In summer 2018, Assistant Professor Matt Aldeman contacted renewable energy alumnus Shannon Fulton ‘11 about purchasing a solar system for his home. Fulton is now a vice president at StraightUp Solar, a company that develops and installs solar systems in Missouri and Illinois. There are now six ISU Renewable Energy graduates working at the company: Fulton, Emma Gilmore ’13, MS ’14, Patrick Schaaf ‘15, Andrew Stetter ’17, Conner Waters ‘17, and Paul Rypkema, a senior who will graduate in May.
Fulton and Gilmore worked with Aldeman in the early stages of the project, and the project was then handed over to Andrew Stetter. Stetter performed a preliminary assessment using satellite imagery of the house. Later, Stetter visited Aldeman’s house to assess the roof, determine the pitch of the roof, inspect the attic space, and determine where the system components (wires, meters, and inverter) would be installed. Since graduating from ISU, Stetter has developed over $3.5 million in solar installations across the state of Illinois.
The first conversations Aldeman had with StraightUp Solar regarding the purchase, design and installation of the solar system were in late June of 2018. The system was commissioned and energized on September 21, 2018. That sounds like a long time, but there are numerous steps to the process. First the system is designed, and the materials procured. Then the system has to be approved by the utility company, and then it can be installed. Installation typically requires several days of good weather. Finally, the system must be inspected by the local building inspector and the utility company before it can be energized. The solar group-buy incentive programs were very successful last summer and fall, which meant that the installation crews had to work very hard to keep up with the demand.
Aldeman’s home faces south, which meant that there was some good south-facing roof area. But the roofline is somewhat complicated, with dormer windows and roof overhangs that reduce the amount of sunlight received by the solar panels. In addition, Aldeman had previously planted several young shade trees in the front yard. He requested that Stetter design and model the performance of the solar array based on the anticipated size of the trees in 15-20 years.
Seventeen solar panels were installed on Aldeman’s roof. The solar panels are made by REC Solar and are each 290 Watts. That makes for a total Direct Current (DC) system size of just under 5 kW (4.93 kW). The output of a solar panel is DC, like the output from a battery. The solar panels are connected in series to an inverter in the home’s basement, which inverts the electricity from DC to Alternating Current (AC), and the output from the inverter is connected into the home’s circuit breaker box. The maximum output of Aldeman’s inverter is 4 kW AC. 4 kW is equal to about 5.4 horsepower, which is comparable in power to the engine of a typical lawn mower.
“Sometimes I like to visualize a lawn mower running at full throttle pushing electricity into my home’s electrical circuit breaker box – except, the fuel for this lawn mower is free and non-polluting, and this lawn mower requires almost no maintenance.” Matt Aldeman
According to Certasun, Illinois solar incentives and federal tax credits cover about 60% of the purchase price of solar. Illinois law requires investor-owned utilities to source 25% of their electric energy from renewable sources by 2025, with 6 percent of the renewable energy required to come from solar. To advance this goal as well as support other energy-industry initiatives, the Illinois legislature passed the Future Energy Jobs Act (FEJA) in December 2016. The act included many energy-related components, including incentives for nuclear energy, energy efficiency, solar development in low-income areas, and Solar Renewable Energy Credits (SRECs). Through this legislation, the Illinois Power Agency purchases SRECs from solar system owners. One SREC equals one megawatt-hour of solar generated electricity. The Illinois Power Agency pays solar system owners for 15 years of estimated SREC production in advance, shortly after the time of solar system installation. Aside from incentives, other funding sources can include loans or leases.
The up-front cost of Aldeman’s solar system was $15,698. He was able to utilize three sources of funding incentives: the federal tax credit, Illinois SRECs purchased by the Illinois Power Agency, and a special McLean County “group-buy” program organized during the summer and fall of 2018. The federal tax credit is equal to 30 percent of the system cost, or $4,709.40 for Aldeman’s system. This tax credit is not refundable, so there must be a tax liability in order to use the tax credit. The 30 percent federal tax credit remains in effect through 2019, after which it is set to gradually decline (26 percent in 2020, and 22 percent in 2021). For the SRECs, the Illinois Power Agency offers an up-front payment for SRECs that will be produced by the system over the first 15 years of the system’s life.
For Aldeman’s system, this amounts to about $5,900. The state uses these SRECs to meet its renewable energy goals. The SREC is actually the “renewable attribute” of a unit of energy, so after a homeowner sells the SRECs from their system, they technically cannot claim that their home is powered by solar energy. Finally, the special “group-buy” program was administered last summer and fall by the Midwest Renewable Energy Association, the Ecology Action Center in McLean County, and StraightUp Solar. As part of this program, the installed cost of the solar systems dropped as more people signed up to install a solar system. Similar group-buy program were administered in East St. Louis and Champaign-Urbana. From this discount, Aldeman will receive a rebate check of approximately $450. A new group-buy program is planned for the summer and fall of 2019.
Aldeman’s funding incentives amounted to more than 60% of the project cost. The initial upfront purchase price was $15,698, and the net price after incentives was about $4,639. The system will save Aldeman about $660 per year in electricity costs, so it will have a payback period of about seven years.
Aldeman rates the experience of installing and using solar power as “fantastic!” While Aldeman may be more of a self-proclaimed “energy nerd” than the average person, he gets a thrill from checking the system’s real-time output using the app on his phone. He checks on the system’s production several times every day. The system has been in operation for six months, and through that time the production has exceeded the initial expectations. In fact, there has not yet been a month where the energy production has been less than the initial projection. So, he is very happy with the performance so far.
“It was a truly rewarding experience to be able to design and sell a solar array to my former professor from the Renewable Energy program. Dr. Aldeman was one of my favorite professors while I was in school. He always did a great job of simplifying the details of renewable energy throughout my many classes with him. The truth of the matter is that this project has been inspirational to me, but the bigger picture is much more important to consider. Dr. Aldeman lives in one of the countless neighborhoods around the globe that are incredibly viable for efficient solar energy production, yet are still almost entirely underutilized. Working with Aldeman on his own project was a profoundly full-circle moment that I am still very proud of to this day.” Andrew Stetter, Renewable Energy ‘17
Stetter sincerely hopes that Aldeman’s decision to invest in solar technology will be an inspiration to his many neighbors that have similar solar opportunities. Stetter respects that Aldeman was willing to practice what he teaches. Most homeowners Stetter has worked with in his solar career need a fair amount of education to understand the details of these systems. Stetter says this was not the case with Dr. Aldeman, who has an excellent roof for solar production and a great understanding of system design and energy analyses. Aldeman gave very useful feedback to the StraightUp Solar team which has since been used to make their proposal templates clearer and easier to understand.