When it comes to covering advances in renewable energy technologies, the focus has primarily been on new ways—and incremental improvements—for bringing down cost. With prices for electricity from solar and wind now reaching close to even with traditional fossil-fuel sources, today’s renewables innovators are starting to create entirely new product categories.
Of course, given the time it takes to bring an idea from initial brainstorm to market-ready offering, many of the latest advances have been in development for a number of years. And some might have been available for specific niche applications, but now they are seeing opportunities in broader markets. Here are three of the latest technologies with the potential to make a lasting difference as distributed and renewable resources become bigger players in the energy marketplace.
Solar shingles—for real
For the last several years, Tesla’s Elon Musk has been promising the company’s solar roof tiles were almost ready for a broad market launch. In June, the company announced that 2019 would be its “Year of the Solar Roof,” by stating that a third-generation version of its power-generating shingles was now in longevity testing. What you might not know, however, is that Tesla isn’t alone in pursuing this kind of building- integrated solar.
Luma Solar, Rochester Hills, Mich., spent 10 years in what Marty Aquino, the company’s chief advisor, calls “stealth mode,” with a light online presence that benefited from Tesla’s solar-shingle boosterism.
“One out of three calls might be, ‘Hey, we’ve been on the Tesla list and we’re sick of waiting,’” Aquino said. “We’re grateful for the marketing.”
Luma Solar’s first-generation offering featured flexible thin-film solar sheets adhered onto metal roofing panels. This approach has since shifted, and the current fourth-generation system uses monocrystalline shingle-shaped tiles fitted onto proprietary metal roofing panels. The panels clip together in an easy-to-assemble manner that Aquino called “not quite paint-by-numbers, but pretty close.”
To help boost electricity production, the attachment design features a slight lip at each panel’s base where it overlaps the row below.
This creates an air gap to help keep the solar tiles cooler than typical rack-based rooftop systems, which is an efficiency-boosting advantage because, as Aquino said, “the enemy of solar production is heat.”
Additionally, the plug-and-play attachment system of the company’s latest lineup allows for both an easy replacement of any single unit that fails and the option for future upgradability, should new solar technologies emerge.
While Tesla is attempting to create a solar-integrated roof system for the masses, Luma Solar is focused on high-end homes. Each installation is custom-designed with all the junction boxes and associated wiring already in place. And, unlike standard rack systems that can be mounted on top of existing asphalt roofing shingles, this system really is best-suited to new construction or a complete reroofing project.
However, when paired with a battery-based storage system, this kind of total-roof solar approach could allow a homeowner to go completely off-grid. This has proved to be a major draw for some of Luma Solar’s Caribbean-based customers, where electricity prices are exorbitantly high, and hurricanes can cause frequent outages. The system also is attractive for high-end homebuyers in California, where most new homes now must be equipped with solar panels.
Aquino is eager to get the word out on Luma Solar to electrical contractors—especially those already working with residential solar equipment.
“The ideal installer is an electrical contractor who is comfortable on a roof or an electrical contractor who hires a good roofing subcontractor,” he said.
While the company does do some of its own installation, Aquino said they’re also very interested in reaching out regionally to introduce the system on a broader basis.
“We prefer to go out and train local groups,” he said. “It’s much more scalable if we can work with a network.”
Meter-beating battery systems
While lithium-ion batteries for home energy storage aren’t exactly a renewable resource, they tend to make the most economic sense when paired with a solar-panel installation. The cost of these batteries has fallen dramatically over the last decade to the point where some electric utilities in Vermont are beginning to offer homeowners incentives to use the systems to reduce demand during peak periods. The rest of the time, the battery is available as a backup resource for customers accustomed to the region’s often-severe winter storms.
Vermont’s Green Mountain Power was the first in the nation to explore such an application. In 2016, the utility began a program of selling or leasing Tesla Powerwall batteries to homeowners at a discount. The goal was to aggregate those batteries’ output as a virtual power plant during peak periods, which reduces the need to either fire up an aging, oil-fired peaking plant or buy power from outside the state on the expensive spot market. In just two days last summer, the utility claims to have saved ratepayers more than $1 million by using the stored energy from more than 600 home-based batteries.
Now, the utility is studying the ability for even more battery-related savings, this time thanks to the metering capability of the communications gateway through which it controls the batteries’ operations. During the last couple years of deployment, the company discovered these gateways provided the same level and accuracy of data as its existing customer meters. Now a pilot is underway to study whether the equipment can eliminate the need for separate meters entirely.
“We can leverage the data, and it’s reliable and consistent,” said Josh Castonguay, vice president and chief innovation officer, Green Mountain Power. The 18-month Resilient Home pilot offer for up to 500 customers total includes two Tesla Powerwall batteries for a $30 monthly fee. Customers also can work with a Powerwall retailer and qualify for incentives under a bring-your-own-device program. Using two batteries ensures the entire home’s electrical demand can be supported and that grid-supplied usage will be appropriately measured.
Customer interest is already strong for the new offering, according to Castonguay.
“We definitely have a huge, immediate level of interest and a lot of interest in battery storage, in general,” he said. “The systems have proven themselves out over the last several years.”
And, though this is just a pilot program, Castonguay said he’s confident it’s only the beginning of broader battery deployment — not just in Green Mountain Power’s service territory but across the country.
“I compare it back to the personal computer when you look back 25 years,” Castonguay said, noting how that device has become an ubiquitous presence in most U.S. homes. “I think it could get to the point where batteries are just a standard part of the home. Battery storage is one of the most flexible resources you can have.”
DC distribution simplified
Solar panels and batteries both produce DC power, which is also what most electronics—including LED lighting—use to operate. Energy is lost transforming that power to the AC used in building distribution systems and then back to DC at the device. While there’s been some study done with DC distribution at the building level, the approach hasn’t ever taken off—possibly because developers haven’t been able to figure out how to distribute the power at high enough voltage without bringing AC back into the system.
A new approach developed by a company called VoltServer could help foster DC distribution at higher voltages. The technology is based on a concept that founder and CEO Stephen Eaves calls “digital electricity,” which is similar to the packet-based communications used to transmit data through the internet. A transmitter breaks the electricity into low-voltage packets and transmits them at a rate of 700 packets per second. A receiver located near the electrical load features capacitors that smooth the current for use by any standard low-voltage device. Most appealing for owners and developers, the transmission can all be accomplished using a standard ethernet cable with no conduit required. The system is completely touch-safe.
Eaves said his East Greenwich, R.I., company’s first market has been communications systems, including cellular service booster antennas in stadiums and other large facilities.
“It went well in communications because it’s a rapidly moving space and being able to get into that kind of venue fast is really valuable to that kind of customer,” he said, emphasizing the value of ethernet-based distribution to project timelines and budgets. “You don’t need to core-bore or run conduit.”
Obviously, there is a direct relationship to existing power over ethernet (PoE) technology, though the VoltServer approach allows for significantly higher voltages. And the company is beginning to enter more traditional building installations through hybrid PoE designs, including in a recent project for a new Marriott Autograph hotel in Ft. Worth, Texas.
“The VoltServer transmitter is based in the basement and powering all the PoE switches in the building,” Eaves said.
Those switches, in turn, power room lighting and other controls. Additionally, the Marriott developers included a large battery system to take the place of a diesel generator for emergency backup. The VoltServer can easily switch over to the battery as a source, with no need for the inverter a traditional AC-based system would require.
The company is also investigating microgrid opportunities that could incorporate on-site solar and storage with their inherent DC power production.
“We’d try not to ever convert to AC to maintain efficiencies and, it’s an intelligent architecture, so the packets can contain data on how building loads are managed,” Eaves said.
Just as GMP’s new battery system could make on-site meters redundant, a VoltServer-based microgrid could lead to downsizing in building electrical equipment requirements.
“It would become the panel—it’s your GFI, it’s your arc-fault protection, it’s your everything,” Eaves said.