How To Store Solar Energy by Lifting Concrete in Your Basement

Storing rooftop solar energy to distribute the load over time is the holy grail of alternate energy researchers today. Batteries are quickly evolving to fill this need, but is it possible to create a basement mass lifting system to provide a low-cost alternative? To find out, I started my research by writing a simple Python program to calculate the basics of storing solar energy by lifting concrete.

Photo by Victor Freitas on Unsplash

There’s a fairly simple formula for how much energy is stored when any mass is lifted. You simply multiply the amount of mass times the height it is lifted times the gravitational acceleration constant g. Of course, you need to pay close attention to the units used, so everything works out correctly.

Here in the U.S. concrete is bought by the cubic yard, and a common metric for how high something is lifted is in feet. I used those units for the two inputs, but immediately converted everything to SI units, such as kg (kilogram) and m (meter). The acceleration of earth’s gravitational field, g, is about 9.8 m/s² so it is already expressed in these SI units.

Solar Energy is in kWh

When the m and kg values for the lifted height and the concrete mass are multiplied with g, the resulting value is in Joules, or kg*m²/s². The number of Joules tells us the…