Does the chalk under Royston affect a ground-mounted array?

Yes, and it is worth raising at survey rather than discovering on install day. The town sits on Middle Chalk, part of the New Pit Chalk Formation, with only topsoil above it — the same near-surface chalk that made the bell pits and dene holes around the town possible, and that Royston Cave itself is cut into. Shallow chalk changes how ground-mount foundations are specified and how cable trenching is dug, and it drains very differently from the clay we work in further south in Hertfordshire. For a roof-mounted system it makes no difference at all. If you are considering a ground mount or a long cable run to an outbuilding, tell us at survey so the groundwork is priced properly rather than assumed.