High-Tech Solar Inverter Industry in European Hands

11 Jan. 2012 by

Solarplaza’s Top 10 on most efficient string inverters (<5kW) contains seven companies from Germany. The other three companies in this Top 10 are Austrian, Dutch and Japanese. This is a big difference to the solar PV module industry which nowadays is dominated essentially by Chinese companies, according to Solarplaza’s Top 10s.

The German company Steca Solar produces the string inverter StecaGrid 3600 which has a highest maximum efficiency of 98.6%, a difference of 0.8% compared to the number two on the list. Maximum efficiency is reached under the best possible conditions. This means the StecaGrid 3600 inverter can convert 98.6% at max of all direct current PV system output into the alternating current electricity used in homes. These string inverters are also used for small commercial grid and off-grid electrical networks. In practice, the real-time inverter efficiency is dependent on various conditions and circumstances. Therefore, the most efficient inverter doesn’t always mean the ‘best’ inverter.

Steca makes use of the Coolcept technology. The advantages of this technology are the small heat dissipation, longer service life and maximum yields. The number two in the inverter efficiency Top 10 is Sunways ' module NT5000, with 97.8%. This week the Chinese company LDK Solar Germany Holding GmbH has made an investment of 33% in Sunways. LDK Solar has also announced its intention to buy all the remaining outstanding shares in the company. The public takeover is expected to be announced end January 2012. More Chinese companies have started activities in the inverter business.

The solar inverter market leader in terms of market share, SMA, is positioned just under the best ten companies. The difference in the claimed maximum efficiency between Steca and SMA is 1.6% - in absolute terms a small difference.  In practice, the energy losses through inverters should be considered over the 10-15 years' lifetime and efficiency in real-life conditions.

See the full Top 10 list of the world’s most efficient string inverters (<5KW) and the link to the complete Top 25 here:

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