On the south bank of the Thames sits the hulk of Battersea Power Station, once the source of 20% of London’s electricity, now a rusting and decaying hulk left to rot by its owners, for whatever reason. Now they claim to have a [planning approved] vision, and have opened it to the public, in conjunction with the Serpentine Gallery, for the first time ever.

It’s open for a month, and when we tried last Sunday we found the gates shut due to overwhelming demand. So we suffered the processing fees for pre-ordering and returned today, finding it open early and with the rules on photography much relaxed. Coming through the gate the south wall looms above you, and below are a collection of bikes to use while exploring the site – an interesting idea, but not nearly enough was open to warrant it. Only the south side was accessible, and so all was within easy walking distance.

The art exhibition is sitting on three floors in the newer turbine hall B. But, like most visitors, we veered off to the left and into the cavern of the boiler hall. The turbine hall at the Tate Modern is awe inspiring, yet only the lack of a roof allows some relief from the size. Since one of the upper walls and the roof were demolished in the 1980s this area has been decaying – old patches of tiles emerge from the dirt and grass on the floor, while rusting girders hold back the holed remnants of the walls. The bulky towers below the chimneys turn out to be held up by a matchstick structure of girders, while the pits, arches and traces of stairways leave visible reminders that this was once a hive of industry.

On either side sit the smaller turbine halls – both still immense in size, hall B like some gigantic post-apolocolyptic office block, while hall A is lined in (apparently) Italian marble, with ornate balconies. Rumour has it that the control room and offices on that side of the building are also in fine art deco style; these, however, remain out of view.

Above hall B lies the exhibition – three vast, dark and mostly empty floors, with only the token piece of machinery or a decaying door sign to remember it’s past use. The art was visual and auditory, and yet mostly overwhelmed by the space. At the top of the block sunlight streamed through the rusty frame and lit upon plywood covering a mammoth hole in the floor, possibly a quicker way out than down the ancient stairway, back into hall B and then out into the scrubland which rings the site.

The scrolls and delicate touches on the facade of this cathedral of power only accentuate the shocking disregard for the building’s state. Since the pipe-dreams of the 80s fell apart and left the building exposed it has been allowed to rot, the developers allowed to sit and twiddle their thumbs while a grade two structure surrenders to entropy. And even as they showcase fantastic designs for a reinvention of the space, with entertainment and shopping facilities surrounded by office space and housing, the Time reports that they may have once again changed their mind, once more backing down, although perhaps this time at least restoring a roof to the site.

Should you be in the vicinity I would highly recommend you pay the meagre £5 they ask and go and explore before they close it again – who knows when you’ll get another chance to do so?