Date: 19/09/2012

Cool bypass switches from STMicro for solar PV modules

STMicroelectronics has introduced efficient cool bypass switches family for solar photovoltaic modules. The SPV15 family of bypass devices can be integrated directly in the photovoltaic module, reducing both installation complexity and cost for consumers.

ST’s cool bypass devices 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 give the total annual electricity consumption of two average European households.

ST’s latest cool bypass devices feature new technology and control techniques that reduce energy losses in all operating modes, by ensuring the integrated power switch has low leakage current when turned off and very low voltage drop when turned on. 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. The SPV1512 is available in 5 x 6 x 0.75mm-high VFQFPN package, which enables the bypass circuitry to be laminated on the back of each solar panel. The SPV15 family features a forward voltage drop of 100mV and a leakage current of 10µA in reverse polarity.

Other voltage options (up to 120 V) to be introduced in late 2012 and early 2013 in industry-standard D2PAK and TO-220AC packages.

As per the International Energy Authority (IEA), the electricity generation using solar panels (solar photovoltaic) is growing faster and the total installed capacity is now around 65 Gigawatts. The IEA’s 2012 Energy Technology Perspectives (ETP 2012, www.iea.org/etp) calls for ongoing investment in solar photovoltaic to reduce system costs and encourage growth in capacity.

“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.

The SPV1512 and SPV1520 are currently sampling to lead customers, with full production planned for Q4 2012. Each unit is priced at $2.00 for volumes in the range of 1,000 pieces.