World leaders convene in Paris on Monday to try to find agreement on addressing climate change. Solar Energy is one alternative to the fossil fuels scientists have linked to changes in the earth’s climate. Tom Martin talked with Matt Partymiller, operating manager of Solar Energy Solutions, a Lexington-based company in business since 2006 and employing 15.
Q: How’s business?
A: The solar industry has definitely grown leaps and bounds especially in the past year or two. In 2006 we had high hopes. We hit the recession. Things did not grow as rapidly as one would have hoped, but in the past four or five years we’ve seen steady growth and this year we’ve seen almost 50 percent growth compared to 2014 in terms of contracts awarded. 2016 should be a big year for us. It’s the expiration of the federal investment tax credit. So we expect a lot of residential and commercial investment in 2016.
Q: Is it possible to estimate the carbon offset that can be expected from powering with solar?
A: In Kentucky we’re over 90 percent coal-fired generation so we’re looking at about two pounds of CO2 per kilowatt hour used. An average home uses about a thousand kilowatt hours a month, which means our average customer is releasing roughly a ton of CO2 per month. Based on the homeowner’s or business owner’s consumption we can then model how much energy the solar array will produce and we’ll translate that in kilowatt hours. So if you need a thousand kilowatt hours a month, I’ll design a solar array to do that and I’ll be able to tell you that this solar array is going to save you about a ton of CO2 a month.
Q: How do I know if I have enough sunlight on my property?
A: We use Google Earth and Bing maps extensively to get satellite-based assessments of the property. And once we’re given that initial feedback that ‘yes you do have a roof facing the right direction, and yes there is some unshaded roof space,’ then we come to the site. We’ll use tools that can take a single image and model shade throughout the entire year within a software program. We’ll then put it right into software to predict how much power we can produce on that site. Historically, we’ve seen that to be accurate within 4 percent.
Q: So if we decide that my roof is an ideal place to install solar panels does anything have to be done to the roof itself? Does it have to be reinforced in any way?
A: We’ll definitely look at that when we’re on-site assessing the roof. For older expiring shingles or roof structures, we’ll work with a home owner to get those replaced before investing in solar. A solar panel is a 25-year warranted product so it’s really a long life product and you don’t want to put it on a roof that’s in the last a few years of its life. We’re just now, 10 years in, getting to our first situations where we’re removing panels to help our customers replace roofs. That process is relatively simple and straightforward but it’s still better to avoid it if you have a roof near the end of its life.
Q: How much does a solar energy system cost and how long does it typically take for it to pay for itself in savings?
A: Typically we’re seeing a return on investment in the Kentucky market at around 10 years. Some utilities in Kentucky have much higher energy rates than others so that can vary. A standard system for a house now costs pretty much the equivalent of remodeling a room. So we’re seeing a $20,000-to-$30,000 initial investment, offset in part by a state investment tax credit - $500 residential, $1,000 commercial - that expires at the end of 2015 and there’s a federal 30 percent tax credit that expires at the end of 2016.
Solar is still novel enough that all our customers are tremendously enthusiastic. So they’re happy before it happens, they’re happy while it happens and then they’re happy after it happens.
Matt Partymiller, operating manager of Solar Energy Solutions
Q: What is net metering?
A: This is the common method for interconnection of solar, electric systems throughout the U.S. It’s the exchange of Kilowatt hours with the utility. So, if you produce a kilowatt hour from your solar array and that is a kilowatt hour more than you need, you send that to the utility company and your meter spins backwards - they credit you fully for that, and you can draw that back at a later time.
Q: Do the panels that you install actually last for 20 to 25 years or do they have to be replaced sometime along the way?
A: Solar panels carry a 25-year warranty from their manufacturer and solar panels are tested by Underwriters Laboratory or similar entities for one inch hail at 50 miles per hour. We have not had a solar electric panel break due to hail to date. They’re essentially tempered glass very similar to a car windshield.
Q: What about cloudy weather? Is that a problem?
A: The amount of sunlight will affect the solar production and we will see solar arrays produce twice as much energy in April-May than we will in December-January.
Q: Do you need a battery to store the power?
A: Modern solar works without batteries and that’s what’s enabled us to reduce costs so rapidly. So, no longer is there any type of physical storage on site. We work with the utility company via net metering to use their grid as storage. What this means is your solar panel is sending power directly to an inverter which syncs with the grid and outputs exactly what the grid would feed into your home. That inverter will literally tie into the breaker in the breaker box and it will back-feed the house. Any excess will work its way up through the grid and you’ll be credited for it.
Q: Does the system lose efficiency over time as it gets older?
A: Yes. Solar panels are essentially going through lots of heat and thermal cycling on a roof and they do lose about half a percent of efficiency per year. So a thousand watt rated array is going to lose a half percent of its production over year one, and then another half over year two. But they are warranted for 80 percent of rated production value after 25 years.
Q: What about doing this work do you enjoy the most?
A: The exciting thing about solar from an installation perspective is this isn’t like installing an HVAC unit where the customer might be happy, but it’s just viewed as part of the home. Solar is still novel enough that all our customers are tremendously enthusiastic. So they’re happy before it happens, they’re happy while it happens, and then they’re happy after it happens. The best experience for us is that month or two after the first install when the customer sends us their first utility bill and it’s like wow it’s really $10 this month. That excitement is infectious.
Tom Martin's Q&A appears every two weeks in the Herald-Leader's Business Monday section. This is an edited version of the interview. To listen to the interview, find the podcast on Kentucky.com. The interview also will air on WEKU-88.9 FM on Mondays at 7:35 a.m. during Morning Edition and at 5:45 p.m. during All Things Considered.