In the quest to make solar power a mainstream electrical power generation source, improving photovoltaic cells’ efficiency has been the industry’s Holy Grail.

Improved efficiency of solar cells effectively drives down the overall price of solar power, since the only costs associated with the technology are for its manufacture, installation and maintenance; the fuel source, of course, is free and unlimited. However, the high costs of the technology—relative to the amount of power generated—have been the main thing keeping solar from being more cost--competitive in mainstream energy markets.

In simpler terms, by converting more sunlight into electricity, the technology can deliver more bang for the same buck.

Conversion efficiencies vary depending on the types of materials used, and new records are frequently achieved for different types of solar power technologies as researchers constantly strive to innovate the output.

Along those lines, a new record was announced this summer for cells using silicon wafers. The San Jose, Calif.-based SunPower Corp. has produced a full-scale solar cell with a sunlight-to-electricity conversion efficiency rate of 24.2 percent at its manufacturing plant in the Philippines.

While this may not seem like a particularly high number, and it isn’t, it is very close to the maximum efficiency of about 25 percent that some experts believe can be achieved for this type of solar cell. The company boasts it is a new world record for large area silicon wafers. The U.S. Department of Energy’s National Renewable Energy Lab validated the claim.

How long the record will last is open to speculation. According to Richard Swanson, SunPower founder and chief technology officer, “The company’s research and development and engineering teams have increased cell efficiency by a full four percentage points over the last five years while radically driving down manufacturing costs.”

Whether that pace will allow them—or one of the company’s competitors—to eke out greater efficiencies transcend the 25 percent ceiling, will be the question to ask going forward.