Go to Energy - European Commission
For data on Spain, take a look at Energía Ministerio para la Transición Ecológica y el Reto Demográfico
For US data, go to the Energy Information Administration from the U.S. Dept. of Energy
Go to Discovery and search by using keywords like "energy consumption" or "small business". Combine with other keywords to narrow your search.
Also, go to OECD iLibrary.
Use Datastream, a database available from Barcelona and Madrid Libraries (through LSEG Workspace).