discodermolide, can you find me a link to one on Ebay? The only ones I have been able to find are either fairly bulk, extremely pricy ($6000>), and even at the very low end range I found some quartz lamps for UV curing purposes (with the right uv spectrum of course), that cost a minimum $900-2000. Most of which was the cost of the ballast, oh, and those companies are all overseas so I would have to buy a transformer if I wish to run it in the US.
Not really sure why I can't find a 100w medium pressure mercury vapor bulb that will screw directly into an edison socket. There is an abundance of high pressure bulbs at the hardware store. I'm assuming the medium pressure bulbs just aren't manufactured as much due to less of a demand. If anything, they would be easier to manufacturer due to lesser pressure, whilst the design would remain the same. I looked at some germicidal (low pressure mercury) lamps online but they only really output in the 254nm spectrum and are really low wattage. Medium pressure lamps encompass the 254nm as well as some of the higher UVB and UVA.
Luckily the [SRN1] reactions I am interested in are largely radical reactions that only need to be [continually] initiated by light, or some other source. Some of these reactions have been reported finishing in 5 minutes - 1 hour, thanks to a radical chain reaction. So intense heat through quartz isn't fully a requirement since an equal molar amount of photons isn't required. More like 0.001% or less of photons can get the reaction going and send it to completion, depending on the substrates of course and how likely chain termination is to take place.
I plan to be experimenting with sunlight among other radical initiators. My main reason for asking this question was to find out if average solar UV on a sunny day is closer to a 100w uv lamp, or a 1w uv lamp. Exactitude can't always be measured as you have said because of atmospheric inconsistencies, but a good approximation may be able to be had.
If I had to take a wild guess... if that guy was sun burned in 5 minutes by a 250-400w uv lamp, then solar UV on a sunny day might be around 25-50w.