A central challenge to renewable energy is one of storage. Alone, solar and wind power lack the flexibility to provide power that can meet consumer demand during peak hours. Energy storage, therefore, is a market with tremendous growth potential-- worth as much as $31.5 billion in 2017 according to Lux Research. Several advanced energy companies are stepping up to meet the demand for storage capacity. The New York Times profiles three such companies: SustainX, a New Hampshire-based company building an isothermal plant to store energy, LightSail Energy, a California-based company using similar technology, and General Compression, a Massachusetts-based company building a salt cavern storage system. The New York Times reports:
With increased interest [in advanced energy storage capacity] has come investment: Venture capitalists and governments are funding research into batteries, pumped hydroelectricity, flywheels and compressed air. […]Current experimental systems aim to be more efficient by retaining or recovering the heat. Some, known as isothermal, use a coolant to absorb it, keeping the air at a near constant temperature. The coolant, stored separately, is tapped later to give back the energy through a heat exchange system. Others, known as adiabatic, allow the temperature of the compressed air to rise and fall, using the air, when hot, to warm heat storage units that retain energy within the system.