We will begin by looking at residential solar PV systems. The reason for this is that residential systems have all the components of even the largest Systems, but of course, in a much smaller scale, making them easier to understand. The steps for installing a residential solar system include the following; selecting a contractor, evaluating the solar resource, designing the PV system, acquiring needed permits, financing the project, engaging stakeholders, constructing the system, and then monitoring system performance when it's up and running. Finally, at the end of its life, we need to decommission the PV system and dispose off the remnants. The first step for a solar residential PV project is to select a contractor for design and installation. When you select the PV contractor, you'll want to get several quotes and then select using multiple criteria. Those criteria can include; time in business, customer reviews, apparent expertise, experience in your community, quoted price of course, and warranties and guarantees for the system. Finally, will they be involved in the system decommissioning at the end of the project's life? The next step is to evaluate the solar resource at the residence. This evaluation typically is undertaken by the contractor. Sources of data may include; solar insulation maps, satellite imagery, or evaluation software. Evaluation considerations should include; the latitude of the residence, roof orientation and pitch, shading potential, wind loading and the possibility of hail damage, snow and dust losses, and annual temperatures at the site. From all this, we should be able to calculate the annual energy production available at the site. Next is the design and selection of PV technology. First, we need to decide on the panel technology be it crystalline, polycrystalline, or thin film. Next, we need to decide on the invertor design, be it centralized, micro, or power optimized. The size of the system then comes. This will determine the size and number of PV panels that we need to achieve our power output. We may want battery backup. We need to understand its purpose and how big it should be. Finally, we probably want monitoring and control systems such as software and online mobile applications so that we can track the performance of our solar PV system. First, we'll need to acquire needed permits. Understand that permitting requirements vary widely by location and jurisdiction on the building permits, electrical permits, wind loading studies perhaps, structural analysis, glare analysis perhaps, and utility design review from the local utility, and finally, project inspections from utility and local authorities. Along the way, we'll need to decide how we're going to finance our PV project. We could pay cash. This is money out of pocket. In that case, we own the system outright. We could borrow money. Again, we own the system outright, but we have to pay back the loan. We could sign up a power purchase agreement with the contractor. In this case, the contractor owns the PV system and we pay the contractor amount of money every month based on typically system power generation. The contractor is responsible, therefore, for the maintenance and the eventual disposal of the system at the end of its life. Finally, we could sign a lease with a contractor. This is a fixed monthly power payment agreement. The contractor owns the PV system and will maintain it and decommission it at the end of its life. The graph to the right shows the relative savings for different financing options. Most attractive is a cash purchase since we own it outright, we don't pay any interest, we don't pay any overhead to the contractor. Next is a solar loan, followed by a solar power purchase agreement, and the lease savings come from the solar lease. Now the benefit of the solar lease is that we don't have any upfront cost. Those upfront costs are borne by the contractor, and we essentially pay back the contractor for those upfront costs over the life of the project. It's always important to engage with stakeholders early to uncover objections and ensure buy-in. Stakeholders may include; neighbors, HOAs, and COAs as homeowner associations or condominium owner associations. We need to make sure we understand their rules and secure authorization for our project. Municipal code offices understand the regulations, procedures, and schedules in your community, and the utility company, of course, will be a stakeholder. We need to secure authorizations from them to connect to the grid and to negotiate power sales terms if our contractors isn't doing it for us. After all this preparation, it's now time to install our solar PV system. Our contractor who will install mounting hardware, mount the panels and wire the panels into strings, install inverters and the battery, if we wanted a battery, commission the system to verify the initial power output and install monitoring software, and other considerations may be coordination with the electric utility and make sure that our contractors using good rooftops safety. You can see in the picture to the right that the workers are wearing harnesses to prevent them from falling off the roof. If available, online software allows continuous monitoring of our PV system. We can monitor the output versus estimated outputs, identify problems early. We can correct shading issues if they occur, and we can determine needed cleaning. We can repair defective equipment and track cost savings with this software. Finally, we can use all of this to justify the initial expense of the system. Now, solar PV systems don't last forever. A typical lifespan might be 25 years for a PV project before it's obsolete needs to be replaced or removed. This is called decommissioning. You disconnect the system from the utility, remove the panels, remove mounting hardware, repair any damage to the roof, recycle panels and hardware. Solar PV recycling companies are emerging that will take solar PV panels to recycle them. Finally, don't send anything to the landfill, check local requirements so before you do. In summary, the steps for installing your residential solar PV system are the following; select a contractor, evaluate the solar resource, design the solar PV system, acquire needed permits, finance the project, engage stakeholders along the way, construct the system, monitor system performance, and then decommission the PV system at the end of its life.
