. When your solar panels are generating and your home battery is already full, the Zappi can divert remaining surplus into your car. When the battery is still charging, you need to decide whether to prioritise filling the home battery or the car battery — this depends on your energy usage patterns and how important an evening electricity reserve is to you.
The myenergi ecosystem also includes the Eddi solar divert immersion heater controller, which works alongside the Zappi to divert solar surplus into a hot water cylinder. Using the myenergi hub, you can set priority rules — for example, prioritising the hot water cylinder before the car — giving you granular control over how your solar generation is used.
The Zappi Harvi: Wireless Solar Monitoring
For the Zappi to operate in Eco or Eco+ mode, it needs to know how much electricity your solar panels are generating. This is achieved either via a wired CT clamp on your consumer unit or using the Zappi Harvi — a wireless energy monitor that attaches to your solar generation circuit and transmits data to the Zappi wirelessly. The Harvi is particularly useful when the Zappi is installed in a garage or outbuilding that is not directly connected to the main consumer unit, avoiding the need for additional wiring.
Installation Requirements
Zappi installation must be carried out by an OZEV-approved installer. A qualified electrician will assess your home's wiring, confirm your consumer unit has adequate capacity, and install a dedicated circuit for the charger. The installation typically takes 2-4 hours. D&R Energy is an OZEV-approved installer and can install the Zappi as part of a complete solar and EV charging package. Visit our EV charger installation page for more details.
Real-World Performance: How Much Free Charging Can You Get?
A typical solar home in the South West with a 4.5kWp system and a Zappi in Eco+ mode can expect to charge their EV for free during a significant portion of sunny days between March and October. On a good summer day, a 4.5kWp system may generate 20-25 kWh of electricity, of which a well-optimised household might divert 10-15 kWh into the car — adding 35-50 miles of range at zero cost. Over a full year, a solar home in Somerset or Bristol can realistically achieve 30-50% of total EV charging from free solar electricity, saving £300-£600 per year on charging costs depending on mileage and grid tariff.
Combined with a solar panel system and home battery, the Zappi creates a highly efficient, low-cost energy ecosystem. To explore your options, contact D&R Energy for a free consultation on solar, battery storage, and EV charging tailored to your home.
