"Be as low tech as you can" is the surprising motto of the heads of solar energy start-up company ZenithSolar.
Roy Segev, the company's CEO and co-founder, reached the conclusion that in order to produce the most efficient solar energy product, it would be necessary to use the simplest means. According to him, it worked. ZenithSolar, founded in December 2005, is currently conducting a first commercial pilot project at Kibbutz Yavneh. After regulatory procedures are completed and after a few technical adjustments, the project is slated, within two weeks, to provide all of the settlement's power and hot water needs, and on top of that to supply power to the national grid.
ZenithSolar is in the field of concentrated power voltaic cells (CPV) technology. This means concentrating the sun's rays by means of a dish onto photovoltaic cells. ZenithSolar is not the only company that uses this technology, but Segev's aim in setting up the company was to find a solution to the problems from which solar energy has so far suffered: low efficiency; high costs; and dependence on subsidies to survive economically.
According to him, over a period of a year a square meter of sunlight yields the same amount of energy as a barrel and a quarter of gasoline. In other words, the sun is a meager energy source, and the challenge is to bring it to high levels of utilization. He says that the measured efficiency of photovoltaic cells in Israel is 10-12%. This is in the case of silicon-based cells and their derivatives (not thin film cells that use only a small amount of silicon but according to Segev reach efficiency levels of 6-8%). It is not enough to test cell efficiency in laboratory conditions, because in the field the cells lose efficiency as they become hot.
ZenithSolar's managers claim that their company has the know-how to reach efficiency levels of 70%. They say that the Z20, an installation measuring 20 square meters, utilizes 21% of the sunlight hitting it to produce electricity and 49% to produce thermal energy, altogether reaching efficiency of 70%. This is in Israeli conditions of 2,000 hours of sunlight annually. Over a year, this amounts to production of nine megawatts of electricity and 22 megawatts of thermal energy, or 31 megawatts altogether.
Learning from Luz's experience
Not only that, but on the critical measure of cost, the company claims to have a substantial advantage over existing technologies. According to Segev, every ten square meters of photovoltaic cells cost $6,000 per installed kilowatt at peak output, yielding the same as one and a quarter barrels of gasoline over a year. "Without government subsidies, production like this is not even close to being economic," says Segev. He himself is not prepared to be dependent on subsidies, because in the past he worked at Luz. Luz, it will be recalled, set up thermo-solar fields that supply power in California to this day, and it did well as long as the US government gave it a following wind. However, when all prices fell at the beginning of the 1990s, the US government gave it the cold shoulder, and the company collapsed. Segev wants to be dependent solely on the company's competitiveness. He therefore aspires to bring to market a product that is economically viable from day one. "We emerged from economics, not physics," he explains.
The company, which was born as an idea in December 2005 and was incorporated after eighteen months by Segev and Professor David Fairman of Sde Boker, one of the world's foremost brains in solar energy, has so far raised $2 million in seed funding and $8 million in a first round. Segev describes the company's investors as "professional investors". Energy investment wizard Neil Auerbach founder of private equity fund Hudson Clean Energy and formerly responsible for alternative energy investment at Goldman Sachs serves as a consultant to the company. He is also believed to be invested in it. The company is currently launching a commercial pilot with a production capacity of 300 kilowatt-peak. Among ZenithSolar's founders is also Professor Ezri Tarazi, who set up and runs the masters program in design at Bezalel Art School, and is another former Luz person.
What is the secret of the technological leadership that the company claims? There are two. The first is that ZenithSolar's system produces two kinds of energy at the same time: thermal and electric. According to Segev there are no commercial systems like this in the world, apart from co-generation systems that produce energy and heat from gasoline or diesel-based turbines and do not belong to the category of green energy.
The second secret is the system's cheapness and the low cost of producing energy from it. Segev estimates that the company's system will cost $29,500 on average. It will have available in Israel an average of 2,000 hours of sunlight a year. Each such installation will produce electricity at a cost of NIS 2 per kilowatt-hour and thermal energy at a cost of NIS 0.25 per kilowatt-hour. Segev puts the payback period of investment in the system at five years. "Capitalized over fifteen years, at the costs described, we can produce a kilowatt-hour at a cost of $0.09, which is a competitive price even against conventional power production and against thermal energy," he says.
Simple components
The system is not yet at 70% efficiency, but it certainly can claim a world record for utilization, set on January 13 this year when it was demonstrated at the German technology institute Fraunhofer Institute for Solar Energy Systems and reached utilization of 41.1%.
To explain how the low costs are achieved, one has to return to the low-tech concept. ZenithSolar's main investment is in a plastic injection molding machine, the largest of its kind in the Middle East. It produces a frame for the dish with a precision that enables precise solar tracking. Solar tracking is critical for efficient operation of the installation. Tracking to a precision within fractions of a degree ensures that the sun will be in the center of the dish at any given moment. To produce frames for all the dishes in the solar filed at Kibbutz Yavneh required less than a single day's work by the plastic injection molding factory. The entire installation is made of simple components: plastic as the basis, to which mirrors are attached with metal fasteners. The only sophisticated component is the receiver at the center of the dish, which is software-based, but even the software is simple. The receiver is about the size of a ceramic tile.
For domestic buildings too
Segev and Tarazi believe that the field at Kibbutz Yavneh will replace the use of 40 tonnes of fuel a year, and that it will produce 150 megawatt hours for the grid. To maximize the use of ZenithSolar's installations, it makes sense to place them close to the customer in or beside the settlement, close to the hotel or hospital, and so on.
"Mounted on our receivers are cells that are used in satellites. They are far more efficient than silicon cells, and are based on geramnium. The great thing about the receiver is that it concentrates the sun onto a small area, producing much higher efficiency," explains the company's COO Dr. Ilan Lozovsky.
So far, no solar energy solutions have been found for existing residential buildings (as opposed to new ones in the planning and construction stages), but one of the interesting things about ZenithSolar's product is that it can be installed on buildings up of to three stories, and can supply most of the residents' electricity needs and all their heating and air conditioning needs. However, the air conditioners have to be adapted for use with ZenithSolar's technology.
The claims for ZenithSolar are not just technological. The system has also won praise for its aesthetic side. A model installation will be presented at the triennial of the Cooper-Hewitt National Design Museum in New York in the Spring of 2010. Warming, cheap, and beautiful too.
Published by Globes [online], Israel business news - www.globes.co.il - on April 20, 2009
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