In past years, the costs associated with residential PV solar systems have been left up to the imagination of the companies installing the systems. The parameters of this industry’s guessing game are about to change according to a recent report from the US National Renewable Energy Laboratory (NREL). The NREL has decided to team up with the Rocky Mountain Institute and the US Department of Energy to construct a more detailed report about potential installation obstacles, cost measurements and reference points. 
This in-depth report will look at two different types of battery systems. The first smaller system is a 5.6kW PV array and a 3kW / 6kWh lithium-ion battery. A larger system is also analyzed in the report. The system is a 5kW / 20kWh. The information being collected is based on the data beginning from Q1 2016. Costs are recorded in regards to the installation of these systems in residential areas. The costs reflect a 17% margin to display the perspective of the installer and the profit that can be made off of the system when a purchase is made by a residential client.
The NREL has released some of the benchmarks for solar PV systems thus far. This information along with the complete report is available to the public at no cost. For example, the report states that installed cost benchmarks for an AC-coupled, small battery system would cost about $29,568 USD. This benchmark cost is significantly lower than the cost of an AC-coupled, large battery projected to cost about $47,171. Having this information published in the NREL report will help installers understand the source of the cost variations for residential solar PV system installations. In the case of AC-coupled batteries, the difference in cost may be attributed to the size and quantity of inverters necessary for the system to operate. The larger battery systems generally require a greater amount of inverters, in addition to inverters of a greater size.
This may be one of the first, but not the last, cost benchmark reports that will be constructed and issued by the NREL. Not only will the information in these reports provide an industry standard, but also, the reports will provide installers with a better sense of wear costs can be cut or reduced. Right now the industry has faced a great deal of trial and error in terms of industry standards and cost reduction measures, but with the publication of these reports, the NREL may be able to alter that completely.
Solar PV is not the only industry in need of an industry standard, or benchmark publication. Levelized Cost of Energy storage lacks this information, and could benefit substantially from this information. NREL and GTM researchers have done some work in this area. Their work has tried to compile more specific, reliable information about residential installation costs for this industry, but these reports still require some greater expansion.
The work and publication of the NREL has already begun to change the way residential PV installations and solutions can take place. As the reports continue to be published for the coming quarters, the industry will continue to find new cost reduction solutions and more reliable benchmark information.
