Five Paths to Unlimited Renewable Energy
If you were trying to design an energy system for a rapidly growing population, it would be hard to do worse than the one we have today. It’s brittle — dependent upon unstable regions and massive centralized networks. It’s dirty — poisoning us with mercury and heating the atmosphere with carbon. And it’s finite — we’re perilously close to running out of one of our key energy resources, oil. Getting away from all of this won’t be easy, and we’re running out of time to make it happen.
But there’s also good news: We know exactly what we need to do to get out of this mess, and we have all of the necessary tools at hand.
We’re at the cusp of a massive transition, from the era of limited, subtractive energy resources to the era of unlimited, renewable energy. For a variety of reasons, we’ve long relied upon energy resources that have finite quantities, and once used, leave us stuck with (often deadly) waste products. These resources were easy to find and cheap to use, but — from a long-term perspective — were never really more than bootstrap technologies, allowing us to get to the point where we could shift to energy resources that are functionally limitless, and entirely renewable. That point is here.
The initial set of transition technologies are undoubtedly quite familiar to you: massive wind turbines, collected in wind farms covering hundreds of acres; solar panels on rooftops and in the desert; and the granddaddy renewable technology, hydroelectric generators in dams and waterfalls. All useful and important, but very 20th century. The next wave of renewable energy technologies are all about getting away from the old-style centralized grid and embedding energy generation into all aspects of our lives.
WIND: GO FLY A KITE
Gone are the mega-towers and spinning blades. Say hello to the age of kites.
On the land, higher-altitude wind power, using kites flying at a kilometer or higher, can generate eight times as much power as traditional wind turbines (and going higher, up into the jet stream, can be even better). Kites have a couple of advantages over traditional turbines: The wind is steadier at higher altitudes, and kite-based wind power can be more readily integrated into dense environments. A set of kites can produce about a gigawatt of power in the same space required by an old coal or nuclear plant.
On the sea, diesel cargo ships outfitted with kite sails can cut fuel consumption by up to 50%. A German company, Sky Sails, has already outfitted two cargo ships as test vehicles. The ships remain in commercial operation, and the preliminary reports have been quite positive.
Proximity: On land, next decade. On sea, next five years
Prognosis: Shipping companies will jump on this; land-based power companies may be harder to convince.
GEOTHERMAL: WE’RE GENERATING STEAM HEAT
Geothermal energy might conjure images of geysers, hot springs, and Iceland. But the cutting edge is with engineered geothermal, taking advantage of the natural geological heat available just about everywhere (no nearby volcanoes required). Also known as “hot rock” geothermal, the process pumps water to around five kilometers underground, where the pressure keeps temperatures high. It turns out that the costs aren’t all that high for setting up an engineered geothermal generator, and that the system can even be used for limited carbon sequestration.
What could it offer? A 2007 MIT study argued that hot rocks geothermal could meet a significant percentage of US energy demand — in principle, up to 100%.
Proximity: Possible now, but probably five-ten years from serious testing.
Prognosis: Could end up being the replacement “base-load” power for areas using a lot of intermittent wind and solar.
SOLAR: FLEXIBLE AND UBIQUITOUS
Glass-plate solar panels, using silicon or germanium, remain the highest-efficiency solar power technologies. Unfortunately, these panels are still typically big, brittle, and expensive. But a real solar breakthrough is just around the corner — and will come not through efficiency, but through ubiquity, driven by both reduced costs and wider applicability.
A 2007 MIT study argued that hot rocks geothermal could meet a significant percentage of uS energy demand — in principle, up to 100%
Welcome to the world of flexible solar. Flexible plastic photovoltaics and paint-on solar dyes will allow previously non-energy-producing surfaces — such as walls and windows — to become micro-sources of power. New production techniques, such as those developed by Nanosolar, get away from glass plates, and can cut production by 90%, immediately making solar competitive with even cheap coal power. On the horizon, carbon-nanotube solar promises to add energy production and storage to nearly any manufacturing material.
Proximity: Possibly this year, but last-minute glitches may mean an early 2010s emergence.
Prognosis: The technology is coming together, but the real question is how long it will take product, building and urban designers to take advantage of the new materials.
HYDROKINETIC: THE MOTION OF THE OCEAN
Hydrokinetic power is undoubtedly the dark horse energy technology. Despite studies from energy think tanks showing that it could provide upwards of 30% of power needs in seaside nations, cleanly and at low cost, few people have heard of it. But wave power is already starting to… well, make waves.
Simply put, hydrokinetic power turns the regular, predictable motion of waves, tides and currents into electricity. Some designs just bob up and down, while others act like undersea wind turbines. One design, still in its early stages, takes advantage of a technology developed for Cold War submarines — the magnetohydrodynamic drive — to produce potentially vast amounts of power. And most of these aren’t just engineering prototypes — working wave power systems are now being deployed along the Oregon and Portuguese coastlines, delivering hundreds of kilowatts of power — with more to come.
Proximity: It’s here. Get used to it.
Prognosis: Funding for it remains low, so it will take awhile before people really notice its potential.
MOTION: SHAKE YOUR BODY
Perhaps the most surprising emerging source of power is you. Yes, you, sitting there. Well, not when you’re sitting there, but when you’re out and about, walking and even dancing. And not just you — anything that moves, from bridges to trees to buildings — could be used to produce power from the motion.
The technologies used to do so vary considerably, from piezoelectric materials generating electricity from pressure, to wobbling microgenerators, to small flywheels spun by moving magnets. In most cases, the amount of power generated is small, but that’s fine if what you’re trying to power are microsensors, bio-monitors, or — if you’re really working at it — MP3 players. But floors that generate power from people walking on them (through piezoelectric materials or magnetic coils), now used in a variety of facilities from dance clubs to fitness centers, can produce up to 60% of a facility’s power needs, just from people doing what they came to do.
Proximity: Slowly being deployed.
Prognosis: Will designers and architects begin to think of floors as power sources? They should.
GETTING FROM HERE TO THERE
Few of these energy technologies offer a drop-in replacement for old-style coal plants and aging nuclear reactors. That’s okay — they don’t need to. The future of energy isn’t in a centralized power grid, but in a loose, distributed network where buildings, vehicles, even people can be both power producers and power consumers. Solar walls and windows, power-generating floors, and neighborhood power kites don’t add up to living off-grid — they add up to becoming the grid. The big energy production sites, even the wind farms and solar panels, are likely to evolve into the backup to the distributed power network.
The advantage of distributed power comes down to resilience. As we’ve seen across a variety of systems, big, tightly linked, highly centralized systems can still fail, and when they go, they go catastrophically. Loosely interdependent, distributed systems tend to have more redundancy and flexibility, and can more readily withstand unexpected shocks.
Fortunately, the energy technologies within our grasp will fit into a distributed grid quite nicely. A good thing, too — it’s likely we still have quite a few big shocks ahead of us this century.
It’s almost as if the ancient philosophers had it right: It all really comes down to air, earth, fire and water — and maybe a bit of dancing.