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Archive for the ‘Southern California Edison’ Category

photo: Todd Woody

I wrote this story for Grist, where it first appeared.

The California Legislature is moving to put into law a regulation requiring the state’s utilities to obtain a third of their electricity from renewable energy by 2020. But how did California’s three big investor-owned utilities do in meeting a previous mandate to secure 20 percent of their electricity supplies from carbon-free sources by the end of 2010?

Close, but not quite. Overall, the three utilities — Pacific Gas & Electric, Southern California Edison, and San Diego Gas & Electric — are getting 18 percent of their electricity from wind farms, solar power plants, geothermal, and biomass facilities, according to a new report from the California Public Utilities Commission.

Southern California Edison fell just short with 19.4 percent of its power coming from renewable sources. PG&E didn’t do as well but 17.7 percent of its electricity is green. The smallest utility, San Diego Gas & Electric, is the brownest of the bunch, with renewables accounting for only 11.9 percent of its power portfolio.

State regulators estimate that the three utilities will collectively hit the 20 percent target — one of the most aggressive in the United States — by the end of 2012. Of course, they have an even bigger mandate to meet eight years after that.

The good news is that the trajectory looks positive, if the growth in renewable energy generation in recent years is any guide. For instance, the percentage of green electricity in PG&E’s portfolio jumped from 14.4 in 2009 to 17.7 in 2010 while Southern California Edison increased its percentage of renewable energy by two points in 2010.

Hitting the so-called RPS — renewable portfolio standard — admittedly is a tricky business. A review of more than 200 renewable energy projects the utilities have signed shows that many have come online, some have cratered, and others are in limbo as environmentalist and developers face off over the impact of big solar power plants on desert flora and fauna.

There have also been big changes in renewable energy technology in recent years. The price of photovoltaic modules has plummeted over the past two years and utilities have been recently signing deals to buy electricity from photovoltaic farms at a pell-mell pace.

Still, expect stricter scrutiny of these deals as the 2020 deadline approaches, pressure mounts to make good on the 2010 mandate, and Gov. Jerry Brown’s new appointees to the public utilities commission weigh in.

Of the hundreds of renewable energy contacts the utilities have submitted for approval, only two have been rejected — a wave energy deal and a wind project.

Meanwhile, regulators list a project to transmit 200 megawatts of electricity to PG&E from an orbiting space-based solar farm as “on schedule.”

Beam me down, Scotty.

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photo: Todd Woody

In Thursday’s New York Times, I write about how the nascent solar thermal boom in California’s Mojave Desert is being derailed by lawsuits from environmental, union and Native American groups:

SAN FRANCISCO — Just weeks after regulators approved the last of nine multibillion-dollar solar thermal power plants to be built in the Southern California desert, a storm of lawsuits and the resurgence of an older solar technology are clouding the future of the nascent industry.

The litigation, which seeks to block construction of five of the solar thermal projects, underscores the growing risks of building large-scale renewable energy plants in environmentally delicate areas. On Jan. 25, for instance, Solar Millennium withdrew its 16-month-old license application for a 250-megawatt solar station called Ridgecrest, citing regulators’ concerns over the project’s impact on the Mohave ground squirrel.

At peak output, the five licensed solar thermal projects being challenged would power more than two million homes, create thousands of construction jobs and help the state meet aggressive renewable energy mandates. The projects are backed by California’s biggest utilities, top state officials and the Obama administration.

But conservation, labor and American Indian groups are challenging the projects on environmental grounds. The lawsuits, coupled with a broad plunge in prices for energy from competing power sources, threaten the ability of developers to secure expiring federal loan guarantees and private financing to establish the projects. Only one developer so far, BrightSource Energy, has obtained a loan guarantee and begun construction.

Like so many of this state’s troubles, the industry’s problems are rooted in real estate.

After President George W. Bush ordered public lands to be opened to renewable energy development and California passed a law in 2006 to reduce carbon emissions, scores of developers staked lease claims on nearly a million acres of Mojave Desert land. The government-owned land offered affordable, wide-open spaces and the abundant sunshine needed by solar thermal plants, which use huge arrays of mirrors to heat liquids to create steam that drives electricity-generating turbines.

But many of the areas planned for solar development — including the five projects being challenged — are in fragile landscapes and are home to desert tortoises, bighorn sheep and other protected flora and fauna. The government sped through some of the required environmental reviews, and opponents are challenging those reviews as inadequate.

“There’s no good reason to go into these pristine wilderness areas and build huge solar farms, and less reason for the taxpayers to be subsidizing it,” said Cory J. Briggs, a lawyer representing an American Indian group that has sued the United States Interior Department and the Bureau of Land Management to stop five of the solar thermal plants. “The impacts to Native American culture and the environment are extraordinary.”

The risk that the suits will succeed in blocking construction could make it more difficult for the builders to get federal loan guarantees or attract private financing.

Officials with the Loan Programs Office of the United States Energy Department did not respond to requests for comment. However, department guidelines classify litigation risk as a significant factor to be considered when qualifying renewable energy projects for a loan guarantee.

Brett Prior, a solar analyst with the GTM Research firm, said commercial lenders also viewed the suits as a negative. “In general, there are more projects chasing project finance than there are funds available, so the investment banks can be selective when deciding which projects to support,” he said. “Projects with lawsuits pending will likely move to the back of the queue.”

The conflict over the California projects has already accelerated a shakeout among competing solar technologies.

Tessera Solar announced last week that it had sold its 709-megawatt Imperial Valley solar dish project, which had become the target of two lawsuits. The buyer, AES Solar, develops power plants using photovoltaic panels like those found on residential rooftops. The move follows Tessera’s sale of its 663.5-megawatt Calico solar dish power plant in late December, a week after the company lost its longstanding contract with a utility. Calico is the subject of three lawsuits, and the project’s new owner, a New York firm called K Road Power, said it planned to abandon most of the Tessera solar dishes and instead use photovoltaic panels.

You can read the rest of the story here.

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I wrote this story for Grist, where it first appeared.

Are Californians forking over too much green for green energy?

A new report from a ratepayers advocacy group found that the price of electricity in 59 percent of renewable energy contracts signed by the state’s three big utilities exceeded the market price referent, or MPR for all you utility junkies.

Without getting into the nitty-gritty regulatory calculus, the market price referent is based on the price of electricity from a 500-megawatt natural gas-fired plant, the dominant power source in California. The MPR is a benchmark to gauge the competitiveness of solar power plants, wind farms and other renewable energy projects.

The “Green Rush” report from the Division of Ratepayer Advocates, which is part of the California Public Utilities Commission, generated headlines in a state that loves to hate its monopoly power providers.

“Of the 184 renewable energy contracts presented to the CPUC for approval since 2002, only two have been rejected,” the report states. “When these renewable contracts start delivering energy, costs will impact ratepayers.”

But a closer look shows that the reality is a bit more complicated.

The ratepayers advocate looked at contracts signed by California’s three big investor-owned utilities – which supply 68 percent of the state’s electricity – since the Legislature imposed a renewable portfolio standard, or RPS, in 2002. The RPS required utilities to obtain 20 percent of their electricity supplies from renewable sources by 2010 and 33 percent by 2020.

According to the report, 77 percent of the contracts signed by Pacific Gas & Electric were above the MPR as were 41 percent of those inked by Southern California Edison and 47 percent of deals with San Diego Gas & Electric.

Regulators keep the terms of those contracts in a black box so it’s impossible to know just how much more utilities are paying for renewable energy. Most contacts are for solar power.

However, not a dime gets paid until a project comes online and begins generating electricity. So, PG&E may well have agreed to exorbitant rates in a contract it signed in 2009 with a company planning to beam solar energy from space generated by an orbiting power plant (really). But unless those rockets lift off with their payloads of solar panels, the ratepayers are off the hook.

According to the report 14 percent of renewable energy contracts have failed so far and 15 percent have been delayed. Since 2002, photovoltaic module prices have plunged and as some projects are scrapped they inevitably will be replaced by cheaper technology.

In December, for instance, Southern California Edison abruptly canceled a longstanding contact with Tessera Solar for the 663.5-megawatt Calico solar dish power plant to be built in the Mojave Desert. A week later, Tessera sold the project to K Road Power, a New York firm that says it will replace most of the solar dishes, which have never been commercially deployed, with tried-and-true solar panels like those found on home rooftops. And this month, Tessera sold a second big solar dish project, the 709-megawatt Imperial Valley power plant, to AES Solar, which builds photovoltaic farms.

Solar module prices have fallen 50 percent over the past two years and it’s probably no coincidence that utilities increasingly are signing big deals for photovoltaic power plants.

When Southern California Edison this month submitted for approval contracts for 20 small photovoltaic farms that would generate 250 megawatts of electricity, all were priced under the MPR.

A word about the MPR: It’s somewhat a theoretical construct as it assumes fuel prices are fixed for the life of the power plant. Natural gas prices, of course, fluctuate wildly and currently are headed down. In a of couple years, who knows? The MPR also does not take into account the cost of carbon that may be imposed on greenhouse gas-spewing power plants in the years to come.

The ratepayers advocate, however, is justified in arguing for more transparency in the approval of these renewable energy contracts. Opening up that black box and letting in some sunshine just might spur more competition for solar contracts.

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I wrote this story for Grist, where it first appeared.

Southern California Edison on Wednesday announced another big photovoltaic power plant deal, this time to buy electricity from a 250-megawatt solar farm to be built by First Solar.

Add that contract to 831 megawatts’ worth of photovoltaic power purchase agreements the Los Angeles utility signed with SunPower and Fotowatio in January, and you’re talking some serious solar — more than a gigawatt. At peak output, that’s the equivalent capacity of a big nuclear power plant. I wouldn’t be surprised to see SoCal Edison execs tooling around town with “I ♥ PV” bumper stickers on their Chevrolet Volts and Nissan Leafs.

(And before you all hit the comment key, we know that a nuclear power plant generates electricity 24/7 while a solar farm only produces power when the sun shines.)

“First Solar’s industry-leading technology makes solar PV an excellent option for clean, emission-free power we can deliver to our customers,” Marc Ulrich, the utility’s vice president for renewable and alternative power, said in a statement. “When we get projects of this magnitude, we make great progress toward our renewable energy goals.”

First Solar’s Silver State South project won’t be built in California, but in neighboring Nevada, as its name implies. Like another First Solar power plant project in Nevada, the 50-megawatt Silver State North solar farm, Silver State South is planned for federal land in the Mojave Desert.

The United States Interior Department last October signed off on a lease for the Silver State North power plant, but the 250-megawatt project for Southern California Edison is still undergoing environmental review.

First Solar spokesman Alan Bernheimer told me Tuesday that the company hopes to secure a lease for 2,500 acres of desert land near the casino border town of Primm by the end of 2011. (The U.S. Bureau of Land Management on its website said it expects to issue a decision on Silver State South in 2012.)

According to Southern California Edison, Silver State South is set to begin producing electricity in early 2014 and will be fully built out by May 2017.

There are some obstacles to overcome, however. The project depends on the construction of a major transmission line proposed by Southern California Edison.

And it would be built adjacent to an area that some environmentalists consider key habitat for the imperiled desert tortoise and other fauna and flora. Last month, a 370-megawatt solar thermal power plant under construction by BrightSource Energy a few miles away became the subject of a lawsuit filed by Western Watersheds Projects. The suit contends the Interior Department and BLM officials failed to properly consider the environmental impact of the BrightSource project on the desert tortoise and other wildlife.

Regardless of the outcome of the Silver State South power plant, First Solar has plenty of other photovoltaic farms in the pipeline. According to Bernheimer, the company has signed contracts for 2,000 megawatts’ worth of big solar projects.

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I wrote this story for Grist, where it first appeared.

Earlier this week, I wrote about the green evolution in California regarding electric cars. Well, when it comes to solar energy, it’s starting to look more like a revolution.

This week, utility Southern California Edison asked regulators to approve 20-year contracts to buy 250 megawatts of electricity from 20 small-scale photovoltaic farms.

Nothing especially newsworthy about that until you start reading through the document submitted to the California Public Utilities Commission (hat tip to Adam Browning of the Vote Solar Initiative). Turns out that in response to its request for bids, Southern California Edison received offers in excess of 2,500 megawatts.

In other words, there’s a whole lotta solar companies out there eager to generate carbon-free electricity.

And willing to do it relatively cheaply. Southern California Edison noted in its submission letter that the 20 projects — which will generate between 5 and 20 megawatts — will produce electricity at a cost below what utility industry wonks call the “market price referent.” The MPR, as they call it, represents the levelized cost over 20 years of a combined cycle gas turbine like those typically found in natural gas power plants in the Golden State.

So in plain English, the developers of these solar farms have told the utility that they can produce electricity cheaper than a fossil fuel power plant.

The increasing competitiveness of photovoltaic power is a reflection of the steep drop in solar modules prices in recent years, thanks in large part to the rapid expansion of manufacturing capacity by Chinese solar companies. But solar modules themselves typically represent just half the cost of a project, so the growing competitiveness of solar energy probably also is due to developers’ increased efficiency at building power plants and cutting other costs.

It was notable that a homegrown technology, concentrating photovoltaics, is among those 20 contracts that came in below the market price referent. Amonix, a Southern California company, will supply the technology for four power plants. The company’s concentrating photovoltaics panels boost electricity production by using plastic lens to focus sunlight on highly efficient solar cells.

The conventional wisdom until recently was the technology was still just too expensive to be commercialized. Guess not.

As Vote Solar’s blog put it, “That’s a lot of solar, at a good price.”

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In The New York Times on Friday, I write about how Suntech has become the first Chinese solar company to win a major U.S. power plant contract:

Suntech, the Chinese solar giant, has won a contract to supply photovoltaic panels for a 150-megawatt project in Arizona, marking China’s entry into a lucrative United States power-plant market dominated by American companies.

The project is the first phase of a planned 700-megawatt project called Mesquite Solar to be built about 40 miles west of Phoenix and operated by Sempra Generation, a subsidiary of Sempra Energy. A California utility, Pacific Gas & Electric, will purchase the electricity produced by the power plant’s first phase, called Mesquite Solar 1.

As photovoltaic panel prices have plummeted in recent years, utilities have increasingly turned to developers to build massive megawatt projects. American companies like First Solar of Tempe, Ariz., and Silicon Valley’s SunPower have captured the bulk of those contracts.

For instance, last month Southern California Edison signed contracts with SunPower to buy 711 megawatts of electricity from three large photovoltaic projects.

While Chinese companies like Suntech, Yingli Green Energy and Trina Solar have grabbed a significant percentage of the American residential solar market — supplying nearly 40 percent of panels in California — they had shied away from huge utility-scale projects.

Suntech has supplied solar panels for much smaller utility projects but expects large power plants like Mesquite Solar to account for a growing share of its United States revenues, according to Andrew Beebe, the company’s chief commercial officer.

“We think it is significant for us to win a project this large but I don’t know if it’s a China-U.S thing,” Mr. Beebe said in an interview. “We are a global company and we sell all over the world though the vast majority of our product is manufactured in China.”

Last year, Suntech opened its first American factory in Goodyear, Ariz., about 30 miles from the Mesquite site. Mr. Beebe said the factory, which is expected to have a capacity of 50 megawatts by the end of 2011, will supply less than 10 percent of the solar panels for Mesquite Solar 1.

You can read the rest of the story here

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photo: Amonix

I wrote this story for Reuters, where it first appeared:

As solar panel prices have plummeted over the past year, photovoltaic power plants have become a more attractive option for utilities under pressure to meet renewable energy targets.

Case in point: Late last week utility Southern California Edison announced it had signed contracts for 239.5 megawatts of electricity to be generated by 20 small-scale photovoltaic farms.

“Photovoltaics are definitely more cost competitive than they were just a couple of years ago,” said Mike Marelli, director of contracts for renewable and alternative power at Southern California Edison. “We’re seeing just a wild response to our solicitations for projects.”

The utility has inked deals in past years for huge solar thermal power plants that can generate 500 megawatts or more. But those projects — which focus large arrays of mirrors on liquid-filled boilers to generate steam that drives electricity-generating turbines –  need vast stretches of desert land.  Transmission lines must often be built or upgraded to carry the power to coastal cities.

The photovoltaic farms, ranging in size from five megawatts to 20 megawatts, are designed to be built near existing transmission lines or substations and plugged into the grid. And in California, for instance, photovoltaic power plants do not undergo the extensive environmental review required of big solar thermal projects, meaning they can be built much more quickly.

In the power purchase agreements reached last week, Southern California Edison also for the first time placed bets on a technology known as concentrating photovoltaics – -CPV — signing contracts for 28.5 megawatts of electricity to be generated by four projects using technology supplied by Amonix,  a Seal Beach, Calif., company.

Resembling supersized solar panels, each Amonix CPV power generator is 77 feet by 50 feet and produces 72 kilowatts of electricity by using plastic lenses to focus the sun on tiny but highly efficient solar cells.

The panels are more efficient than conventional photovoltaic modules but high production costs, technological challenges and other hurdles had kept CPV on the sidelines with just a few small installations operating around the world.

You can read the rest of the story here.

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photo: Todd Woody

I wrote this story for Grist, where it first appeared.

When experts try to describe the smart grid, their favorite analogy is the internet.

Just as the internet enabled interactive, two-way communication, the smart grid, we’re told, will deploy sensors and software to digitize a century-old analog electricity distribution system, transforming it into one capable of integrating renewable energy and decentralizing power production.

But while the benefits of the internet are manifest — YouTube, Facebook, Grist! — what will the smart grid do for you and me?

For most people, the most familiar part of the smart grid is the smart meter, those wireless digital devices being installed in homes by the millions so that residents can monitor electricity use in real time rather than through a monthly utility bill that arrives long after the power has been consumed.

Smart meters have been controversial in Northern California, where a number of communities have moved to ban the devices over fears about the potential health effects from their emission of electromagnetic frequencies. (Mobile phones, televisions, and other electronic devices also emit electromagnetic frequencies, and so far there has been no scientific evidence to support the health claims about smart meters.)

A sunnier view of the smart meter as a gateway to a new energy future emerges in Los Angeles, where utility Southern California Edison has built a model home with smart grid technology embedded in everything from the dishwasher to the thermostat.

“It’s much easier to show than tell,” says Mindy McDonald, a Southern California Edison project manager. She is standing outside the “Smart Energy Experience” home that’s been constructed inside the utility’s Customer Technology Application Center, just off the 210 freeway in the inland suburb of Irwindale. “Grappling with the smart grid, it’s much easier to just walk people through,” says McDonald.

The idea is to show people how smart grid technology can cut their electricity bills, reduce the need to build additional fossil fuel plants, and therefore cut greenhouse gas emissions.

A Coda electric car is parked in the stylish suburban ranch’s garage. Solar panels, a solar hot water system, and a wind turbine sit on the roof. LEDs provide the home’s lighting, and every appliance contains communication chips, allowing them to “talk” to each other and to the utility through the smart meter attached to the front of the house.

A video screen in the living room displays the home’s energy management system, and a large flat screen in the kitchen tracks the amount of electricity being consumed and its cost.

When McDonald turns on the washing machine and the air conditioner and then plugs in the car, an “energy speedometer” on the screen shows the cost of electricity rapidly accelerating from 11 cents an hour to $2.81. The display also tells the homeowner how much electricity has been consumed so far in the day and the price per kilowatt-hour.

“It’s really has an impact when you can see how much it’s costing and they realize that maybe they should turn something off,” McDonald says. “Most people don’t pay any attention to what electricity costs until they get their bill and it’s too late to do anything about it.”

The utility so far has installed smart meters in about a fifth of the 4.9 million households and businesses it serves. Beginning in January, those customers can set a monthly electricity budget and receive a text alert, email, or phone call when they’re on track to exceed their limit, according to McDonald.

Another upcoming program, called Save Power Days, will let customers sign up to have their electricity consumption automatically curtailed when demand — and prices — spike, say on a hot summer afternoon. In return, they could save up to $200 a year on their bills.

“Your meter would receive a notification and send it to your programmable communicating thermostat, and it would automatically raise or lower the home’s temperature,” says McDonald. “If you have energy management system, you could set it up any way you want.”

She touches the iPad that controls the house to show how a smart house would react. When the meter signals the energy management system, it adjusts the thermostats, turns off the air conditioner, and switches on ceiling fans. Window blinds lower to block sunlight and keep the house cooler while the lights are dimmed.

“It’s all automatic,” notes McDonald. “If you are home and you don’t want to participate, you can opt out by turning up thermostat temperature, or just push ‘opt out’ on the screen.”

Theodore F. Craver, Jr., chief executive of Edison International, the utility’s parent company, said in an interview that these technologies will change people’s relationship with the energy system.

“Most people think it’s out of sight, out of mind — as long as the light switch goes on and an appliance can be plugged in, that’s it,” he says. “Now the customer will interact with the grid instead of just being passive.”

The question is just how successful utilities will be at persuading people to become active participants in managing their energy consumption.

“Too many of them are saying just giving people more and better information about electricity use, for example, is automatically a huge environmental plus,” Ralph Cavanagh, the co-director of energy programs for the Natural Resources Defense Council, said at the E2 Environmental Entrepreneurs recent conference.

“I’m all for better information but the average electric bill in the average U.S. household is $3 a day,” he continued. “If all you’re talking about is giving people more and better information about their $3 a day, at some point many of them are going to conclude that they have more important things to do with their time.”

Said Jesse Berst, president of the Center for Smart Energy, a research and consulting firm in Redmond, Wash.: “I think it’s a lot easier to teach devices to be smart about energy than to teach people to be smart about energy. I don’t see people clustered around the warmth of the home energy management console.”

They might well start paying more attention when utilities begin introducing what is called “time of day” pricing. Since the smart grid lets utilities monitor electricity consumption in real time, they can start charging consumers higher prices when demand spikes and thus the cost of power rises.

In other words, if you set your air conditioner at arctic temperatures when all your neighbors are cranking up their units on a sweltering day, you’ll pay the price. The flip side is that your smart meter could tell your smart washing machine and dishwasher to delay switching on until power prices drop in the evening.

The smart grid offers Joe and Josephine Ratepayer other benefits as well. For instance, if a storm knocks out a power line, all the 1,500 homes on a typical Southern California Edison circuit served by that line will lose electricity. The utility usually doesn’t find out about such outages until customers call to complain. It can be hours before a repair crew can be dispatched and the problem located and fixed.

As part of its smart grid program, Southern California Edison will be installing sensors on the top of power poles to monitor the circuit. If a line goes down, sensors will reroute power to minimize the number of homes affected by a blackout. The sensors will also notify the utility of the problem and its location and the system will automatically dispatch a repair crew.

That means fewer people sitting in the dark.

Edison International’s Craver says that a grid with this kind of smarts could make a huge difference. “There’s such a high potential for change, and a perhaps pretty radical difference that will start to be created where the grid has a two-way communications capability, and some level of intelligence actually built into the system.”

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photo: Todd Woody

I wrote this story for Grist, where it first appeared.

If you want a birds-eye view of the future of power, scramble up to the roof of a 562,089-square-foot warehouse in Ontario, a city that sits in the smoggy heart of Southern California’s Inland Empire east of Los Angeles.

On a roof the size of several football fields, workers are busy installing 11,591 solar panels that will generate 2.55 megawatts of electricity. Across the street is another massive warehouse blanketed in photovoltaic panels. Beyond that lie two more warehouses with solar arrays under construction.

Warehouses themselves use relatively little electricity, so owners lease their roofs to utility Southern California Edison, which own the solar arrays and feeds the power they produce into the grid. Over the next five years, the utility will install 250 megawatts worth of photovoltaic panels on big commercial rooftops and buy an additional 250 megawatts from solar developers that will build and operate warehouse arrays. At peak output, those solar arrays will generate as much electricity as a mid-sized fossil-fuel power plant.

“In the Inland Empire you’ve got big buildings and good sun,” Rudy Perez, manager of the utility’s solar rooftop program, said as we stood on the top of the warehouse where solar panels covered the roof as far as the eye could see.

He noted that the number of applications from solar developers to connect rooftop photovoltaic projects to the grid has tripled in the past six months alone.

“It’s one thing when you have one building in an area with a big solar array, another when you have five,” said Perez. “As you get into the higher and higher numbers, that’s where you really need smart grid technology.”

That’s because the rise of renewable energy and electric cars will vastly complicate how the power grid operates.

“We could literally have more change in the system in the next 10 years than we’ve had in the last 100 years,” Theodore F. Craver, Jr., chief executive of the utility’s parent company, Edison International, said in an interview after meeting with executives from French utility giant EDF. The French had come to Los Angeles to learn about Southern California Edison’s smart grid efforts.

In the current, mostly analog grid, the distribution of electricity is fairly straightforward. A utility or another company builds a fossil-fuel-powered plant and flips the switch. For the next 30 years or more, electricity flows into high-voltage transmission lines hour after hour, day after day.

The transmission lines carry the electricity to a distribution system where transformers “step down” the power to a lower voltage and then send it to homes and businesses. And though technological improvements have been made over the decades to the grid, it remains essentially a one-way system. And while storms and accidents can bring down power lines and blackouts can occur when demand soars on a hot day and electricity generation can’t keep up, power flows 24/7 from a natural gas or coal-fired plant.

Now consider the challenges posed by intermittent sources of electricity like solar and wind, not to mention the prospect of thousands of cars plugging into the grid at once to recharge their batteries.

“A rolling cloud can cut electrical output by 80 percent in a just few seconds,” says Perez. “That’s one reason why we have to be smart about where we put [solar].”

And why it’s necessary to build a digitalized grid that deploys software, sensors, and other hardware to monitor and manage electricity distribution and troubleshoot problems.

Instead of relying on dozens of big power plants, the smart grid of the future will increasingly tap thousands or millions of individual rooftop power plants and wind turbines. It will need to collect information about their electricity output and balance the flow of electricity throughout the grid — to ensure that a neighborhood doesn’t go dark because a large cloud is hovering over the solar array atop the local Costco.

“As we start to replace more of the generation with different technologies, we are altering the physics of the system,” said Pedro Pizarro, Southern California Edison’s executive vice president of power operations.

This drizzly October morning is a case in point. A ceiling of gray clouds hangs over the four Ontario warehouses that altogether would be generating some 7.59 megawatts if the sun were shining at peak intensity. So the smart grid also needs to be able to forecast the weather and know, say, that for the next few days electricity production is going to fall in one area while it might rise another, sun-splashed one.

“There’s new technologies that allow for much precise control of the grid,” Perez said. “One of the concerns would be that the intermittency of one of these buildings causes problem for our customers.”

Down the coast at the University of California, San Diego (UCSD), researchers have built what looks like a mirrored hemispherical bowl that scans the skies and snaps two photos a minute to predict when clouds will form over the campus’ one-megawatt worth of solar panels that are installed at seven locations.

“We do a 3-D characterization of all clouds on the horizon every 30 seconds,” Byron Washom, director of strategic energy initiatives at UCSD, said at a solar conference in October. “And then in the next second we note its vector, its speed, its height, its opacity and we characterize it.”

“So we actually begin to forecast what type of cloud is going to intersect where the sun is,” added Washom. “We know where it is at all times in the sky [in relation to] each individual panel on campus.”

He said the scientists’ goal is to be able to use the machines, which cost $12,000 apiece and have a range of one kilometer (0.62 miles), to do hourly forecasts with 90 percent accuracy.

“So a capital investment of less than $1 million could bring this to the Southern California rooftop market if we crack the science,” said Washom, referring to the concentration of warehouses in places such as Ontario.

Another smart grid strategy is to store energy generated by solar arrays in batteries and feed power to the grid when renewable energy production falls or demand spikes.

Washom showed a picture of a device that looks like the back end of a DVD player. The Sanyo lithium ion battery can store 1.5-kilowatt hours of electricity. UCSD plans to stack them like servers in a data center so it can store 1.5 megawatts of electricity produced by campus solar arrays.

In the San Francisco Bay Area, SolarCity, a solar panel installer, and electric carmaker Tesla Motors have received a $1.8 million state grant for a pilot project that will put lithium ion car batteries in half a dozen homes with rooftop solar arrays.

The Sacramento Municipal Utility District (SMUD), meanwhile, plans to install lithium ion batteries in 15 residences as part of its smart solar homes program. The utility will also put two 500-kilowatt batteries near substations to test energy storage on a larger scale.

Such systems are expensive but if the price eventually falls, utilities would be able to use them to release power to the grid when, say, a one of Washom’s cloud-forecasting devices predicts electricity production will fall off. (SMUD also will deploy 70 solar stations to help it forecast weather conditions that could affect electricity production, according to Mark Rawson, the utility’s project manager for advanced, renewable and distributed generation.)

So will the smart grid and increasing production of rooftop solar and other renewable energy spell the end of big centralized power stations and the multibillion-dollar transmission infrastructure? Will the future bring some sort of Ecotopian nirvana where power is put in the hands of the people (or at least on their rooftops)?

Not anytime soon, according to Pizarro of Southern California Edison, barring technological breakthroughs that dramatically reduce the cost of photovoltaic power.

“Right now solar is increasing but it’s not overwhelming the system,” says Pizarro, noting that rooftop photovoltaics remain a tiny percentage of the overall power supply even in places like California, where utilities must obtain a third of their electricity from renewable sources by 2020.

Still, renewable energy “has the potential to reduce the generation from central stations,” Pizarro said. “It’s a question of how much and how soon.”

The other wild card is the price of oil and natural gas, notes Craver, Edison’s chief executive. When the cost of natural gas — the dominant energy source in California — rises, renewable energy becomes more attractive. When natural gas prices plunge, as they have over the past couple of years, installing solar becomes far more expensive in relative terms.

At last month’s solar conference, SMUD’s Rawson said his utility currently relies on photovoltaics, or PV, for less than one percent of its electricity generation. But that will likely change dramatically in the years ahead, he says, as the smart grid evolves to handle the widespread distribution of solar power.

“We’re trying to change PV from something that is tolerated by the utility to something that is controlled by the utility,” he said.

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photo: PG&E

I wrote this post for Grist, where it first appeared.

Amid the hullabaloo over government-chartered mortgage giants derailing the green financing program known as Property Assessed Clean Energy, or PACE, the march toward distributed generation of renewable energy – that is, generating electricity from decentralized sources such as rooftop solar panels or backyard wind turbinescontinues.

Case in point: The Sacramento Municipal Utility District (SMUD) announced Wednesday that it had awarded contracts to San Francisco’s Recurrent Energy to install 60 megawatts’ worth of solar panels in the region surrounding California’s state capital.

Rather than construct a central solar power station, Recurrent will scatter a dozen five-megawatt installations around two cities in Sacramento County. Each installation will be located near an existing substation, which means that the solar arrays can be plugged directly into the grid without requiring any expensive transmission upgrades.

As I wrote earlier this year in Grist, when SMUD put 100 megawatts of renewable energy contracts out for bid, the allocation sold out within a week. The utility is paying the solar developers a standard premium for their photovoltaic energy — called a feed-in-tariff. But according to calculations done by Vote Solar, a San Francisco non-profit that promotes solar energy, SMUD will pay no more for this clean green solar electricity than it does for fossil-generated power at peak demand times. A 40-percent plunge in solar module costs over the past year has made solar photovoltaic energy increasingly competitive with natural gas, the main fossil fuel used in California to generate electricity.

California’s two big investor-owned utilities, PG&E and Southern California Edison, have launched similar distributed generation programs, which will bring 1,000 megawatts of photovoltaic installations online over the next five years. At peak oputput, that’s the equivalent of a nuclear power plant.

Two weeks ago, PG&E cut the ribbon on the first project to come online as part of its 500-megawatt distributed generation initiative. The two-megawatt Vaca-Dixon Solar Station is built near a utility substation 50 miles north of San Francisco.

It took just nine months to install the fields of solar panels for the Vaca-Dixon station — that’s light speed in a state where the first new big solar thermal power plant in 20 years, BrightSource Energy’s Ivanpah project, has been undergoing licensing for nearly three years.

Solar thermal power plants generate electricity by using mirrors to focus the sun on a liquid-filled boiler. The process creates create steam that drives a conventional turbine which can generate hundreds of megawatts of electricity. Solar thermal projects, by nature, are large centralized facilities, the clean and green versions of a big fossil-fuel power plant.

Photovoltaic farms, on the other hand, generate electricity when sunshine strikes semiconducting materials in a solar cell. If you want to produce more power, you just keep adding solar panels.

While BrightSource hopes to secure a license for its solar thermal project soon, the developer of a hybrid biomass solar trough power plant to be built in California’s Central Valley pulled the plug on the project last month, after spending 18 months and untold millions of dollars in the licensing process before the California Energy Commission.

PG&E has been depending on both those solar thermal projects to supply electricity to help it meet its renewable energy mandates. No wonder then, the utility’s growing enthusiasm for solar panel power. Photovoltaic farms do not have to be approved by California Energy Commission and can be built on already degraded land or close to cities.

And as I reported last month, the developer of another project being built to generate electricity for PG&E, the Alpine SunTower, decided to drop solar thermal technology made by its partner, eSolar, in favor of photovoltaic panels. The official explanation for the switch was that project was being downsized due to transmission constraints and solar panels proved a better fit.

But one has to wonder if economics as much as energy was behind the change. If so, deals like the one SMUD struck could be a recurrent theme.

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