We installed panels to begin with, and we were fairly dissatisfied with the life and efficiency of those panels. So, we were looking for some more efficient panels with increased longevity. We also had lead acid batteries, if anyone remembers those. We were having problems with the batteries and had a quote for replacing the batteries with lithium-ion and adding to the number of panels. One of the issues that I had previously, the system was not harnessing much power at all. We bought our microwave with us from previous house and we found that if we did that, use the microwave, it would start heating the batteries very, very quickly and we have to go to a manual recharge using an external generator. We did a Google on local suppliers, he seemed very competent, very enthusiastic, and above all very honest. We chose the panels he explained the greater efficiency and longevity of life and it's been beautiful ever since.