Predictability Is Paramount: More Knowledge of Advancing Technologies Is Key to Achieving Desired Outcomes

Solar arrays, energy storage systems, electric vehicle (EV) chargers, high-efficiency heating and cooling equipment. These have huge potential to improve grid management and customer satisfaction.

But what if they’re deployed or used, unknowingly, in ways that prevent them from meeting their expected outcomes? That’s a problem.

Efficient technologies may be inefficient at inopportune times

Consider heat pumps. Highly efficient. Great for comfort and humidity control. Quiet.

But standard air-source systems, on their own, may be adding to demand when the grid can least handle it.

We studied manufactured homes that used either an electric furnace or a heat pump. Across multiple winter seasons, the heat pumps were more efficient overall, but as the outside temperature dropped and auxiliary strip heat kicked in, the equipment began demanding more power than the furnaces.

Now, there are workarounds. Changing the cut-in temperature, for example, will update when strip heat turns on. But that doesn’t happen automatically and comes with its own obstacles.

Technology is also improving. Dual-fuel and cold-climate heat pumps (which we’re researching as well) avoid the need for supplemental heat. Still, around 40% of North Carolina households rely on heat pumps for heating, and if a good chunk of those aren’t relieving the grid as much as expected, that’s worth knowing.

Different control strategies should be better understood

When it comes to implementing demand response, improper configurations — whether in relation to device communication, dispatch or installation — can be a major hurdle.

We looked at the effects of different control setups on heating and cooling curtailment. Study participants had their systems controlled through either adjustments to their smart thermostats or a switch attached to their outdoor compressor.

The households relying on their smart thermostat had their energy use managed as planned. However, those with the control switch initially did not: The switches weren’t deploying correctly and didn’t reduce demand at all. Through data monitoring — comparing actual with expected system load profiles — we learned that this occurred because of how they were configured in the dispatch software.

Flexible loads can interact in inconvenient ways

As consumers add more flexible loads at home, understanding how they might interact is critical.

We studied households with battery storage and rooftop solar. Some participants also owned an EV.

Battery storage and solar helped the grid when called upon for demand response. But occasionally, EVs were charging and pulling electrons from the battery while an event was called, and this affected the amount of curtailment that could be achieved.

Other settings and configurations — charge ceilings and floors, setpoints, severe weather-related programming — can also influence the availability of battery storage systems as a controllable asset.

Solar inverters may not be tuned to utility requirements

Inverters help guide under what conditions utility-scale solar facilities stay online or disconnect from the grid. If their settings are programmed such that they don’t align with the necessary requirements, utilities may not be able to count on these sites to perform as projected based on their models and studies.

That’s exactly what we’ve been finding over nearly a decade of inspecting and commissioning distribution-connected solar sites, and it’s why we believe third-party verification is essential.

Utilities rely on predictability, so it pays to know what can be trusted

So much of successful grid management depends on predictability. That this resource or these loads will act as expected. When systems are installed or implemented without a thorough understanding of how they’ll behave, utilities — and customers — might be anticipating an outcome that doesn’t become reality.

Technology evolves quickly. Our goal is to give utilities the knowledge they require to trust that their resources will be there when needed.