Solar, batteries and EV charging: buy for open interfaces, not for Matter

The specification is finished. The shelf is empty.#

The dates are worth having straight, because the gap between them and reality is the whole story.

Now the certified product counts from the alliance's database as of September 2026:

Two EV chargers, and the first of those is a 12 or 24 volt switching controller for recreational vehicles and boats, not a wallbox you would put in a garage. Device energy management, the cluster that would let a controller shed or shift load across a whole house, has no products at all more than two years after it was published.

Nor is anyone visibly working on it. There is no certification record and no published Matter roadmap from Enphase, SolarEdge, Fronius, SMA, Tesla, Wallbox, Easee, Zaptec, myenergi or EcoFlow. That is effectively the entire mainstream market for residential solar, storage and charging.

The big three expose none of it#

Even for the small amount of energy data that does flow over Matter, the mainstream ecosystems are not a route to it.

• Apple Home. Apple's own list of supported Matter accessory types runs: air conditioners, bridges, lights, locks, outlets, switches, thermostats, blinds and shades, and sensors. No energy device types, and no energy measurement display.
• Alexa. Amazon's supported Matter category documentation, updated April 2026, has categories for appliances, closures, HVAC, lighting and plugs, robotics, sensors, and switches. There is no energy category.
• Google Home. More interesting: Google's developer documentation does list Electric Meter, Electric Utility Meter and Electrical Energy Tariff at Matter 1.3, and maps each of them to a Home ecosystem type of N/A. The device types are recognized and there is nowhere for them to surface to a user.

Even the humble case works only in three places. The electrical power and energy measurement clusters that a Matter smart plug uses to report watts are displayed by Home Assistant, SmartThings and Homey, and not by Apple Home or Alexa. That detail, and which plugs actually implement it, is in smart plugs and energy monitoring.

Where home energy actually works today#

Three platforms. All three of them read your hardware directly rather than waiting for a standard.

Home Assistant is the center of gravity. Its energy dashboard takes production, consumption, battery charge and discharge, grid import and export, individual device usage and gas or water, and turns them into daily and hourly views with cost. It ingests from local APIs, Modbus, MQTT and utility integrations. If you are serious about energy in the home, this is the tool the rest of the market is measured against.

SmartThings displays Matter energy measurement and integrates Samsung's own appliance and inverter ecosystem. Note the 2026 change: Samsung is ending free SmartThings API access in October 2026 with a paid Personal Plan for individual developers, which is a variable to watch if you plan to build on it.

Homey reads Matter energy data and has a usable energy view, and its Matter Bridge app can push devices from other radios into the ecosystems that cannot see them natively.

The comparison across all seven platforms is in the seven platforms compared, and the scoring behind local control claims is in the Local Control Index.

What to buy now#

The rule is simple and it has held for a decade: buy hardware that exposes a documented local interface, and treat every cloud API as temporary.

Solar and batteries#

• Enphase publishes a local gateway API on the IQ Gateway, so production and consumption data is readable on your own network without going through Enphase's cloud.
• SolarEdge inverters speak Modbus TCP using the SunSpec register model, which is the closest thing solar has to a real standard. If an inverter supports SunSpec over Modbus, any platform can read it and no vendor can turn it off remotely.
• Tesla Powerwall has a local API that Home Assistant and others consume directly.
• Circuit-level metering is where you get real granularity: Shelly EM and Pro 3EM devices clamp onto circuits, expose a local HTTP API and MQTT, log locally, and are supported natively. HomeWizard P1 meters read a utility meter's P1 port directly where your utility provides one. Emporia is the common whole-panel option, though its current hardware requires an internet connection and has no local storage.

EV charging#

The working open standard here is not Matter. It is OCPP, the Open Charge Point Protocol from the Open Charge Alliance. Version 1.6 is still the most widely deployed, 2.0.1 was approved as an international standard in 2024, and 2.1, published in 2025, adds bidirectional charging and distributed energy resource control. A charger that speaks OCPP can be pointed at a management system you choose, including one running on your own hardware.

Ask three questions of any charger:

1. Does it speak OCPP, and to a backend you can change?
2. Does it have a local API or Modbus interface, so basic control survives with no internet?
3. Does load management or solar-surplus charging require a subscription?

Open interfaces to look for, in priority order#

Why energy is the strongest current argument for a local platform#

Every other category has a defensible cloud story. Energy does not, for four reasons.

Polling rate. Useful energy control runs on seconds, not minutes. Diverting surplus solar into a water heater or a car means reacting to a cloud that changes second by second. Cloud APIs rate-limit, and a round trip to a data center to decide whether to raise charging current by one amp is the wrong architecture. The latency arithmetic is in local versus cloud control.

Data volume and retention. Energy is the one smart home dataset you genuinely want to keep for years, to compare a season against the same season two years ago. Vendor clouds routinely keep months. A local database keeps whatever your disk holds.

Outage behavior. A battery and a solar array are things you own specifically because the grid or the internet might not be there. An energy system whose control logic lives in someone else's data center fails in the exact scenario it was bought for. See what still works when the internet goes down.

Longevity. Solar arrays are twenty-five year assets. Batteries are ten to fifteen. Nothing in consumer software lasts that long. The only durable plan is hardware that speaks an open protocol on your own network, read by software you can replace independently.

What would have to change#

For Matter to become the right answer here, three things need to happen in order: a mainstream inverter or charger vendor certifies a product, a major controller ships a user-facing energy view, and device energy management gets an implementation that can actually shed load. None of the three has happened. We track it in the Matter feature gap tracker, and Matter for energy covers the cluster detail.

Until then, the buying rule does not change: open interfaces, local reads, and a platform that can hold the data.