Investing in clean energy, efficiency and electrification is the only path to get us there. : Jesse Jenkins is an assistant professor of energy systems engineering and policy at Princeton University. Thanks to a remarkable oil and gas boom, the United States has achieved the long-sought goal of energy self-sufficiency: We now produce more oil and refined products, natural gas and coal than we consume. In particular, horizontal drilling and hydraulic fracturing — fracking — transformed the United States from the world’s largest oil importer to a net exporter of both oil and gas.