SPECTRUM: “Swarm Electrification” Powers Villages in Bangladesh

SOLSHARE image 1489315010

SOLshare’s power controllers link up homes or businesses to form a DC distribution grid. Image: ME SOLshare

Bangladesh hosts the world’s largest collection of off-grid solar energy systems. Rooftop panels and batteries electrify over 4 million households and businesses there. The Dhaka-based startup ME SOLshare believes it has the technology to link these systems and foster a solar energy-sharing economy. If the company succeeds, home systems will morph into village minigrids, offering wider access to more power at lower cost.

SOLshare’s European founders—Sebastian Groh, Hannes Kirchhoff, and Daniel Ciganovic—conceived their “swarm electrification” power-sharing platform during grad-school brainstorming sessions in Germany and California. The three moved to Dhaka to define, engineer, and launch their product, starting with power measurements in off-grid solar homes.

What Groh and his cofounders discovered upon arrival in 2015 was plenty of spare power going to waste. Typically, the batteries in home systems are sized to capture the power generated during the relatively dim monsoon season. As a result, during much of the year there is extra power available that isn’t captured. On average, about 30 percent of each system’s potential output is lost.

SOLshare’s technology is designed to share this extra power.  A smart power controller, called a SOLbox, is installed in each home or business and linked with cables to other local SOLboxes to form a DC distribution grid. The SOLbox enables users to set how much power they want to share with or draw from the network, and at what price…

… READ ON AT SPECTRUM.IEEE.ORG

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Solar Microgrids May Not Fix the Caribbean’s Devastated Power Systems

After the destruction inflicted across the Caribbean by hurricanes Harvey, Irma, and Maria, renewable energy advocates are calling for a rethink of the region’s devastated power systems. Rather than simply rebuilding grids that delivered mostly diesel generation via damage-prone overhead power lines, renewables advocates argue that the island grids should leapfrog into the future by interconnecting hundreds or thousands of self-sufficient solar microgrids.

“Puerto Rico will lead the way for the new generation of clean energy infrastructure. The world will follow,” asserted John Berger, CEO for Houston-based solar developer Sunnova Energy in a tweet before meeting in San Juan with Puerto Rico Governor Ricardo Rosselló this week. Rosselló appears to be on board, inviting Elon Musk via tweet to use Puerto Rico as a “flagship project” to “show the world the power and scalability” of Tesla’s technologies, which include photovoltaic (PV) rooftops and Powerwall battery systems.

Some power system experts, however, say the solar-plus-batteries vision may be oversold. They say that the pressing need to restore power, plus equipment costs and other practical considerations, call for sustained reliance on centralized grids and fossil fuels in the Caribbean. “They need to recover from the storm. Unfortunately I think the quickest way to do that is to go back to how things were before,” says Brad Rockwell, power supply manager for the Kauaʻi Island Utility Cooperative that operates one of the most renewable-heavy grids in the U.S. Continue reading

Seattle’s Bullitt Center Shines

Online at Architectural Record:

The designers of Seattle’s Bullitt Center have overachieved. The designers set out to demonstrate that a six-story office building could generate all of the energy it needs, but after one year of operation, it is sending a sizable energy surplus to the local power grid, according to data released by its developer, the Bullitt Foundation.

Consumption is simply far lower than what its architects and engineers projected for the 52,000-square-foot building. Instead of using 16kBtu per square foot—half the energy-use intensity (EUI) of Seattle’s best-performing office building—consumption during its first year was just 10kBtu/sf …

read on

Minnesota Finds Net Metering Undervalues Rooftop Solar

Utilities should be paying more for their customers’ surplus solar power generation according to a solar pricing scheme approved by Minnesota’s Public Utility Commission last month and expected to be finalized in early April. Minnesota’s move marks the first state-level application of the ‘value of solar’ approach, which sets a price by accounting for rooftop solar power’s net benefits, pioneered by the municipal utility in Austin, TX.

Minnesota is one of 43 U.S. states that requires utilities to pay retail rates for surplus solar power that their customers put on the grid. Utilities across the U.S. are fighting such net metering rules, arguing that they fail to compensate the utility for services that their grid provides to the distributed generator. So last year pro-solar activists and politicians in Minnesota called the utilities’ bluff, passing legislation tasking the state’s Department of Commerce with calculating the true value of rooftop solar power. Continue reading

Vertical Farming Grows Up

Plantagon's integrated office-farm

Plantagon’s integrated office-farm

Community-gardening advocates have sold urban farming as a sustainable local alternative to industrial-scale farming and as an educational platform for healthier living. And municipalities are buying in, adopting urban ag to transform vacant lots into productive civic assets. In the last two or three years, however, entrepreneurial urban farmers have opened a new frontier with a different look and operating model than most community gardens. Their terrain is above the ground, not in it. Working with help from engineers, architects, and city halls, they have sown rooftops and the interiors of buildings worldwide. “There’s a lot of activity right now, and there is huge potential to do more of it,” says Gregory Kiss, principal at Brooklyn-based architecture firm Kiss + Cathcart. Continue reading

Listening to Building Occupants

Power to the People

Sabotage: GreenSource’s how-to guide for occupants

New technology lets occupants work with building systems rather than against them, to improve their comfort while reducing energy costs.
By Peter Fairley

The stats on occupant comfort are disappointing, and green buildings are no exception. Consider, for example, heating and cooling performance. Thermal-comfort standard standards stipulate that such systems should satisfy at least four out of five occupants. “Very few buildings actually perform that well,” according to John Goins with the Center for the Built Environment (CBE) at UC Berkeley. Out of the 609 buildings in CBE’s database, only 13 percent meet ASHRAE’s performance threshold; among those that are LEED-certified, 20 percent make the grade.

There is increasing recognition that all that discomfort may be translating into a lot of wasted energy. Goins estimates that the average office building wastes 4 percent of its energy just by cooling and heating more than occupants want. The indirect impact could be even bigger when one considers how disgruntled occupants—who in most buildings lack an effective channel for requesting change—fight back against the machine. They may block air vents or plug in space heaters to combat excessive air-conditioning…

Excerpted from the May/June edition of GreenSource Magazine. Read the story at GreenSource.

Building-in a Force of Nature

Turbine House: Design by Michael Pelken & Thong Dang

Turbine House: Michael Pelken & Thong Dang’s residence with horizontal-axis wind turbine

As design teams work toward harnessing air flows around buildings, they are producing some intriguing structures. But just how viable is wind power as a source of on-site renewable energy?
By Peter Fairley

Wind power is the fastest-growing source of megawatts thanks to the jumbo-jet-sized turbines sprouting en masse worldwide. But it also has a significant presence in the city, where gusts regularly send umbrellas to landfills. Rather than considering it a nuisance, architects increasingly view urban wind as a renewable resource for on-building power generation.

Building-integrated wind power (BIWP)—wind turbines mounted on or incorporated within an occupied structure—may lack wind farms’ economies of scale. But like the leading source of on-building renewables—photovoltaics (PVs)—wind turbines offer some advantages in architectural applications. No roads get cut through wilderness to erect towers, and they deliver electricity without power lines and transmission losses. Wind turbines are also attractive to designers and clients looking to express a commitment to sustainability.

Such benefits provide potential for dramatic growth, says mechanical engineer Roger Frechette, principal in the Washington, D.C., office of Interface Engineering. “If there’s data showing that BIWP works and testimony that it’s a good thing to do, there will be an explosion,” he predicts…

Published in the April 2013 issue of Architectural Record Magazine. Read the whole story.