Loss of power steering zafira?

Driving my 2005 zafira 1.6 I heard what sounded like gravel hitting the underneath near the front wheel wells. It didn't last for long. A few miles down the road I noticed the red battery light. A few miles further I lost power steering and the Rev counter and speedo stopped moving. I seemed to still have indicators, and elec Windows working. The central locking hasn't been working for many months and I have been locking with a key. It didn't want to lock and unlocked itself a number of times before it stayed locked