I agree with Peter Ackers that it is time to look again at Severn tidal power.
Doubtless any scheme would involve environmental hazards and probably strong objections - everything has its price. But I do not think we can afford to dismiss projects out of hand at the mere mention of environmental concerns, and without regular review.
The balance for and against may look quite different since it was last reviewed, a generation ago.
Barry Rydz (F), 6 Kingsdown House, Corsham, Wiltshire SN13 8AX