Installing solar panels and a heat pump is usually framed as the finish line: you've electrified, you've gone renewable, the savings will follow automatically. In practice, the hardware is only half the story. Two households with identical solar arrays and identical heat pumps can end up with very different electricity bills, and the difference almost always comes down to one thing: controllability — whether the system can be steered to actually use the energy you generate, instead of just producing it.

What "Controllability" Actually Means

Controllability is not the same as having a smart-looking app for your inverter. It means two specific capabilities:

• Visibility — you (or an automation) can actually see what's happening: how much the panels are producing right now, how much the heat pump is drawing, what the battery is doing.
• Steerability — you (or an automation) can act on that information: tell the heat pump to run now because there's solar surplus, or hold off because electricity is expensive at this hour.

A system that only has the first half is a dashboard. A system with both is an optimizer. Most PV and heat pump installations ship with just enough of each to satisfy the installer's own app — closed, single-brand, and not built to talk to anything else.

Why Solar Alone Isn't Enough

The core problem is timing. A typical home generates most of its solar power in the middle of the day, when nobody is home and consumption is low. Without a plan for that surplus, most of it gets exported to the grid at low compensation rates — and the same household buys electricity back at full retail price in the evening, when demand (and the heat pump) actually runs.

Self-consumption — using your own solar power directly instead of exporting and re-buying it — is the single biggest lever most homeowners have. It doesn't require a bigger array or a bigger battery; it requires the biggest controllable load in the house (almost always the heat pump, sometimes an EV charger) to run when the sun is producing, not on a fixed schedule set at installation.

The Heat Pump Is Your Biggest Controllable Load

A heat pump typically draws several kilowatts while running — more than almost anything else in the house — which makes it the natural target for solar-aware control. Two things make this possible:

• Thermal mass as storage. A house's structure and its hot water tank both hold heat. Running the heat pump a little harder while solar is abundant, then coasting on that stored heat later, works like a free thermal battery.
• Standard signaling. Many heat pumps support a simple interface (often called SG-Ready in Europe) that lets an external controller tell it "there's cheap or surplus power available, ramp up" or "hold back." Without this signal — or without something reading and acting on it — the heat pump just runs on its own internal logic, blind to what the solar array or the electricity tariff is doing.

The same logic extends to dynamic electricity tariffs: even without solar, a heat pump that can shift its heaviest running to the cheapest hours of the day captures savings a fixed schedule simply can't.

Three Ways Controllability Pays Off

Getting There: Concepts, Visibility, and Reach

Turning a passive installation into a controllable one comes down to three separate problems, and it's worth being honest that no single product solves all three:

• Understand the concepts first. Before you can evaluate whether a heat pump or inverter is genuinely controllable — or just marketed that way — you need the vocabulary: what SG-Ready actually promises, why flow temperature affects efficiency, what "local control" buys you over a cloud-only app. QLines' free Energy Planning Guide was written for exactly this: a vendor-neutral walkthrough of PV and heat pump fundamentals, including a dedicated chapter on why local control matters and how to coordinate PV surplus with a heat pump in practice.
• See what's actually happening. Controllability decisions are only as good as the data behind them — you need to know your real consumption and cost patterns before you can tell whether a change helped. UtilityControl tracks electricity, heating, gas, and water meters over time, so you can see the before-and-after of any optimization instead of guessing.
• Have the infrastructure to reach your devices. Local control setups — a Raspberry Pi running Home Assistant, an ESP32 talking Modbus to an inverter, a small hub bridging the heat pump's SG-Ready contacts — need to be monitored and managed like any other piece of infrastructure. RemoteControl provides secure, agent-based monitoring and remote management for exactly these kinds of embedded devices, so the hardware making your automation possible doesn't become its own maintenance burden.

Frequently Asked Questions

What does SG-Ready actually mean?

SG-Ready ("smart grid ready") is a simple, standardized two-contact interface many heat pumps support, letting an external controller signal one of a few operating states — such as "run harder, cheap or surplus power available" or "reduce consumption." It's a starting point for coordination, not a full remote-control protocol, and its practical limits are worth understanding before you rely on it.

Do I need a dynamic electricity tariff to benefit from controllability?

No. Self-consumption of your own solar surplus already pays off on a flat tariff, since the alternative is exporting cheap and buying back expensive. A dynamic tariff adds a second, independent savings lever on top of that.

Can I add controllability to a system I already own?

Often, yes. Many existing inverters and heat pumps expose a local interface (SG-Ready contacts, a Modbus register, a manufacturer API) that was simply never connected to anything. The gap is usually not the hardware — it's the visibility and the automation layered on top of it.

Does UtilityControl or RemoteControl control my heat pump directly?

No — they solve adjacent problems. UtilityControl gives you the consumption and cost visibility to know whether your setup is actually working, and RemoteControl gives you secure remote access and monitoring for the devices (like a Home Assistant hub) that do the actual steering. The Energy Planning Guide is where you learn the concepts to set that steering up correctly in the first place.