While solar-energy technology can capitalize on an array of benefits—from lowering electricity bills to minimizing carbon footprints—it would be unwise to think of any solar system as a one-size-fits-all solution. Geographic location, site constraints and the customers themselves all play a role in determining which solar products are best suited to a particular project. The good news is that location or solar-exposure are no longer limiting factors to solar installation as there are many system options that address site-specific restrictions.
Review of Solar-Energy Equipment Types
As a quick review, photovoltaic panels can be mounted on roofs or mounted on the ground. Ground-mounted panels have the option of being fixed or attached to trackers, the latter of which rotate on an axis to follow the sun and capture more available solar energy.
Considerations that Contribute to Your Choice of Solar System
Roof-mounted PV panels have the most restrictions, as the roof's direction, pitch and construction all play a role in determining whether solar is an energy system option. Ideally, PV panels should face south within a 20-degree window depending upon how far north or south you are in the States. In addition, the pitch of the panels should be set to optimize solar capture during the peak time of day. When optimal orientation is not an option, an alternative is to face the panels up to 45 degrees east or west of true south and to look at increasing the number of panels to capture the necessary energy. Decreased efficiency adds to the cost of the project and it may reach a point where a roof-mount system is not economically feasible. For these situation, a ground-mounted solution is an excellent option. With ground-mount systems the site should be chosen to optimize solar capture and minimize shading. For additional efficiency, a dual-axis tracker is worth considering. These systems are designed to follow the sun as it moves through the sky each day and also allow for adjustment of the panels throughout the year to increase solar exposure.
Further considerations for panel location include the amount of shade produced by trees, chimneys and other objects. Snow cover can also hinder solar production. Depending upon how the panels are strung together, snow cover or a shadow cast on just part of one solar panel in a solar array can compromise the output of the whole system. It is important to consider all times of day and all times of the year when looking at the effects of shade and snow on a solar installation. It is often easier to minimize the effects of trees and other objects with a ground-mounted tracker. Another advantage of a tracker system in areas of high snow is that they are designed to shed snow and are easier to access for snow removal.
In order for a project to be worth the investment, the customer's energy needs must be taken into account. It is important to look at the current energy usage and discuss the energy requirements they might need in the future. You need to know exactly what appliances are powered by electricity. Is their hot water heater gas or electric? Do they use space heaters in the winter to warm certain rooms? How many people live in the house? Will this change moving forward? (For example--there is nothing like a teenager taking long, hot showers to spike the hot water usage of a household.) The addition of air-sourced electric heat pumps or the purchase of a plug-in electric vehicle will change the electric needs of a household. By determining the requisite kilowatts that need to be produced per month, you can figure out how many panels are needed to produce this energy within a particular geographic area. There is a limit to the number of panels that can be placed on the roof. If the energy needs are high, or are anticipated to grow, a ground-mounted system that can produce up to 45 percent more energy should be considered. In addition, a ground-mounted system is more easily scalable if the energy requirements increase at a later time.
Once you are clear on their current and potential use it is important to understand their motivation and desire for adding the Solar System. Are they looking at this as a straight economic decision and will they look solely at the costs and Return-On-Investment? Or is there also an environmental aspect to their interest? Are they looking to reduce their carbon footprint and offset some or all of their current use?
And, of course, aesthetics also play a role in matching product to project. While some customers have no choice but to put panels on the roof due to having less open-air property or yard space available, others may prefer roof panels to avoid seeing a solar system on their property. If you, as a provider, believe a roof-mount system is not optimal in meeting energy needs, it is worth taking the time to discuss the benefits of ground mounts and tracker systems. Many homeowners like the look of ground-mount systems and enjoy watching a dual-axis tracker move throughout the day.
Once you have a good understanding of the customer's needs and desires you can start to define the scope of the project and, as a result, the cost for the entire project. At this stage it is critical that you fully capture all the direct and indirect costs associated with the project. These include such things as system design and layout, on-site work, sub-contractors who might be needed, labor costs for site work and installation, costs for all the hardware and incidental parts that may not be included from your suppliers.
A good estimate will require a certain amount of upfront time and energy on your part. You will need to make certain measurements and research must be done. If the customer is thinking about roof installation, you need to look at the construction of the roof and determine whether it can support the system. In some cases, you may want to offer options for a ground-mount system or the addition of trackers. Having a good working relationship with your suppliers is critical in your estimating. They should be able to help you define the scope and time required to do the installation and also alert you to things to check on or clarify for the site.
You also need to be clear on the warranty on the system--what is covered and what is not covered. For example--do you cover the work in the event of a natural occurrence like a hailstorm or hurricane? Do you include an ongoing inspection and maintenance plan with the project?
Once you have collected your costs, don't forget to include some room for contingencies and your profit. The unknowns of the site work, especially on a roof-mount system, can totally swamp an estimate. It is best to be upfront with the customer on what things really cost and not try to skimp to get the business. Remember, in the end, you are not doing yourself or your customers any favors by having an inaccurate or incomplete estimate.
The overhead costs associated with the design of a roof-mount system also need to be considered. Each roof is distinctly different and requires system engineering; there is often no standard installation price that fits all roof-mount customers. Many ground-mount or tracker systems come pre-engineered and enable you to more efficiently calculate the cost of an installation as there is little, if any, change in system design or labor time from one location to the next. Partnering with a supplier who can help you with system design and overhead cost containment can make your cost calculations more accurate and make you more effective at meeting your customers' needs and growing your bottom line.