Xant, a small-scale wind turbine maker based in Belgium, is looking to speed up off-grid electrification with a pre-integrated "utility in a box."
The plug-and-play PowerTower system includes a 50-kilowatt wind turbine, 50 kilowatts of PV and between 100 and 500 kilowatt-hours of lithium-ion battery storage, delivered in four twenty-foot containers weighing about 30 tons. It can be assembled without needing a crane.
The DC-only system is governed by a Sustainable Power Systems microgrid controller that allows for standalone, grid-tied and dual operation, and can automatically dispatch back-up diesel generation if needed.
Speaking at the 5th Microgrid Global Innovation Forum in Barcelona, Spain, this month, Xant CEO Alex DeBroe said the $600,000 package is intended to cut microgrid complexity and levelized cost of energy (LCOE).
A similar-sized microgrid built from scratch would cost an additional $50,000 due to engineering requirements, he claimed. “We’re advocating a more product-like approach to these markets, especially with small systems,” he said.
“There is a cost advantage to bringing standardized systems to the market,” he commented.
The exact level of cost reduction that could be achieved through a prepackaged system would depend on the solar and wind resource, he said, but typically the LCOE might be 10 to 15 percent less than for a customized setup.
Even in a worst-case scenario, the standardized microgrid would be comparable in cost to one built from scratch, he said.
If customization is required, he said, this could most easily be achieved by modifying the amount of storage, which is why this is the only variable component in the PowerTower.
Furthermore, "Standardization doesn’t only lead to cost reduction but also to less complexity and [thus] more robust systems," DeBroe said.
The PowerTower has been designed according to a design philosophy known as JEEP (for "just enough essential parts"), to make it less likely to fail in remote locations.
Xant says the system could yield from 183 megawatt-hours a year, with a mean wind speed of 5 meters per second and a daily global horizontal irradiance of 3 kilowatt-hours per square meter, to 348 megawatt-hours at 8 meters per second and 3 kilowatt-hours per square meter.
The company is commercializing the PowerTower in partnership with Sustainable Power Systems. The two companies are also selling another integrated system, called WindWell, for off-grid water pumping.
WindWell is made up of a 100-kilowatt wind turbine, a multi-stage submersible pump and a Sustainable Power Systems controller.
Like the PowerTower, the package comes in four 20-foot containers, does not require a crane for installation, and is fully DC, reducing cost and complexity.
In many parts of the world, said Sustainable Power Systems CEO Steve Drouilhet, “clean water often has to be pumped from considerable depths, which requires energy. That represents an opportunity for renewables.”
Since storing water is cheaper than storing electricity, he said: “I consider water-pumping to be a perfect application for renewable energy, which is inherently intermittent. When you think about it, when you pump water, it is embedded energy.”
So far, though, commercialization of these standardized off-grid energy packages is in its infancy. Xant has shipped a containerized turbine to Singapore as part of the Renewable Energy Integration Demonstrator-Singapore project being built there by Engie Lab.
But it seems the PowerTower and WindWell systems have yet to be deployed. Furthermore, the idea of standardized microgrids ran somewhat counter the view of other forum speakers who stressed the need for a customized approach to microgrid design.
Alex Riri Mari, an energy and IT analyst at Strathmore Energy Research Centre in Kenya, unveiled details of several microgrids in Chad, Ghana and Tanzania. “Even in the same country, they needed customization,” he said.
And Dean Cooper, global sector coordinator for innovative finance at the Dutch development organization SNV, confirmed that “you’ve got to be adaptable” when building microgrids.
However, Dr. Thomas Hillig, an energy consultant, said that although there was no evidence it would work in a microgrid setting, offering a standardized product might improve bankability by showing that production of a given system could be scaled up easily.
“The banks like standardization,” he said.