Solar + Home Assistant USA: Self-Consume After NEM 3.0 (2026)

If you put solar on your roof in California before April 15, 2023, you are now living in two electricity markets at once. The kilowatt-hour you consume inside the house is still worth somewhere between roughly $0.30 and $0.45 during PG&E, SCE or SDG&E peak hours. The kilowatt-hour you export under NEM 3.0 — the Net Billing Tariff that replaced retail-rate net metering — is worth, on annual average, somewhere around $0.05 to $0.08. That is a four to seven times gap on every exported kilowatt-hour, every sunny afternoon, on a system you have already paid for. Home assistant solar self consumption is the lever that closes the gap, and for newer California solar owners it is no longer optional if the array is going to pay back inside a decade.

Outside California the numbers are kinder, but the shape of the problem is the same. Hawaii has been on time-of-export rates for years. Arizona's investor-owned utilities (APS, SRP, TEP) settled on avoided-cost-style exports long before NEM 3.0. Texas has no statewide net metering at all — your export rate is whatever your retail provider's "solar buyback" plan happens to be that month, anywhere from 4¢ to 20¢ per kWh. New York's VDER stack pays less than retail. Massachusetts SMART and the remaining traditional net-metering states still credit close to retail, and there the self-consumption ratio is closer to 1.5–3x. Read your tariff before you read the rest of this guide, because the maths of which automations are worth the trouble depends entirely on that ratio.

Why solar default behavior fails US homes

A typical US residential solar system is 6 to 10 kW and produces somewhere between 8,000 and 14,000 kWh a year depending on latitude — Phoenix and Seattle differ by roughly 2x. Generation peaks between late morning and mid-afternoon. The household, meanwhile, runs the opposite curve: morning rush, empty house, baseline of a refrigerator and a router, then everyone home for the AC, oven, dishwasher and EV plug-in starting around 5 or 6 PM. Under PG&E's E-TOU-C, that 4–9 PM window is the most expensive electricity you buy all year.

Your inverter, on its own, does almost nothing about this. Enphase microinverters and SolarEdge string inverters convert DC to AC, report production to a cloud portal, and dump anything the house is not using to the grid at the export rate. Tesla Solar and Sol-Ark hybrid systems will hold some energy in a Powerwall or coupled battery for the evening, but none of them will talk to your heat-pump water heater, your EV charger, your pool pump, or your thermostat. They have no view of tomorrow's forecast, no view of your TOU schedule, and no view of the fact that the dishwasher is a 1.2 kWh load that would run perfectly happily at 1 PM on a Tuesday.

Home Assistant is the layer that stitches those pieces together. It reads the inverter in real time, watches what the rest of the house is doing, pulls a solar forecast, knows what hour your utility considers "peak", and moves loads around to soak up generation before it leaves the property at avoided-cost rates. Before you build any of it, work out where your time-of-use rate spreads bite — the TOU electricity guide is the companion read.

Reading your inverter into Home Assistant

None of this works until Home Assistant can see your solar data, and the integration story for US inverters is a mixed bag.

Enphase has the strongest local-first story in the US market. The Envoy gateway exposes a local JSON API that Home Assistant's native Enphase integration reads directly — no cloud round-trip, fast polling, survives Enphase's own cloud outages. The well-known gotcha: on recent Envoy firmware, the local production endpoint is rate-limited and requires a per-installer token unless you subscribe to Enphase's paid Enlighten tier. The community has documented the token refresh dance thoroughly, but expect a few hours of setup friction. Polling intervals on non-Enlighten setups land around once every few minutes, which is fine for dashboards and slow automations and marginal for fast load-shedding.

Tesla Solar and Powerwall have an official Home Assistant integration as of 2024, talking to the local Tesla Gateway. Solar production, Powerwall state of charge, grid flow and home consumption are all exposed cleanly. This is one of the smoothest setups in the US market once you have it adopted.

SolarEdge has a native Home Assistant integration that uses the SolarEdge monitoring cloud API. It works, but it is rate-limited and polls slowly, which makes it useful for reconciliation and dashboards but weak for fast automation triggers. A local Modbus TCP connection to the inverter's Ethernet port is the better option if your installer enabled it — most did not, and re-enabling Modbus typically requires a service call.

Sol-Ark hybrids are popular with off-grid and resilience-focused owners and have a well-maintained community Modbus integration. Generac PWRcell has cloud-only access through Generac's portal and a brittle community integration — treat it as data-only, not as an automation surface. Schneider XW users mostly go through a Modbus gateway.

If you do not have an inverter integration you trust, the fallback in the US is a whole-home circuit-level monitor. The Emporia Vue 3 (base unit from $99, multi-circuit bundles around $160) is the price-performance winner and has a clean Home Assistant integration via HACS. The Sense Home Energy Monitor at $349 uses ML inference to break out individual loads and has a native integration too — accurate on generation and total consumption, less reliable on its appliance-level guesses. For owners who want whole-home programmable load control, the Span Panel at $3,500 to $5,000 is overkill for monitoring but unique in letting you script which circuits get power at which times.

The four big self-consumption moves

Once Home Assistant can see what your panels are doing, there are four moves that deliver most of the savings. Under NEM 3.0 the order changes — battery and EV charging move up the list because the export rate is so poor. Under traditional net metering, the order matters less.

Self-consume into a heat-pump water heater

The US equivalent of the UK's solar diverter-into-an-immersion is the heat-pump water heater. The category is dominated by the Rheem ProTerra (also sold as Performance Platinum, Wi-Fi enabled, schedulable from Home Assistant via the Rheem cloud integration), the AO Smith Voltex (similar capability, sometimes via local Econet), and to a lesser extent the older GE GeoSpring family. These are 4.5 kWh-per-day appliances on a typical household profile, drawing roughly 500W in heat-pump mode and up to 4.5 kW if they fall back on the resistive backup element.

The play is straightforward: schedule the heat-pump cycle into the solar peak rather than letting it run on demand or overnight. On a sunny day, that absorbs essentially all of the water heater's daily energy at zero export cost. On a cloudy day, you let it fall back to its normal schedule. Home Assistant decides which day it is based on the morning forecast.

For homes without a heat-pump water heater but with a traditional tank-style electric water heater, a smart relay or contactor on the heater circuit can deliver a crude version of the same behavior — turn on when solar export exceeds the element draw for a sustained window, turn off otherwise. The savings are smaller than a true diverter but the hardware cost is trivial.

Note that the UK pattern of a dedicated proportional solar diverter (Eddi, iBoost+) barely exists as a category in the US, because the typical US home does not have an immersion-heater-on-a-tank in the UK sense, and because rooftop systems are usually large enough that the binary on/off approach captures most of the value anyway.

Charge a home battery on solar, discharge into peak

Under NEM 3.0 specifically, adding a battery to a California solar install changes the math of the whole system. Every kWh you store at solar's $0.05–$0.08 avoided-cost export rate and discharge during the $0.30–$0.45 peak window is worth roughly $0.25–$0.40 of arbitrage. That is the economic case the CPUC explicitly engineered when they designed the tariff.

The dominant US residential battery options are the Tesla Powerwall 3 (13.5 kWh, integrated inverter, 11.5 kW continuous), the Enphase IQ Battery 5P and 10C (modular AC-coupled, pairs naturally with Enphase microinverters), the Franklin aPower 2, and the Generac PWRcell. All four expose state of charge and dispatch controls to Home Assistant to varying degrees — Tesla and Enphase are the smoothest, Franklin is workable, Generac is read-only in practice.

The Home Assistant logic is the same in shape across all of them: charge from solar surplus during the day, hold the charge through the late afternoon, discharge to cover household load through the utility's peak hours, sit empty overnight unless the forecast says tomorrow will be cloudy in which case top up on off-peak grid. A pure manufacturer app cannot reason about tomorrow's forecast; Home Assistant can.

California owners should check whether they qualify for the SGIP (Self-Generation Incentive Program) rebate before they buy. The equity-tier rates are dramatically higher than the general-market tier, but eligibility is narrow and the program is oversubscribed in waves. Outside California, ConnectedSolutions in Massachusetts, Rhode Island and Connecticut pays homeowners per kWh dispatched during summer demand events; ConEd in New York runs similar demand-response programs. Home Assistant can be configured to participate in those events while still protecting a reserve for the household.

Ramp EV charging to solar production

An EV is the largest controllable load most US households will ever own. A Level 2 charger pulls 7 to 11 kW, which means a 7 kW solar array on a sunny day can run essentially nothing but the car. Under NEM 3.0 that is the difference between exporting at avoided cost and using your own production at retail.

The cleanest US setups: a Tesla Wall Connector managed via the TWCManager add-on (the local-protocol bridge is the most flexible way to ramp Tesla charging in real time), a Wallbox Pulsar Plus with its solid native Home Assistant integration, an Emporia EV charger which is one of the cheapest options with HA support, or a ChargePoint Home Flex through the ChargePoint cloud integration. The automation pattern is the same across all of them — read solar export every 30 to 60 seconds, ramp the charge current up or down to match available surplus, hold the car at minimum-charge-rate (typically 6 A, about 1.4 kW) when surplus drops below that, and pause entirely below a configurable threshold.

Tesla vehicle integration (separate from the Wall Connector) is now a native Home Assistant integration built on Tesla's Fleet API — added to HA Core in 2024 after Tesla deprecated the older Owner API. Presence detection, charge state and charge limits are available without third-party services like Teslemetry or Tessie, though both of those remain popular for richer feature coverage.

Schedule big loads around solar and TOU

Dishwashers, clothes washers, dryers, pool pumps and HVAC pre-cooling are the controllable loads worth automating after the big three. Pool pumps in particular are a US-specific opportunity — a typical variable-speed pool pump in California or Florida runs 6 to 10 hours a day at 500–1,500W, which adds up to 1.5 to 3 kWh of daily load that can sit entirely inside the solar peak with no behavioral cost.

HVAC pre-cooling is the other lever and it is enormous in the US South and Southwest. The pattern: between 1 PM and 3 PM, with solar running and grid rates still in shoulder or off-peak territory, drop the thermostat setpoint a few degrees below your evening target. The house mass absorbs that cooling. When 4 PM peak hits and your utility starts charging $0.45 a kWh, the AC barely runs because the house has already been pulled down. Ecobee, Nest, Honeywell T9 and Mysa thermostats all expose setpoint control to Home Assistant cleanly. The savings on a hot California or Arizona afternoon under NEM 3.0 plus E-TOU-C are larger than almost any other single automation in this guide.

For owners with a Span Panel, all of this collapses into a single dashboard — each circuit can be programmed against the solar production and TOU price signals directly at the panel level. Span is expensive for what it is, but for new-build or major-renovation projects it removes a lot of the per-appliance integration work.

Summer vs winter, north vs south

US solar is more seasonal than people expect even in the Sun Belt. A 10 kW Phoenix array in June can comfortably run the AC, charge a Powerwall, heat the water and put 30 kWh into an EV in a single day. The same array in December is producing maybe 25 kWh total, most of which the house consumes in baseline load. In Seattle or Boston the December reality is harsher and the optimization shifts toward "do not waste the little there is" — charge the battery on cheap off-peak grid, schedule the water heater for a shoulder hour, and skip solar-following automations entirely until February.

This is where Home Assistant earns its keep over any single-vendor app. It can pull a Solcast or Open-Meteo forecast, see that tomorrow's production will be 8 kWh instead of 50, skip the solar-charging automation for the day, and pre-heat the water on an off-peak grid window instead. None of the inverter or battery vendors do this reasoning natively.

What to watch for

A few things that catch US solar owners out, worth knowing before you wire any of this up.

NEM 3.0 export rates are time-varying, not flat. The Avoided Cost Calculator value changes by hour and by month, and the worst export hours are the same midday hours when your array is producing the most. That asymmetry is the entire reason self-consumption matters so much under the new tariff. A Home Assistant automation that thinks "any export is fine" is leaving real money on the table — it needs to know the current export rate to decide whether to nudge a load on or off.

True-up bills are annual under NEM in California. PG&E and SCE settle the year once, on your true-up anniversary date. That means an automation that goes silently wrong in May might not show up in the bill until the following April. Build alerting that pages you when the inverter integration stops returning data, when the battery stops cycling, when the water heater schedule fails to fire. The longer the feedback loop, the more important the monitoring layer.

Enphase rate-limits hit fast automations. If you are ramping an EV charger off live solar export, the Envoy local API on non-Enlighten setups will not give you the polling frequency you want. Pair the Envoy with an Emporia Vue or Sense for fast-loop data and use the Envoy for the slower-loop reconciliation.

Texas, ERCOT and competitive retail. Your "export rate" is whatever your retail provider's solar buyback plan pays this month, and the plan-shopping market is volatile. Build the automations so the export rate is a configurable number, not a hard-coded assumption. The same goes for any state where utilities revise net metering rules — Arizona, Nevada and Hawaii have all changed terms on existing customers in the last decade.

The setup without the homework

Everything above is buildable by a determined owner with a few weekends, a fast internet connection, and a tolerance for cloud APIs that occasionally rotate without warning. The hard part is not the initial setup. It is that Enphase ships a token format change, the Tesla integration breaks for a release cycle, the Solcast free tier moves its rate limits, your utility quietly publishes new TOU hours, and the automation that was saving you $80 a month in August quietly stops working in October and nobody notices until the true-up bill arrives in April.

If you want the self-consumption gains without owning the maintenance, that is exactly what habbb does in the US BYOHA program. You bring your existing solar, battery, EV charger, water heater and thermostat; we adopt the Home Assistant instance, build the automations against your specific TOU plan and inverter, and keep them running — tested updates, monitoring, daily backups. Have a look at the US managed service overview, and if you want the wider context of how solar fits alongside HVAC, EV and TOU plays, the US energy savings guide is the bigger picture.

The panels are already on your roof. Under NEM 3.0 the value gap is wider than it has ever been. Closing it is the cheapest energy upgrade you will make.