In permaculture, Catch and Store Energy is about more than electricity. It points to a design habit: notice what arrives in abundance, then find ways to hold some of that value for later. That value might be water, fertile soil, stored heat, or living biomass. At OMF, we treat this principle as a practical question before adding new inputs: what is already flowing through a place, and why does so much of it slip away?
What “Catch and Store Energy” Means in Permaculture
David Holmgren presents Catch and Store Energy as Principle 2 in his 12 design principles, within the permaculture tradition he developed with Bill Mollison in the 1970s. The term permaculture itself comes out of that early work, including Permaculture One, published in 1978.
In plain language, the principle means this: when something useful is abundant, do not let it pass through the system without asking whether part of it can be held in a durable form for later use. That might mean water held in soil or storage, warmth held in thermal mass, fertility held in organic matter, or solar energy held in plant growth and biomass.
This matters because abundance is often temporary. Rain comes in bursts. Sunlight shifts by season and by hour. Organic matter breaks down or washes away. A place may feel rich in resources one moment and strained the next. The principle is not about hoarding everything. It is about recognizing which flows are valuable, then designing so some of that value remains available when conditions change.
Why Permaculture Talks About Storage, Not Just Supply
Many systems respond to weakness by adding more inputs. More irrigation. More fertilizer. More heating. More purchased materials. Sometimes those additions are necessary. Still, a system can take in plenty and remain fragile if it loses water, heat, fertility, or labor faster than it can recover them. Catching and storing energy shifts attention from chasing bigger inputs to holding value longer.
That is one reason this principle reaches beyond gadgets and infrastructure. Storage can happen in living systems, in buildings, in soil, and in household patterns. A healthy soil profile stores moisture and nutrients where roots can use them. A well-oriented building can hold warmth after the sun drops. A stand of trees can store years of growth while also changing wind, shade, and microclimate.
From OMF’s vantage point, this is where permaculture becomes practical. The question is not only what a site receives. The more useful question is what a site keeps, and in what form.
Water: Catch the Flow Before It Leaves
Water is one of the clearest beginner examples because the pattern is easy to see. Rain falls quickly, often more quickly than the land or a household can use it in the moment. If that flow is captured, diverted, or stored, it becomes available later instead of disappearing as runoff. The U.S. Department of Energy describes rainwater harvesting as a system for capturing, diverting, and storing precipitation for later use, most often for non-potable purposes.
That simple idea explains why the principle matters. A rainfall event may last minutes or hours. The need for water may stretch across days or weeks. Storage bridges the gap. In permaculture terms, the event is the catch. The container, soil, or landscape feature that holds part of it is the store.
Capturing rain can also reduce runoff, erosion pressure, flooding pressure, and pollutant transport when the system is designed and maintained well.
Even here, the principle has limits. Storage needs to match reality. Catchment size, tank capacity, maintenance, permits, and local regulations all matter. A neglected system, or a badly sized one, may create more frustration than resilience.
Soil: Store Fertility and Moisture Where Plants Can Reach It
One of the most overlooked storage systems is soil itself. In permaculture, soil is not just a place to anchor roots. It is a living storage medium. The Natural Resources Conservation Service notes that soil organic matter increases water holding capacity and nutrient holding capacity. It also helps improve soil structure, infiltration, and biological activity.
That changes how we read a landscape. A site with better soil is not only more fertile. It is better able to hold onto the gains it receives. Rain is less likely to vanish as fast runoff. Nutrients are less likely to move out of reach. Plant growth has a better chance of turning seasonal abundance into longer-lived stability.
Mulch works on the same logic at a simpler level. Colorado State University Extension notes that mulch can reduce surface evaporation, moderate soil temperature, and improve water infiltration. In other words, it helps the ground keep what it has instead of losing it quickly.
This is also where tradeoffs show up. Building soil is not instant, and it is not identical across climates or soil types. NRCS notes that outcomes vary with conditions, and transitions can involve short-term management challenges before longer-term gains appear. Good storage is often slower than people want.
Sunlight and Heat: Store Today’s Warmth for Later
Sunlight is another resource that often arrives in excess for part of the day and disappears later. Passive solar design works by using orientation, glazing, and thermal mass to collect and hold some of that heat so it can be released after temperatures fall. The Department of Energy describes thermal mass as materials such as masonry or water that absorb heat and release it later.
This is a clean example of the principle because the pattern is direct. Heat arrives. A surface stores part of it. The building benefits later, when outside conditions are less generous.
What matters here is not just capture. It is fit. DOE treats successful passive solar design as a balancing act among glazing, shading, insulation, thermal mass, site conditions, and budget. A design that gathers winter heat but creates summer discomfort is not good storage. It is just an unresolved tradeoff.
That warning matters in permaculture more broadly. Storage is not automatically wise because it sounds efficient. Some methods are awkward, expensive, unhealthy, or poorly matched to the context. DOE, for example, does not recommend rock-bed storage for solar air systems because of inefficiency, condensation, and mold concerns. The principle still holds. The method has to earn its place.
Living Systems Store Energy Too
Permaculture gets clearer when we stop thinking only in mechanical terms. Plants are storage systems. The U.S. Energy Information Administration explains that plants convert solar energy into chemical energy, which is why biomass can be understood as stored solar energy.
That makes a tree more than scenery. It is years of captured sunlight held in wood, roots, leaves, and the living processes around it. USDA climate guidance also notes that trees and agroforestry systems store carbon in biomass and soil while contributing shade and wind protection.
This kind of storage is slower than a tank or a wall. It may also be more durable. A longer-lived planting can hold value across seasons and years while also shaping the conditions that affect water, heat, shelter, and soil.
That does not make living storage effortless. Trees take time. Plant systems need care, appropriate siting, and patience. Still, permaculture keeps returning to them because they store value in ways that become more useful as the system matures.
Not All Storage Is Good Design
This principle can sound so sensible that readers assume more storage is always better. It is not. Storage that is poorly chosen, poorly maintained, or poorly matched to the place can fail.
A rainwater system may look smart on paper and disappoint in practice if the catchment is too small, the tank is undersized, or maintenance gets ignored. Passive solar can do the same if heat gain, shading, insulation, and mass are out of balance. Even the basic idea of storing energy can go sideways when the storage method creates side effects that outweigh the benefit.
That is why the principle should be read as design discipline, not as an excuse to collect equipment. Good storage reduces losses, fits the context, and pays back in usefulness. Bad storage adds cost, complexity, and false confidence.
What OMF Wants Readers to Notice
At OMF, the most useful shift is often observational. Start by asking what leaves a site too quickly. It may be roof runoff, soil moisture, seasonal warmth, plant growth, or the steady fertility that disappears when organic matter is treated like a leftover instead of a resource.
That way of seeing changes the work. Instead of beginning with scarcity, you begin with flows. Instead of assuming the answer is more supply, you look for leaks. Instead of treating resilience as a slogan, you ask what can actually be held and reinvested inside the system.
That is where this principle earns its place in an introductory permaculture series. It trains the eye. It pushes design toward retention, timing, and usefulness. It also connects naturally to later questions about yield, renewable resources, and waste.
Conclusion
Catch and Store Energy is a reminder that abundance is only part of the story. What matters just as much is whether a system can keep useful value long enough to benefit from it. In permaculture, that value may take the form of water, fertile soil, stored warmth, or living biomass.
Seen that way, the principle is not abstract. It is a practical rule for building steadier systems: notice what arrives, notice what leaks away, and design so more of what matters stays available when it is needed.