Deputy electrical engineer, University of Oxford

We have somewhere in the region of 300,000 light fittings
We’re responsible for the functional estate of the university, so we deal with all research and teaching spaces. There are about 350 buildings and we estimate we have somewhere in the region of 300,000 light fittings. THese buildings vary from Grade I-listed up to the ultra-modern buildings for various academic research departments.

We need to discreetly light these buildings
We’ve got a number of Grade I-listed buildings like the Radcliffe Camera and the Duke Humphreys LIbrary, which is always very popular with film companies – you’ll see it in Harry Potter for example. Lighting in those areas is always a challenge, because we need to discreetly light the building how it was back in the early days.

Some of these go back to the 17th century – or even earlier. Fortunately we don’t revisit them too often, thanks to the upgrades. In listed buildings, we need to get our building conservation [experts] involved and the Victorian Society. We need a very sensitive approach before we can actually start, we then have to go through our own internal processes.

We’re trying to coax the manufacturers into being proactive
In March 2011 the university committed itself to a 33 per cent reduction in CO2 emissions by 2021. We never really had a lighting philosophy before, just a guidance note saying, ‘use high frequency fluorescents’. Now we’ve put down some key targets, like 60 luminaire lumens per circuit watt in general office environments and 70 lumens per circuit watt for a downlight. We’re trying to push these technologies further and coax the manufacturers into being more proactive. I think they’ve been quite slow really.

End-users can force manufacturers to push up the efficiencies. You can’t get away with throwing in the usual sort of cheap and cheerful product.

If you look at maintenance it becomes clear how we can justify the expenditure
You can only push efficiency so far before it becomes ineffective. I think when you compare LEDs with compact fluorescents, yes you get massive energy savings of up to 70 per cent, but when you try to justify the cost of the luminaire on energy alone, it’s difficult. You have to take the maintenance factor into account. When you then start to consider how much it costs to bring an electrician to site, it becomes clear how we can justify the installation expenditure.

When tungsten is gone, we’ll have to look at alternative sources
Some of Oxford’s research facilities are highly sensitive. If they’ve got microscopes in the area, or they’re looking at lasers, you have to be careful what you do with the lighting. THey’re not allowed to have fluorescent lights on, so there’s all sorts of other ways we have to light it: some of the academics still require tungsten lamps to run their experiments. In a few years, when tungsten is gone, we’re going to have to look at alternative light sources for them.

You don’t need a BMW just to drive to the shops
We don’t necessarily want the best. Everyone would like the best, but you don’t necessarily need a BMW just to drive down to the shops. If we ask for a high efficiency luminaire, generally we’re going to get a better quality product, some of the mid-range and low-range manufacturers won’t ever achieve those efficiency targets. By setting high efficiencies, we’ll screen out some of the low end of the market.

We always have issues educating end-users
What I found useful when I went to the LuxLive exhibition in London last year was the information about the advances in streetlighting and controls. You can program them to go down to 25 per cent at one in the morning, for example. It doesn’t need to be running full bore when no one’s around. We always have issues educating end-users. As part of the philosophy document I’ve written, we’re asking for absence detection in all areas with Dali controls so we can interface with daylight and start turning items off.

John McDonnell

Managing director, Harvard Engineering

Simon Fisher

General manager, indoor, design & application, GE Lighting