Renovating American Infrastructure, Step 3: Power
Overhauling inefficient plants and an ancient grid
A 2006 study at Lawrence Berkeley National Laboratory found that power interruptions cost the economy about $79 billion annually, or about one third of national electric spending, thanks to our aging grid. Meanwhile, energy use is expected to grow by 1,150 terawatt-hours—the equivalent of adding 13 New York Cities—by 2030. A smarter power grid will surely help, but we’ll need additional innovations like these to keep up with spiking demand.
Make Energy like Plants Do
Task: Convert sunlight into chemical energy
Status: Last year, scientists found a plentiful raw material that can free oxygen from water
Solar panels are not the only energy-harvesting strategy under the sun. For years, scientists have also been trying to do what plants do—use sunlight to photosynthesize fuel. Until now, most approaches relied on impractically scarce materials like iridium as a catalyst that triggers the reaction. But last year, researchers at Lawrence Berkeley National Laboratory figured out how to use cobalt oxide, one of the most abundant industrial catalysts. To overcome the relative inefficiency with which cobalt oxide uses sunlight to crack water molecules and free the oxygen, researchers layered the catalyst on a tightly stacked scaffold that makes it effectively 1,600 times as efficient. The net result: Arrays of cobalt-oxide panels could provide a steady supply of oxygen, protons and electrons. The next goal is to find a similarly efficient second catalyst to transform the by-products into an energy-dense fuel like methanol to give gasoline a run for its money.
Hang Superconducting Cables that Won’t Leak Electricity
Task: Replace miles of copper wire with cables that carry up to 10 times as much electricity per cubic inch
Status: 10–20 years to wide use
Instead of clearing paths for thousands of miles of new power lines to carry renewable energy across the country, we could restring the existing ones to run with high-temperature superconducting cables like those being studied at Oak Ridge National Laboratory. The cables transmit electricity along a one-micrometer-thick superconductive layer of tape wrapped around a stainless-steel tube full of liquid nitrogen that cools the line down below –321ºF. In that chilled superconducting state, the lines lose no energy to resistance (today’s copper cables lose 5 to 7 percent).
Cram More Copper Underground
Cram More Copper Underground
Task: Replace thousands of miles of buried wire with a better-insulated version that carries 25 percent more power
Status: 5–10 years away from widespread use
In urban areas, overhead power lines are a nuisance and a danger, which means most electricity crosses the city in underground tubes. As urban power demands increase, we could rip up streets to lay new lines, but an easier solution is just to cram more copper into the conduits we already have. That’s what the Electric Power Research Institute (EPRI), an industry R&D consortium, is aiming for with a new insulation material that’s embedded with vinylsilane-coated particles of silicon dioxide to give it 33 percent more insulating ability than existing line coatings. That means the next generation of power lines could carry up to a quarter more current without adding any more bulky insulation.
Underground Power Lines that heal themselves
Task: Coat cables with a self-repairing salve
Status: Commercially available in 10–15 years
Another way to dig up fewer streets is to avoid unearthing cables for small repairs. Whenever there’s a nick or hairline crack in an insulation sheath, the electrical field in the underlying copper subtly shifts. In a new insulation being developed by EPRI, nanoparticles sensitive to this shift heat up and melt surrounding polymer molecules, forming a fresh protective scar. As today’s decrepit lines gradually go kaput (about a quarter are already past their intended lifetime), EPRI hopes to replace them with these self-mending ones.
Task: Deploy fleets of nimble robots that scoot along power lines, looking for flaws so that humans don’t have to
Status: First commercial versions around 2012
Conventional inspection is slow and expensive, often requiring a helicopter flyby. EPRI is working on a robot that can autonomously survey an 80-mile length of line twice a year for cheaper and more reliable inspections. The robot will straddle the line, carrying a camera, a diffused scanning laser and on-board image-analysis software, which it will use to construct both a visual history of the deterioration of the line, as well as a 3-D map of encroaching tree branches and other potential problems.
Add Storage to the Grid
Task: Build plants full of spinning drums that store electricity, so we can finally save surplus energy
Status: 20-megawatt plant under construction in Stephentown, N.Y.
Incredibly, today’s grid has practically no storage capacity. The electricity coming out of your socket was generated less than a millisecond ago, so power plants have to continually generate enough energy for the biggest spikes. To prepare for the power fluctuations endemic to renewable energy, we’ll need to inventory excess power to use during cloudy, windless afternoons and nights. The Massachusetts-based company Beacon Power’s solution is to store the grid’s surplus energy in hundreds of spinning carbon-fiber-and-fiberglass drums. Each of its Generation 4 flywheels features a 2,500-pound rotor mounted on magnetic bearings and sealed in a vacuum to create a near-friction-free environment. Energy coming in from the grid accelerates the three-foot rotor to 16,000 rpm (about Mach 2), where it keeps spinning with at least 97 percent efficiency. To pump energy back into the grid, some of the rotational energy is bled off to power a generator on the main shaft. Each flywheel can store a 15-minute, 100-kilowatt charge and can discharge 150,000 times over 20 years.
Add Storage to the Grid
Read the rest of PopSci’s plan to rebuild America here.