I use about 3,000kWh of electricity per year so if I produce more than that does this mean I won’t need any electricity from the grid?

Unfortunately not. Solar panels produce most of their electricity in summer and much less in winter, whereas most homes use more electricity in winter and less in summer. On a sunny day in summer your panels could produce 30kWh and not many houses use this amount in a single day. On a dull winter’s day they may produce less than 1kWh.