What Regeneration Actually Returns: Reading the Efficiency Figure as Written

Cost & justification · 4 min read · 7 cited facts

The current catalogue prints a regeneration figure at least six ways: ≥ 92% at Max. Power, up to 96%, up to 92%, approximately 95%, nearly 95% of the loaded energy, up to 95% of loaded energy. Six phrasings is not sloppy copywriting. They are different manufacturers answering slightly different questions, and the differences are exactly what a spreadsheet flattens out.

Roughly half of Intepro's catalogue is manufactured by partner companies and supplied and integrated by Intepro. The efficiencies below belong to the manufacturers who measured them, and their current datasheets — noted product by product — are the documents of record.

Six figures, read as written

• PAS-F grid simulator (Intepro): regeneration efficiency ≥ 92% at Max. Power. The only entry that names its operating point — a floor guaranteed at one condition, rather than a ceiling.
• Procyon PTS 2100-20 battery test system (Intepro): sink mode recoups up to 95% of loaded energy, while the power stage itself is quoted at >93%. One product, two efficiencies — an energy fraction over the loading, and a converter figure — and both are true.
• ELR 9000 regenerative DC load (manufactured by EA Elektro-Automatik, supplied and integrated by Intepro): a 3U chassis sinking 3.5 kW to 10.5 kW, recovering energy to the local mains at approximately 95%. 'Approximately' is an engineering estimate, and 'local mains' names where the energy goes.
• SM Series DC supplies (manufactured by Delta Elektronika, supplied and integrated by Intepro): regeneration efficiency up to 96% — the highest figure in the catalogue, and a ceiling.
• B2C+ bi-directional DC converter (manufactured by Cinergia, supplied and integrated by Intepro): regeneration efficiency up to 92%.
• Vega power racks (Intepro, built on ELR and PSB stages): nearly 95% of the loaded energy recovered to the AC grid.

These are not one measurement made six times. 'Of the loaded energy' is an energy ratio across a test; a bare percentage beside the word efficiency is a converter figure at an operating point the sheet does not always disclose; '≥ at Max. Power' is a specification with a stated condition; 'up to', 'approximately' and 'nearly' are each doing quiet work. None of the six is comparable with another without knowing the condition behind it, and only one of them states its condition.

Operating efficiency is a different line on the same sheet

The DC supply offering prints two efficiencies for its bi-directional products because there are two directions. Reading the wrong line is the commonest way a regeneration figure gets inflated in a capital request — the numbers sit one row apart, and a glance does not separate them.

The ADG-L row is the point. An operating efficiency exists for every converter ever sold, including ones that cannot regenerate at all. If a figure is not labelled regeneration, sink or recovery, it is not a regeneration figure — it is the cost of running the box in the forward direction.

Partial load, and the difference you still buy

An efficiency quoted at maximum power is not the efficiency you get at a partial load, and the catalogue's own wording concedes as much — that is what 'at Max. Power' and 'up to' are for. None of these sheets prints a partial-load curve. That absence is worth stating plainly, because the honest move when a curve is not published is to ask the manufacturer for the figure at your operating point, not to assume the headline holds everywhere.

And whatever the true fraction is, a system that regenerates is still buying the difference. The energy that does not come back is drawn, metered and paid for — every cycle, for the life of the equipment. Regeneration shrinks the bill; it does not end it. What the difference costs per year depends on load, hours and tariff, and that arithmetic is worked through separately in /insights/regen-payback-calculation/, with inputs chosen so the answer is allowed to come out negative.