Heat Battery — Thermal Storage That Decouples Heat From Time

A heat battery stores energy as high-temperature heat in cheap solid mass (brick, refractory) and releases it on demand. It is the storage counterpart to every heat-driven technology in this KB: heat-driven cooling only runs when the driving heat is present, and a heat battery moves heat in time so the cold can be made when it’s wanted, not only when the heat happens to be available.

Rondo Energy — the registry’s single entry

The Zotero registry’s Heat Battery collection holds exactly one item: Rondo Energy (webpage, 2023). The registry records only the title, type, year, and URL; no content from the page has been ingested. What can be said at that level is that Rondo is the commercial heat battery the collection chose to represent the theme — a company whose public positioning is low-cost, zero-emission industrial heat from renewable electricity stored in solid mass. The mechanism generally described for this class (resistive charging of brick mass on cheap intermittent wind/solar, continuous discharge of high-temperature process heat) is stated here as the concept the entry points at, not as a verified specification.

Why a cooling KB cares about a heat battery

Three connections to heat-driven cooling:

1. Firms up the drive heat. An adsorption chiller or desiccant system needs a steady desorption-heat supply. Waste heat (a roaster’s exhaust) and solar thermal are intermittent. A thermal store buffers them — charge when the roaster runs or the sun shines, drive the chiller through the gaps.
2. Load-shifts cooling onto cheap/clean electrons. Charge the store with off-peak renewable electricity, then make cold from stored heat during expensive on-peak hours — moving cooling demand off the peak without a battery of lithium cells.
3. It’s the same “store the cheap energy” instinct as cold storage (chilled-water/ice tanks, the off-peak strategy the ASHRAE canon in vapor-compression cooling describes) seen from the hot side. Either end of the loop can hold the buffer.

Source caveat: one vendor webpage, metadata only. The concept is general thermal-energy storage; Rondo is the high-temperature industrial instance most relevant to a waste-heat/renewable drive. Confidence is rated low accordingly — the article’s role claims (buffering, load-shifting) follow from the physics of heat-driven cooling elsewhere in the KB, not from this source.

Latent storage — the low-temperature cousin

A brick heat battery stores sensible heat at hundreds of °C. The other half of thermal storage is latent heat — a phase-change material absorbing and releasing energy at a fixed melt temperature. At comfort-range melt points, PCMs store far less per kilogram than a glowing heat battery but do it at room temperature and inside the envelope itself — translucent PCM glazing that melts by day and refreezes at night, flattening the indoor swing without any tank or machine (figures in the linked article, not sourced here). Same “decouple heat from time” instinct, opposite end of the temperature scale.

---

See also

• EGS — in-reservoir storage (round-trip 59–93%) as the underground counterpart to a heat battery for firming drive heat
• Adsorption Cooling — the heat-driven load a thermal store buffers
• Solar Thermal — intermittent heat source the battery firms up
• Desiccant & Free Cooling — other low-grade-heat-driven cooling that benefits from buffered heat
• Translucent PCM Glazing — latent thermal storage at the envelope, the room-temperature cousin of a sensible heat battery
• Thermophotovoltaics (TPV) — a heat→electricity discharge path for a high-temperature storage block (cells surround the mass, draw power on demand)
• Cooling Technologies Index
• Adsorption Cooling — Limitations & Mitigations — storage as the mitigation for fluctuating drive heat
• Adsorption Cooling — Performance, Working Pairs & Numbers — buffering intermittent drive heat against derating
• DIY PCM Encapsulation for Secondary Glazing — Containers, Sealing, Failure Modes — latent storage at the window as the small-scale counterpart
• Dome Cooling — Passive Cooling from Curved Geometry — PCM roof modules as latent storage in a curved envelope
• Hydronics — Water as the Distribution Fabric — buffer tanks and storage on the same water loops

Sources

• Zotero cooling source registry — the Heat Battery collection: the single Rondo Energy entry (webpage, 2023) that anchors this theme; title/URL metadata only