Energyland

  • Game board by Illustration Farm
  • At Idaho National Laboratory, fuel for next-gen nuclear reactors is blasted with radiation, then cooled in an adjacent canal.
  • The algae collection at the University of Texas at Austin contains over 3 000 strains, which it frequently provides to biofuel researchers.
  • The MIT Cogeneration Project uses waste heat to generate electrical and thermal power.
Date:1 September 2010 Tags:, , , , , , , , , , ,

The road to clean energy is full of enticing opportunities – and perilous pitfalls. Picking the best path requires avoiding both starry-eyed hype and cynical fatalism. In this special report, PM debunks 10 of the most pernicious myths that could derail our progress.
By Elizabeth Svoboda

Myth No 1
Nuclear power isn’t a safe solution
In a recent US poll, nearly three-quarters of respondents expressed concern about potential accidents at nuclear power plants. Some opinion-makers have encouraged this trepidation: Steven Cohen, executive director of Columbia University’s Earth Institute, has called nuclear power “dangerous, complicated and politically controversial”.

During the first six decades of the nuclear age, however, fewer than 100 people have died as a result of nuclear power plant accidents.

Comparing modern nuclear plants with Chernobyl – the Ukrainian reactor that directly caused 56 deaths after a 1986 meltdown – is like comparing World War I fighter planes with the F/A-18. Newer nuclear plants, including the fast reactor now being developed at Idaho National Laboratory (INL), contain multiple autoshutoff mechanisms that reduce the odds of a meltdown exponentially – even in a worst-case scenario, such as an industrial accident or a terrorist attack. In addition, some have the ability to burn spent fuel rods, a convenient way to reuse nuclear waste instead of burying it for thousands of years.

Power sources such as coal and petroleum might seem safer than nuclear, but statistically they’re a lot deadlier. Coal mining kills several hundred people annually – mainly from heart damage and black lung disease, but also through devastating accidents, including explosions.

The sublethal effects of coal-power generation are also greater. “The amount of radiation put out by a coal plant far exceeds that of a nuclear power plant, even if you use scrubbers,” says Gerald E Marsh, a retired nuclear physicist who worked at Argonne National Laboratory. Particulate pollution from coal plants causes nearly 24 000 people a year to die prematurely from diseases such as lung cancer. Petroleum production also has safety and environmental risks, as demonstrated by the recent oil spill in the Gulf of Mexico.

INL nuclear lab’s deputy associate director, Kathryn McCarthy, thinks the industry can overcome its stigma. “It’s been a long time since Chernobyl and Three Mile Island,” McCarthy says, “and people are willing to reconsider the benefits of nuclear energy.” Nuclear plants emit only a tiny fraction of the carbon dioxide that coal plants do, and a few hundred nuclear facilities could potentially supply nearly all the energy the United States needs, reducing dependence on fossil fuels.

Myth No 2
Sure, maize ethanol is problematic – but switchgrass will save the day
The renewable energy movement’s darling for years, maizebased ethanol, has fallen out of favour for not making good on its promises of efficiency. Cellulosic ethanol – made from plant parts containing cellulose, such as grass and wood chips – seems poised to be the next star of the biofuel circuit. Its fuel crops require less fertiliser and use water more efficiently than maize. Plus, it can be created from waste products such as lawn clippings and tree branches.

But the upstart fuel will have to surmount sizable environmental and financial challenges. For one, it takes a tremendous amount of cellulose to produce ethanol in industrial quantities, which means a lot of land would still have to be devoted to fuel production. “The low density of the supply is a problem,” says Tad Patzek, a chemical engineer at the University of Texas. “To supply fuel to, say, the (San Francisco) Bay Area, you would need an area of switchgrass that is larger than all the agricultural land in California.”

And since cellulose is tough and fibrous, it requires heavyduty enzymatic decomposition processes to convert the plant matter into simple sugars that can be fermented into ethanol. These amounts of energy and are so pricey that a study in Bioresource Technology last year concluded that cellulosic ethanol won’t be competitive with petrol unless oil prices remain above $90 a barrel.

When that day comes, cellulosic could play a modest role in boosting supplies. And that’s worth more research today. But hopes that grass clippings will end our oil habit are overblown.

Ethanol emissions
According to a USDA life-cycle analysis, maize-based ethanol results in only a 20 per cent reduction in greenhouse gases relative to petrol. Cellulosic ethanol, in contrast, can achieve an 86 per cent reduction. It also requires only a quarter of the irrigation and fertilisation of row crops.

Myth No 3
Wind power is far too unreliable
First things first: wind power is intermittent; it’s just the nature of, well, nature. Due largely to the unpredictability of weather, turbines typically generate only about one-fifth of the energy they’d make if they actually ran 24/7. That said, energy planners have devised tactics to make wind power reliable.

One of the best ways to balance wind’s now-it’s-here-now-it’s-not quality is to construct grid connections between different regions. “We have monitoring systems that show us the winds as they proceed through different regions,” says George Van Hoesen, a managing partner at Global Green Building, an environmental consulting firm in Missouri. “We understand the currents and the flows.” Armed with this data and computer models, utilities can plan to shunt surplus power generated in one part of the country to areas that need it.

Science supports that strategy. A recent Stanford University study found that, when many wind farms are interconnected through the grid, about one-third of the electricity they generate can be counted on as a reliable source of around-the-clock power. (Less reliable wind energy sources can still be put to profitable use – to charge batteries for electric vehicles or produce hydrogen transportation fuel, for example.) And a University of Delaware study concluded that an offshore grid, connecting wind generators along the East Coast, could provide relatively stable output. Over a simulated five-year period, power never petered out entirely. “In the eastern United States, storms typically move along the coast,” says Willett Kempton, a lead author. “Thus, if offshore wind farms are connected by a transmission line, the power from the whole set is more consistent.”

Still, even the savviest grid connections have limits. The most optimistic projections calculate that wind can supply about 30 per cent of the planet’s electricity by 2030, so power sources such as nuclear, hydropower and solar will be needed as supplements. It might not be a great idea to place all bets on wind, but with the latest turbines able to generate pollution-free electricity at less than 40 cents per kilowatt-hour, it wouldn’t be smart to let wind go by the wayside while we invest in less sustainable fuels, either.

Myth No 4
Algae grows anywhere, so turning it into fuel will be cheap

It grows in ponds. It grows in streambeds. It even grows in your sink if you forget to scrub it. Algae is so omnipresent that startups such as Solix and Aurora Biofuels make it easy to envisage the microscopic green organisms meeting all the transportation needs of the planet at cents a litre for eternity.

But in-depth experimentation suggests that algae-fuel supremacy isn’t going to come easy. The strains of algae that work best for biodiesel are specialised lipid-producers that won’t thrive in just any circumstances. Algae-fuel researchers have tried growing the organisms in open ponds for decades, but the water often becomes contaminated with native algae, which quickly outcompete lipid-rich strains.

Closed bioreactors come with their own set of issues. “Even relatively inexpensive ones are going to add dramatically to capital costs,” says biochemical engineer John Sheehan, who worked on a stalled US National Renewable Energy Laboratory algae-fuel project. Plus, as bioreactors scale up, decreased surface-area-to-volume ratios often make it difficult for all the algae to get the solar energy they need, making them subpar for fuel production. Algae fuel may eventually take off, but it’s going to require a lot of testing, technical tweaking and expensive infrastructure to get there.

Myth No 5
Tidal power is a lost cause
As the sea level rises and falls, tides roll in and out twice a day, unfailingly. It’s hard to imagine a more predictable source of power. Yet tidal power’s showcase project in the United States, an array of underwater turbines anchored in the East River in New York City, hasn’t exactly been an overnight success. Two initial turbine designs flopped over the course of several years; blades and hubs snapped off because they weren’t strong enough to withstand the nearconstant force of the water.

Still, it’s too soon to give up on tidal power. The Rance tidal power plant in France has an installed capacity of 240 megawatts and has been in continuous operation for more than 40 years. Its axial-flow turbines are capable of operating as the water flows in both directions. And after several false starts, Verdant Power’s array operated for more than 9 000 hours in a 2008 trial, delivering 70 mega-watt-hours of energy to two end-users. This summer, the startup Natural Currents Energy Services plans to install proprietary turbines in two projects that will power marinas in New Jersey. “We’re talking about the entire ocean moving in one direction or another,” says Global Green Building’s Van Hoesen. “The sheer volume of energy makes it very attractive.”

Myth No 6
Clean coal can clear the skies of emissions
The phrase “clean coal” has recently entered the argot of energy planners and political candidates, implying that coal – in addition to supplying cheap, reliable base-load power – can be an environmentally friendly energy source. US Energy Secretary Steven Chu endorsed this viewpoint, announcing that the country’s Department of Energy would spend more than R20 billion to fund facilities that capture carbon dioxide from coal and stash it underground, reducing air pollution.

Unfortunately, clean, cheap coal is still a pipe dream. According to the National Energy Technology Laboratory, the cost of capturing carbon dioxide from coal plants and storing it in underground locations will increase the price of electricity from 30 to 100 per cent, depending on the method used. In addition, coal-fired power plants that perform sequestration burn one-quarter more coal than their unimproved counterparts to produce the same amount of electricity. That means more destructive mining operations, more CO2 emissions from transportation and more coal ash, the toxic byproduct of all coal-burning. “We have implemented some technologies that are cleaning the air,” says Mary Fox, an environmental scientist at Johns Hopkins University, “but that has led to a displacement of some of those waste products into solid waste.”

That displacement can lead to serious health consequences, as in the case of the coal-ash slurry that broke through a dike in Tennessee, sullying water supplies with mercury, lead and arsenic. Disposing of toxic ash responsibly could cost in excess of R30 billion annually, so efforts to pass more stringent government controls on solid waste have stalled. For better or worse, coal produces roughly half of the USA’s electricity, so technology for next-gen facilities is worth developing. But no breakthrough will cause the nearly 500 plants already operating in the US to magically clean up their act.

Coal casualties
Abt Associates found that US power plant pollution causes more than 38 200 heart attacks and 554 000 asthma attacks per year. The health cost of such pollution is R1,3 trillion annually.

Myth No 7
The risk of earthquakes makes deep geothermal unrealistic
Horror stories about deep geothermal drilling began circulating after a series of earthquakes shook the Swiss city of Basel during 2006. In fact, a scientific analysis concluded that a geothermal system likely set off the quakes, causing a similar project in California to be scuttled.

But deep geothermal, also called enhanced geothermal, has distinct advantages, too. Because it taps into the hot, dry bedrock kilometres below the surface, drilling could be widespread. A recent study led by MIT identified 200 000 exajoules of extractable deep geothermal energy, which could supply more than 2 000 times the USA’s annual energy use.

Odds are very low that enhanced geothermal power would ever cause a quake on the scale of, say, the recent shake-up in Chile, says Colin Williams, a geophysicist on the US Geological Survey earthquake hazards team. Even the largest quake in Basel, a 3,4 on the Richter scale, caused only minimal damage. And experts say that, if enhanced geothermal plants are constructed farther away from cities – in rural areas of Europe or the western US, for example – any induced seismicity would have even less effect on the human population. “Should we say the technology is dead?” says scientist Domenico Giardini, who analysed Basel. “Absolutely not.”

Unlike ordinary geothermal power generation, which involves harvesting energy from steam beds that form up to a few thousand feet below the surface, deep geothermal involves injecting water into hot bedrock roughly 3 miles down. The high pressure and the flow rate fracture the rock, and after flowing through the cracks hot water is drawn back up through a second drill hole. If the fracturing rock intersects an active fault line, minor earthquakes can result.

Myth No 8
Shale can provide energy independence
Shale oil hasn’t received much attention since the oil crisis of the 1970s. But today, proponents are once again pointing out that there are more than a trillion barrels of oil locked in the shale deposits of Colorado, Utah and Wyoming, more than all the proven crudeoil reserves on the planet. That would be enough to meet current US oil demand for an entire century.

The problem, then and now, lies in the financial and ecological costs of extracting the oil. Shale oil naturally occurs in the form of kerogens, solid, waxy substances with a texture similar to that of LipIce. Once the kerogens are heated to over 260 degrees, they exude hydrocarbons, which must be treated with hydrogen so they can be processed into usable fuel – a highly energyintensive process that releases large amounts of CO2.

And just to get at these kerogens, energy companies would have to mine and process millions of tons of shale from the earth – leaving behind toxic heavy metals and sulphates that could seep into groundwater. “There’s a water contamination issue,” says Olayinka Ogunsola, an engineer at the US Department of Energy. “There’s also a land reclamation issue – (mining) would create a lot of disturbance in the area.” Mining and processing shale require vast amounts of water, too – producing 2,5 million barrels of shale oil a day would require 400 million to 1 200 million litres of water daily. That might be the biggest deal breaker of all for parched western states.

So whereas extracting the oil from US shale may be technically possible, the scale of such an enterprise, as measured in acres and natural resources, may never make it worthwhile.

Oil shales were deposited in the US in two large lakes millions of years ago, during the Eocene epoch. They now lie beneath wide swathes of present-day Colorado, Utah and Wyoming.

Myth No 9
Solar energy will never pay for itself
Solar panels are certainly expensive – Terry Moss of Allpower in Port Elizabeth quotes R24 a watt for a typical installation – but eventually, you’re destined to end up on the positive side of the equation.

According to the California Solar Electric Company, it may take from eight to 12 years to recoup in saved energy costs the investment put into a basic residential photovoltaic (PV) solar array. But this estimate varies greatly depending on factors like the size of the array and the amount of sunlight that hits it, and advances in PV technology continue to shorten the payback period.

“The shortest payback with new thin-film cells is less than a year,” says Burr Zimmerman, a chemical engineer and co-founder of the Kairos Institute, which ushers new technologies into the marketplace. Thanks to ramped-up production and cheaper materials, upfront costs continue to plummet as well; the price of solar cells has fallen fifteenfold since 1980.

After a solar array’s initial payback period, you start to reap some serious financial benefits. Assuming solar cells have an average life expectancy of 30 years, more than half of the power solar cells generate ends up being free. “There are maintenance issues,” Zimmerman says, but over time, “solar cells are definitely making you money.”

Solar stats
A photovoltaic cell needs to operate for about four years to recoup the energy that went into manufacturing it. With the newest thin-film solar cells, you can recover your investment in less than a year.

Myth No 10
We have to drill our way out of the energy dilemma
Discussions of America’s energy future tend to focus on increasing production. There’s no question that more mining and drilling can modestly increase overall. However, as recent accidents have shown, at a steep human and environmental cost. Renewable sources show promise but will take time and money to implement. “I’m a big advocate of renewables, but I’m also an advocate of common sense,” says David Hughes, a fellow at the Post Carbon Institute. “Radical conservation has to be number one.”

The US Energy Information Administration projects that, under existing policies, total energy consumption will grow by 14 per cent by 2035. That doesn’t have to be the case. A report published last year by McKinsey & Company calculates that widespread deployment of energy-efficiency measures can decrease consumption by 23 per cent of projected demand by 2020. What’s more, such measures would result in R9,3 trillion in savings, far more than the R4 trillion investment required to implement them. The corresponding reduction of greenhouse gas emissions would be like taking an entire US fleet of passenger vehicles off the road.

Personal actions certainly help. A 2008 trial by Baltimore Gas and Electric showed that customers who had smart meters reduced their energy use by up to 37 per cent during peak periods. And semiconductor-powered light-emitting diodes (LEDs) have the potential to reduce lighting-related energy consumption to one-sixth of its current level. The DOE estimates the US could be well on our way to that goal by 2025, cutting lighting energy use by 29 per cent – and collectively saving R1 trillion.

There’s also ample room for industry to streamline its energy consumption. If plants such as oil refineries and steel mills convert exhaust heat into electricity via cogeneration, they could reap an extra 100 gigawatts, reducing CO2 emissions by about 400 million tons. Energy saved, it turns out, is the cheapest new source.

5 Home energy myths
Myth: Wood stoves are dirty and polluting.
Truth: Old wood stoves spewed 20 to 40 grams of particulates an hour. New wood and pellet stoves emit less than 1. And they replace heating oil with a renewable fuel that grows almost anywhere.

Myth: Old single-pane windows are bad. Replace them.
Truth: A properly operating single-pane wood window with weatherstripping and a storm window has an R-value of about 2. That’s roughly equal to a doublepane wood window’s R-value of 1,61 to 2,04.

Myth: Coasting to a stop in neutral saves petrol.
Truth:A car actually consumes more fuel coasting in neutral than it does in gear. That’s because, without any throttle input, an engaged engine reduces the flow of fuel to the injectors.

Myth: Cordless lawnmowers are zero-impact.
Truth:Although cleaner than twostroke petrol engines, cordless mowers rely on carbon-intensive electricity. LPG-burning lawnmowers emit up to 70 per cent fewer hydrocarbons than small petrol engines.

Myth: Driving with the a/c off and windows open saves fuel.
Truth:It takes 1,5 to 6 kW to run the aircon, so when driving at city speeds, turning it off does save energy. But on a highway, open windows can signi. cantly increase drag.

Latest Issue :

May / June 2021