I've been selling solar energy systems for a number of years and have learned a thing or two about helping people select the solar panels that are right for them.  I love being back in Kansas City and hope you'll come in to see some of the solar power equipment on display and ask some questions. 

Making a solar photovoltaic (PV) system purchase can be intimidating to say the least.  There are many things to consider - correct placement, the variety of technology and innovative solutions now available, are among them. I'm going to try and shed some light on the process for you. It may help you to see some of what I'm talking about in our showroom. 

We carry traditional solar panels as well as the solar PV laminates (which are somewhat less efficient) and the more upscale solar roof tiles.  While there are some similarities, there's a wide a variety of differences in panels, and they are suited to fit particular situations. 

Our staff at The Energy Savings Store has the most experience installing solar panels in Missouri, Kansas and Illinois - we have a pretty good sense of what's going to work well in our area and for your particular situation. (As a side note, we also ensure that our clients get all the available financial incentives.) If you talk with  different installers, you'll want to be informed about what the important issues are: I've outlined them below. 

Your Utility Bills
First take a look at your last twelve months of utility bills. Your electric bill will show you the present and previous meter readings, along with the difference, which is your usage.  This is how you’re billed for electricity used, measured in kilowatt hours (or kWh for 1,000 Watt hours).  You’ll likely have peaks in the summertime due to the cost of air conditioning, and even greater peaks in the wintertime if you have electric heat.  For homes with non-electric heating, the average usage is about 12,000 kWh per year.

Assuming you’ve already completed a number of projects to make your home more energy efficient than average, we’ll suppose you use 10,400 kWh annually.  You then need to decide what percentage of that total you’d like to offset with clean, renewable solar energy.  For this example, we’ll assume you want to produce half of your electricity with the solar.  Now you can contact several solar installers to find out what it will take and cost to do that.

Example A
Let’s say Installer A proposes to install eighteen 230 watt (W) panels from a leading solar panel manufacturer with a good reputation.  The 230 W power rating is calculated using standard test conditions accepted in the industry.  This means that that each panel is capable of generating 230 watts of power, and under ideal circumstances the panel could produce 230 kWh in an hour if operating under perfect conditions.  The array of 18 panels forms a total of 4,140 watts, or 4.14 kW.  You’re told that the system will require approximately 400 ft² of roof space, and can be expected to produce 5,206 kWh of power annually.

Example B
Installer B provides you with a proposal to install sixteen “high-efficiency” panels from a different manufacturer, which are also rated at 230 W.  Because of the higher efficiency (18.1% compared to 14.2% for the competitive panel), this 3.68 kW system is expected to produce 3% more energy than the larger system – 5,363 kWh annually – for about the same price.  It also requires only about 250 ft² of roof space to install.

What's the Difference?
On the surface, it might appear that the higher rated system would be the better value.  However, if the southern exposure on your roof is limited, you might opt to go with the higher efficiency panel with the smaller footprint.  The return on your investment, though, is best measured in the actual output, or the kWh produced.  By looking at the total amount of energy produced over the life of the system, you can project a fixed cost of the electricity produced.  Panels typically last 40-50 years, but degrade slightly (about 1% per year) over time, so 30 years is commonly used as a typical life span of a system.  By multiplying the annual production by the 30 years, the larger system (A) produces 156,180 kWh, while the smaller, more efficient system (B) produces 160,890 kWh. By dividing the rebated cost by the total energy production, you come up with a fixed cost p/kWh.  Given the available financial incentives, in most cases this will be only slightly more than current rates. 

We all expect energy prices to rise – the question is how much.  In the past 25 years, electric rates have risen an average of 4.4% per year nationwide.  Industry analysts predict 6-9% annual increases over the next 25 years.  If you take a conservative 5.5% annual increase, you’ll see a $0.09 p/kWh rate turn into $0.19 in 15 years.  In 30 years, it will be $0.42.  So if your fixed rate ends up being 10-12 cents, you can rest assured that you’ll be smiling about your investment in future years.

Conclusion
The bottom line here is to ask questions about how much energy a system will produce, and how the installer arrived at that number.  Ask to see how the efficiency ratings stack up against other panels.  Picking the best solar PV panel is one of the most important decisions that you will make for your solar power project. We can help you through the process as well as make sure you get all the financial incentives possible.