Leslie Dewan has a plan to power the entire United States, with zero carbon emissions, for the next 100 years while simultaneously getting rid of our mountains of nuclear waste. With fellow M.I.T. Ph.D. candidate Mark Massie, Dewan founded TransAtomic in 2010 with an eye toward perfecting a new kind of nuclear reactor. They call it the Waste Annihilating Molten Salt Reactor (WAMSR). Instead of solid uranium fuel rods used in common light water reactors, the core of the WAMSR will contain liquid fuel -- predominantly consisting of "spent" fuel rods from old reactors dissolved in a salt solution. "Nuclear waste is not really waste at all,” says Dewan. “It still has a tremendous amount of energy in it." They hope to have a pilot plant built by the end of the decade. -- Reported by Christopher Helman and Todd Woody
Leslie On Social

    • Trisha Andrew

    • 27
    • Organic Chemist
    • 2011 L'Oreal USA For Women in Science Fellow
    Her research at MIT involves devising next-generation solar cells that are built by printing layers of nanoscale materials like quantum dots and chromophores, or color molecules, and combining them with optoelectronic materials. The end result will be solar cells that seamlessly collect ambient light and re-emit it as light of a particular color.

    • Priyanka Bakaya

    • 29
    • Founder
    • PK Clean
    Graduate of Stanford and MIT has perfected a process to transform plastics back into oil. Pilot plant in India gleans 80 barrels of diesel from every 20 tons of plastic and generates enough electricity to power itself. Lots of interest from waste management companies.

    • Manuel Wiechers Banuet

    • 25
    • Founder
    • Ilumexico
    This group has installed 1,000 solar panels on the homes of impoverished families to provide a source of light that is safer and greener than candles and oil lamps. Seeking to achieve 4,000 installations in 2013 with public and private financing.

    • Rachel Barge

    • 26
    • Partner
    • Greenstart
    A green business veteran at 26, Barge’s renewable energy incubator Greenstart takes minority stakes in early-stage startups focused on software and apps and then brings them in-house for three months of work developing their business model, products and brand.

    • Gene Berdichevsky

    • 29
    • Founder
    • Sila Nanotechnologies
    After Stanford, was an engineer at Tesla; now launching Sila to devise next-gen drop-in materials to get more power out of lithium-ion batteries. Has $1.7 mm in DOE grants. Also backed by Sutter Hill Ventures and Matrix Partners.

    • Jonny Cohen

    • 17
    • Inventor
    • GreenShields
    When only 12, Cohen figured there must be a way to make school buses more aerodynamic. Spent five years building prototypes with help of faculty at Northwestern University; now perfecting an airfoil to mount on top of buses. New version weighs 8 pounds, costs $30 and improves gas mileage by 15%.

    • Russell Conard

    • 23
    • CTO
    • Ornicept
    Conard turned down PhD programs  to develop a machine vision system that crunches big data to detect hawks, eagles and other birds near wind farm sites. That could be worth millions to developers facing pressure to avoid bird kills.

    • Danielle Fong

    • 25
    • Chief Science Officer
    • LightSail Energy
    A college grad at 17 who attended Princeton’s physics PhD program, Fong is developing a novel energy storage system for wind farms and other power plants. Since her apperance on the 2012 30 Under 30, LightSail has raised $37.3 million from billionaire investors Bill Gates, Vinod Khosla, Bill Gates and Peter Thiel.

    • Eden Full

    • 20
    • Founder
    • Roseicollis Technologies
    As a Thiel Foundation fellow, Full, also named to the 30 Under 30 list in 2012, continued to work on her low-cost solar tracking and water filtration system for developing countries. She’s now testing her SunSaluter in Uganda and other African countries.

    • Kathryn Cunningham Hall

    • 26
    • Founder
    • Power Up Gambia
    Power Up Gambia is a non-profit that provides reliable electricity and water to healthcare facilities in Gambia through solar energy. It was founded in 2006 when Kathryn was a University of Pennsylvania undergraduate. She is currently a pediatric resident at the Children's Hospital of Philadelphia.

    • Allison Hannon

    • 29
    • Cofounder
    • Root3 Technologies
    Tony Blair’s The Climate Group hired Hannon to open its North American operations. Then the University of Chicago MBA moved on to co-found Root3 Technologies, where she develops software that taps Big Data to help municipalities, universities, schools and hospitals ratchet up the energy efficiency of their onsite power plants. First big customer: Her alma mater, the University of Chicago.

    • Qichao Hu

    • 27
    • Founder
    • SolidEnergy Systems
    While working in the lab of renowned MIT professor Donald Sadoway, Hu developed a polymer ionic liquid (PIL) rechargeable lithium metal battery that can operate at room temperature and manufactured in a variety of shapes. Says PIL batteries will be safer, smaller and can hold twice as much energy than lithium ion.

    • Param Jaggi

    • 18
    • Inventor
    • Vanderbilt Univ.
    In high school, Jaggi invented an algae-filled device that fits over a car's tailpipe and turns carbon dioxide into oxygen. Now he's working on a thermo-voltaic wind system that can be installed in an exhaust system to capture energy from waste air and heat.

    • Melissa Lott

    • 29
    • Researcher
    • Department of Energy
    Lead researcher on thermal storage at the International Energy Agency. Has worked on analysis and design of energy systems for the Dept of Energy, Dept of Defense and NSA. Graduate of UC-Davis and University of Texas at Austin.

    • Richard Matsui

    • 27
    • Cofounder
    • kWH Analytics
    A former McKinsey consultant fluent in Mandarin, Matsui co-founded kWH Analytics to crunch performance data from thousands of solar systems to create transparency for investors so that solar leases can be securitized, lowering cost and opening a new revenue stream for solar companies.

    • Alexander Miller

    • 29
    • Assistant Professor
    • University of North Carolina at Chapel Hill
    Miller is researching novel catalysts for use in the sustainable manufacture of next-generation fuels. In addition to converting natural gas and biomass to more convenient liquid fuels, his group is developing catalysts that utilize solar energy to convert water and carbon dioxide directly to liquid fuels and oxygen.

    • Brenden Millstein, Raphael Rosen

    • 29, 27
    • Cofounders
    • Carbon Lighthouse
    Helps companies reduce energy use at buildings up to 30% by installing systems of smart sensors and valves. No government incentives needed. Millstein previously handled budget of $87 million at New York State Energy Research and Development Authority. Cofounder Rosen worked at Lux Capital and researched super-conducting magnets at Lawrence Berkeley National Lab.

    • Meredith Perry

    • 23
    • Founder
    • Ubeam
    Perry invented and is commercializing a device that can recharge gadgets remotely using ultrasound transmitters. Featured in Best Buy commercial this year. Scored $750k in venture capital [DELTETE: cash] from Andreessen Horowitz, Founders Fund, Marissa Mayer, Tony Hsieh and CrunchFund.

    • Robert Petroski

    • 27
    • Nuclear Engineer
    • TerraPower
    At company backed by Bill Gates, working to develop the Traveling Wave Reactor, which may be able to squeeze 30 times more energy out of common forms of uranium fuel and generate far less waste. Work at TerraPower contributed to his completion of MIT Phd at 25.

    • Daniel Rosen

    • 27
    • CEO
    • Mosaic
    Since Rosen appeared on the 2012 30 Under 30 list, Mosaic has evolved from a Kickstarter that crowdsources funding for community solar projects to a vehicle for green-minded investors who want to put their money in solar – and get a return on their investment.

    • Kelly Twomey Sanders

    • 27
    • PhD Candidate
    • University of Texas at Austin
    Studying the energy-water-nexus. The amount of energy tied to water consumption totals just under half of all the energy this country uses. So save water and you save energy.

    • Yaniv Scherson

    • 27
    • Inventor
    • Stanford Nitrogen Group
    His process creates power from sewage plants by capturing ammonia from the treatment process, converting it to nitrous oxide, then burning it to generate electricity. A pilot plant is operating in Oakland, Calif.

    • Matthew L. Scullin

    • 29
    • CEO
    • Alphabet Energy
    Scullin, who put himself through grad school by DJing and once appeared with M.I.A., led a team that invented a solar panel-like device that generates electricity by absorbing waste heat from factory smokestacks, automobile exhaust and other sources. His startup, Alphabet Energy, has raised more than $16 million from investors as well as contracts from the U.S. military.

    • Daniel Schnitzer

    • 27
    • Founder
    • EarthSpark
    Working in impoverished Haiti, Schnitzer is distributing cheap solar-charged lamps and energy-efficient stoves and working to develop pay-as-you-go "micro-grid" electric systems.

    • Rick Thielke

    • 26
    • Portfolio Manager
    • SandRidge Capital
    Has generated scorching returns as co-manager of a hedge fund devoted to natural gas and energy. Completed Stanford MBA at age 22 and apprenticed as energy trader at ConocoPhillips, Louis Dreyfus and Merrill Lynch.

    • Patrick Walsh

    • 28
    • Cofounder
    • Greenlight Planet
    Devised a solar-recharged LED light dubbed 'Sun-King' that Greenlight is actively distributing to impoverished rural families in India, helping to replace smoky kerosene lamps. Payback period on the $15 lamps is about one year. A day's solar charge gives 16 hours of light.

    • Max Webster

    • 22
    • Cofounder
    • Communificiency
    The newly minted Yale grad started Communificiency to crowdsource local energy efficiency projects for schools, churches and small businesses. Investors in return receive rewards from businesses in return for the retrofits.

    • Chris Wilmer

    • 29
    • Cofounder
    • Numat Technologies
    With colleagues at Northwestern, invented algorithm to find and synthesize highly porous nanomaterials, 300 of which show the ability to store more natural gas than any other known material. Huge implications for creating fuel tanks for natgas-powered vehicles. Received $1 million in funding so far.

    • Taylor Wilson

    • 18
    • Inventor
    • Thiel Fellowship
    At age 14, Wilson became the youngest ever to build a nuclear fusion reactor. He then invented a cheap and highly sensitive device to detect enriched uranium. Now working on engineering a small neutron-generating device, and plutonium detector to inspect cargo containers. This year he received a Thiel Fellowship.