The heat is on

The sun is so hidden by the clouds of the grey and threatening winter sky that it’s hard to believe anyone even remembers its warmth. But in the offices of Solel in the Beit Shemesh industrial zone, the forecast is downright balmy. In fact, the future’s so bright, as the 1980s song goes, they’ve gotta wear shades.

It is here that engineers of a technology once thought impossible to commercialize have turned sunshine into big business. Sales at the solar power company jumped from a meager $4 million in 2005 to more than $25 million in 2006 – and they’re about to make a huge leap forward in 2007, nearing the $100 million ark. A facility that until recently housed 80 employees is now packed with 240.

Contracts to upgrade the world’s largest solar energy fields, in the Mojave Desert in California, have made this sleepy spot in the wooded hills outside Jerusalem a truly sun-drenched locale.

It’s a far cry from where the company was 15 years ago. Then, it was just a bunch of engineers from Israel’s first solar success story, Luz, which built the celebrated fields in California that Solel is now overhauling. Luz crashed in 1991 as conventional energy prices dropped and American subsidies for solar research and electricity fell through. It seemed then that the promise of solar power had fizzled.

‘When we first started, people thought we were crazy,’ Solel’s chief technology officer, Eli Mandelberg, says now. They don’t seem so crazy anymore.

In the past few years, Solel has changed its strategy from just selling its technology to also selling the electricity that its technology produces; that is, it now builds and operates ready-to-go ‘turn-key’ power stations. The company has also expanded its reach by entering into a partnership with a Spanish firm to carry out projects in that country, which is currently undergoing a solar revolution of its own.

Solel isn’t the only Israeli firm to enjoy solar success these days, it’s just the largest. Most local solar energy companies deal mainly in installing small systems from components made by large international companies – although one of these small companies, SolarPower, won a contract last year to supply a rural energy roject in Ethiopia.

OUTSIDE ISRAEL, too, solar power is literally one of the hottest issues in the energy industry. Electricity production is increasing on an almost daily basis, and billions of dollars per year are being spent to create
even more.

Companies around the world are cashing in on an energy source that is nearly perfect: clean, renewable, safe and – the cost of the equipment notwithstanding – free. Yet solar power is not new. Based on a phenomenon first recognized in the 1800s, and taken up quite seriously after the oil crunch of the early 1970s, the idea of harnessing the power of the sun to create electricity has been kicked around before. So why is it taking off now? A number of factors are combining in the sun’s favor.

One is the increasing environmental awareness of developed countries. Although they are not the overriding issue – financial considerations still reign – concerns over the long-term effects of burning fossil fuels for energy are playing a larger role in national energy policy than ever before. Decades of alarm over pollution have moved the subject from a pet project of the ‘green’ lobby to the mainstream consciousness. Numerous countries have passed laws requiring that alternative energy sources be used to provide at least a small percentage of total electrical output in the next few years.

‘Relying solely on coal for the world’s energy needs would be an ecological disaster. I don’t think there’s even an argument over that anymore,’ says Michael Epstein, head of the solar research center at the Weizmann Institute of Science in Rehovot.

Another factor is the relatively high cost of conventional energy. As in the case of the fuel scare three decades ago, continuous volatility in the price of oil and natural gas – and the fact that much of these resources are controlled by unstable regimes – have led researchers to seek reliable alternative sources for energy. And in countries that are still developing, small solar-powered electricity systems are an easy, cheap way of providing power to areas in which the costs of creating new conventional power plants, or extending the existing power grids, would be prohibitive.

But one of the most influential factors in the sudden resurgence of interest in solar power is the technological advancement that has brought its cost down to earth.

Solel, for example, having refined the old solar thermal technology that Luz pioneered in the mid-1980s, has produced a system that is 40 percent to 50 percent more efficient than its predecessor.

‘We took what Luz did and improved it, updated it, to the point that today we can sell solar energy at a price that is competitive,’ says Mandelberg.

Again, Solel is not alone. Progress on this front, according to Prof. David Faiman of the National Solar Energy Center, ‘requires two things: lots of desert, and sophisticated scientific research facilities in that desert. Israel happens to have both.’

THEY RESIDE in the Negev, where the desert’s unique features make it a natural choice for solar research. The National Solar Energy Center, which is part of the Jacob Blaustein Institute for Desert Research at Ben-Gurion University’s Sde Boker campus, is taking advantage of these conditions by conducting experiments that are helping several companies, including Solel and leading foreign firms, make solar power cheaper than ever.

Faiman and his colleagues in Sde Boker have something else, too, and it didn’t come from Mother Nature: their own advanced solar power system, in the form of what looks like a huge satellite dish. The 10-meter-wide dish houses dozens of angled mirrors that focus the Negev’s already potent sunlight onto a silicon photovoltaic (PV) solar cell, which converts the light into electricity. What results, says the excited scientist, is the energy equivalent of up to a thousand suns.

‘What this means is that you’re actually reducing the cost of the unit by a thousand times,’ Faiman exclaims.

In any PV system, the greatest expense comes from the complex silicon panels where photons collide with
electrons and produce an electric current (other kinds of film are being created as an alternative to silicon,  but they are also expensive, unique materials). The Sde Boker dish circumvents the cost problem by using only a single PV cell and letting mirrors – very high in precision but much, much cheaper than silicon – do the bulk of the work.

Faiman explains the significance: ‘Suppose a PV system costs in the order of $8,000 per kilowatt hour produced. About $3,000 of that would be what the builder takes for his workers, etc. You’re left with about $5,000 for the system. Now, of that $5,000, $4,000 is the cost of the panel.’ So, if the solar panel is a thousand times more efficient, ‘you’ve effectively reduced its cost to zero.’

The rest of the apparatus is a relatively simple construct from concrete, steel tubing, hydraulic shocks, glass and electrical wiring. On a commercial scale, it becomes a heavy-duty power plant that doesn’t pollute, yet produces electricity at roughly the same cost as conventional power plants. Even better, there’s no additional cost for the fuel. That – sunlight – is free.

THERE IS another, slightly different system built by scientists at the Weizmann Institute of Science. Yet another option is being touted by Dov Raviv, who has turned his attention to solar energy after a long career in aerospace technology during which he developed the Arrow missile and the Shavit satellite. What all these projects have in common is the ability to create affordable electricity in a way that could make tiny Israel into a huge player in the world’s energy market.

‘If you have solar energy, you can create hydrogen, and ethanol, and provide alternatives for all aspects of the entire energy situation. The possibilities are tremendous… As soon as we can show that we have the systems, China and India are wide open to us,’ Raviv says.

The ‘solar economy’ (cycle of energy production) is the opposite of the fossil fuel economies upon which our industrialized world is based. Solar power stations require a higher initial investment than conventional power stations – which in turn contributes to the relatively higher initial cost of electricity – but afterward, the costs of producing electricity are much lower because sunlight costs nothing. There are also the hidden costs of burning fossil fuels, such as pollution, that are usually overlooked because they don’t appear on your monthly electric bill.

‘In Israel, we are paying about 10 cents per kilowatt hour of electricity, and it is costing the electric company something like five cents per kWh to generate it,’ Faiman explains. ‘With a solar power station, once you pay for the infrastructure, the only cost is the operation and maintenance, which we estimate at half a cent per kWh.’

Within a few years, Faiman and his colleagues promise, the total cost of solar power will be equal to or less than conventional power. There is, however, a snag. Unlike countries such as Germany, Japan, Canada and the US, Israel has offered very little in the way of support for solar electricity. Subsidies and tax credits for solar energy or land allocation for a major solar power station have been minuscule to nonexistent, comparatively.

At a time when government investment in other countries has increased, Epstein says, funding for research and development in Israel has decreased over the past several years. It’s a mistake, he says.

‘Israel doesn’t have coal, it doesn’t have gas, it doesn’t have wind energy. All it has is sun,’ notes the Weizmann scientist. ‘Once the projects get started and the costs start to drop, the potential is huge.’

Turning results from the laboratory into large-scale power stations takes investments that universities and start-up companies can’t afford to make. It also requires a sizable plot of land.

‘In our country, the problem is much more a lack of land than an issue of technology,’ says Epstein.

With so much of the Negev left uninhabited, that shouldn’t be a problem. The army retains rights over huge swaths of the desert for firing zones, but there is still a vast amount of available land that the military doesn’t need to control.

Despite the apparent ease of finding suitable land, plans for a solar power plant that would provide electricity to thousands of homes in the Negev are still far from fruition, thanks to years of foot-dragging and reversals by the government.

‘You go to the government and tell them what you could do with a little help, and how do they react? They
say, ‘Oh, very nice.’ But more than that, nothing,’ complains Raviv, who is pushing the state to make a significant investment in solar power. ‘The government makes statements about solar energy being at that top of its priorities, but those statements are not translated into anything practical.’

With the country’s electricity demands set to double in the next 30 years, the government will have to build a lot of power stations of one kind or another. Raviv believes choosing solar power is no less than an existential priority.

‘The exorbitant price of fuels in the future will not allow Israel to exist,’ he insists. ‘Without a reasonable source of energy, you can’t survive these days. Solar power is the only solution that can ensure the existence of the country.’

EVEN IF that outlook is a bit too bleak, the government’s disinterest is odd for another reason: It has already shown great confidence in the potential of solar energy in the past, having mandated the use of solar water heaters. The simple units, based on a 1950s design, are ubiquitous. Some 95% of households have them, providing between 2% and 3% of the country’s electricity each year. No other country in the world uses solar power to heat its water to this extent.

Could it be that the government lacks faith in the ability of today’s technology to do more than keep our
showers warm?

‘You can’t say that the technology isn’t ready,’ Mandelberg says, a bit defiantly. ‘Not only is the technology ready, it has proven itself. When I tell you that Solel has improved the efficiency of Luz’s solar fields by up to 50%, it is not just talk. If we hadn’t already proven that, we wouldn’t have gotten the contract to upgrade all those solar fields [in California].’

That’s in the Mojave. What would it take to recreate such a bold venture here? To generate enough electricity to compete with a conventional power plant would require a good deal of space – about 10 square kilometers, by Faiman’s estimation. But that’s another advantage, he says, from a security perspective.

‘Look, if someone drops a bomb on your [conventional] power plant, there goes your power plant. But it would take you a hell of a lot of bombs’ to destroy a solar power field. ‘If you were to destroy part of it, the
unharmed section would still be able to produce power.’

Building rows upon rows of mirrors to harness the sun’s rays could even, he says, be a boon for tourism and become a kind of trademark image for Israel.

‘You might think that having vast solar power fields would ruin the landscape,’ says Faiman. ‘But, you know, many years ago, people in Holland complained that all the windmills were ruining the landscape. Now those old windmills are one of the things that make Holland beautiful.’

(BOX) Manipulating the sun

If you’ve ever held a magnifying glass over a piece of paper on a bright summer day, you can appreciate the
potential of concentrated solar energy. What scientists have had to do to realize some of that potential, though, has turned that simple phenomenon into a complicated operation that now entails p-n junction diodes, depletion regions and the Czochralski process.

Different approaches to capturing and transforming solar energy have led to a number of amazing

The simplest, called a hot box, goes back 240 years – when a Swiss scientist who took notice of the
greenhouse effect, in which a glass enclosure traps heat from the sun, started building contraptions to do
just that. By the end of the 19th century, crude systems for heating water had been developed; today their descendants, not much more complex than the originals, can be found on rooftops all over the country (and the world). The same concept can be used to make low-tech devices offering a cheap, safe cooking method for the world’s poorest people.

That the sun can produce heat seems obvious. That it can be used to produce electricity is another matter,
and requires a whole lot more engineering. There are essentially two ways to go about it. One way exploits
the heat of the sun’s rays, while the other exploits its light.

The Israeli company Luz developed one of the world’s most stunning examples of solar thermal power by
utilizing parabolic troughs. These curved mirrors reflect and amplify the sun’s heat, directing it onto a pipe carrying a liquid that is capable of reaching and maintaining very high temperatures. The liquid flows to a facility where its heat turns a turbine, and the turbine generates electricity. With rows upon rows of troughs in a large solar field – and with improvements to the technology from Beit Shemesh-based Solel significantly increasing its efficiency – the method can produce enough electricity to power hundreds of thousands of homes.

‘So far,’ notes Prof. David Faiman of the National Solar Energy Center in Sde Boker, ‘this approach has proved the most economically viable.’

A similar idea is to use flat mirrors arrayed in a circle or a semi-circle to reflect sunlight onto a central tower, where the heat can be used to create electricity. This is the approach used by the Weizmann Institute of Science in Rehovot.

An alternative to solar thermal energy is using the sun’s light to manipulate a metal’s molecules.

As their name implies, photovoltaic (PV) systems turn light into electricity. Photons in sunlight come
zooming through the atmosphere and smacking into an absorbent material, knocking electrons loose and
setting off a reaction that gets a direct current (DC) flowing. An inverter turns this into alternating current (AC), which can then be directed into your home to power your appliances.

PV technology is highly adaptable. Since a series of breakthroughs in the mid-1950s that allowed satellites
to use solar panels to power themselves in space, PV systems have been used for a wide variety of
applications – from solar-powered wristwatches to solar-powered factories and villages.

In Israel, PV panels power remote Beduin encampments, small schools and cash-strapped clinics, street lights and even irrigation systems. The traffic probe readers that monitor the Trans-Israel Highway and its
automated billing system are powered by PV panels; the system is the first of its kind in the world.

A major downside of PV technology is its reliance on silicon. Although the wafers of semiconductive
material used in solar panels are incredibly thin, they still amount to a huge expense because the material is scarce and very expensive to create. Competition with the computer industry for access to silicon has been fierce; both fields are growing at a tremendous rate, and production of silicon is limited.

Researchers around the world, including numerous teams here, are developing alternative materials that can be made into multi-layered, thin-film composites and used instead of silicon. Other avenues include
light-absorbing dyes and even more complicated technologies such as photoelectrochemical cells,
polymer solar cells and nanocrystal solar cells. None of these has proven yet that it can replace silicon.
And in the meantime, silicon systems are being designed with greater efficiency to reduce the amount of the material needed.

Taking that idea a giant step further, the contraption that Faiman and his colleagues set up in Sde Boker
uses only one silicon solar cell. Like the solar thermal systems, it uses mirrors to concentrate
sunlight – for its light in this case, not for its heat.

No matter which of these approaches is used, though, solar electricity is hampered by one obvious drawback: the sun only shines for half the day.

In theory, this is not as big of a problem as it seems. Peak energy demand time is during the day;
there is much less demand for electricity at night. Since a conventional power plant cannot just be shut
down after sundown, because it needs to be kept firing constantly – a huge waste of resources, alternative
energy proponents note – most of the electricity that a conventional power plant creates at night just goes
to waste. That’s why electricity costs much less at night than it does during the day. In that sense, a solar plant is much more efficient.

However, there is no denying that at least some power needs to be generated at night. To overcome their
inability to function after dark, solar power systems can be outfitted with supplementary power generators
fueled by coal or natural gas, if need be. The combination of the two would provide the efficiency of
solar power with the stability and on-demand production of conventional power.

(Another solution would be to add batteries to a solar power plant to store excess energy from the day for
use at night. At present, such storage solutions are impractical, but a commercial-level model may be ready
within a few years.)

For now, it seems that solar power is destined to augment, rather than replace, conventional
electricity. Even for those involved in solar power’s development, like Faiman, that’s not a bad scenario.

‘I think that, for now, one doesn’t want to replace conventional electricity,’ he says. ‘First of all, there is a tremendous amount of money invested in the infrastructure, and to simply junk that would be a major perturbation to any country’s economy.

‘Secondly, major international companies rely on these power plants to keep them in business, and if you were to threaten to put them out of business, you would generate a backlash and they would probably destroy you. What is necessary is for them to perceive solar power not as a threat, but as something that they themselves could eventually offer.’

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