Welcome to Exploring Renewable Energy Technology from Bounce Energy! Because the ERCOT portion of Texas can be thought of as a “walled garden,” renewable energy sources in Texas now make up a significant portion of the energy supply mix. It’s also a dynamic technology with new innovations, discoveries, and issues arising every week. Each month, we will examine the latest news in the industry to better understand what (if any) changes might come to the Texas energy supply.

Storm Aftermath — Mobile PV Gensets

One thing both hurricanes Harvey and Irma have taught recently is that getting the electricity back on after a catastrophic storm can greatly reduce the problems of hunger, clean water, and, especially in Texas and Florida, air conditioning. While homes may need to wait a while, storm shelters, hospitals, and other infrastructure institutions need power right away.

The problem that’s been around for years is that even IF these places have fossil fuel generators, both storm movement and damage to roadways and pipelines interrupt and reduce the fuel supply as well as increase the cost of the fuel. Complicating matters is that in some cases, large back-up generators installed at ground level get damaged because they are not placed above flood elevation. Additionally, there are maintenance costs such as after periods of long operation when the oil needs to be changed (on average) after every 100 hours. Lastly, portable generators are often involved in dangerous accidents, including fires, explosions, and suffocation. Most recently, three people were killed and four hospitalized with carbon-monoxide poisoning from a portable generator being kept in a closed garage in post-Irma Florida.

Still, after a year of plummeting Solar panel prices, portable solar generation shows this costly and tragic situation doesn’t need to be this way.

Mobile photovoltaic generators are usually fabricated by putting solar panels either on slanted mounts or fold out arrays on trailers. Like fossil fuel generators, they’re quick to deploy and set up. Power output isn’t puny, either. Mobile arrays can kick out from 1.8 kilowatts (kW) to 675 kW. Some battery-supplied systems can supply several megawatt hours of power.

The idea of mobile photovoltaics for emergency use is nothing new.

• Back in 1989, a Solar Emergency Response Vehicle built in Arizona and trucked to South Carolina following hurricane Hugo to help supply 115 and 220 volts AC of electrical power for 24 hours a day to a law enforcement traffic facility and later an orphanage. The biggest expense came from the commercial rush cross-country shipment. In 1991, another trailer-mounted PV array supplied 120 volts AC to power site communication and lighting following the Northridge Earthquake in California.
• 1999, the Department of Energy’s Federal Energy Management Program technical assistance report Counting on Solar Power for Disaster Relief recommended including portable PV gensets as a part of emergency preparedness.
• In 2011, the National Park Service (NPS) tested a single mobile photovoltaic system at Yellowstone to supply a remote ranger station. NPS found the trailer-mounted solar array provided an average of 23 kWh per day.
• In 2012, mobile PV gensets were used in New York during following hurricane Sandy, with three units rated to 10,000 watts.
• In 2013, the Meister Consultants Group, Inc published a fact sheet, Solar PV Emergency & Resilience Planning, in concert with the DOE’s SunShot initiative, showing that solar energy was a vital part of future emergency resilience planning and that mobile systems provided critical service with multiple benefits.

New Tools Tested to Understand Future Grid

Utilities are well aware of the rise of distributed electricity resources —or rather homes and businesses with solar arrays and batteries with excess electricity they’d like to sell. The trouble is that while there’s been a lot of discussion and planning about how to incorporate this resource into the grid, there’s not a whole lot of utilities getting their hands dirty. Part of the reason is that the combination of remotely controllable hardware with matching software tools is still being developed.

Specifically, batteries will be used as a cheaper alternative for grid-balancing ancillary services (that is, maintain frequency or voltage levels) during times of peak demand. Since the US grid relies on electricity that alternates polarity 60 times a second (60 hertz AC), it’s important to keep generation sources synchronized to avoid burning out all sorts of machines and electronic. Consequently, a certain amount of electricity is generated just for that purpose. In Texas, when demand gets high, the price for “ancillary services” also increases the overall price for electricity.

Part Eye Sculpture, Part High Efficiency Solar Power Collector

German Architect Andre Broessel’s “beta.ray” looks like a glass eye suspended in the middle of a graceful upright fork. In reality, it’s an incredibly efficient spherical electricity generator that collects both heat and photovoltaic electricity. It works by tracking the sun and focuses the incoming light onto a small number of solar cells, which increases the intensity. The output is 50% more than a standard panel of the same size. The system works so well at converting photons to electricity that it can even convert moonlight to electricity!

All the “gee-whiz” aside, concentrating photovoltaic (CPV) technology is not new and most can harvest moonlight, too. The technology has an excellent track record for improving efficiency. Current energy efficiency improvement for solar cells now runs between 14% and 23% depending on the model and manufacturer. The record for solar energy efficiency was set in 2014 by a solar concentrating photovoltaic (CPV) cell in direct sunlight that cracked 46%. Recently, George Washington University researchers tested a prototype for a solar cell that harvested energy from nearly all of the light energy in the solar spectrum. That includes the longer wavelengths of light energy that are not in the visible light spectrum. The cell reached 44.5% energy efficiency.

Renewable energy technology is getting more common and more advanced all the time. With its increasing ability to provide power, we may see more of this technology in our everyday lives, and hopefully it will also help us in emergency situations like natural disasters.