The Solar Thermal Set-up :: Inside the Pro’s Home
BMore apparently a suburb of DC
I am fortunate really that around me here in Lauraville there are many forward-thinking, creative, and community-oriented people. Revitalization, as you might have read, is abounding; new shops and reclamation are the norm. Mixing new with old, the locals here are creating a kinda 21st century stew.
And when I am not off in some distant land fantasizing about my own remodeling biz super-success, I may catch a glimpse of the solar panels sitting on Bill O’Connor’s roof. Sure, I noticed when they first went on, but I did not actually stop until recently to think — Hey, what might it take to integrate this newish technology with an old house?
Then, one Saturday afternoon, the girls and I stumbled upon our new local street market. And there, below them, as if they were almost powering the activity, those solar panels came up. In the course of chatting at the Baltimore Main Street table, Bill’s wife, Sue, asked, Are you going to the solar tour today?
I said, Well, I don’t know; what is that?
The 19th Annual Washington Metro (b-more apparently a suburb of DC) Solar Home Tour was stopping at Bill’s house, and I did ultimately pop in. It was that day when I first pitched Bill on the idea for this article. I said to him, I see it growing every day, interest in solar; and I am sure my readers (as if you number in the many) would love to know what it takes to implement this technology in an old house.
A few weeks later feeling a little bit like Kevin O’Connor (no relation)
There have only been a handful of times when this job has made me feel a little bit like Kevin O’Connor. But this is one of them. There, as I sat sipping pear cider with Bill and his buddy, Roger Perry, we discussed the process of installing a solar hot water, aka thermal, system for Bill’s house.
Close friends – you could tell. Motorcycling buddies, they have both been in their respective lines of work for 30 plus years. Roger, the owner of Solar Energy Services, survived the dark days of solar (my words), and Bill, the House Mechanic (as his business is called), now collaborate frequently on each other’s projects.
Bill admits when he initially contacted Roger regarding solar, he was interested more in solar’s ability to provide power for his home. Roger, and probably working more together, quickly steered Bill away from this as his starting point.
Known as photovoltaic (PV), installations that convert sun power into electrical voltage are pricey, almost three times pricier than the other solar set-up, thermal. So they agreed, instead, to start there – with a thermal system used for domestic potable hot water and radiant hot water space heating.
These systems are, as Roger tells me, more efficient; they offer more bang for the buck, he says.
While I certainly have a little experience with plumbing and heating, the concept of integrating solar into a water set up is still totally new to me.
So that day, as we sat on the front porch, I started with questions like: Did you have to add structural support to the roof to handle the weight of those things (as I pointed upwards towards the panels)?
And — “Did you have to crane them up there (again referring to the panels)?”
As I was quickly set straight, I learned that these are not big concerns when working with a solar configuration. In turns out, too, that this line of questioning may actually be even a little further from some of the most common misconceptions about solar.
Bill, that day, told me of some of his early encounters with passers-by. On spotting the panels, some would ask, What’s it like to live without BG&E (local energy supplier — Baltimore Gas & Electric)?
Sizing things up
While there are certainly systems that can get you off of the grid, Bill’s isn’t one of them. Virtually all thermal/hot water systems are supplemental only, and they work in tandem with gas, propane, or oil-fired equipment to do what they do.
Bill’s specifically is known as a closed-loop glycol (that’s anti-freeze) system with flat plate collectors. It is not an uncommon set-up (more on this in a minute). The collectors as I learned are actually only big aluminum boxes — black of course, that contain copper tubing, paired with a copper-coated plating. (Copper has good heat transfer properties.)
The ones on Bill’s roof weigh only about 150 lbs each. They were hoisted (hand & rope) up onto the roof and were shimmied into place — where they were then attached. Bill’s roof, and there are reasons for this, holds five four by ten plates. These then service a 120 gallon water tank, which is found in his basement.
This set-up is a little larger than most solar thermal set-ups. Roger, whose company recently did an install at the Governor’s mansion (MD), says his most common job is a family of four moving off of an electric hot water heater. In that configuration, we are talking typically about two four by eight panels servicing an eighty gallon tank.
So why go larger with Bill’s set-up? I ask.
Roger’s initial response came back as one word, Load. But he continued, Well, we had to look at what we needed to do. For Bill, we were not only going to support the potable hot water and the space heating, but we also had to think about his hot tub out back.
Still . . . why five panels?” I asked.
“Well, we simply had the room.” Roger answered. “Plus, Bill’s roof is a little east-facing.
In terms of solar collection, you can actually think of the sun as a limited resource. Here in the northern hemisphere, plates are ideally set to face due south. But thanks to the siting of houses, and multiple roof forms, that may not always be possible.
Add to this clouds and occasional rainy periods, and there is sometimes a need, as in Bill’s instance, to go with slightly larger, and more, plates. The additional plates, however, do nothing but make the collection of solar rays a little easier. As you can see with the built chase shown above, the intrusion into and through the house remains relatively insignificant.
Hot water is easier to heat
Through Bill’s expertly remodeled kitchen, passed his world class bumper sticker collection (which lines the walls), and through his workshop (where he happens to be working on a “picklewood” countertop for Roger), he lead me to the real goodies. And there, in his mechanical room, that’s where it really happens – the interfacing — to use Roger’s words.
As you can see in the picture, the tank is actually quiet impressive. The closed loop continues via 1″ copper pipe through this point.
You could think of this tank as something of a hub. The boiler and the hot water heater, upgraded too for this project, access pre-heated water in this tank.
By claiming already heated water, the boiler and the hot water heater (still dependent on fuel) have far less work to do. They fire only when the temperature of the water needs to be elevated. Now . . . they often have to work only long enough to bring temps up a few degrees. And . . . equipment that works less, firing for shorter periods, burns less fuel and saves money.
While there is no special requirement on equipment per se – Bill’s home is fitted with a super high efficiency condensing boiler (enough to make this housephile drool). The decision to upgrade this appliance was suggested, too, by Roger very early in the design process.
Think about it – As Roger puts it, You don’t want to plug a system like this into house that has a boiler or a hot water heater going on 20-25 years old.” And I see what he meant — kinda like putting high octane gas into poorly maintained 1984 Chevette. You would never realize the full benefit of the upgrade.
Million dollar questions (aka so how much did it cost and how much will it save?)
It is tough to say exactly how much a system like Bill’s would cost in your house. A project similar to Bill’s would price out right around $25k; I know that. In Bill’s house, he and Roger not only upgraded both water service appliances, but they also reconfigured some of the existing baseboard heating to create four more logical zones.
While Bill certainly receives Energy Star tax credits on his new appliances, he also received both a grant from the Maryland Energy Administration (MEA) as well as a federal tax credit for renewable energy. As I understand it, in total, he got a few thousand back once the installation was complete. (And, every little bit helps.)
For that family of four that I mentioned above, their cost would run somewhere in the range of $8-$10,000 for install. They could expect a four for five year payback on their investment by saving between $600 and $800 in annual energy costs.
Bill currently is saving about a 1/3 on his gas bill, and should expect to see a full return on his investment in six to eight years.
One last thing
These systems are in my opinion very intelligent – using (or should I say harnessing) natural elements to run efficiently. And this article only roughly outlines the set up, so you may want to explore more deeply with your local solar expert.
The technology has evolved as such that maintenance on these systems is almost negligible. The glycol (remember anti-freeze) in Bill’s system will require a flush and change every five years at a cost between $200 and $400. But Roger tells me, this is really the only major maintenance consideration. Cool, huh?
Thank You both, Bill for opening your home, and Roger for taking the time to drive up for the meet.
>> More Moxie (Related Links):
Solar Energy Services: http://www.solarsaves.net/
Very good overview on thermal solar systems courtesy of RemodelCrazy.com and written by Solar Energy Service‘s Senior Residential Solar Consultant, Rich Schroeher. This article outlines several options in solar thermal and provides a great graphic showing such things as the sensors found on both the exterior and interior portions of the set-up: http://www.remodelcrazy.com/2009/green/solar-collectors-part-2.html
19th Annual Washington DC Solar Tour: http://www.solartour.org/
This Old House host Kevin O’Connor: http://www.thisoldhouse.com/toh/biography/0,,441624,00.html
Energy Star Appliances (Boilers): http://www.energystar.gov/index.cfm?c=boilers.pr_boilers
Maryland Energy Administration :: Solar, Geothermal and Wind Grants: http://www.energy.state.md.us/incentives/residential/index.asp
IRS Form 5695 :: Residential Energy Efficient Property Credit: http://www.irs.gov/pub/irs-pdf/f5695.pdf
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About jb bartkowiak (324 posts)
A one-time construction manager, and always handyman, turned blogger and editor - Your Home Project Assistant. My wife, Jen, and I are on our 6th property (. . . yes, together). She is a real estate agent. We have two beautiful daughters Evyn and Eva. We currently live and are restoring an 1889 farmhouse in Baltimore's Lauraville area.