Energy Storage: The Holy Grail

A 2 MW battery at the AES Huntington Beach power plant. (Photo: Lauren Sommer)

Energy storage is something we’ve come to take for granted in everyday life. Our cell phones, iPods, cars and computers all depend on batteries. But storing large amounts of energy for the electric grid is another matter entirely. It’s a technical challenge that has yet to be met–but will need to be for the coming age of renewable energy.

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 (ISO) have to ensure that the energy supply meets the demand in the state, something that’s known as “balancing” the grid (you can see today’s electricity forecast on the ISO site). As a result, they coordinate the one piece of the system that they have control over: the power plants. Continue reading

Creating Power from Both Light and Heat

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. Continue reading

The Biggest Solar Project in the World

It’s just outside Phoenix. No, it’s in the Mojave. Wait, no, it’s in San Benito County.

A solar-thermal array uses mirrors to concentrate sunlight. (Image: BrightSource Energy)

On a media call this week in which executives and investors from the solar industry stumped for extensions to key federal incentives, I heard Fred Morse of Abengoa Solar say that the company’s Solana project in Gila Bend, Arizona, will be, as described on the project website, “the world’s largest solar plant.” Later that same day, an email came in from Oakland-based BrightSource Energy, (not in response) touting its Ivanpah project as “the largest solar project in the world.” Similar terms have been used to describe Solargen’s proposed 4,700-acre photovoltaic array in San Benito County. Continue reading

A Clean Energy Plan in a Messy Situation


A plan to help homeowners afford solar panels and other energy-efficient appliances is in limbo. In 2008 California was the first state to pass legislation enabling  PACE (Property Assessed Clean Energy) programs, which provide loans for property owners to buy expensive energy-saving devices. The Obama Administration has supported the plan, granting millions of dollars in stimulus funds for the programs. Cities and counties, once their states have given them the go-ahead, set up programs that issue bonds for the appliances. The homeowners then repay the loans through add-ons to their property taxes.

That’s the heart of the problem, according to letters sent by Fannie Mae and Freddie Mac to lenders in May. When homeowners default, usually tax assessments take priority over the mortgage when the debts are repaid. But the federal mortgage backers warn in their letters that “an energy-related lien may not be senior to any mortgage.” (from the Freddie Mac letter (PDF); the Fannie Mae letter (PDF) has slightly different wording). The news has thrown lenders into a state of confusion.

According to articles in Grist and a blog post in the New York Times, now cities (including San Francisco) are suspending their PACE programs, and solar installation companies are losing work–and laying off workers.

The first PACE bond in the country was issued in Berkeley, in January 2009. Since then San Francisco, Sonoma County, and Yucaipa, among other cities and counties in the state have begun PACE programs. San Diego and LA have plans in the works. But without more clarity from Fannie Mae and Freddie Mac on if they will back mortgages given to homeowners who have taken advantage of PACE, it’s unclear if the programs will continue.

California’s Future Energy Mix

The Quest/Climate Watch series “33×20: California’s Clean Power Countdown” continues on Monday, with the first of two parts on one company’s attempt to build one of the nation’s largest PV solar arrays in San Benito County.

(Image: Solargen Energy)

(Image: Solargen Energy)

With its ambitious 33%-by-2020 renewable energy goal, California will be looking for renewable megawatts from all corners of the state. While the state may hit 18-19% by the end of this year, reaching 33% will require approximately a doubling of renewable power, since the state’s energy appetite will continue to grow in the meantime.

So, where will the energy come from? According to the California Public Utilities Commission, wind and solar will have to carry much of the “load.” Check out the CPUC projections in the charts below.

New Solar Manufacturing Plant for Silicon Valley

SunPower CEO Tom Werner and Gov. Arnold Schwarzeneggar announcing the creation of a new solar manufacturing plant in Milpitas, CA (photo: Gretchen Weber)

SunPower CEO Tom Werner and Gov. Arnold Schwarzenegger. Photo: Gretchen Weber

Silicon Valley-based solar cell manufacturer SunPower Corp. announced today that it’s decided to site its newest manufacturing plant in California, a move that CEO Tom Werner says will create hundreds of jobs and may prompt an “economic cluster” that will attract similar projects.

SunPower has partnered with contract manufacturer Flextronics, and plans for the Milipitas-based operation to be up and running by the end of the year, producing high-efficiency solar cells.

Werner and Flextronics CEO E.C. Sykes were joined at the announcement in Milipitas by Gov. Arnold Schwarzenegger, who sported a green tie and chastised the assembled crowd for not celebrating Earth Day with similar fashion choices.

“I am so excited about this,” said Schwarzenegger about the new project. “This proves that protecting the economy and protecting the environment can be done simultaneously.”

Werner said locating the manufacturing operation in California makes sense both for economic reasons and because California is home to a large solar market, thanks to  the state’s Renewable Portfolio Standard, requiring 33% renewable energy by 2020, and the Million Solar Roofs Initiative.  Werner added that a record 50 megawatts of rooftop solar power were installed last month in California.

“You want to be close to your customer for logistical reasons, and also because you learn from your customer and you build it back into your product,” Werner told me following the staged media event.  “And by being local you can learn faster than you can if you’re distant.”

Other California selling points were a green manufacturing equipment sales tax exemption, which enabled SunPower to buy equipment for the facility tax-free, and low-interest loans from Recovery Act funds granted through the City of Milpitas, said Werner.

Governor Schwarzenegger used the occasion to warn Californians against taking the state’s environmental laws for granted.

“Right now there are greedy Texas oil companies that want to come in here and spend millions of dollars to roll back AB 32 (the state’s 2006 carbon legislation) and our other environmental laws,” he said. “Why? Because they don’t like that there’s alternative energy being created.  They don’t like what you are doing here.”

Hope, Skepticism at Renewables Conference

One section of a solar-thermal array on display at UC Riverside. Thousands of these mirrors gather solar radiation to heat a synthetic oil, which drives electrical generation at huge desert facilities. Photo: Craig Miller

One section of a solar-thermal array on display at UC Riverside. Thousands of these mirrors gather solar radiation to heat a synthetic oil, which drives electrical generation at huge desert facilities. Photo: Craig Miller

Perhaps the most telling moment at the Governor’s Renewable Energy Policy Conference this week, was when the Governor’s own senior advisor on renewables, Michael Picker, asked for a show of hands. How many present, he wondered, actually thought that California would attain its goal of 33% renewable power by 2020. Amid the 370 or so gathered on the campus of UC Riverside, about a dozen hands went up. How many, he asked, thought we’d make it to 33% by 2050? Another dozen or so hands.

Bear in mind that this was a room containing some of the most knowledgeable people on the topic, from government, industry and environmental organizations. These were people invested in getting there, yet most seemed to doubt that we would.

Their pessimism was not entirely shared by the questioner. Picker told me afterward that he expected about 8,000 megawatts of new power to be approved by year-end. That’s approved, not necessarily financed. Solar arrays that generate 250 MW or more are considered large-scale operations.

Meanwhile, developers are pushing to get major projects approved before the year is out. To qualify for federal stimulus dollars, projects have to break ground this year and spend a certain percentage of project costs.

“It’s a hard state to develop in,” said Matt Handel, a vice president with NextEra Energy Resources. The Florida-based company is already a major player in both solar and wind generation in California, and Handel says the stimulus money is essential for two major new projects that NextEra has in mind for the southern California deserts.

“There is hope,” Handel told me. “It is difficult. There are a lot of constituencies out there pulling in different directions.”

Virtually all of those stakeholder groups were present in Riverside, in some form. Local (especially desert) communities, environmentalists, Indian tribes and representatives from federal agencies such as the Bureau of Land Management and National Park Service were there.

Identifying the most appropriate sites for large-scale wind and solar plants has been complicated by more than bureaucracy, said Kim Delfino, California Program Director for Defenders of Wildlife. “The landscape we’re working in is already changing due to the effects of climate change, which presents a challenge as to which areas to protect,” said Delfino in a panel discussion.

Picker says he’s “not so sure” that the state is doing the best possible job of moving projects efficiently through the pipeline (to borrow a metaphor from the fossil fuels era), and he conceded that some developers will be left standing in line as the year-end deadline expires. But he calculated that if, over the next five years, 20% of the biggest projects on the drawing board can get approved, the state should make its 2020 goal.

Wind Picks Up While Solar Costs Drop

Solar Gain

In green building circles, the term “solar gain” refers to how much a place heats up during the day, from sun exposure. This week marked “gains” for both solar and wind energy development in California. For years, the buzz around solar power has centered on how rapidly the cost of photovoltaic systems would drop enough to make it truly competitive.

Solar panels shade the parking lot at Genentech in Vacaville.

Solar panels shade a corporate parking lot in Vacaville, CA.

Lawrence Berkeley National Lab released its second annual “Tracking the Sun” report this week, which actually tracks the cost of harnessing the sun’s energy in the U.S. It finds that the last decade (1998 to 2008) has seen the cost of installed photovoltaic power drop by 30%, averaged nationwide, although there were some short-term quirks. Among the “key findings:”

Preliminary cost data indicates that the average cost of projects installed through the California Solar Initiative program during the first 8½ months of 2009 rose by $0.4/W (per watt) relative to 2008, while average costs in New Jersey declined by $0.2/W over the same period.

That’s an interesting quirk at a time of generally low inflation and would seem to resonate with our recent report from Rob Schmitz, comparing the “red tape” cost factors between California and Japan (sorry, we didn’t get to New Jersey). Of course in markets, as in climate science, short-term fluctuations aren’t necessarily meaningful.

While the authors surveyed data from 16 states, they note that the results are “heavily skewed towards systems in California and New Jersey, where the vast majority of PV systems in the U.S. have been installed.” So clearly, California is participating in the longer-term trend of declining costs.

Average installed costs vary widely across states; among ≤10 kW systems completed in 2008, average costs range from a low of $7.3/W in Arizona (followed by California, which had average installed costs of $8.2/W) to a high of $9.9/W in Pennsylvania and Ohio. This variation in average installed cost across states, as well as comparisons with Japan and Germany, suggest that markets with large PV deployment programs tend to have lower average installed costs for residential PV, though exceptions exist.

The report noted three incentive programs in California that are encouraging solar installations in new construction: the Emerging Renewables Program, the New Home Solar Partnership Program, and the California Solar Initiative, and confirms that solar has gone mainstream, with 88% of systems connected to the grid. The LBNL report finds that overall, the main driver in recent cost declines has been the cost of PV panels themselves, as opposed to other components that solar systems require.

The report contains a wealth of charts and graphs to fascinate the solar wonk. You can download the 50-page report as a PDF file.

Wind picking up

Also this week, the American Wind Energy Association (AWEA) released third-quarter figures (PDF download) for large-scale wind energy  installations, logging 1,649 megawatts (MW) of new power generating capacity. The figure shows growth from the previous quarter and a running total of 5,800 MW of new capacity for the year, so far.

California clocks in at third among states with the most installed wind capacity, behind Texas and Iowa–but the Golden State does not place in the top five, in recent growth.

AWEA continues to voice consternation over a longer-term tailing off in wind turbine construction and manufacturing, especially in the U.S:

…the 5,000 MW now under construction is nearly 38% lower than the over 8,000 MW under construction at this time last year. A firm, long-term national commitment to renewable energy is still needed for the U.S. to become a wind turbine manufacturing powerhouse and create hundreds of thousands of jobs.

AWEA calculates the total operating wind power capacity in the U.S. to be about 31,000 MW, enough to power “the equivalent of nearly 9 million homes, avoiding the emissions of 57 million tons of carbon annually and reducing expected carbon emissions from the electricity sector by 2.5%.” Average power consumption per household varies considerably from state to state.

Powering Paltown: Pushing PV in Japan

Thank you, Paltown. Asako Sugawara with her son, Sota. The Sugawaras received free solar panels in exchange for living in the middle of a government experiment.

Thank you, Paltown. Asako Sugawara with her son, Sota. The Sugawaras received free solar panels in exchange for living in the middle of a government experiment.

It may have a silly name, but its mission is all business: Paltown, a neighborhood of around 800 homes outside the Japanese city of Ota, built by the government to study what happens when an entire neighborhood goes solar. This is what I find most fascinating about the Japanese: they’re so meticulous in tackling problems that they establish entire towns as part of their tinkering.

Each of the 758 homes in Paltown has photovoltaic panels on top of it. Paltown’s purpose is to work out the kinks of concentrating PV capacity in one neighborhood. One of the problems they’re looking at: On PV homes, the excess energy goes back to the grid. If the grid’s transmission lines are at capacity, a suppression system on most arrays kicks in, reducing the amount of power they generate. This, in turn, squanders the panels’ full generating potential. Engineers at Paltown prevented the suppression system from kicking in by storing excess energy in  batteries on the sides of the homes. That energy is then used in the evening, when the panels aren’t generating any electricity. Since it was established in 2002, Paltown has rarely generated too much electricity for the grid to handle. In fact, it has only happened during the holidays, when the biggest electricity consumer, the local Subaru assembly plant, shuts down. But when it has, the batteries worked.

Paltown's 758 homes all have solar panels on them.

Paltown's 758 homes all have solar panels on them.

Another thing they’re looking at is developing a system to stop sending electricity to the grid during a natural disaster. Japan is one of the most seismically active countries on Earth. When earthquakes damage homes, PV panels will usually continue to generate electricity, making a damaged system very dangerous for anyone near it. Paltown engineers have developed technology that will turn them off in these situations, they’ve patented the technology, and will soon start selling it to PV manufacturers.

Paltown pulled the plug on the battery experiment last year. The battery packs were removed but the working panels remain, along with the people who actually live here, in this renewable energy petri dish. What do they think? Asako Sugawara moved here with her husband and three children five years ago. They earn between thirty and eighty dollars a month from their solar panels. That will almost double when Japan’s Feed-in Tariff kicks in. She meets up with other housewives in the neighborhood each day, and the conversation inevitably turns to new ways they can save money. Lately they’ve been talking about the new feed-in tariff system. They’ve also shared methods of using electricity to get the biggest bang for their buck. “I’ve learned that electricity rates are the lowest after 11 at night, so I and many other housewives I know set timers on all of our appliances so that they use electricity in the middle of the night,” she told me. So much for using renewable energy when it’s available.

Rob’s radio series on energy efficiency in Japan concludes Monday morning on The California Report. All of Rob’s radio reports, blog posts, photos and video clips are collected on the Rising Sun series page.

Mapping Out Solar Power Hotspots

Somewhat overtaken by the other headlines of the week, dominated by celebrity obits and California’s financial meltdown, was the release by federal agencies of some new solar maps. They pinpoint federal lands in seven western states that present–in the government’s view–some of the best potential for building out utility-scale solar power production.

The four California locations (.pdf link) combine more than 350,000 acres in San Bernardino, Riverside and Imperial Counties. They supposedly represent the best combination of production potential, least conflict with other land uses and environmental concerns, and proximity to existing transmission lines or power plants. Areas were also mapped in neighboring Nevada and Arizona.

Update: Scott Streater has more on the controversy over planned renewable power sites, including California’s Iron Mountain site (see map, below),  in a New York Times Greenwire post.

All California locations are on BLM property in the state's southeastern deserts. Image: DOE/BLM

All California locations are on BLM property in the state's southeastern deserts. Image: DOE/BLM

The maps appeared just as California’s main regulator of power companies issued an update on solar projects in the state. The California Public Utilities Commission reported that the rate of new solar installations nearly doubled last year, from 2007 levels.

The CPUC tally shows California with over 500 MW of solar photovoltaic (PV) connected to the electric grid at almost 50,000 customer sites. The report notes that all those electrons combined are equivalent to one large power plant. About half of the current total went in under the California Solar Initiative, which has reached 13% of it’s 10-year goal, with another 8% in pending applications.

Also this week, more than $300 million fell from the federal money tree for a hydrogen power project in southern California. Cash from the American Recovery and Reinvestment Act (better known as the federal stimulus plan) will flow to the Hydrogen Energy California (HECA) project in Bakersfield. The project is designed to provide power for 150,000 homes in the area, by converting oil to hydrogen.

A statement from the California Recovery Task Force (CRTF), a conduit for federal stimulus funds, describes the HECA project as “an Integrated Gasification Combined Cycle power plant that will take petroleum coke, biomas, coal or blends of each, combined with non-potable water to convert them into hydrogen and carbon dioxide (CO2). The hydrogen gas will be used to fuel a net 250-megawatt power station.”

Perhaps more significant are the plans for the carbon dioxide generated in burning the oil. The CRTF statement says that “The CO2 will be transported by pipeline to nearby oil reservoirs and injected for permanent storage which will enhance U.S. energy security and enable additional production from existing California oilfields.”

CRTF says the project will “avoid” emissions of more than two million tons of greenhouse gases per year.