Open energy system databases are websites or computer programs where people can find out about different kinds of energy sources, like electric power, natural gas, and oil. This information might include how much of these sources are being used in different places, the cost of using them, the environmental impacts of using them, and more. By having open energy system databases, people can use the information they find to make decisions about the types of energy they use and how they can help reduce pollution and other environmental problems.