STMicroelectronics has introduced its latest-generation high-efficiency cool bypass switches family for photovoltaic modules, enabling an even higher percentage of harvested energy to reach end users and further reducing the cost per Watt of renewable energy. ST’s bypass devices have been designed so that they can be integrated directly in the photovoltaic module, reducing both installation complexity and the cost for consumers.
These devices look to combine efficient power switching and intelligent control in a single chip to compensate for the variable effects of hotspots and shadows on the solar panel surface. The new devices can save up to 1% of the energy produced and normally lost through conventional bypass diodes; in a 1MWp solar array farm this loss could provide the total annual electricity consumption of two average European households.
ST’s cool bypass devices feature new technology and control techniques that have been designed to minimise energy losses in all operating modes, by ensuring the integrated power switch has ultra-low leakage current when turned off and very low voltage drop when turned on. Thanks to the reduced power losses, a further advantage of these devices is a reduction in typical operating temperature, leading to increased reliability and longer lifetime. Solar installations can achieve a lifespan of 25 years using this device.
The SPV1512 and SPV1520 cool bypass switches are rated for operation up to 12 V and 20 V respectively. Other voltage options (up to 120 V) will be introduced in late 2012 and early 2013 in industry-standard D2PAK and TO-220AC packages.
The SPV1512 is available in a small 5 x 6 x 0.75mm-high VFQFPN package, which enables the bypass circuitry to be laminated on the back of each solar panel and this simplifies design and installation by eliminating large numbers of junction boxes and interconnects, and can reduce the cost of each panel by around 5%.
Electricity generation using solar panels (solar photovoltaic) is the fastest growing renewable energy technology of the past decade according to the International Energy Authority (IEA), which states that total installed capacity is now around 65 Gigawatts.
The IEA’s 2012 Energy Technology Perspectives calls for ongoing investment in solar photovoltaic to reduce system costs and encourage growth in capacity. This investment is needed to help cut more than 50% of energy-related CO2 emissions by 2050, compared to 2009 levels, if global temperature rise is to be kept within 2 °C.
“As installed photovoltaic capacity continues to rise, efficient and cost-effective power solutions such as our cool bypass switches will make an increasingly significant contribution to saving energy and reducing greenhouse gas emissions,” said Matteo Lo Presti, General Manager of ST’s Industrial and Power Conversion Division.