Guardian: The electricity meter was changed last week because the old one had been running backwards. This phenomenon had originally caused consternation on a sunny day in summer when workmen, sent by the electricity suppliers to renew the earthing system, wanted to call the police. Only a consultation with head office persuaded them this was not a felony but a 1970s-style meter responding to output from a new set of solar panels on the roof. The panels were exporting electricity to the grid. Since then…