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<title>Storage Is Sized by Variance &middot; Incoprea Theory VIII</title>
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<header class="masthead"><div class="wrap">
<a class="wordmark" href="../vestibule.html">Incoprea <i>Theory</i></a>
<div class="meta">Volume VIII &middot; 100</div>
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<article>
<p class="kicker"><b>Theory 093</b><span class="sep">/</span><span>Energy &amp; Environment</span>
<span class="sep">/</span><span>Grid planning</span></p>
<h1>Storage Is Sized by Variance</h1>
<p class="dek">Storage is sized against the peak. The requirement may be set by the spread.</p>
<div class="claim"><span class="lab">The claim</span><p>The storage needed to firm a renewable supply is set by the variance of the residual load rather than by its peak, so a system with a higher peak but lower variance can need less storage.</p></div>

<section><h2><span class="num">01</span>The evidence</h2><p>Storage requirements vary widely between systems with similar peaks, and the variation tracks the variability of the residual rather than its maximum.</p></section>
<section><h2><span class="num">02</span>The tension</h2><p>Planning uses peak demand and peak shortfall, which predicts storage from the maximum and misses the duration and frequency of deficits.</p></section>
<section><h2><span class="num">03</span>The mechanism</h2><p>Storage must cover the cumulative deficit between supply and demand, which depends on how long and how often the shortfall persists, not only on how large it is at its worst.</p><p>That makes variance and duration the determinants, and predicts storage should scale with the variance of the residual rather than its peak.</p></section>
<section><h2><span class="num">04</span>What this is not</h2>
<div class="not"><span class="prior">Peak-based storage sizing</span><p>Peak sizing covers the worst hour. This covers the distribution, which predicts more storage for volatile systems at equal peak.</p></div></section>
<section><h2><span class="num">05</span>Predictions</h2><ul class="preds"><li><span class="tag">P1</span>Storage should scale with residual variance.</li><li><span class="tag">P2</span>High-peak low-variance systems should need less.</li><li><span class="tag">P3</span>Duration should matter more than magnitude.</li></ul></section>
<section><h2><span class="num">06</span>Refutation</h2><p>Storage tracking peak at controlled variance would restore peak sizing.</p></section>
<section><h2><span class="num">07</span>What it changes</h2><p>It would change grid planning methods.</p></section>
</article>
<nav class="pager"><a href="solar-forecast-advection.html">&larr; Solar Forecast Error Follows Advection</a><a class="mid" href="../vestibule.html">Contents</a><a href="hydrogen-leak-seal-ratio.html">Hydrogen Leakage Is a Seal Ratio &rarr;</a></nav>
<footer><strong>Incoprea Theory, Volume VIII &middot; 093 of 100.</strong>
A hypothesis written 30 October 2026. The background is established science; the causal ordering and the
predictions are the author's. Not peer reviewed.</footer>
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