What Jim Carroll Saw Coming
Original archive: 2009-10-01 — Article : The Future of Energy.
In “The Future of Energy” (October 2009), Carroll described an emerging intelligent energy infrastructure and the promise of controlling energy use at the individual level. He illustrated the idea with internet-connected thermostats in his own properties. Energy storage extends that original insight: when electricity can be saved and dispatched later, control moves beyond consumption to timing and supply.
What has changed in the real world
Electricity is unusual because supply and demand must balance continuously. A solar panel can generate abundant power at noon but none after sunset. A battery can move some of that energy into the evening, helping a grid use renewable electricity more effectively. The crucial measurements are power, expressed in gigawatts, and stored energy, commonly expressed in gigawatt-hours. A large power rating alone does not tell us how many hours the system can operate.
Carroll’s 2009 energy writing explored an expanding set of technologies and constraints. Today’s storage industry is far more concrete than a speculative invention list, with large deployments tracked by energy agencies. The economics remain complicated. Short-duration batteries can handle rapid balancing and portions of evening peaks; long periods without wind or sunlight may demand different resources. The storage question changes when it moves from a household backup box to a national electricity planning problem.
A fact that changes the scale of the question
108 gigawatts of new battery storage power capacity were installed worldwide in 2025, the International Energy Agency reports. The original source is International Energy Agency, Global Energy Review 2026. The distinction behind the number or capability matters just as much as the headline: Gigawatts measure the rate of discharge; available energy depends on duration, which the IEA notes still varies across projects. The point of introducing the fact here is to show the actual scale of the machinery, knowledge, data or infrastructure involved in this particular voyage. It is not evidence that the imagined 2040 destination is inevitable.
2040: one possible destination
An imagined scene, not an account of an event that has happened.
Imagine a growing town in 2040 whose electricity is supplied by several sources. On a sunny afternoon, batteries fill while ordinary demand is modest. At dusk, they discharge to reduce the immediate need for expensive peak supply. When a cold weather system lasts several days, the town relies on a different combination of firm generation, interconnections and demand choices. The point is not that batteries solve every hour. They give operators more choices about when electricity is useful.
One image captures the possibility: Stored electricity fills the gap after solar production fades in a fast-growing town. The conditions behind that image deserve attention. A future built around this capability would also change work, trust, operating costs or personal choices for someone outside the technology industry. That is why this voyage is less about predicting the arrival date of a device and more about understanding the environment that would let it matter. Different communities and businesses could arrive at the same destination at different speeds, or choose a different route altogether.
The detour that could change everything
Battery deployment requires minerals, sites, fire-safety planning, permits and reliable grid connections. Costs vary by region, and electricity-market rules determine how projects get paid. The fastest-growing technology in a sector can still be the wrong solution for a particular duration or location. A grid that depends on a single storage technology may be less resilient than one built around several complementary options.
There is no requirement that technical progress and adoption advance together. People may welcome one application and reject another. The most persuasive future is the one that survives comparison with cheaper, simpler or better-understood alternatives. This is also where the archive has value: an old idea can be supported in direction while the timetable, commercial model or surrounding institutions evolve in ways that could not have been obvious at the start. That history deserves to be told rather than edited into perfect hindsight.
The next chapter is still being written
Compare the total cost of storage across different durations, including replacement, interconnection and system operation. Watch whether measured dispatch reduces price spikes and curtailment over years. The future worth following is not simply bigger battery numbers; it is a better balance of reliability, flexibility and affordability.
The practical test is this: Distinguish storage duration, round-trip efficiency and costs from energy creation The question for the people making choices today is not whether the imagined 2040 scene is visually convincing. It is whether emerging evidence alters a real decision: where to invest, what to build, which safeguards to demand, and which assumptions should be checked again next year. How does cheap storage change generation, prices and resilience without replacing firm supply? The answer is not locked in. That is what makes tomorrow a voyage worth taking.