Can a VPP Fool a Grid Operator?

EnergyHub's Huels Test gives US utilities the first standard benchmark to measure VPP reliability against gas peaker plants

10 Apr 2026

A US energy software company has released the first standardised framework for measuring whether virtual power plants can genuinely substitute for gas peaker plants, as the technology advances but has yet to meet the reliability bar most utilities require.

EnergyHub, whose software runs across more than 120 US utilities, published a white paper in December 2025 introducing the Huels Test: a benchmark named after company data scientist Matthias Huels and modelled on Alan Turing's test for artificial intelligence. The central question it poses is whether a grid operator, reviewing live dispatch and telemetry data, can distinguish a virtual power plant from a conventional gas generator. If not, the VPP passes.

The framework defines a five-level maturity model, from Level 0 basic demand response through Level 4 full autonomy. Passing the Huels Test requires Level 3, at which a VPP must deliver sub-five-minute telemetry to the utility control room, execute multi-hour shaped dispatch schedules, and maintain year-round availability without human intervention. These criteria mirror the operational standards applied to conventional generation.

EnergyHub tested its platform against the model through pilots with Arizona Public Service, Duke Energy, and National Grid. Results placed its system between Levels 2 and 3. A Mid-Atlantic pilot sustained stable load reduction across three consecutive hours, a configuration the company values at approximately $105 per kilowatt. Level 3 or 4 performance, it projects, would deliver between $160 and $210 per kilowatt in combined grid and customer value.

"In order for us to build our reliance on VPPs, they do need to pass the Huels test," said Lauren Shwisberg, a principal at Rocky Mountain Institute who co-authored a separate VPP reliability study.

US VPP capacity stood at 37.5 gigawatts as of early 2026, though analysts at Wood Mackenzie note most programmes are still broadening participation rather than deepening capability. With gas turbines on extended backorder and electricity demand from data centres rising sharply, the question of when distributed energy can be formally counted as firm capacity, rather than a supplementary resource, remains unresolved for utilities and regulators alike.