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For PV installers in the U.S., any installation cost reduction strategies that they implement will receive an automatic boost from the ongoing industry-wide drop in module prices. Solar thermal installers, who enjoy no such equivalent bonus, must rely more heavily on equipment selection and labor strategies in order to bring their system costs down. (See “Installers Fine-Tuning Their Strategies For Solar Thermal Cost Reduction” in the May 2011 issue of Solar Industry.)

Currently, the solar thermal balance-­of-system (BOS) space tends to offer the most opportunities for savings, as the mature technologies used in solar thermal collectors lack the type of downward cost-trajectory potential seen in the PV module sector.

In the residential solar thermal market, which some installers have found to be more economically challenging than the commercial and industrial segments under current conditions, all-in-one systems provide one possible route to labor and BOS savings.

While not appropriate for every building layout or type of customer, all-in-one solar thermal systems can potentially provide installers with noticeable time savings from equipment selection through final installation. In some cases, this difference can even ensure the economic feasibility of a project that could otherwise fail to pencil out.

All-in-one systems and similar offerings, which may be advertised as plug-and-play systems, pre-packaged systems or solar thermal kits, generally win praise from both installers and end users for their simplicity. Taking this approach one step further, Boston-headquartered Wagner Solar Inc., a subsidiary of Germany-based Wagner Solar & Co., eliminated several components traditionally found in a thermal system from its Secusol appliance, an all-in-one kit.

The Secusol, which operates as a non-pressurized hybrid drainback system, requires neither a separate drainback tank nor a traditional pump station. Instead, fluid drains directly into the heat-exchange coil, while the pump is attached to the bottom of the heat exchanger. All circulation components are contained in the storage unit.

When the pump goes idle, all of the liquid drains back into the system, leaving none in the collectors and avoiding the risk of overheating, explains Stephen Sawicki, technical director at Wagner Solar Inc.

“On the roof, you just have the collectors and the racking,” he says. “The lineside connection can run on the outside of the building or inside, and on the inside, all you’ll see is a tank with insulation around it.”

For system installation personnel, the Secusol can provide additional labor savings through its factory-­preset controller, insulated line set with integrated sensor wire, and siphoning and pouring options during the filling step, according to Sawicki.

“People call during the filling stage because it seems too easy,” he says. “You don’t need to set the pressures of the system or anything like that.” In all, the company claims that the product can provide a 50% decrease in installation time and labor compared to traditional solar thermal products.

The Secusol is currently available in approximately 12 different kit designs, with options including 66-­gallon or 93-gallon tanks, collectors situated side by side or on top of each other and two types of collectors: a Southern-climate collector or a larger, better-insulated Northern-climate collector.

 

 

The installer experience

Regardless of how promising any solar thermal product’s specs may be, its real test, of course, is whether it lives up to its hype in real-life installation settings.

Jack Bingham, owner of Barrington, N.H.-based installer SEA Solar Store, says his company participated in the installation of two of the first prototype installations for the Secusol. Since the completion of those projects a few years ago, the company has gone on to install at least a dozen more Secusol systems - nearly all in residential settings - across its territory in New Hampshire and Maine.

Bingham reports that so far, the product has withstood harsh Northern New England winters and produced hot water reliably, with zero repair issues. “They have lived up to expectations and are overperforming,” he says.

Allura Solar, headquartered in Scotia, N.Y., has completed one Secusol installation so far - a retrofit system in upstate New York. The customer has been “absolutely raving” about the system’s performance, says Michael Cellini, president of Allura Solar.

A second installation is currently under way in a new-build application, which Cellini believes offers the best market opportunity for this style of installation.

“With a new build, we can always do an all-in-one system, because the wall will be open - it doesn’t matter what the floor plan will be like,” he explains. “We can pre-install empty conduit in the walls, and whether the customer wants solar or not, it’s solar-ready.”

For retrofit applications, on the other hand, layout for the Secusol can be trickier than with a pressurized system. “It’s a drainback-style system, so there have to be parameters where you can have your collectors above your tank,” Cellini says. “Not every install can be accommodated in that way.”

Building height also affects where the Secusol can be used. According to Wagner Solar’s Sawicki, the product’s 20-foot height limitation accommodates a typical two-story colonial home with the system’s tank placed in its basement.

Both Cellini and Bingham report a streamlined labor experience with the Secusol, although Cellini believes the claim that the install can be completed in a single day to be a bit of a stretch.

“But it’s definitely faster than doing a pressurized system because there’s no internal piping that you have to do,” he says. Bingham, meanwhile, says his crew found having the pump and controller pre-installed on the tank to be especially helpful.

 

Making the economics work

Elsewhere in the plug-and-play solar thermal system space, Milwaukee-­based Caleffi has long offered a range of residential system kits. As a differentiation strategy, the company began providing these packaged systems immediately upon its entry into the solar market approximately six years ago, says Bob Rohr, training and education manager at Caleffi.

The kits include everything from the collectors to the controls to the tubing to the propylene glycol. “All you really need to supply is the screws to put it on the roof,” Rohr says. “No torches are required, and there is no soldering pipe together.”

Like Wagner Solar, the company aims to reduce costs for both installers and end users with its kit configurations.

The advantages of packaged systems extend to other parts of the supply chain as well. Dealers, for instance, appreciate not needing to deal with follow-up calls from customers who forgot a particular component, Rohr notes.

“We make it as easy as humanly possible,” he says, adding that installation personnel can also benefit from streamlined access to all necessary components on and off the roof.

Even so, dealing with rooftop labor still presents a challenge for some installers, according to Rohr. In order to avoid physical hassles and potential problems, some installers have shifted their projects to ground-mount designs when feasible, while others have entered referral partnerships with roofing companies.

“If you’re a plumber or a handyman, it’s a pretty simple installation,” he explains. “But roofs do involve fall hazards.”

In the residential solar thermal market these days, every bit of cost-cutting and time-saving helps. But can simplified all-in-one systems save a market segment that, as Rohr admits, has seen its share of challenges lately?

“When [our kits] first came out, it was a huge residential market,” he recalls. “It’s switched now - we’re doing more commercial work.”

In some cases, inexpensive product offerings can help bridge the financial gap and allow installers to continue closing residential system sales. Given its price point, the Secusol tends to appeal to economy-minded customers, Sawicki says. In fact, Wagner claims that the unit is the lowest end-user priced solar thermal system available in the company’s home state of Massachusetts.

Rohr, however, cautions that while creating savings through BOS streamlining and installation strategies can be effective, the solar thermal industry must avoid taking this “lower-priced is better” strategy to an extreme in order to chase a magical mark, such as a 10-year payback period.

“It’s the money that makes the average residential customer say yes, and there is only so low you can go and still offer quality,” he says. R