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New tech can make your house a solar microgrid

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Image of a house with solar panels

Enlarge / Modern single story house with solar panels and wall battery for energy storage. (credit: imaginima)

In 2020, the average United States resident experienced a little more than eight hours of electricity blackouts, according to stats from the Energy Information Administration. The report noted that this was the highest number seen since 2013 when the organization began collecting this data.

During huge storms or massive oppressive heatwaves, the power can go out, and many of the amenities—TV, the Internet, fridges, etc.—Americans enjoy simply go kaput. Currently, the primary options for avoiding this fate are batteries and backup generators. However, a company called Enphase says it has created a product that can let your house run directly off its solar panels if they're producing, though it comes with some caveats.

Shouldn’t solar panels work during an outage?

You'd think so, but no—mostly. Solar panels affixed to homes (and other structures) that are connected to the power grid will also go kaput during power outages. The outage doesn't stop them from producing power; the power just can't be used in the absence of a functioning grid. That's because the microinverters are part of an integrated system that includes the grid, power meter, and other associated hardware.

(There are two exceptions to this. The first is off-grid buildings that are set up to generate electricity from solar panels. The other exception is structures that have battery systems hooked up, though these can cost a lot—around $14,000 to install in some cases.)

To increase the number of exceptions, Enphase created the IQ8 Microinverter. Inverters convert direct current (DC) produced by solar panels to the alternating current (AC) supplied by the grid. A microinverter is just a small version of it. According to Enphase co-founder and Chief Products Officer Raghu Belur, microinverters function while attached to each solar panel instead of having many panels all fed into a larger inverter. This approach of having a distributed architecture has proven to work well in other applications, such as in computers and data centers, he said.

"The advantage [of putting inverters at every solar panel] is that, when you do power conversion at the panel itself—when you convert from DC to AC—you get better performance," he told Ars. "The reason you get better performance is because the output of one panel is not dictated by the output of another solar panel, unlike in a centralized case."

Another advantage is that there is no single point of failure; each panel and inverter acts as an independent energy producer. Further, the microinverters are all linked to software that, among other things, uses a mathematical model to predict power usage in whatever structure they're attached to. That's why its name includes "IQ." Because it's smart. (Maybe. We didn't actually ask about that.)

OK, how does it power my house when the grid’s down?

A collection of these microinverters on a house can act as a microgrid. Each one contains a chip that—when the main power grid suffers a power failure—switches from an on-grid to an off-grid mode. In this mode, the microinverters ignore the grid and direct any power to the building they're attached to. In essence, it can operate as part of a grid-integrated system or part of a microgrid.

Once in off-grid mode, if the sun is still shining, the solar panels will send their power directly to the house. But, if the power goes out because of, say, a huge storm, the panels wouldn't be producing anyway, and the building would need to have a battery system to maintain power. However, according to Belur, the microinverters can extend the time the building would have power and make it so the owners wouldn't need to purchase a particularly large battery setup.

There are two types of configurations that property owners can choose. The first is the Sunlight Backup System, which uses the microinverters without a battery. This setup requires the microinverters and a lot of other Enphase hardware: a combiner box like the IQ Combiner 4, a system controller like the IQ System Controller, a load controller, and a rapid shutdown switch. (To be clear, some version of all this hardware is needed for the panels to function.) The other configuration is functionally the same but also includes a battery or batteries.

According to Enphase's website, one of the company's more affordable systems can run between $6,000 and $8,000. This cost is potentially much cheaper than some higher-end battery systems.

So, it's technically true—the IQ8 will increase the odds your house or business will have power during outages. Will it cover you 100 percent, regardless of the weather or time of day? No. Is it cheaper than many high-end battery systems? Yes.

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LeMadChef
9 hours ago
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University of Idaho Advised To Stop Providing Birth Control Thanks To State Abortion Ban

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A hand holds up a small handwritten cardboard sign against a city sky background reading "We won't go back"

Since the moment we learned the Supreme Court was going to overturn Roe v. Wade (and long before that, actually), abortion rights activists warned that the anti-abortion movement was never going to stop at just banning abortion. Rather, it was just the first step in an all-out war on a whole host of other human and civil rights.

That war is advancing at the University of Idaho, where students and staff have reportedly been told the school should stop making contraception available, so as not to violate a 50-year-old penal code.

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LeMadChef
12 hours ago
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Trombone Champ is even better with a real trombone controller

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Trombone Champ - a little cartoon guy in a suit plays the trombone over incoming notes; the game’s background is made up of some truly majestic horses.
Image: Holy Wow

Breaking it down Riker-style

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LeMadChef
17 hours ago
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These stunning Lego minifig photos are a fantasy genre all their own

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A ninja Lego minifig being chased by a lego-built monster flinging dirt in the air as its claw reaches forward
Photo: Marco Zanconi/Chronicle Books

Put Pigsy’s Noodle Tank in a Lego Movie sequel immediately

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LeMadChef
17 hours ago
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US installs record solar capacity as prices keep falling

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Image of two people standing in front of solar panels.

Enlarge (credit: NREL)

This week, the US Department of Energy's Berkeley Lab released its annual analysis of solar energy in the US. It found that nearly half the generating capacity was installed in the US during 2021 and is poised to dominate future installs. That's in part because costs have dropped by more than 75 percent since 2010; it's now often cheaper to build and operate a solar plant than it is to simply buy fuel for an existing natural gas plant.

The analysis was performed before the passage of the Inflation Reduction Act, which contains many incentives and tax breaks that should expand solar's advantages in the coming years.

Solar, by the numbers

In terms of large, utility-scale solar installs, the US added over 12.5 gigawatts of new capacity last year, bringing the total installed capacity to over 50 gigawatts. Texas led the way, with about a third of the total capacity added (3.9 GW) going online in the Lone Star State. Combined with residential and other distributed solar installations, solar alone accounted for 45 percent of the new generating capacity added to the grid last year.

That growth showed up in figures on how much energy solar supplies. Five states now receive more than 15 percent of their electricity from solar power, including Massachusetts and Vermont, with California receiving 25 percent of its electricity from the Sun.

Solar's expansion has largely been driven by falling costs. The DOE estimates that the price of building a solar plant has been dropping by an average of about 10 percent a year, leading to a fall of over 75 percent since 2010. That has left prices averaging about $1.35 for each watt of capacity in 2021. Large-scale plants benefit the most, with projects over 50 megawatts costing about 20 percent less than those under 20 MW.

The drop in prices is causing some somewhat odd trends, driven by the fact that it's becoming increasingly economical to install large facilities in states that don't get as much sun, like Maine, Michigan, and Wisconsin. As a result, the past several years have seen the average incoming energy at newly constructed facilities (measured as daily kilowatt-hours per square meter) drop by about 20 percent.

That has helped cause a large spread in what's called the capacity factor, which is calculated by dividing the amount of energy produced at a facility by the maximum energy it could have generated if it produced 24 hours a day. The median capacity factor of solar plants in the US was 24 percent, but outliers were as low as 9 percent and as high as 35 percent. As prices continue to fall, this spread may become more pronounced, with more plants at the low end of the range.

More to come

In parallel with the drop in construction costs, the cost of electricity generated by solar farms has been dropping as well. The new analysis has tracked this via both the cost of power purchase agreements and the levelized cost of electricity (LCOE), the latter being a measure that compensates for the benefits of tax incentives to provide a more direct measure of how much a method of generation costs.

Both of these are dropping. The LCOE has plunged even faster than the cost of construction, dropping 16 percent annually since 2010, for a total drop of 85 percent. In concrete figures, the LCOE of solar was about $230 per megawatt-hour in 2010; it's now $33 per MWh. If the tax incentives are included, it drops further to $27 per MWh.

(An aside about those tax breaks. Before the passage of the Inflation Reduction Act, the only way to get a tax break on a battery installation was to pair it with a renewable generating facility in what's termed a hybrid power plant. As a result, over a quarter of the installed solar capacity was part of a hybrid power plant. Collectively, those facilities brought 6.9 GWh of battery storage online last year. With batteries getting tax incentives of their own, that trend may end up being short-lived.)

In the western US, where solar productivity is highest, most power purchase agreements are going for even less than the LCOE, with most priced in the area of $20 per MWh. Elsewhere in the US, they're typically in the $30-40 range. By this measure, that means solar is now competitive with wind in many areas of the US—exactly which of the two is cheapest will depend on the wind and solar resources at a site.

But the most striking thing about this figure is that the DOE says it's competitive with "the cost of burning fuel in existing gas-fired generators." In other words, it can potentially be more economical to not operate an existing gas generator and use the money you'd spend on fuel to install a solar farm instead.

Given those numbers, it should not surprise you that the DOE sees a lot of solar in our future. It's projecting that annual installs (both utility-scale and distributed) will more than triple by the end of the decade, reaching about 75 GW in 2030, and continuing to grow from there. And it notes that its analysis was based on data prior to the passage of the Inflation Reduction Act, "which is likely to stimulate significant additional deployment." The report also looks at potential solar installs that are in the planning stage, based on requests for connection to the grid. While many of these will never get past the planning stage, there are a lot of them—nearly 700 GW at the end of 2021. By contrast, wind is at about 200 GW, and natural gas 100 GW. All other generating sources are negligible.

Even if only a fraction of that is ultimately built, it's likely to dramatically change the grid. Increasingly, non-solar generating capacity is going to be forced off the grid at mid-day on sunny days, and the value of solar itself will drop in some areas as generation starts to regularly exceed demand. This will make batteries (both personal and grid-scale), which can charge up during this excess, more valuable while dropping the value of rooftop solar. And these changes are likely to be felt before the decade is out.

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LeMadChef
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Amazon hires unsafe trucking firms twice as often as peers, WSJ finds

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Amazon hires unsafe trucking firms twice as often as peers, WSJ finds

Enlarge (credit: Robert Nickelsberg / Contributor | Getty Images News)

For years, people in cars stuck behind blue delivery trucks in traffic have echoed media reports criticizing Amazon for clogging American roadways. It’s well-known that the Amazon drivers steering these fleets of trucks and vans don’t actually work for Amazon but are hired by companies contracted by Amazon, and Amazon has repeatedly denied liability for any dangerous driving reported, though.

Because Amazon has contracts with more than 50,000 firms, just how dangerous Amazon’s contracted drivers really are remains a question that is hard to track. However, The Information reported last year that horrific car crashes are part and parcel of Amazon’s culture of convenience. And then more recently, The Wall Street Journal provided another window into how deadly America’s favorite speedy delivery service can be. Since 2015, WSJ reported this week, “Trucking companies hauling freight for Amazon have been involved in crashes that killed more than 75 people.”

To arrive at this number, WSJ partnered with Jason Miller—a Michigan State University professor who researches transportation safety—to analyze various sources of government data from “3,512 trucking companies that were inspected by authorities three or more times while hauling trailers for Amazon since February 2020.”

The resulting report, WSJ said, “for the first time showed how the safety performance of Amazon’s trucking contractors compared with their peers.” And their results didn’t appear good for Amazon. For example, a review of Department of Transportation data on unsafe driving scores of more than 1,300 Amazon trucking contractors from February 2020 to early August 2022 found that contractors who worked the most with Amazon were “more than twice as likely as all other similar companies to receive bad unsafe driving scores.”

WSJ also found evidence of dozens of companies that Amazon contracted that had “conditional” ratings, which is like DOT putting them on probation—a black mark that typically alienates most firms from contracting them. One Illinois-based company contracted by Amazon “scored worse than the level DOT officials consider problematic” every month of WSJ’s review period.

DOT did not immediately respond to Ars’ request for comment.

Amazon’s response

Amazon spokesperson Kelly Nantel told Ars that WSJ’s report “contains misleading and inaccurate assertions.”

“First and foremost, the insinuation that Amazon puts more value on meeting deadlines than on human lives is categorically false,” Nantel told Ars. “Any accident involving one of our partners or community members is a tragedy, and we always work with our contractors to prevent accidents or learn from them, so they don’t happen again.”

However, WSJ reported that, although Amazon suspends contractors who violate its safety standards, that doesn’t always end concerns of dangerous driving. The Journal’s review of government data showed one Amazon contractor that continued hauling 55 loads after Amazon suspended its contract.

The safety director of Amazon’s freight unit, Steve DasGupta, told WSJ that Amazon’s goal for its “very safe network of tens of thousands of carriers” is “zero accidents, zero fatalities.” A company spokesperson told WSJ that Amazon “offers condolences to families of people killed in crashes that involve its contractors” and noted that Amazon contractors had “a rate of fatalities per vehicle mile about 7 percent lower than the industry average in 2020.”

Since WSJ first contacted Amazon about their report more than two months ago, Amazon has suspended all contractors involved in car crashes described in WSJ’s report, suspended or terminated 80 percent of contracts where WSJ found unsafe driving scores, and made changes to its screening process.

Amazon also told WSJ that “so far this year it has warned or suspended about 1,200 companies in connection with violations” where WSJ found contractors were sub-contracting deliveries—yet another scenario where the keys to the big blue vans could end up in the hands of drivers who might not meet Amazon safety standards.

Nantel told Ars that another issue with WSJ’s report was that the thousands of firms in WSJ’s sample were not representative of Amazon’s network, which contains more than 50,000 contractors. Amazon’s DasGupta told WSJ that the company also prefers to analyze a company’s safety score over a monthly period, not the nearly two-year period that WSJ relied on for its analysis. However, Miller—who helped WSJ with its methodology for their data analysis—told Ars that the two-year window is more appropriate because inspections can be so infrequent.

“Amazon's critique that only one month of scores should be examined has minimal merit,” Miller told Ars, noting that the longer window ensures “enough inspections are present for meaningful decisions to be made.”

Could Amazon ever be held liable for drivers?

WSJ reported that Amazon has argued in court “that it has little role in overseeing its contractors’ safety on the road.”

Last year, after an Amazon delivery driver barreling down a highway nearly 14 miles per hour over the speed limit slammed into a Tesla, the Tesla driver, Ans Rana, wound up with life-threatening injuries, including spinal cord damage and traumatic brain injury.

Rana sued Amazon, and his case seemed to be the first test of whether Amazon could be held liable for the drivers it contracts. Rana accused the company of everything from informing the driver of the wrong speed limit on its app to negligent practices like sending text message reminders to seemingly prompt drivers to go faster when they fall behind promised delivery times—or risk being terminated.

Among claims Rana made about Amazon’s negligence in the suit was a claim of “mandating a delivery schedule that was unrealistic such that it forced the drivers to rush to the point it was unsafe and as a practical matter made it impossible to drive safely.”

Rana’s case was due to drag on for many more months, with discovery extended until 2023, but Rana’s trial attorney Scott Harrison of Monge & Associates told Ars that mediation has begun. In the next few weeks, the mediation results could reveal more about the larger role that the courts might see Amazon playing when it contracts services from allegedly unsafe delivery drivers. Amazon declined to comment on the lawsuit.

Crash victims demand safer roads

With everyday drivers, Amazon’s delivery drivers share roads that experts have said are getting increasingly dangerous. Last year was “one of the worst years for roadway safety ever recorded,” according to Truck Safety Coalition, a national network of crash victim and survivor volunteers. The National Highway Traffic Safety Administration reported that “fatalities in crashes involving at least one large truck” have gone up 13 percent between 2020 and 2021, resulting in 5,600 deaths in total last year.

Truck Safety Coalition executive director Zach Cahalan told Ars that frustration among truck crash victim and survivor volunteers reached a boiling point. Earlier this week, the coalition met with Congress members to discuss urgently needed solutions to make roads safer.

Senator Alex Padilla (D-Calif.) told those gathered that “we know that better pay and working conditions create safer outcomes for all truck drivers and roadway users.” To work toward that, he helped introduce the Guaranteeing Overtime for Truckers Act (GOT) to provide more stability for truck drivers.

Trucker jobs have gotten harder since truckers have been pushed to become independent contractors, said Steve Viscelli, a sociologist at the University of Pennsylvania, who studies trucking. In 2016, he published The Big Rig: Trucking and the Decline of the American Dream, tracking how deregulation and breaking up trucker unions led truckers to take on longer routes, longer hours, and less pay.

This decline in quality of life has led to less experienced drivers taking on the job, Viscelli told Ars, which contributes to dangerous road conditions.

“In trucking, like most things, you get what you pay for," Viscelli told Ars. "If you cut corners in trucking, you get more accidents. If you pay drivers poorly and pay them based on how much they drive and then make them sit unpaid for long periods, you will only get inexperienced drivers and drivers who can’t get better jobs. And then those already less safe drivers will be forced to choose between their paycheck and safety. That is a recipe for tragedy—literally.”

And as much as truckers like Amazon delivery drivers are criticized for making roads more dangerous, Cahalan told Ars that truckers must also confront increasing roadway risks.

“Truck driving is a grueling job with poor pay, poor flexibility, and poor benefits,” Cahalan said, describing a trend where large motor carriers lead most drivers to burn out and quit every year. "On top of all that, it’s regularly listed by the Bureau of Labor Statistics as one of the most dangerous jobs in America, with 800-900 fatalities annually,” Cahalan said.

Truck Safety Coalition truck crash survivor and victim volunteers are pushing Congress to weigh policy solutions. Better pay for truckers through Congress passing the GOT Act would help, Cahalan told Ars, as well as strengthening oversight of trucking companies by the Federal Motor Carrier Safety Administration within the DOT.

There are also technology solutions to consider, though. Cahalan told Ars, “We need to do all we can to implement low-cost, proven safety measures that will drastically reduce the likelihood of death or severe injury.” These include making Automatic Emergency Braking and Advance Driver Assistance Systems standard tech in all commercial motor vehicles to improve driver safety.

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LeMadChef
1 day ago
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