Ascher’s work provides readers with a glimpse into the inner workings of New York’s power system, while simultaneously suggesting ways to improve the City’s capacity for sustainability. Such methods include the consumption of more green power, or electricity derived from natural, renewable sources, as opposed to energy generated by fossil fuels. Biomass fuels, for example, are produced from the decomposition or burning of organic matter. Hydroelectric energy, or electricity generated by water-powered turbines, accounts for 4% of New York City’s power consumption, and nearly one-fifth of New York State’s. In order to become a “greener” city, Ascher proposes that New Yorkers invest in alternative energies, despite the fact that the production of green power may cost significantly more. Central Park’s NYPD precinct is powered by a fuel cell, which combines gas and steam to produce hydrogen and ultimately, a direct current. Although the 200-kW fuel cell was expensive to install, it creates much less pollution and makes the police station immune to any interruptions to the New York State power grid. The fact that housing is responsible for the most energy consumption in the City sheds light upon the need for New Yorkers to become more aware and considerate of how much energy they burn as individuals. With the cooperation of citizens (and a little coaxing by the law), the amount of electricity consumed by New York on a regular basis may decrease, in the end lowering the City’s carbon footprint and improving the environment for future generations.