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Reporter's Notes: Building an Artificial Leaf

 

Lauren Sommer by Lauren Sommer  November 20th, 2009
37.8768, -122.251

Quantum mechanics and Foosball? Credit: RickyDavid.

When I began this story, it seemed pretty simple. I'd heard that scientists at Lawrence Berkeley National Lab were working to mimic photosynthesis and create a man-made version of the process that could supply us with renewable energy.

The premise is to create a "closed-loop" energy system. Artificial leaves would use water, sunlight and carbon dioxide as inputs to create fuels like butane. Those fuels would be used for transportation or fuel cells. And by burning those fuels, we would produce carbon dioxide. The cycle goes on from there.

I never thought that quantum mechanics would enter the picture. That's what I discovered at the UC Berkeley lab of Graham Fleming. He says we have a lot to thank photosynthesis for. It produces the oxygen we breathe and is the basis for the entire food chain on the planet.

Fleming's lab is dedicated to understanding how photosynthesis works so well. And one of the things they've found is that plants are somehow tapping into quantum mechanics to improve their efficiency. It's pretty complicated – but with the help of the folks in Fleming's lab, they helped me understand it through, of all things, Foosball. Here's an audio version of it to help you out.

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Listen to the Building an Artificial Leaf radio report online, and listen to our Web Extra: Photosynthesis and Foosball.


Top Ten Energy and Water Efficiency Tax Credits and Rebates

 

Jim Gunshinan by Jim Gunshinan  August 28th, 2009
37.8686, -122.267

get tac redits and rebates for doing the right thing? What could be better? Image source: Mark_WIt's a good time to get energy efficient at home, what with a down economy and efforts by federal, state and local governments, and utilities to decrease our overall energy use and create a new, more secure, job-creating green economy.

Top Five Federal Tax Credits (for improvements made from January 1, 2009 through December 31st, 2010)

1.      Adding qualifying insulation to an existing home-30% of cost, up to $1,500 for all upgrades other than renewable energy systems.

2.      Energy Star-qualified metal roofs or asphalt roof replacements-30% of cost, up to $1,500 for all upgrades other than renewable energy systems.

3.      Efficient gas, oil, propane, and electric heat pump water heater replacements-30% of cost, up to $1,500 for all upgrades other than renewable energy systems.

4.      Solar water heating systems in new or existing homes-30% of cost.

5.      Photovoltaic (PV) systems in new and existing homes-30% of cost.

The feds are also giving money to the states for appliance rebates and is offering tax credits for certain window and door upgrades for new and existing homes, small wind energy systems, biomass stoves, geothermal heat pumps, fuel cells, efficient cars, and other equipment. For more detailed information about the federal tax credits, go to the California Building Performance Contactors Association.

*Top Five State Rebates (not time limited but rebates usually last until the money for rebates in each category runs out)

1. Adding qualifying insulation to an existing home-PG&E offers $0.15 per square foot in rebates.

2. Qualifying "Cool Roofs" replacement roofs-PG&E offers $0.10 or $0.20 per square foot depending on roof type.

3. Efficient gas and electric storage water heater replacements: PG&E offers $30 rebates.

4. Energy- and water-efficient clothes washers-PG&E offers $35 or $75 rebates depending on efficiency level and East Bay Municipal Utility District offers $125 rebates.

5. Irrigation systems and high-efficiency toilets-East Bay Municipal Utility District offers up to $1,000 rebate for qualifying water saving irrigation hardware and landscape material costs; up to $500 for WaterSmart replacement irrigation timers; and up to $150 for high-efficiency toilets (HET).

*This only lists rebates offered through PG&E and the East Bay Municipal Utility District, since these are the utilities that I know best. But most utilities offer similar rebates. For more detailed information about these and other California rebates for efficiency upgrades and water and energy efficient appliances, see Flex Your Power.

Is Your House Haunted by Electronic Vampires?

 

Jim Gunshinan by Jim Gunshinan  August 27th, 2009
37.8768, -122.251

Before You Invest in Photovoltaics, make sure your house isn't haunted by phantom loads.Some Devices Suck Power While They Sleep

When writing about energy efficiency in California, I know that emphasizing heating systems doesn’t carry much punch. I might as well try to get Californians interested in who makes the best deep- dish pizza. (That’s Chicago, of course. Zachary’s isn’t bad though.) Cooling systems are accounting for more and more of a share of residential energy use as we continue to build out from the cities near the Bay in hot dry climates. But overall, when it comes to climate, the inside and the outside of Bay Area homes are pretty much the same for most of the year. But let’s not get soft on energy efficiency! There are other energy users in California homes that threaten to lift us in the future to the level of, say, what a Wisconsin home uses in the winter today.

Miscellaneous electric loads are electric loads other than heating and cooling, water heating, refrigerators, and lighting, and include consumer electronics, outdoor lights, and portable inside lighting fixtures. The U.S. Department of Energy’s Energy Information Agency estimates that these “other” electric loads, along with televisions and office equipment, made up close to 30% of U.S. residential electricity consumption in 2006; this will rise to about 35% by 2020. Part of the reason for the growth in energy use of these devices as a percentage of total home energy use is that homes are heating and cooling more efficiently, with better HVAC equipment, tighter building envelopes, and more insulation.

Rich Brown and Greg Homan of Lawrence Berkeley National Laboratory, measured electricity use in 13 new California homes in 2007 and came up with some interesting results. They metered plug-in devices in standby, off, or low-power mode. Since the homes were not yet occupied, they estimated the annual energy use by using typical use patterns and the energy use of the plug-in devices in active mode, or “on,” measured in other studies. Some of the homes were model homes and packed with appliances and electronics like TVs, and others had only the plug-in devices installed by the builders. Builder installed devices include things like garage door openers, structured wiring, and gas fireplaces. The homes were in four different subdivisions and span the range of typical new construction to super efficient homes with PhotoVoltaic (PV) systems installed.

The builder-installed devices use on average 800 kilowatt-hours (kWh) of electricity per year, or about $80 worth with electricity at a low $0.10 per kWh. That does not include lighting energy. That’s interesting. About half of the energy used by the builder-installed devices is used by devices that are supposed to be turned off, or are in standby mode! That’s very interesting. This is like having a 50-Watt light bulb on 24 hours a day, 365 days a year, lighting nothing.

One of the model homes, the biggest energy user of the 13, used close to 2,500 kWh per year ($250) for two large televisions, a structured wiring panel that uses 20 Watts continuously to power three security cameras and an Internet router, smoke alarms, garage door openers, a washer/dryer, a very big refrigerator, and a few more devices. Add in lighting and that house is a major energy hog, even with super efficient heating and cooling systems and PV panels on the roof.

So what to do? Don’t even think of getting that PV system until you spend some time reducing your electricity load. The PV system you need to meet that load then won’t be so expensive. When it’s time to buy a new appliance, always look for the Energy Star label. Energy Star appliances use about 20% less energy than typical new appliances. Anything that uses a remote control, such as televisions and set-top boxes, or that displays the time of day all day, such as some stoves and microwave ovens, uses energy when officially off. Look for electronic devices that are really off when they say off, or that use 2 Watts or less in standby mode. For your other sleep slurping electronics, plug them into a power strip, and turn the power strip off when you aren’t using the devices. Then look into that sexy new PV system for your roof. More on that in my next blog.

Producer's Notes – Climate Watch: Unlocking the Grid

 

Sarah Kass by Sarah Kass  August 25th, 2009
38.246308, -122.904797

And old, 19th Century windmill in contrast to wind turbines today.

Last summer I visited the Netherlands, the original home of the windmill. Surprisingly, I saw hardly any of the quaint structures we associate with Dutch wind power. One hundred years ago Holland had about 10,000 wooden windmills dotting its landscape. Today, barely 10% remain. What I saw instead were high tech wind turbines, white and spare and gracefully generating electricity with wind from the North Sea. Many view these modern day towers as an eyesore, but I see them as a sign of hope. Like giant flowers across a landscape, they symbolize for me a clean energy future. But wind power, and solar, have a handicap that fuels claims that renewables will never be more than a small percentage of U.S. power. These energy sources can't be counted on when night falls or the wind subsides. Their inconsistent and therefore unreliable nature poses a problem for a world with an enormous appetite for electricity. If only excess power could be stored on a grand scale, it might solve many of our energy problems.

It isn't that electrical energy isn't currently storable, but as Andrew Tang, Senior Director of PG&E’s Smart Meter program points out, the current generation of batteries can’t store electricity at a price that's cost effective. But both he and Steve Berberich from California System Operators were optimistic about future storage possibilities. Tang described an experimental project that uses a sodium sulfur battery the size of an 18-wheeler trailer. The battery would be located next to a substation, or somewhere in the network, and its stored power would be used during times of peak demand. He also talked about the future of plug-in electric cars whose batteries could both store energy and in theory put it back onto the grid when the car's not in use. Steve Berberich envisioned several possibilities for storing excess power. He proposed converting it to hydrogen, which could be burned in a gas plant or could be used in a fuel cell. And he suggested using power to compress air, which could be injected into the ground and called upon when the wind's not blowing and the sun’s not shining.

Whatever the final solution to storage, you can guarantee it will be a game changer in the renewable power industry. No longer will wind and solar be looked upon as unreliable. Hopefully this missing puzzle piece will go a long way towards helping us detach from our dependence on fossil fuels. But we’ll still be left with the challenge of getting all that clean, green energy onto the power grid. And you can be sure that environmental concerns, zoning, aesthetics, and cost will undoubtedly be cantankerous issues for years to come.


Watch the Climate Watch: Unlocking The Grid television story online.


Are Power Towers the Future of Solar Energy?

 

Christopher Smallwood by Christopher Smallwood  August 24th, 2009
37.762611, -122.409719

Abengoa's solar power tower, PS10, near Seville, Spain. It is capable of supplying 11 megawatts, or approximately 5,500 households worth of power.Photo: afloresmSouthern California's Antelope Valley is famous for its poppies, luring prospective residents with fiery-orange photographs of the State's most celebrated flower and drawing as many as 60 thousand people each spring to the California Poppy Festival. The region also encompasses the western tip of the sun-scorched Mojave Desert and as a result has recently become the home of one of the most aesthetically striking new designs in alternative energy. On August 5th, the company eSolar flipped the switch on the Sierra Sun Tower, the newest example of what have come to be known as solar "power towers."

Comprised of one or two tall narrow towers surrounded by an enormous field of shimmering mirrors beaming sunlight back up from ground level, these power plants work by essentially the same principle you might have exploited as a child in using a magnifying glass and a hot sunny day to burn holes in the leaves of a backyard playground. A magnifying glass focuses sunlight from a round disk into a single bright dot. A solar power tower's field of mirrors focuses light onto a single water tank high in the air. The concentrated light boils the water, and the steam is used to generate electricity.

In other parts of the world the concept of the solar power tower has gained dazzling momentum as well. Last April, the Spanish company Abengoa commenced operation of a new power tower of its own, dubbed PS20. The power output is still a pittance compared to some of the largest fossil fuel or nuclear plants, but at 20 MW it is currently the largest power tower in existence.

The surge of excitement recently in solar power towers may be grounded on more than hype. Other solar technologies tend to be limited in their promise by cost. Caitlin Cieslik-Miskimena, an eSolar press contact, said that many of the components employed in the company are relatively cheap. She noted, for example, that the mirrors used to collect the Sierra Sun Tower's light are "just a step above a bathroom mirror" in quality. Because they are relatively small, they can also be manufactured to be flat, which is considerably less expensive than the parabolic mirrors used in some other designs.

Nevertheless, solar power towers are just one design in a rich assortment of ideas that people have had for harnessing solar energy. Photovoltaic cells are already used ubiquitously to energize calculators, solar-powered cars, and many satellites, and rapid advances continue to be made in this area. A less flashy form of solar thermal power known as SEGS (Solar Energy Generating Systems) uses curved mirrors to heat long troughs of water. The largest solar power plants in the world today are based on this method. Some companies are even proposing that we exploit solar energy by heating air beneath what amounts to a gigantic clear skirt. (Visit this link for a wild virtual tour of one such proposed plant.)

Time will ultimately tell which (if any) of these will turn out to be commercially viable options as the future marches toward us. Still, we are certain to have a wide array of ideas to explore.

Reporter's Notes: Do We Need Nuclear?

 

Craig Miller by Craig Miller  August 21st, 2009
35.211713, -120.855018


More people appear to be saying "yes" these days, even if grudgingly. The question is: Is it too late?

The Public Policy Institute of California has been tracking public support for expanded nuclear power over the past several years. Survey participants are offered a menu of four potential energy options, one at a time.

The question posed is: "Thinking about the country as a whole, to address the country’s energy needs and reduce dependence on foreign oil sources, do you favor or oppose the following proposals?" Then the four options are offered, including: "How about building more nuclear power plants at this time."

As recently as 2002, adults surveyed in California opposed the idea by a margin of 59% to 33%. But that gap has been closing steadily in the years since and by this July, Californians were split just about down the middle on the question, with 46% in favor and 48% opposed. The poll has a margin of error of about 2%, making it a virtual tie.

When you dig into the numbers a little deeper, some demographic preferences emerge: support increases with both age and education. Californians 55 and older support more nuclear by a wide margin (58% to 36%) as do college graduates (50%-43%).

Many people use cost as an argument against nuclear but just as the PPIC was phoning around for opinions on the matter, the Palo Alto-based Electric Power Research Institute was finishing up its own report , concluding that trying to reach greenhouse gas reduction goals without baseload technologies like nuclear power, could end up costing much more. Dan Kammen, who runs an energy lab at U.C. Berkeley, would appear to agree. He said in a recent interview for Climate Watch that "Without knowing exactly where things will come down on nuclear, I think that it absolutely has to be part of the equation in a way that it has not been in the past. Energy costs from fossil fuels are rising at almost 5% a year now, and the damage we are doing and are going to do more of, if we don’t stop our fossil fuel expansion, in terms of greenhouse warming, is so large an issue that these technologies have to be back on the table.

But there's a serious question of whether the nation– let alone the state– is in a position to embrace nuclear as it did in the 1960s. Kammen is also a professor of nuclear engineering, and noted with some alarm the rate at which the industry is "graying." Now in his mid-forties, he told me that when he attends technical meetings for nuclear engineers, he's often "the youngest guy in the room–by 20 years." Since the U.S. more or less abandoned its nuclear hopes following the Three Mile Island debacle, the nation has ceded most of its nuclear industrial capacity to other nations, and few young people have chosen to enter the field.

The effective ban on new nuclear plants that California has had in place since 1976 could be reconsidered. But ultimately electric utilities will have to want it and I sense a certain "nuclear fatigue" in that arena.

The Sacramento Municipal Utility District (SMUD) shut down its only reactor in 1989, after a thumbs-down referendum. When I called to ask for an interview on the prospects for a nuclear revival, they declined. They didn't even want to talk about it. Managers at PG&E, whose twin reactors at Diablo Canyon produce nearly a quarter of the utility's output, still claim an interest in nuclear. But when I asked CEO Peter Darbee about it recently, he said he had the sense that most people in California would prefer to look elsewhere for energy solutions. Of course, that was before the latest PPIC poll.

Listen to the New Nuclear radio report online.

Check out an interactive "atomic timeline," marking some of the milestones in nuclear power history in the U.S. By former Climate Watch intern Amanda Dyer.

Those Intermittent Renewables – Part 1

 

Rachel Zurer by Rachel Zurer  May 8th, 2009
37.7626411, -122.409253

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.


Reporter's Notes: Smart Grid at Home

 

Lauren Sommer by Lauren Sommer  April 10th, 2009
37.79184, -122.3961

Hourly energy use data, now online.

I've never paid much attention to my electric meter. For most of us, it's just that box on the side of the house with a small white disk spinning inside, keeping track of our energy use. But over the next three years, all the meters of PG&E customers will be getting a major upgrade to a new, digital SmartMeter.

I met one customer, Ken Kube in Castro Valley, whose meter has already been upgraded. Since the new meters track his home energy use digitally, Kube can log into his PG&E account and see his real-time energy use. On one level, it's really the ultimate tool for parents who like to remind their kids to turn out the lights. But it's also a powerful conservation tool. Kube could see how much energy he uses at night, when his appliances are drawing power in stand-by more (what's known as "vampire" power).

These meters are just a small piece of the puzzle when it comes to a smart grid. Just what the smart grid is depends on whom you ask, but most people agree it comes down to one thing: communication. The energy landscape is changing rapidly. In addition to increasing demand, there's more renewable power like large-scale solar and wind coming online – which are often far from urban areas and are available intermittently. There's also small-scale solar on building rooftops – which means energy consumers are becoming energy producers. There will also be plug-in electric cars, which need to draw power from grid.

To manage all this, utilities and grid operators need more information than they have. And that's where meters come in. But as Kurt Yeager of the Galvin Electricity Initiative describes, it's a huge networking challenge – and a huge market opportunity.

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A number of companies have jumped into the smart grid market as a result, from Silicon Valley start ups to international corporations. As Eric Miller, the Chief Solutions Officer for Trilliant describes, managing the information flow in smart grid will be the biggest challenge.

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Other smart grid companies are banking on the consumer market. Google is developing the PowerMeter, an online tool that tracks home energy use. They're partnering with GE, who is positioned to work with utilities, with its meter technology, and with consumers, with smart appliances, as Sunil Sharan, the Director of the Smart Grid Initiative explains.

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More on the smart grid: check out the Smart Grid at Home radio report and a slideshow of grid technology, old and new.


Reporter's Notes: Big Solar on the Ballot

 

David Gorn by David Gorn  October 3rd, 2008
37.8721, -122.258

Proposition 7 is one of the green propositions – in more ways than one.

The amount of cash that's being spent on this so-called Big Solar initiative is prodigious. It is one of the most expensive measures on the ballot. On one side you have a little more than $5 million to pass the proposition, all from Peter Sperling, the son of the man who created the online college, The University of Phoenix. And on the other side, three utility companies have pitched in well over $27 million to defeat it.

Interestingly, the companies that stand to profit from this initiative – the many small companies that make up most of the solar and wind energy industry – are actually against the bill.

PG&E and Southern California Edison are the two biggest donors, chipping in more than $13 million apiece. To see a list of spenders, for and against proposition 7, click here.

For more on the debate, check out this discussion from KQED's Forum.


Listen to the Big Solar on the Ballot radio report online.


A fishy odyssey through the delta

 

Ann Dickinson by Ann Dickinson  July 7th, 2008
37.825718, -121.596422

Talk about a wild ride.

Every year, millions of fish make a strange and harrowing detour through the Skinner Fish Facility, part of the State Water Project's facilities in the Delta.

In my last post, I wrote about my visit to the Banks Pumping Plant, whose giant pumps slurp water from the Delta to help quench California's thirst. As the volumes of water are sucked up, both resident and migrating fish come along for the ride. The Skinner Facility, in operation since 1968, was built to protect fish from being killed at the pumps–an effort that sadly is not as successful as one would hope (more on that below).

I was amazed to learn there is a whole art and science to fish screens, which range from physical barriers–called positive barriers–like perforated plates or wire mesh, to behavioral barriers like sound, light, or other stimuli aimed at keeping fish away. Well-designed screens minimize both entrainment (fish being pulled into the pump or diversion) and impingement (fish being trapped or injured against the screen itself due to water velocity).

Both physical and behavioral barriers are used at the Skinner Facility. Fish being pulled toward the pumps first encounter a trash rack that diverts many bigger fish, along with floating debris. Next, fish encounter a large, v-shaped array of metal louvers. The louvers create turbulence that functions as a behavioral signal, encouraging the fish to swim away into bypass pipes that function, as our tour guide put it, like "a big vacuum system."

From the bypass pipes fish travel to another set of louvers and pipes, concentrating them into a smaller volume of water, and then into holding tanks in a nearby warehouse. Giant, suspended cone-shaped buckets are used to periodically sample the fish, which are identified, counted, and measured. Some 90 species turn up in the facility, including Chinook salmon, steelhead, white sturgeon, and delta smelt. (I asked our guide if delta smelt really do smell like cucumbers. He confirmed it. In fact, when a school of smelt comes through–an event that has become rare–the warehouse smells "like a salad.") When enough fish have been collected, they are loaded into trucks and driven back to the Delta.

Here's the rub. Many fish caught in the pull of the pumps are lost to predation before even reaching the screening facility. Then, the facility does not effectively screen fish smaller than about 1.5 inches, meaning that littler, less powerful species and juveniles are still vulnerable to the pumps. For the fish that make it to the holding tanks, the process is such a trauma–with big and little fish squashed together in the tanks, buckets, and trucks–it's no surprise there are casualties; in fact, the delicate delta smelt often do not survive. And even for fish that make it through the entire process and out the other end, there's a final, fatal hurdle: the trunks routinely dump salvaged fish at the same locations, where more predators have learned to cluster for a free lunch.

Scientists agree that the loss of fish at the huge state pumps–and other pumps and intake pipes throughout the Delta–is a major contributor to plummeting populations. How much water we use makes a difference: The higher the export rates, the more fish are entrained. There also is broad consensus that more state-of-the-art fish screening facilities are needed. That could come with a hefty price tag. But with our fish disappearing, can we afford not to invest in their survival?

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