The coal-fired San Juan Generating Station in New Mexico. (Photo: Matt Preusch)

"We currently have unit four offline, but units one, two and three are operating at full load," says Pat Themig, Vice President of Generation for PNM, the New Mexico utility that runs the plant.

"If you see the line where the stack is, everything going behind that is scrubber," he says, pointing past a towering smokestack.

Those scrubbers remove pollutants from the air emissions. But PNM has struggled to meet air quality standards and last month, the Environmental Protection Agency ordered the plant to install new pollution control equipment. Those costs are generally passed on to the power plant owners, which, in this case, are utilities in Arizona, New Mexico and California. The San Juan Generating Station supplies power to several California cities and the Southern California Public Power Authority.

"People would be very surprised to know, particularly in Los Angeles, that historically, more of our electricity comes from coal fired power than from any other source," says Evan Gillespie of the Sierra Club's "Beyond Coal" campaign.

"Several decades ago, Los Angeles made a number of bad bets on coal fired power plants – that that would be the way of the future. That has clearly turned out to not be the case," he says.

Gillespie is talking about one particular utility: the Los Angeles Department of Water and Power (DWP). It's the largest municipal utility in the country.

Challenges for Los Angeles Utility

"We get about 40 percent today from coal and that is all out of state coal," says General Manager Ron Nichols. It comes from two coal-fired power plants, the Navajo Generating Station in Arizona and the Intermountain Power Project in Utah.

Historically, coal has been attractive to utilities for two reasons: it's reliable and cheap. "Coal tends to come around 5 to 6 cents a kilowatt hour. Our renewable portfolio today is around about 11 cents," says Nichols.

But that's changing, according to Nichols and most of the energy industry. Renewable energy is getting cheaper, while coal is getting more expensive due to stricter air pollution rules.

Two years ago, Los Angeles Mayor Antonio Villaraigosa set a goal for DWP. "I'm directing the CEO of the Department of Water and Power to take every action necessary to reach these goals and eliminate the use of coal by 2020."

Meeting that 2020 goal isn't something DWP managers have committed to. That's because DWP's contract with the Utah coal plant isn't up until 2027. Nichols says ending it early is difficult because they have to negotiate with the plant's many owners.

But perhaps the bigger challenge is: that coal power has to be replaced with something else.

"Within a decade and a half, we're going have replaced on the order of 70 percent of our total power supply. And for a utility that thinks in decades, that's rocket fast," says Nichols.

DWP must generate a third of its electricity from renewable sources by 2020, according to state law. But the problem with solar and wind power is that it fluctuates. The sun doesn't shine all the time and the wind stops blowing. Utilities often use electricity from natural gas power plants to fill in power gaps. But DWP has a problem there too.

Billion-Dollar Revamp for Natural Gas Plants

DWP relies on three coastal natural gas power plants, including the Haynes Generating Station in Long Beach. The 1800-megawatt power plant was built more than 50 years ago.

"If we walk out here, I'll show you how we get the ocean water," says DWP projects manager Nazih Batarseh. "For these old power plants, we use ocean water for cooling. And then we return it back into the ocean."

The technique is known as once-through-cooling. Everyday, almost 700 million gallons of seawater is pumped through power plant. That water holds fish larvae and plankton that die in the process. So last year, the State Water Resources Control Board ruled that coastal power plants must switch to a new cooling method over the next decade.

"It's a huge project. It is something that requires us to take plants down, plant by plant, and completely rebuild them. And those are plants that are key to our reliability," says Nichols.

Ron Nichols says rebuilding three natural gas plants will cost DWP $2.2 billion dollars. The utility recently convinced the water board to give it an extension to 2029.

Add that to investing in more renewable energy and moving away from coal power and it's a challenging time for the utility.

"It is a transition that every utility in the country will make says," Evan Gillespie of the Sierra Club.

Gillespie says Los Angeles's challenges are a snapshot of what utilities around the country will be facing as the country gradually puts national global warming rules in place. And he says those that embrace renewable energy first will benefit the most.

"A lot of these investments, while they create a lot of jobs, jobs that we desperately need, these are also investments that are going to modernize the utility. And I think the opportunity here in Los Angeles is to help provide that roadmap to help these other utilities around the country manage that transition," says Gillespie.

 Airborne Wind Energy Educator Guide

A dreamer stares up into the sky, watches the clouds slowly pass by and ponders what could be. From da Vinci to Newton to the Wright brothers to the little kid down the street, sometimes there’s a fine line between the day-dreamer and the visionary. And now a group of innovative thinkers are looking at those same passing clouds in a whole new way.

Looking up at the jet stream, Ken Caldeira, a climate scientist from the Carnegie Institution of Global Ecology at Stanford University says, “We find that there’s more than 100 times the power necessary to power civilization in these high altitude winds.” 100 times the energy to power the world is going to get people's attention.

The global need for clean energy is pushing scientists and engineers to search for new, untapped sources of energy. “To solve this problem we need a real revolution in our system of energy development,” continues Caldeira, “We need huge amounts of power, and the things that can provide huge amounts of power include fossil fuels like coal, oil and gas; nuclear power, solar power and wind.” The strongest and most consistent winds are found in the jet stream as high as 30,000 feet above the earth. But how do you harness the wind power from that high? Now the race is on to find the answer to that question.

It may seem pie-in-the-sky, but over 20 companies around the world are now working to develop technology to tap the strong and consistent power of high altitude wind. One company we profiled here on QUEST, Makani Power in Alameda, California, has received a $15 million grant from Google to build a wing concept that would autonomously fly in high circles, capturing energy with small turbines and sending the power down its tether. Other companies are exploring the use of kites, parachutes, balloons and other fanciful flying machines.

There is no shortage of skeptics and there are plenty of obstacles to hurdle before true high altitude wind energy can get off the ground. But still, it’s fun and interesting to stare up at the floating clouds and dare to dream.

Sometimes, the wind and the waves whip the ocean into a lather. And that word—lather—is a pretty accurate description of sea foam. Sea foam is made of dissolved organic matter, a substance that is so important in the world ocean that it gets its own acronym, DOM. DOM consists primarily of the broken-down bodies of phytoplankton, including microalgae and bacteria. Algal blooms, when they start to die off, create lots of DOM. In sea foam, the DOM acts like soap, creating small bubbles that float on the water.

Dissolved organic matter is full of proteins and lipids (plus lots of carbon, which we’ll get to later). The DOM molecules can act as surfactants, similar to soap and other detergents. The molecules have a hydrophilic end that sticks to water and repels oil, and a hydrophobic end that sticks to oil and repels water. The DOM decreases water’s surface tension and promotes the creation of bubbles as the water is stirred by wind and waves.

Big storms can create huge amounts of sea foam. In 2007, the area north of Sydney, Australia was dubbed the Cappuccino Coast, as foam engulfed 30 miles of shoreline. All this foam can obscure things like rocks and sea snakes, so foam frolickers should frolic with caution.

The best part about sea foam, in my opinion, is not these big foam events, but the fact that sea foam calls attention to dissolved organic matter. We rarely see it (it is dissolved, after all), and we rarely think about it, but DOM plays a massively important role on Earth. It is a key part of the marine food web, though it is hard to eat, because the particles are so tiny. Bacteria are some of the few organisms can eat DOM.

Also, the DOM in the ocean is one of Earth’s largest carbon reservoirs. DOM is produced in the upper ocean, where the phytoplankton and zooplankton live—DOM is made of the spilled contents of their bodies and their cells. The DOM that is not consumed at the surface gradually drifts downward in the water column; it can be found in the deepest parts of the ocean, albeit at lower concentrations than at the surface. As we continue to pump carbon dioxide into the air, some of this carbon ends up as DOM, and it travels slowly throughout the ocean. Next time you see sea foam, think of the dissolved particles of organic matter and the important role they play in the ocean.

37.759458 -122.509881

A 2 MW battery the AES Huntington Beach power plant.

Energy storage (through batteries) is something we use everyday in our cell phones and computers. So it may be a little surprising that when it comes to the electric grid, storing energy is something that's rarely done.

California's grid is designed to deliver electricity on a real-time basis. Every four seconds, the grid operators at the California Independent System Operator have to ensure that the energy supply meets the demand in the state – something that's known as "balancing the grid." (You can check out today's electricity forecast on their site). As a result, they coordinate the one piece of the system that they have control over: the generators, like natural gas plants.

Luckily, most generators produce a steady power supply. But California is adding increasing amounts of solar and wind power to the grid each year.  Since the output of a solar or wind farm depends on the sun or wind, the power they produce is variable (here's a time-of-day profile of renewable energy on the grid today).  That causes problems for the grid operators on a number of levels.  Wind farms produce most of their power at night, but that's when demand for power is lowest. Solar farms using photovoltaics can drop off substantially when the sun disappears behind clouds. And large solar thermal farms ramp up extremely fast when they are first hit by the sun in the morning.

Energy storage is one of the ways that utilities and grid operators can address this intermittency.  By having some extra electricity on hand, they can smooth out the bumps caused by these renewables.  Just how to store energy is another issue.  Here are some of the ways it can be done.

Pumped Hydro

In the energy storage world, this is as old school as it gets.  Hydro power uses water and gravity to generate electricity.  Storage is added by pumping that water back uphill to the reservoir, so it can generate power again.  Of course, it takes electricity to run the pumps, but usually this is done a night when there is cheaper or excess power on the grid. California's largest pumped hydro facility is PG&E's Helms Pumped Storage Project outside of Fresno, which has a 1.2 gigawatt capacity (for more on how it works, check out this powerpoint). PG&E is reportedly looking at 2 gigawatts of new pumped storage at two other sites in California.

Batteries

There are a number of different kinds of batteries that can be used in grid-scale installations. I visited a 2 megawatt battery in Southern California that uses lithium-ion cells, much like a hybrid car uses. Southern California Edison is working on an 8 MW battery project near the Tehachapi wind farms.  But lithium-ion technology has plenty of competitors, many of which have been awarded federal stimulus funding.  The primary barrier for batteries is the cost. A Beacon Power flywheel.

Flywheels

This technology uses rotational energy to store power. Flywheels have an internal rotor that uses electricity to spin at high speeds.  When energy is needed, the rotor slows down and generates electricity through a motor.  This is used for what's known as "frequency regulation" on the grid.  Since they can charge and discharge power on a second-to-second basis, flywheels can smooth out the short-term fluctuations on the grid. Beacon Power has installed flywheels in Tehachapi, California as part of a demonstration project there.

Compressed Air

Using energy produced at non-peak times (at night), compressed air energy storage projects pump air into large underground caverns. When demand for energy is high, it's released to run power turbines. PG&E is now planning a 300 MW compressed air facility in Kern County.

Of course, for all these technologies, cost is major issue, not mention the siting and planning considerations. For a good comparison, check out thesetechnology comparison charts from the Energy Storage Association.

Listen to Energy Storage: The Holy Grail radio story online and check out the rest of our stories in the 33×20 renewable energy series.

37.398255 -122.14449

Where did California go wrong? And as other states try to learn from its lessons, does the Golden State have any hope of reaching its next ambitious target – 33 percent renewable by 2020? Follow KQED’s environmental and science initiatives, QUEST and Climate Watch as we explore the obstacles to achieving California’s ambitious renewable energy goals. Over the next several months we will explore some of the challenges including: finding a home for big solar and wind farms, energy storage, California’s complex permitting process and where to build new transmission lines.

Can California get one-third of its electricity from renewable energy by 2020? Stay tuned to our series 33 x 20: California’s Clean Power Countdown.

We’re launching the series this week with a story from Lauren Sommer about how we got here and how far we have to go. But what are your questions about renewable energy? What would you like us to cover in the months ahead? Leave us a comment and let us know!

37.733106 -121.652541

Martian dunes, captured by NASA's Mars Reconnaissance Orbiter

The motor in question powers a fan in an exhibit built to demonstrate the physical processes of duning—the fluid transport and deposition of solid particulates into collections and patterns. The fan blows up a constant micro-gale within the exhibit enclosure, and visitors get to play Mother Nature by turning a handle and redirecting the wind. Meanwhile, a mass of tiny white glass beads is constantly whipped up into a fair recreation of a sand storm on planet Arakis….

After the chore of installing the new motor, I rewarded myself by enjoying the exhibit a bit. I piled up all of the sand on one side of the tank to see how the fan would redistribute it; I sent the wind from different directions, watching how the freshly blown grains were scattered across the pristine black undersurface; I placed all of the pyrite rocks, which serve as wind obstacles, in one pile. It was a lot of fun.

One thing I noticed that I hadn't paid much attention to in the past was how the dune actually moved, or migrated. Maybe I hadn't watched long enough before, or maybe it was easier to witness because I had stacked the deck by mounding the sand all in one corner, but it was fascinating to see the process.

On the windward side of the giant dune, the scouring wind picked up the sand and carried it racing to the top—slowly peeling away the front face of the dune. As soon as the sand-laden wind reached the crest and took a sudden turn downward, it was slowed a bit, becoming less able to support the sand grains, which then fell out onto the leeward side of the dune in a sandy-wind version of precipitation. The buildup of sand on the lee side eventually formed small avalanches that slid down the face in little dry floods.

In this fashion, the dune moved along, slowly being erased on its windward side and formed on the lee.

Almost coincidentally, a few days later I read a report from NASA about sand dunes on Mars. In some areas, dunes have been observed to migrate over time, while on others the patterns have remained stock-still—some of them for perhaps thousands of years, or longer.

So I had successfully created the right conditions for a migrating sand dune. What about static dunes? Well—I had noticed already that some of the pyrite rock obstacles that I placed in the sand stream formed small dunes in the wind-shadows of their leeward sides. The rocks weren't moving, and so the dunes they were nurturing and protecting remained in place.

Some of the static dune ripples observed in Meridiani Planum—where the rover Opportunity is exploring—have been explained as possibly being protected by the presence of "blueberries": tiny nodules of gray hematite that have eroded out of Martian rocks, but which themselves are erosion-resistant, and too large (1-3 millimeters) to be carried by the wind. The blueberries, as the explanation goes, embed in the sand and form a protective "armor" layer for the dune ripples, which remain safe and still in their lee.

Where else do we find dunes, other than Earth? Well, you need wind of sufficient strength and sand of sufficiently small size, for starters. We don't know about dunes on Venus; Venus has a thick enough atmosphere, but the winds may be too sluggish to whip up much of a sand storm. The only other object with a thick enough atmosphere and a solid surface is Saturn's moon Titan—and in fact we have pictures of Titanian dunes taken by Cassini.

Now I'm feeling that old itch to make another trip to my favorite place in the Solar System, Death Valley, to explore the macroscopic dunes of Stovepipe Wells . I'll send a postcard….

37.8148 -122.178

California's wind power. Credit: Elizabeth Pepin.

When it comes to renewable power, California has had one main message: bring on the solar power, bring on the wind turbines! California and the country are heading fast towards a clean energy future. But renewables aren't perfect. As wind, solar, and other nature-dependent technologies start to make up a bigger and bigger part of our electricity mix, power providers are thinking about how to deal with a very real problem: you can't tell nature when to produce.

The issue with these variable, intermittent sources of power is that electricity is a "just in time" commodity: you use it as soon you make it. When you flip on the light switch in your house or push start on your electric dryer, a power plant somewhere is whirring away right at that moment, creating those electrons for you to use.

In most of California, that complicated balance is coordinated by the California Independent System Operator, or ISO, a nonprofit that serves as a link between power generators and the utility, such as PG&E. Every four seconds, the ISO "takes the pulse" of the grid to make sure that the supply of electrons flowing out of the power plants matches the demand for electricity. If there's a mismatch, the ISO can tell plants to cut back or ask other ones to turn on.

That's not an instantaneous process, though. What makes the ISO's job complicated is that power plants have different levels of responsiveness. Nuclear plants, for example, are slow to turn on or off, so they usually just hum away at a relatively constant rate, providing "baseload" power – the minimum amount of electricity we always need. Other plants, including hydroelectric and natural gas, can ramp up and down quickly throughout the course of a day, as factories switch on their machinery and air conditioners rev up.

Unfortunately, renewables such as wind and solar are even less accommodating. The wind blows when it blows – often at night, when demand for electricity is low. The sun is more predictable, but passing clouds can change a solar panel's output, and just because we know when the sun will be high doesn't give us any control over it. Put too much of this kind of energy on the grid, and the system stops being reliable (though researchers disagree about how much exactly is "too much").

According to California's policies, more solar and wind is what's in store. The state has an ambitious goal of getting 33% of its electricity from renewable sources by 2020. So how can power providers make sure the right amount of juice is flowing through the grid when more of those electrons come from sources you can't "dispatch" on-demand? One answer might be energy storage. Stayed tuned for an upcoming post on that.

37.762611 -122.409719

I have nothing against solar panels, but they do seem to illustrate our collective love of gadgetry. Why else would we leap (or at least dream of leaping) to spend $5,000-$10,000 on solar panels when many of us could make a significant dent in our utility bills with a trip to Home Depot? Small things, like weather-stripping your doors, or making sure you have a well-insulated attic, can make a big difference in how much heat or AC your house consumes.

If you qualify as low-income (in this case, that's less than $44,000 for a family of four) you can get help with this project. If you live in California, you'll find your local participating agency here (or by calling 1-866-675-6623). Elsewhere, begin by contacting your state agency, found here. The Weatherization Assistance Program has received a 10-fold budget increase under the American Recovery and Reinvestment Act, so now's a great time to apply.

WAP won't replace your TV, but you might consider doing so yourself. Televisions tend to be the third biggest electricity user in the house (after heating/AC and refrigerators). But they don't have to be. All the new features — plasma screens, HD, widescreen — can be (and are, in some models) achieved using less electricity. The California Energy Commission is proposing new TV standards that would cut electricity use by a third.

James Sweeney, who heads the Stanford University Precourt Energy Efficiency Center, calculates that collectively – with current, affordable technologies, and without sacrificing our quality of life – Americans could cut our energy use by 30 percent.

Here's the kicker: To produce that same amount of electricity, we'd have to increase solar and wind by 60-fold. That means, for every solar panel and wind turbine in the country, we'd have to build 59 new ones, plus all the power lines and roads they'd entail. Or, to consider another non-fossil fuels alternative, that's four new nuclear power plants for every existing one.

Listen to the Let's Weatherize! radio report online, and watch our Weatherization Slideshow.

38.63861 -121.46020