The Solar Budget

Something has to change for food systems to change. Right now industrial farms optimize for man-hours per acre instead of productivity per acre. Maximum calories per unit of labour is the goal. What we need is the reverse — spare no labour to achieve maximum calories per acre.

That’s not an easy transition. It means more people growing food on their own quarter-acre instead of paying the lowest bidder. Joining co-ops, getting their hands in soil. But how do you convince anyone to make that shift while cheap food stays cheap?

why farms went this way

High labour costs and low food prices pushed farms in a specific direction. Wages are expensive, commodity grain is not, so profitability means minimizing the human input. That’s rational for any individual operation. But zoom out and you see the system drifting away from where I think we need it to go — toward higher productivity per acre, regenerative processes, and living within the solar budget.

Every acre receives a fixed amount of sunlight. That’s the budget. A well-managed system captures that energy through plants, cycles nutrients through animals, and builds soil. An industrial system bypasses it entirely — fossil energy subsidizes the fertilizer, the irrigation, the harvest, the transport. You get enormous output per worker, but you’re drawing down a capital account (soil, aquifer, fossil carbon) instead of living on the interest.

food wasn’t always expensive

People assume hunter-gatherers spent all their time finding food. They didn’t. They had it comparatively easy — spending less of their day on food than early agrarian cultures, because they could relocate when an area got overexploited or climate-damaged. They ate a more varied diet too, and were better nourished for it.

What they couldn’t do is create a surplus that supports city-states. City-states project power over a larger area than a tribe can, and power means taxes. Taxes mean you aren’t just supporting your tribe — you’re feeding a city too. So the work goes up. Early agriculture was brutal precisely because it had to fund something beyond the household.

Now food sits at maybe 10% of a family’s budget. That’s historically strange. It’s not because we got spectacularly better at farming — it’s because we got spectacularly better at substituting fossil energy for human effort. When that subsidy gets repriced, the 10% figure won’t hold.

grain and livestock

We feed grain to livestock. That’s where this goes sideways. Grain should be expensive, and livestock should eat wastes and forage that we can’t digest — grass on land too rough or dry to crop. Around here in Alberta, there’s plenty of that. When cattle eat solar-sourced carbon captured on land that would otherwise just sit there, they’re doing their proper role. Converting sunlight we can’t use into protein we can.

Feeding them grain flips that completely. You’re taking calories humans could eat, running them through an animal at a ~10:1 loss ratio, and calling it efficient because the feedlot minimizes labour. The efficiency is real, but it’s measuring the wrong variable.

the efficiency trap

People hear “solar budget” and immediately reach for solar panels. Photosynthesis is only 3–6% efficient at converting sunlight to stored energy, and most leaves in a forest aren’t even in direct light — they’re under canopy. So the number drops to something like 1%. Surely a panel at 20% is the obvious winner.

But this misses what a forest actually does. Under a dense canopy it’s cool and dark, and that’s because the plants have used almost all the incoming sunlight in one way or another. The canopy is additive, not subtractive. Leaves don’t just embody energy — they reflect light and release water, cooling the forest to optimal temperatures for growth. The whole system is tuned to capture the budget.

Now ask whether solar panels can pay for their own construction the way a tree does. A tree builds itself from air, water, and sunlight. A panel needs aluminum smelting, glass manufacturing, copper refining, diesel trucks hauling minerals between mines and factories. Run an aluminum smelter on solar panels and redo the math. I suspect panels are deeply in the red once you count the fossil energy in their supply chain.

Grass and trees are some of the best solar collectors evolution has produced. They have to be managed responsibly and they can’t support a complicated civilization on their own, but they’re self-replicating, self-repairing, and they build soil while they work. They’re not in the same league as panels — they’re playing a different game entirely, and it’s the game that actually runs within the budget.

what has to change

I keep circling back to the same problem. The transition from labour-minimizing to land-maximizing agriculture requires people to value food differently — not just “buy organic at the grocery store” differently, but structurally differently. Actually growing something, actually knowing a farmer, actually spending time on where your calories come from.

But right now the price signal says don’t bother. Cheap energy makes cheap grain makes cheap meat makes cheap groceries. Every step in that chain would have to shift before the economics reward a different kind of farming. And the people most able to grow food in their yards and join co-ops are the ones least pressed to do so, because the cheap food works fine for them.

I suspect something in that chain will break, because the fossil subsidy isn’t permanent. Whether we build the alternative before or after — that I’m less sure about.