Great photo. I'm not an expert on bats. Size would give a clue - the tiny bats at Minsmere, which are most common are pipistrelles - we get both common and soprano pipistrelle but you probably need a bat detector to tell them apart. Larger bats might be serotines and larger still are probably noctule (thoguh they are still small mammals). It doesn't look like a long-eared. There are other species that occur here too.