A version of this story originally appeared on NoCamels – Israeli Environment News
By Aya Ephrati
Solar cells and panels have been around for decades, but researchers are still trying to develop affordable double-sided panels – able to capture both direct and reflected sunlight.
bSolar, an Israel-based startup, says it has developed bifacial solar panels that can boost energy yield by up to 50 percent.
bSolar believes it has overcome the technical challenges that stand in the way of producing them cheaply and claims to offer a high-power, yet still affordable, alternative to traditional panels. The company’s panels were launched in April. Moshe Fink, CFO of bSolar, tells NoCamels that the company is currently the only one offering inexpensive bifacial panels.
How does it work?
According to Fink, the USSR space program first developed this technology for use on satellites. Until now these Photovoltaic (PV) cells were too expensive to produce for any commercial use. The scientists who founded bSolar, with previous experience in the solar panel industry, re-developed the production method and final product to minimize costs.
According to the company, bSolar’s cells can generate significantly more power per area compared to monofacial standard panels: ten to 30 percent higher energy yields (kWh) in standard applications like flat rooftops, and up to 50 percent higher energy yields (kWh) in vertical installations such as facades.
Yossi Koffman, co-founder and CEO, said that bSolar engineered special silicon wafers, the principle components of solar panels, that have the ability to capture reflected light on both their sides. This means that the backside of the solar cells can also absorb light. After sunlight is absorbed, electrical conductors, called electrodes, ferry the electricity out of the cell.
The key to double-sided absorption, in this case, is boron. This material is the ingredient that allows the silicon wafers to capture reflected light, and it is used to prevent the deterioration of electrodes when sunlight is converted to electricity. Traditionally, aluminum is used in wafers to absorb light, but it has a tendency to stress and break thinner silicon wafers.
This increases cost because thinner wafers are cheaper. Boron, on the other hand, does not cause this problem. Unfortunately boron is hard to source and hard to use in production, which can explain the fact that bifacial cells are not widely available in the industry.
Like other PV solar cells, bSolar’s panels can be placed almost anywhere – but not all locations will offer the same return. “If you have a roof painted white, preferably an industrial roof of a certain size, this is the ideal location,” Fink explains. “You can get 15 percent in reflected energy in a normal field, as opposed to 25 up to 30 percent on a flat rooftop.”
A sun-powered future
bSolar only manufactures the cells and partners with local companies that will market, sell and distribute its product. Panels are sold largely for industrial uses, but bSolar wants to expand into the private sector as well.
To date, all of the company’s panels are produced in Heilbronn, Germany, at a converted solar cell production plant. It will be at full capacity by the end of 2012, and Fink says the major advantage of producing there, rather than more cost-efficient countries like China, is “the know-how the people have there.”
bSolar plans to significantly expand its production over the course of 2012 and 2013 worldwide. “We are aiming for the entire world and we’re very limited in resources to decide where to invest the time. You have to find the right partners everywhere,” adds Fink. “So that’s the right strategy: to find the right partners – local partners – everywhere in the world.”
Shahar energy, an Israel-based company that offers sales and installation of photovoltaic systems, has partnered with bSolar to market their panels in Israel. bSolar’s other big market is Japan, where the company has won a 730 kWp project from Tokyo Solar Building Materials Corp (TSBM).
There are a number of other solar companies that are planning to incorporate bSolar’s bifacial cells, including Aleo Solar, asola Solarpower and Solar-Fabrik.
A growing number of believers?
Indirectly, bSolar competes with companies that produce high-efficiency solar cells. Fink declined to comment on the price of the bifacial cells, but said that it “is based on the amounts placed, the efficiency, the type of customer, the manufacturer…it’s not necessarily the market price of the solar cells.”
Currently, the main shareholder of the company is the Israeli venture capital fund Genesis Partners. They have contributed $3 million out of the $10 million bSolar has already raised.
“The typical investor,” says Fink, “has to be a risk taker interested in new technologies with an understanding in the solar market. We found that it’s very difficult for outsiders to see the differentiation of the product we offer. For some investors, the solar industry is just one thing and it’s too dangerous and too risky at the moment.”
The venture-backed bSolar was founded in 2007 and now employs 50 people in Israel and Germany. The company showcased its new solar cells at a trade show in Germany last month, and more recently at CleanTech 2012, the Tel-Aviv based green technology conference.
photo by h080