i'm an idiot with this, but i'll do my best. it's black and it's pretty smooth. no rough materials embedded (aka, basically tar paper). i'm not sure about the insulation.
summer it normally hovers around 1000-1100kwh, winter time around 6-700kwh. since i'm at 1000kwh i'm going to wait until it gets a bit warmer to see how high it goes.
shitty job i'll explain later when i get home from work.
Edit: forgot to update. When they did the replacement they failed to secure the drain which caused a leak that accumulated and caused my bathroom ceiling to collapse.
Sorry for the late reply. It sounds like you have a BUR (built up roofing) system with no coating. Generally they are at least flood coated with asphalt and graveled but considering this is a residential roof the structure might not have been able to handle it.
The very first thing I would do is go to a roofing supply store (NOT Home Depot or Lowes) and buy a reflective roof coating. Buy the good stuff, it will be a bit expensive but you aren't covering that many SF so it shouldn't cost you too much and you can easily install it yourself. Pressure wash the roof clean and you literally paint it on with paint rollers on the end of a stick. This will serve two purposes, first it protects your roof from the sun that your currently black roof is just sucking up like crazy. Secondly it drastically reduces your roofs temperature which in turn drastically reduces the heat that is transmitted from the sun to your roof to your attic to your conditioned living areas. It is also supposed to keep heat in during the winter but I'm in the deep south so our only goal is lowering cooling costs.
I honestly would not put a solar system on a bare built up roof system without some sort of coating on it. The roof is just way too likely to degrade fairly quickly and it will cost that much more to reroof. Step number one in going solar is making sure the substrate, in this case your roof, is very likely to remain in good working condition for a long time.
With that said, there are some pretty nifty non-penetrating racking systems for flat roofs. If I get a chance I'll try to look up the wind speeds in your area to see what sort of ballast would be required and see if you think your structure can handle it. If you do go with a penetrating system (they put screws through your flat roof) GET A ROOFER TO INSTALL THE FEET TO THE RACKING SYSTEM. I can't stress that enough, solar barely know that the roof goes on top. They get away with it on steep slope systems because the water naturally wants to get off the roof very quickly so a few dabs of caulk will work. On a flat roof caulk is NEVER used as a primary waterproofing product, never ever ever. I can't tell you how many pretty ass flat roofs I've been called out to look at because they had solar installed and the very next rain it literally leaked like a sieve. I was able to repair them but not a single one of those roofs will ever be in anywhere near the condition as they were the day before the solar guys got there.
Matter of fact, if you decide to coat the roof you should email me the name of the product your roofing supply store tries to sell you. Andek is my favorite product but you might not have a distributor in your area and it's expensive as shit to buy online.
Over 20 years experience in estimating/managing commercial roofing and 7 years experience in solar design and management.