You can employ an alternative approach, such as bottom-up methodology, in estimating energy demand. For instance, instead of linking industrial energy demand forecast solely to GDP or growth targets, you could utilize metrics like production projections for fertilizer, ammonia, or iron and steel in the industrial sector for activity level. Similarly, for the transportation sector, you could utilize stock turnover rates or mobility demand, derived from stock/mobility projections based on population or sales forecasts. In commercial settings, you might consider using labor force projections multiplied by floor area per worker, while for residential areas, tracking appliance penetration projections could be beneficial.

From my interactions with some energy modeling tools, I've found that LEAP offers significant flexibility. While it's possible to integrate economic data with other approaches, attempting to model without economic data would require substantial data inputs.

Please note that the model may not always be entirely accurate. However, adopting a bottom-up modeling approach can provide richer and more insightful information.