How many gallons to run that microwave?

Lauren Sommer / KQED

A natural gas power plant in Long Beach that uses "once-through" cooling.

We hear a lot about how green our energy is in California. Instead of using coal, the state runs on natural gas and increasingly, renewable power.

But there’s a hidden cost to our energy supply: water use. In fact, every time you turn on a light, it’s like turning on your faucet. It’s been calculated that it takes 1.5 gallons of water to run a 100-watt light bulb for 10 hours.

The way water and power work together is a lot like a tea kettle. Steam drives the power industry.

How Power Needs Water

You can see it at the Gateway Generating Station, a natural gas power plant in the northeast Bay Area. The plant looks complicated but making power is pretty simple. Step number one: burn natural gas. That produces a lot of heat.

“You’ve got 1,700-degree exhaust energy, or waste heat,” says Steve Royall of PG&E, who is giving me a tour through the maze of pipes and compartments. The heat hits pipes that are filled with water and the water is boiled off to create steam. That’s step number two: make steam to turn a steam turbine, which is attached to a generator. It’s the water that’s making the power.

Source: National Renewable Energy Laboratory. Illustration by Andy Warner.

But water has another job in power plants. That steam, even after it makes power, is still hot. So, most power plants use water to cool it down. “You’ve got to have the ability to cool everything down so the cycle can continue and your equipment doesn’t overheat,” says Royall. (Learn more about how power needs water in this illustration).

Nuclear plants and coals plants use water the same way, in some cases, millions of gallons a year. In fact, nationwide, power plants need more freshwater than farms do, according to a U.S. Geological Survey study.

Newer power plants reuse water, but a lot of it is lost to evaporation, which means it has to be replenished. “Typically water has been the most abundant resource available,” says Royall, “but as water resources become more valuable, it’s extremely important that we think about water use.”

Future of Water Scarcity

“There is a general understanding that the era of abundance is over,” agrees Heather Cooley of the Pacific Institute, an Oakland-based think tank focused on water issues.

“Water resources are limited and there is a growing demand. We have growing population in the West. We have a growing economy.”

And then there’s the climate – which is changing. “The climate models suggest that water availability will be more variable. So we’ll have wetter years, we’ll have drier years. We’ll have a smaller snowpack,” says Cooley. In some places, power plants are already feeling the effects of tightening water supplies.

Power plants can cut their water impact by using recycled water. “We can look at less water-intensive renewable energy systems. So looking at wind and at solar panels,” says Cooley.

But it turns out, some renewables need water, too.

Solar Technology Grapples with Water Costs

In a parched corner of California’s Mojave Desert, construction equipment shimmers in the mid-day heat. These 3,500 acres near the Nevada border are the site of the Ivanpah Solar Project.

“The Ivanpah project, when it’s operational, will be the largest solar thermal project operating in the world,” says Joseph Desmond with BrightSource Energy.

You’ll notice he said “solar thermal,” a technology that’s different than the solar panels you see on rooftops. The plant is a huge field of mirrors that are specially angled to focus the sun’s heat at a tower, 400 feet tall.

“Inside the top of that tower is a boiler. All of the energy is then is used to create high temperature, high pressure steam in excess of 1,000 degrees Fahrenheit,” says Desmond.

That spins a steam turbine that makes electricity. Just like a natural gas plant, that steam has to be cooled back down, which is normally done with water. In the desert, it’s not easy to find. “You have to dig down, I want to say about 840 feet,” says Desmond.

The Ivanpah solar project under construction. (Photo: BrightSource Energy)

So, the Ivanpah plant will use a new technology called “dry cooling.” Instead of using water, the plant uses massive fans to blow air over the pipes of hot steam. “Air cooling allows us to reduce the water consumption by as much as 90%,” says Desmond.

But there’s a catch. Dry cooling uses more energy, so the plant’s not as efficient. It’s even less efficient when it’s hot out.

It also costs more to build. “It can range between one and five percent more. Now, that may not seem like a lot but when you’re competing and every penny counts, it’s an important factor,” Desmond says.

Three of the seven solar thermal plants planned in California won’t use dry cooling. But Desmond says, even though the state needs renewable power, he doesn’t think agencies would approve that today. “I think it’s safe to say if somebody said we’d like to use water cooling, that getting a permit for that would be challenging to say the least.”

The same could be true for fossil fuel plants, too, as California’s future water supply is called into question more and more.

Explore the Water and Power series and hear Lauren’s radio story on KQED’s The California Report.

Kimberly Ayers

Feed-in tariffs from private solar arrays like this one enable the world's largest source of renewable energy.

The Los Angeles Department of Water and Power (LADWP) now gets to ramp up a pilot phase that could add up to 150 megawatts of renewable electricity after 2016 — enough to power 22,000 homes — all with an eye toward hitting the state-mandated goal of 33% of its power from renewables by 2020. The measure awaits the mayor’s signature, expected late next week.

A common example of the new program would be a commercial real estate or large warehouse owner installing a rooftop solar power system and selling that power back to the local utility. The simplest definition I’ve found comes from another city that just approved a similar program for solar energy, Palo Alto: “Feed-in tariff programs involve a utility paying a fixed price, a “tariff,” for the power that is “fed into” their electric grid from local generation systems.”

The pros, cons and history of this trend, known as “distributed generation” or simply “DG,” are covered in plain language and plenty of colorful graphics in this presentation from the Department of Energy’s National Renewable Energy Laboratory (NREL). ”FiT” programs, as they’re known, certainly aren’t as dramatic as acres of solar arrays stretched out across the Mojave but they offer two key advantages, according to LADWP’s presentation to the City Council and the NREL explainer:

1. Proximity:  if your local utility is receiving power from a source right inside its coverage area, then there are no expensive transmission lines to fund and string out over miles of possibly difficult terrain, like the 35 miles worth approved for Southern California Edison’s Ivanpah solar project near the Nevada border.
2. Diversification: According to a Federal Energy Regulatory Commission (FERC) study, diversity can spell reliability: if all your “power” eggs aren’t in the same basket, then the chance of one power source’s problem taking out a huge swath of customers for a long period of time is less.

But that diversity can still be a disadvantage. Here’s why: our model for the past 100 years has been large power generating plants — mostly run with fossil fuels — sending electricity out to the grid and on to individual consumers. “Distributed” means the power is coming back the other way from a variety of sources in a variety of amounts at any given time of day — a whole lot trickier, given the need to constantly keep electrical generation and demand in balance. The power grid runs best on an even and constant supply of power. Solar is by nature intermittent, but even the technology to store solar-generated power is getting better all the time.

One other upside to solar power is that it is produced when it’s needed most: during daylight hours when most businesses are open and in the summer when people crank up their air conditioners. According to the FERC study, distributed generation can take some of the wear and tear off parts of the grid, reducing replacement costs and possibly avoiding a few more power failures along the way.

Just how big can distributed generation get in California? According to the 2010 California Clean Energy Future report, the state’s publicly owned utilities’ goal is to install 700 MW of distributed solar by 2017.  Back in 2007, the California Energy Commission said it wanted distributed generation and co-generation built by utilities and others to meet 25% of the state’s peak load demand by 2020. Governor Jerry Brown aspires to 12,000 MW of “renewable distributed generation” by 2020. As of last year, the state had nearly 1,000 MW of customer-side distributed generation systems and another 2,200 MW from wholesale systems. UC Berkeley researchers recently issued a detailed roadmap for achieving that 12,000-MW goal. Its draft report calls for streamlining the permitting process at the state and local level; adopting a faster and less expensive utility interconnection process, and asks utilities to develop local geography-driven plans for integrating these new energy sources into the existing grid.

Gretchen Weber

The Navajo Generating Station is coal-fired power plant in Arizona, just outside the Grand Canyon National Park. It's one of two coal plants that supplies more than 40% of Los Angeles' power.

Here in California, you hear a lot about our “green” reputation.  We have one of the most ambitious greenhouse gas reduction goals in the country, and the state is certainly a hotbed for new solar and wind energy investments and installations. We also have a law that says electricity providers have to get 33% of their power from renewable sources by 2020.

So… you might be surprised to hear that coal — that’s right, dirty ol’ coal — is still very much a part of the power supply in parts of Southern California. If you’re one of the 1.4 million residents of Los Angeles who gets power from the city’s Department of Water and Power, about 40% of your electricity comes from coal.

But how’s that possible?  Here in California, we don’t have much in the way of coal deposits, and no significant coal power plants. But we do have several public utilities that own portions of out-of-state coal power plants, and that entitles them to lots of less-than-clean, coal-fired energy.

There are five out-of-state coal plants providing power to California, and according to the Sierra Club, two of them — the Four Corners Power Plant and the San Juan Generating Station, both in New Mexico — are the two top mercury-emitting power plants in the United States. Here’s the lineup:

1. Navajo Generating Station – Arizona
Total Capacity: 2,409 Megawatts (MW)

• The Los Angeles Department of Water and Power owns 21.2%of the plant (510 MW). The contract expires in 2019, but LADWP General Manager Ron Nichols told KQED QUEST reporter Lauren Sommer that the utility is looking into ending the contract as early as 2014.
• According to the Sierra Club, the plant was, as of 2004, the fifth-largest emitter of CO2 in the nation (among power plants), and uses eight billion gallons of water from Lake Powell each year for cooling.

2. Reid Gardner Generating Plant – Nevada
Total Capacity: 612 MW

• California’s Department of Water Resources owns more than 67% of this plant (183 MW).  According to the DWR, Reid Gardner supplies more than 18% of the agency’s power. Its contract expires in 2013, and DWR has said it will not renew the agreement.
• In 2007, the Environmental Integrity Project rated Reid Gardner Generating Plant as the nation’s dirtiest coal plant in terms of CO2 emissions. (3,500 lbs of CO2 emitted per megawatt-hour, compared with an average of 2,000 lbs.)

3. Intermountain Power Plant - Utah
Total Capacity: 1,640 MW

• Several California companies, primarily LA’s DWP, own rights to 96% (1,574 MW) of energy generation.

4. Four Corners Power Plant – New Mexico
Total Capacity: 2,070 MW

• Southern California Edison, which supplies power to approximately 14 million Californians, owns 48% of this plant (786 MW). The utility has applied to sell its share by 2012.

5. San Juan Generating Station – New Mexico
Total Capacity: 1,848 MW

• Two of the plants four units are owned in large part by California cities, towns, and agencies.
• As Sommer reported in her radio piece, PNM, the parent company of the San Juan GeneratingStation, “has struggled to meet air quality standards and the Environmental Protection Agency ordered the plant to install new pollution control equipment.”

Here’s a map from the Sierra Club showing where the coal plants that supply California are located.

View California Coal Plants in a larger map

Listen to Lauren Sommer’s radio report about California’s struggle to quit coal.

PG&E substation near San Jose. The drop in emissions applied to both power generated in California and imported from neighboring states. (Photo: Craig Miller)

If you’re ready for some good news on the climate front: California’s carbon emissions from power generation dropped in 2009 and 2010.

That’s according to a new analysis from Thomson Reuters’ Point Carbon that looked at power generated here in California, as well as electricity imported from out of state.

According to the report (available by subscription only), emissions were down 12% over the study period. Part of the drop, not surprisingly, was due the global recession and the state’s slowed economy in 2009. But the study found that even when the economy started growing again, emissions continued to decline.

Sound mysterious? Not really, according to study co-author Ashley Lawson.

“It was actually the weather,” she said. “It was relatively cooler in 2010, so people were running their air conditioners less, and it was also relatively wetter, so there was more water available for producing hydroelectricity.”

So, despite a slight uptick in the economy, demands on the electrical grid were less due to milder temperatures — and the state was able to meet more of its electrical needs with carbon-free hydropower, which meant less demand for coal or gas, and hence, fewer emissions.

Lawson said that new solar and wind installations in California also contributed to the drop in emissions, and, while they played a smaller role than hydropower (just 15% of the reductions), she said, in one way, they are more significant.

“Hydro power will only generate electricity as long as the conditions stay good for it,” she said. “It’s a temporary situation. Renewables like wind and solar will lead to keeping emissions low because they aren’t going to go away.”

The study also looked beyond power generation and analyzed all of the stationary sources in California that will be subject to the state’s cap & trade program as of 2013. That includes power plants as well as manufacturing facilities and other large industrial plants that emit more than 25,000 tons of greenhouse gases per year. The study found that emissions from those 343 sources also experienced a decline of 11% over the same period, although the results varied by sector. Emissions from mining fell nine percent, and those from cement, lime, and glass production fell 34%. Meanwhile emissions from chemical plants rose 21%.

The study did not track emissions from cars, trucks and other transportation sources. Electricity generation is about a quarter of California’s total carbon emissions “pie.”

Photo: Shuka Kalantari

A new study from Lawrence Berkeley National Lab could help California’s homeowners decide whether or not to “go solar.” Researchers found that on average, homeowners who recently installed solar photovoltaic (PV) panels recouped most or all of their investment when they sold their homes.

“A house that has a PV system compared to a house that doesn’t have a PV system is expected to sell for more,” said Ben Hoen, the lead researcher on the study and a principal research associate at Berkeley Lab. “This is for systems that are relatively new – between 1.5 to 2.5 years old.”

Neal DeSnoo, an energy program officer at the City of Berkeley Office of Energy and Sustainable Development, said the average Berkeley homeowner keeps their home for only six years, so he suspects many hesitate to make such a costly investment. This study, he said, may sway their opinion.

“The fact that solar installations are reflected in home values is important,” DeSnoo said. “It would make people more willing to make an up front investment if they know they could get the cash out when they do sell it.”

DeSnoo said the study is a step towards reducing greenhouse gases for Berkeley, which has a goal of reducing emission 33 percent by 2020.

Billi Romain, the sustainability coordinator for the Berkeley Office of Energy and Sustainable Development, said she hopes the study will also sway home appraisers.

“It all depends on the property appraisers, whether or not they acknowledge the property value of solar panels,” said Romain. “If a study comes out that says there is a premium for solar, appraisers are more likely to accept that.”

Read the full report

2011 Prize winner Ursula Sladek (Photo: Goldman Environmental Prize)

The 2011 Goldman Environmental Prize winners were honored in San Francisco last night. In a ceremony at the Opera House, they were each awarded $150,000 for their grassroots work addressing pressing environmental issues around the world.

Environmental degradation from energy production is a common theme in the work of at least half the winners: Dmitry Lisitsyn, who’s worked to protect the ecosystems of Sakhalin Island from rapid destruction caused by companies exploiting the region’s petroleum reserves; Hilton Kelley, for environmental justice work on the Texas Gulf Coast, a region plagued with air-quality-related health problems due to emissions from the major refineries and petrochemical plants in the area; and Ursula Sladek, who created Germany’s first cooperatively-owned renewable power company.

This The New York Times story describes Sladek’s journey from homemaker disturbed by the effects on her own community from the Chernobyl disaster, to clean-energy activist.  As Felicity Barringer notes in the story, Marin County has had its own battles surrounding the creation of a local utility, the Marin Energy Authority, which has a goal of providing 100% renewable energy by 2020.  Currently, the company serves 9,000 customers in Marin with an energy mix containing 27% renewables (the state requires 20% currently), according to project coordinator Jamie Tuckey.

Sladek’s cooperatively-owned company aims to provide its 100,000 customers with 100% renewable energy by 2015.

“Climate change continues to be one of the world’s greatest challenges,” Sladek told a packed house, just before she accepted her award. “We all have to solve this problem, but not at the cost of nuclear pollution.”

Invoking the legacy of Russia’s nuclear disaster at Chernobyl and fresh images from Japan, Sladek’s call for the US to lead a global clean energy revolution was met with wild applause from the audience.

“Once again we are shown that the uncalculated risks of nuclear energy are too great to bear, especially as true alternatives exist today,” she said. “Germany’s transition from fossil fuels to clean energy sources has created enormous benefits. The United has even more superior green energy resources.  The United States has far greater financial infrastructure.  The United States should be the global leader in clean energy.”

Another common theme among the award winners this year is water.  Prigi Arisandi of Indonesia was recognized for his efforts to stop industrial pollution of a river that provides drinking water for three million people, and Francisco Pineda of El Salvador won for his work (in the face of death threats) that has stopped or delayed a Canadian gold mining development from devastating a major source of the country’s water supply.

Pineda said that 90% of El Salvador’s surface water is contaminated.  Through a translator, he told the audience, “We can live without gold, but we cannot live without water.”

Two of this year’s winners, Hilton Kelley and Raoul du Toit, were guests on KQED’s Forum program yesterday. You can listen to the interviews online.

A key component of new solar panel technology being tested at Stanford. (Photo: Nick Melosh)

In a kind of cruel paradox, heat has always been the enemy of solar panels.  At higher temperatures, photovoltaic cells become less efficient, which is problematic in an industry where efficiency is the name of the game. That heat also represents wasted energy.

Today, researchers at Stanford University announced that they may have helped solve that problem. Nick Melosh of Stanford’s Materials Science & Engineering department set out to make use of the wasted heat. He and his colleagues created a solar cell technology that uses both light and heat to generate electricity. It’s called “photon-enhanced thermionic emission” (or PETE for short). “This is the first time that a process has been reported that can use the heat and the photons together harmoniously,” says Melosh.

Traditionally, solar power falls into two camps; those that make solar power from sunlight, which is what photovoltaic (PV) panels do, and those that make solar power from heat, which is what concentrating solar power plants collect. Melosh is hoping that this technology would bridge the gap between the two.

The PETE process is designed to work at temperatures above 400 degrees F, much hotter than silicon solar panels can stand. For that reason, Melosh sees the panels being used in solar farms in the desert. “It’s probably not something that you would  put on your rooftop, but out in the desert, they would be perfect,” he said. Melosh hopes to see the efficiency eclipse 50%, which would be double that of most solar panels today.  The panels could also be added to existing solar thermal farms, since the high-temperature waste heat from the PETE process could be fed into system.

The technology is still confined to the lab, but Melosh hopes to see a prototype in three years. In the meantime, his lab will be testing different semiconductor materials that could boost the efficiency of the process.

The ultimate model for clean fuels? (Photo: KQED QUEST)

Amidst all the fretting over the development of solar and wind technology, it hasn’t been lost on some scientists that there are organisms on the planet that have already cracked the renewable energy code: plants.

Photosynthesis is a highly efficient way of converting sunlight to fuel. So why not try to copy them?

That’s a bet that Energy Secretary Steven Chu is taking. Today, the Department of Energy announced $122 million in funding to create the Joint Center for Artificial Photosynthesis, a new research hub based in California. The California Institute of Technology (Cal Tech) and the Lawrence Berkeley National Lab will lead the effort, along with other universities around the state.  Their goal will be to create an “integrated solar energy-to-chemical fuel conversion system” and to make it commercially viable.

Artificial photosynthesis isn’t a new idea. Research has gone on for decades in search of the right chemistry to make it happen. But plant mimicry is no easy task. Last year, I visited the lab of Heinz Frei at LBNL, one of the researchers there working on the chemistry. His big breakthrough was developing a chemical catalyst that speeds up the process of using light to break apart water molecules.  That’s the same thing that plants do, but they create sugar molecules as a result. The sunlight-to-fuel process would create liquid combustible fuels, like benzene.

Finding a way to make these fuels at scale would be a “transformative breakthrough,” according to the Department of Energy, given our current dependence on oil. DOE is making the bet that even if cars and trucks run on electricity in the future, liquid fuels aren’t going away anytime soon.

The firm is tapping more than a half-billion dollars in federal loan guarantees to build a manufacturing plant for its photovoltaic (PV) technology. Governor Schwarzenegger and Energy Secretary Steven Chu have also used Solyndra as a backdrop for showcasing California’s burgeoning clean tech sector. The company has developed a new type of PV technology designed for commercial rooftops.

Solyndra's rooftop solar panels use a new type of cylindrical module. Image: Solyndra, Inc.

Today in Silicon Valley, the big, green hype machine was running at full tilt. Solyndra’s CEO, Chris Gronet, talked up the California location. “If our factory was someplace else (outside the US), we probably would not have the supply chain across 29 US states,” he told KQED’s Cy Musiker today.

Mike Mielke of Silicon Valley Leadership Group added to the frenzy: “Clearly California’s leadership in the emerging trillion-dollar clean energy technology market has put us in an ideal investment position,” he said in a statement issued after the Presidential appearance.  “We would not be as competitive without the state’s landmark clean energy policies like AB 32.”

But some temperance was injected into the festivities by Severin Borenstein, co-director of the Energy Institute at UC Berkeley’s Haas School of Business. Asked if investments in solar panel production necessarily translate to permanent job growth, he told Musiker: “The evidence from a longer-run perspective really doesn’t support that.”

Borenstein says what history does demonstrate is that dominance in a given technology lasts just about as long as the government subsidies supporting it. He pointed to both Germany and Spain, both of which have recently lost some of their edge in production of solar components. Much production of solar and wind energy products has already moved to China.

“This idea that you’re going to create a permanent competitive advantage in producing green technology by subsidizing it now is really not very well born out in the data,” said Borenstein, who doesn’t deny that federal stimulus funding has “helped push forward” some key technologies. In the absence of a meaningful price mechanism for carbon emissions, Borenstein says that “pushing forward on some of these alternative technologies is the best thing we can do.”

Regarding California’s landmark climate law, the aforementioned AB 32, Borenstein agrees with the state’s Legislative Analyst that implementation would not have a significant impact on California’s overall economy, in either direction. But Borenstein doesn’t see the point in abandoning the state’s primary comprehensive climate strategy to save jobs, as some have suggested it would. “Climate change is real and it is potentially catastrophic,” said Borenstein. “If every time we have an economic setback, we put the environment second, we’re never going to make any progress.”

The idea seems simple enough: In order to get energy, we burn carbon. In most cases, that carbon comes out of the ground in the form of natural gas or coal. So instead of releasing the resulting carbon dioxide emissions into the atmosphere, why not put it back into the ground?

Of course, carbon capture and storage/sequestration (CCS) is much more complicated than that. Nonetheless it’s a strategy that’s being pursued aggressively by both international leaders and US Energy Secretary Steven Chu, who would like to see it deployed in ten years.

There are obstacles on both the “capture” and “storage” side of the equation. In terms of technology, however, “storage” is much further along, thanks to the oil and gas industry, which is already using CO2 in oil recovery. Injecting compressed CO2 into oil fields forces more oil to the surface in a process known as enhanced oil recovery. As many in the industry will remind you, they have three decades of experience doing this.

Keeping it underground is another matter. In the western US, the West Coast Regional Carbon Sequestration Partnership (WestCarb) is setting up a number of pilot projects to study how CO2 can be safely stored underground. As Technical Director Larry Myer explained to me, one of the primary goals is to simply work out the regulatory, siting, and liability issues.

As with any waste issue, choosing the site is the most important–and often most difficult–issue. California’s Central Valley has plenty of underground saline aquifers and depleted oil and gas fields that could hold CO2. But the trick is finding a site where the geology can securely store it and where there’s little risk of groundwater contamination. On the plus side, scientists know that CO2 is slowly immobilized underground, which lessens the risk over time. But how long that takes is still under study.

As for the “capture” issue, there are three ways to separate CO2 from power plant emissions.

• In today’s Climate Watch story, I describe Oxyfuel technology, in which natural gas is burned in pure oxygen. Since the outputs are steam and carbon dioxide, the CO2 can be easily siphoned off. But that requires building new power plants from scratch.
• The second option seeks to deal with the carbon dioxide before the fuel is burned; a “pre-combustion” approach. Or for all you wonks out there: Integrated Gasification Combined Cycle (IGCC). The downside to this process is that it requires gobs of energy, which makes it expensive.
• Finally, there’s the “post-combustion” approach. That’s where the CO2 is “scrubbed” from flue gas after the fuel is burned. Existing plants can be retrofitted with this technology, but it also comes with large energy penalty, just like IGCC.

A price on carbon, through either a cap-and-trade system or carbon tax, would change the economic case for CCS, but there are a lot of strikes against the technology. So why pursue it?

The argument goes like this: In order to achieve steep emissions cuts–say an 80% reduction worldwide by 2050–it may be an important tool (or stabilization wedge).  The world will continue to use fossil fuels in the near term and despite the enormous growth of renewable energy, it’s still a drop in the bucket. That’s why many believe that CCS is a crutch the world needs to wean ourselves from fossil fuels.