KNOWLEDGE BASE
Articles on heat storage and the energy transition
Here we collect technical articles, background pieces and case studies on thermal storage, the heat transition and the technology behind Caldum. Aimed at housing corporations, builders, policymakers and anyone seriously engaged with the energy transition.
FOUR KNOWLEDGE AREAS
What you can expect here
Technology & research
How heat buffers work, material choices, energy density and lifetime.
Comparisons
Caldum alongside the hot water cylinder, the home battery and the heat network.
Getting started
What seasonal storage is, whether it suits you and how large a buffer gets.
New articles will appear here once available. Have a specific question you would like to read an article about? Let us know.
Recently published
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District heating or your own installation: when does which one win?
In the Netherlands, district heating networks are still presented as the logical solution for the built environment. The question of when a heat network actually performs better than individual solutions — technically, economically and socially — is rarely asked out loud. In plans for gas-free neighbourhoods the heat network is a much-used instrument. Municipalities, housing…
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Fifty years without degradation: what service life really means
A storage system that is still standing neatly in the garden after twenty years but only reaches sixty per cent of its original capacity is not sustainable. It simply has not broken yet. That distinction is systematically underrated in energy engineering. When service life comes up, attention usually goes to whether a system still functions.…
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Grid congestion: where is that electricity supposed to go?
In more and more places in the Netherlands, solar panels and wind turbines temporarily have nowhere to send their electricity. The grid is full. Installations are curtailed or switched off, generated energy evaporates, and in some cases owners of generating capacity will eventually pay for the privilege of feeding in. In the media, grid congestion…
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Hot water storage versus thermal storage: what’s the difference?
Hot water storage versus thermal storage ultimately comes down to one question: how long does the heat need to be preserved? Water is the standard choice for bridging a day. Want to bridge an entire season? Then you run into a physical limit that no amount of pipe pressure or insulation solves. Why water is…
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Storing solar heat: how do you save summer sun for winter?
Storing solar heat means something different from storing solar electricity. A battery keeps the electricity from your solar panels for the evening. The biggest surplus from a solar roof, however, falls in summer, and the biggest demand falls in January. Anyone who takes that difference seriously ends up looking at heat storage instead of just…
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Heat storage without degradation: why doesn’t a thermal buffer wear out?
Heat storage without degradation sounds like a marketing claim. It’s a direct consequence of the technology involved: a lithium battery returns less energy after ten years than on day one. A PCM that has melted and solidified hundreds of times loses part of its capacity to subcooling and phase segregation. A salt buffer that’s heated…
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Overview of phase change materials: properties, advantages and limitations
Phase change materials: overview of PCMs for thermal storage Phase change materials, or PCMs, store heat during a phase transition. In practice, latent heat is only part of the story: sensible heat, thermal conductivity, cycling stability, corrosion, safety and cost are often just as important. This overview is intended as a technical selection map: temperature…
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How large should a thermal buffer be?
The right size for a thermal buffer depends on heat demand, generation, desired autonomy, placement — and above all on resident behaviour.
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Why a home battery doesn’t solve the same problem as a thermal buffer
A home battery shifts electricity within a day. A thermal buffer bridges seasons. Why that distinction decides what fits your situation.
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What is seasonal heat storage?
In July your PV panels work overtime; in January you’re cold. Seasonal storage bridges the gap: heat from summer kept for winter.