IES Residential

Outstanding experience working with IES. Michael explained everything in detail. The whole project was completed in 1 day and looks great!! Saved $100’s on monthly electric bill!! Highly recommend IES!!

"IES was the best choice"
David N. & Juan did an excellent job troubleshooting my 12 year-old 4600 KW solar system, updating some components and bringing it up to standards as if it were new. I'm very pleased with their work, knowledge and customer care

Overall, system quality is good, and the services provided by IES were good as well.

-So why the 2-starts instead of 5?

I didn’t particularly appreciate how the system was presented in terms of numbers and expectations. Basically, what was presented was misleading.

-Why is the information presented to clients misleading?

In simple terms, any house in the US (or I should say the world) runs on AC power, but the system is presented and advertised in DC power. Note that companies offer their systems in DC Power. Also, they do present (on paper only) the AC Power output after you sign the initial contract.

-Why is it essential to run the numbers with the max AC Power output and not DC?

In simple terms, the max AC Power output is limited (clipped) by the inverter’s efficiency or the inverter’s max AC Power output, whichever is less. So with this being said, your panels could be producing 340W DC, but the AC Power output could be 290W AC because of the max power output of the inverter (295W AC Max).

-How has this impacted my system?

My system was presented to me as a 7.82 kW DC system (23 panels of 340W). All numbers were presented using the DC Power number, numbers such as how much the system could produce in a year (11,382kWh), how much offset I was going to generate (64.93%), etc.
After the system was installed, I expected an AC Power constant peak output of something close to 7.59kW due to the inverter’s efficiency. But, to my surprise, I was only able to get a continuous peak of 6.67kW. After looking back at the design, I realized that the AC Power output was 6.67kW because the inverter’s max output is 290W/295W Max per inverter (the system uses one inverter per panel, so 290W x 23 panels). So, all the numbers presented were based on DC power output, although to compare apples to apples, you should compare to the AC power output.

-What IES had to say about this?

So IES tried to explain why they used the microinverters they use, which have a max AC Power output of 290W. This I already knew after doing my homework and not trusting the first thing I see on paper. Basically, the microinverter that can output more AC Power starts working at a bit higher voltage than the ones I got. This matters because when you don’t get too much sun, your system will produce a little bit of power. So to decide which inverter is best, you have to see the pros and cons. Anyways, this was not my question to them; my question was why their advertisement was misleading. To this concern, they tried to shift my attention to the annual production number presented in the initial contract, which was 11,382kWh. I was told that their program considers AC Power and other factors. Still, to those of you that know how solar energy production is calculated and to those who don’t, it is calculated based on 4hrs of direct sun per day in other words, Annual Production = Watts per panel * Number of panels * 4hrs * 7 days a week * 52 weeks. So, if we take my system in DC Power, Annual Production = 340W per panel * 23 panels * 4hrs * 7 days a week * 52 weeks in a year = 11,386kWh DC Annual Production…. If we take my system in AC Power, Annual Production = 290W per inverter * 23 inverters * 4hrs * 7 days a week * 52 weeks in a year = 9,712kWh AC Annual Production…. Now, why do I believe I was told to look at the Annual Production instead? Well, surprise, we are in Texas, and we get more than 4 hrs of direct sun. So yeah, I’ll get to that number eventually.

-Would this have impacted my decision to go solar (or at least with IES)?

Yes! As you can see, I know one or two things about solar and how the system works and, systems are overpriced everywhere. So, I would have put more thought into it before deciding. I just failed by trusting the numbers that I was given.