Power usage question

I plan on running a 250 watt HPS with about 50 watts of other equipment (blower, pump, etc). I live in an old building with 15A 120V (ithink?) GLASS!! fuses which have to be replaced as they go. Will i be able to run my setup without constantly blowing fuses?
and
How much will this setup cost me to run a month? Is it worth it to explore other methods, wind or fuel cell?

You will be just fine. It's easy to calculate wattage to amps. Add up the total wattage of everything that is on that circuit, that comes to 300 watts from your list. Take that 300 and divide it by your voltage which is 120V. So 300 / 120 = 2.5 amps well under your 15 amp fuse. Leave your self a little extra headroom, at least an amp under that fuse rating, especially with the wiring in an old building.

Now if you plug in a 9 amp vaccum and a fish tank you might be in trouble.

As for how much it will cost you, take a look at your electric bill and find out what they charge for a kilowatt hour or kWh. Around here I think it's like $0.10. Read carefully, the may charge a different rate during peak periods during the day, it might be cheaper for you at night. To figure out your usage, you were at 300 watts which is .3 kWh, multiply that by how much they charge for a kWh and thats how much it cost per hour to run your setup. So for your setup at my rates it would be $0.03 per hour, $0.72 per day at 24/0.

Oh, as for alternate methods such as wind or fuel cell, probably not worth it for you just yet. The amount of time it would take you to get your return on your investment would be measured in decades. For less than the cost to feed a starving etheopian you could run your setup.

Thanks a bunch man! Im gonna run it all on one fuse just to be safe since i can (workout room), maybe add some LED's or somefin small for vegging in that case. Wasn't really very seroius about alternate methods. lol indeed far above my head at the moment.