then you take the system size in cec, california energy commission a.c. watts. that term is understood by the people in the industry. that means they use the c.e.c. ratings to determine the a.c. wattage. you get the per watt price. you divide this by this. you get the price per a.c. watt. you want to ask about permit fees as well. each city typically will charge fees. now those fees are coming down and we're working very hard to get them standardized and clear. there is some cost. sometimes the installers will pass that on to you. ask how they're dealing with it. you say, ok, what's my watt. let's see it was four d.c. but you'll have 18% less here, so that's the number you want, you divide this by that and you get that. so this would be 926 a watt. therefore, you can compare apples to apples. they have a standard calculator that they use on the web and they include that printout on your bid and they have to file that printout in your rebate application. so there is another possibility of lowering costs, the group buy. when i went, in i went in with a bunch of fri