myenergi eddi — solar power diverter
Heat your water with sunshine you'd otherwise sell for pence.
Export pays buttons; hot water costs real money. The myenergi eddi watches your solar surplus and quietly sends it into the immersion heater instead of the grid — free hot water on every decent day, fitted by NICEIC electricians.
How it works
Surplus in, hot water out.
The eddi monitors generation and consumption, spots surplus power, and makes intelligent decisions multiple times a second about where to send it. Instead of leaving for the grid at pennies a unit, that exact surplus modulates into your heating.
Panels over-produce
Midday surplus builds — the house can't use it all.
eddi catches it
Export is detected in real time and redirected to the cylinder — even a low-generation trickle gets used.
Tank stores it
Your cylinder becomes a heat battery — hot water tonight, no oil or gas burned.
Why the eddi
The market's leading diverter, for good reason.
myenergi's research suggests most homeowners use less than half of what their panels generate at the moment it's generated — the rest drains to the grid for a fraction of what you pay to buy it back at night. The eddi closes that gap: designed to maximise self-consumption, it redirects surplus to your immersion heater, storage heaters, underfloor heating or any electric heater up to 3.68 kW.
- Boost when you need it — timed top-ups on cheap-rate power for winter mornings.
- App monitoring and control — see every diverted kilowatt-hour in the myenergi app.
- Single or three-phase — eddi for most homes, eddi+ for three-phase supplies.
- Plays well with batteries — battery fills first, eddi mops up what's left.
The myenergi ecosystem
eddi, meet Zappi.
The eddi shares an app and an ecosystem with the myenergi Zappi — the solar-aware EV charger we already install. Together they queue your surplus properly: car first, tank first, or balanced between them, all visible in one place. Add a harvi sensor and the wiring stays tidy too.
- One app for car and cylinder — myenergi's ecosystem, configured by us.
- Zappi GLO from £1,050 installed — on our EV charging page.
- Retrofit friendly — the eddi joins new or existing solar in an afternoon.
Straight answers
Diverter questions, answered honestly.
Do I need a hot water cylinder for an eddi?
For hot water, yes — the eddi feeds an immersion heater in a cylinder. But it can also divert to storage heaters, underfloor heating or any resistive electric heater up to 3.68 kW with a mechanical thermostat. Combi-boiler homes with no cylinder and no electric heating can't use one, and we'll say so rather than sell you a box that does nothing.
Diverter or battery — which first?
An eddi is a fraction of the cost of a battery and targets one job: turning surplus into hot water. A battery does more but costs more. Plenty of homes run both — battery fills first, eddi mops up the rest. We'll model which combination suits your usage — see battery storage.
How much of my hot water will solar cover?
In the brighter months, a well-sized array often covers most of a household's hot water. In winter it contributes rather than covers — and the eddi's boost function can time cheap-rate top-ups. It's a boiler's summer holiday, not its replacement.
Does the eddi work with the Zappi EV charger?
Yes — eddi and Zappi are both myenergi devices and share one app and one ecosystem. Surplus goes where you want it: car first, tank first, or balanced. We install and configure both.
Stop exporting. Start soaking.
Add an eddi to an existing array or a new install — fitted, configured in the app and working in an afternoon.