What do you mean by a "true" apples to apples comparison?
A big advantage of PV solar technology is that there are a standard set of equations that can be used to calculate the benefits a buyer can expect to receive from their installation. However, the person doing the calculating still has the opportunity to choose the numbers the use in the equations. In other words, different individuals can get different results for the benefits of a system, even if they are using the same equations, simply by choosing different inputs.
So, in the real world, when you compare proposals from different installers, you are almost guaranteed to see very different estimates for expected financial benefits, even if they are proposing the same equipment. This creates an obvious problem when comparing each proposal side-by-side.
We do our own analysis on each proposal our clients receive, using the same set of inputs for each project. This is called using a “standardized approach” and is only way to truly compare solar proposals side-by-side, apples-to-apples.