Just over a year ago, Kevin Tofel took the plunge at his house and covered the back roof with solar panels: 41 of them, to be exact. After 12 months, they’ve created 13.8 megawatt hours of electricity while using only 7.59 megawatt hours. The energy surplus becomes a credit on their electric bill and once per year, the electric company issues a check for any unused credit. So what was the installation and usage experience like? Overall, it’s been excellent and he shares the pros, cons, and actual costs of the project in an effort to shed more light on any solar panel projects you might be considering.
First: Decisions and costs
Their family has always tried to be green when possible but never had the money to “go solar” even though they wanted to. That changed due to a unique financial situation. Kevin’s wife inherited a family member’s IRA account several years ago and the law required that the funds be liquidated over a five-year period. Approaching the final year in 2011, they realized that they were going to be hit with a large tax bill on the remaining IRA funds and decided to invest the funds into something with a tax incentive. After much research on solar energy and return on investments, they decided to invest in solar panels in part due to the fact that their rear roof faces south.
After he requested quotes from companies in the area, a local contractor (a certified solar panel installer) gave the best price at $5.50 per watt. Next he looked at their electricity usage for the prior year and over-specified the system capacity by 25% in order to maximize the tax benefit, which was a 30% federal tax credit on the entire project. The specified 9.43 kW (DC) system turned out to be 41 panels (230 Watts each), which produced 12.05 megawatt hours of electricity from Nov. 1, 2011 to Oct. 31, 2012. The build-out cost $51,865 and included installation, permits, inspections, parts, labor and warranty. The federal tax credit totaled $15,560, which helped offset taxes on the IRA liquidation. Pennsylvania also provided with a rebate on solar projects that returned around $7,100 once the system was up and running. After the federal and state incentives, the net cost was $29,205.
It’s also worth considering companies in some states offer no-money down solar panel systems: essentially you let them install a system on your property and then lease the system. The company itself reaps the incentive benefits, but you may save money on your electricity bill.
Installation of the puzzle pieces
Solar Panel Framing
Kevin thought the system would be complicated by many parts, but it’s actually quite simple. The panels generate electricity from sunlight. The panels themselves are attached to the roof with aluminum framing so the install process is fairly simple. You install the frame, connect the microinverters to their respective panels, attach the panels to the frame and link the microinverters.
All of the power coming off the solar panels is DC (direct current), so the system needs an inverter for AC power. We considered one single inverter but instead opted for individual microinverters attached to every panel. There are several benefits to this approach; (1) if one panel or inverter fails, it’s easier to locate and fix the issue and (2) the microinverters feed real-time data to a server included for monitoring purposes. click here for the data
Electrical Meters for Solar Power
The microinverters converts the DC power from its connected panel to AC power. Each microinverter is linked to the next one in the solar panel array, which makes them “plug-and-play” devices. The last microinverter feeds a power line through the attic and down along the outside of the house to the electrical meter. Two additional electrical meters were needed. We still have the original meter that measures our electricity use from the grid but a new meter is needed to measure power output and a third measures the difference between electricity created and used.
How does it perform?
The system has worked great. Below you can see exactly how much energy produced each day. The graph essentially illustrates a history of the weather. Drops on the graph represent days with little or no sun – on a cloudy day a little energy is still generated. You can also see when the days get longer and provide more direct sunlight to the roof.
Solar Energy Generation Numbers
Solar Energy Generation Results
There has been no maintenance to the system, panels or microinverters, which have a 25 year warranty. There has been a hiccup… During a power outage, there was not enough electricity in the solar energy system to sustain the house. One of the early decisions you’ll need to make when planning a solar panel system is choosing to be on or off the grid. There are pros and cons to each. Kevin has an on-grid system, so they had no power during Hurricane Sandy because all of the power the panels create is fed back into the grid. In an on-grid configuration, they can still get power from the electric company when necessary; However, during an outage, grid-tie systems are automatically disabled. If they house were to feed electricity back into the grid during an outage, it would be unsafe for the workers trying to fix the outage.
While an on-grid system costs less up front while off-grid provides stored power during the evening hours or during an outage. To go completely off-grid and have batteries store excess power would have added another 20% to up-front project costs.
Is there a the net ROE (return on energy)?
The biggest issue for most is likely the large up-front cost involved. Though high, Kevin said that he would add some type of battery backup but isn’t sure of the costs involved with that addition. With the system as is, the payback period (variables: type of system, installation costs, location, and electricity rates) can be high. Kevin’s break-even point is around 7.3 years, which includes some home appreciation expected due to the system. The next owner of the home will probably never have an electric bill. Furthermore, the house is making enough excess power that he is considering a plug-in car to replace their current vehicle to let the sun power their wheels and cut down on their gasoline costs at the same time.
Lastly, Kevin also has a significant hedge against a rise in electricity costs… any price increase means he will get more for excess energy production.
Completed Solar Panel Home
Original story here