Well, if energy alternative A has a 3:1 EROI and energy alternative B has a 5:1 EROI, one might be tempted to choose B, ceteris paribus. But if one knows discovers that society currently runs on an EROI of 12:1, then neither is fully acceptable and conservation, lifestyle, infrastructure have to be changed IN ADDITION to introducing the new energy source -frankly I think the absolute level of energy gain is much more important than the relative.

This just seems like a hopelessly crabbed, narrow, unworthy view of life. There's more to life than just saving energy. If the 3:1 alternative is the one that serves best overall, then I'll take the 3:1 alternative. Which, I suppose, is why we have economists, and which, I suppose, is why those off-center folks who take energy as the be-all and end-all seem to hate economists.

Actually, society would not function on a much lower EROI - energy allows to do work, which includes water, food, heat, shelter, etc. Thats the whole ball of wax with net energy analysis. If a system is conditioned to high energy gain, yet the alternatives are only low energy gain, changes or consequences must follow, by definition. Sorry if its crabbed or narrow - its reality.