You are correct that using gravity-based energy storage alone may not be the most efficient method for storing large amounts of energy. The example you provided, where a kilogram moving down a meter supplies only 1 watt for 10 seconds, demonstrates the limited energy output for a small-scale system.
Gravity-based energy storage systems, such as pumped storage hydroelectricity, rely on utilizing the gravitational potential energy of raised objects or water to generate electricity when needed. While these systems have been used effectively for grid-scale energy storage, they have certain limitations and are not suitable for all situations.
Scaling up gravity-based energy storage systems to store significant amounts of energy can indeed be challenging. It requires large-scale infrastructure, significant land area, and suitable topography for constructing reservoirs or other storage mechanisms. Additionally, energy losses due to friction, inefficiencies in energy conversion, and other factors can further reduce the overall efficiency of the system.
To address the limitations of gravity-based energy storage, it is common to combine them with other forms of energy storage, such as batteries or compressed air systems. These hybrid approaches aim to maximize the benefits of each storage method and achieve a more efficient and reliable energy storage solution.
It's important to note that energy storage is a complex field with various technologies and approaches, each with its own advantages and limitations. Different methods are suitable for different applications and requirements, depending on factors such as energy capacity, response time, cost, and environmental considerations. Ongoing research and development efforts are focused on improving energy storage technologies and exploring innovative solutions to address the challenges associated with storing large amounts of energy efficiently.