By Nina Chestney and Christoph Steitz
LONDON (Reuters) -Shares in Siemens Energy continued to fall on Monday following a record sell-off in shares last week that was triggered by major issues at the company's wind turbine division Siemens Gamesa.
Shares in Siemens Energy fell 5% to the bottom of Germany's blue-chip index, as several brokerages, including Citi and Jefferies, cut their ratings or price targets on the stock amid uncertainty over the size of the problem.
Here are details on the most pressing issues:
WHAT'S THE ACTUAL PROBLEM IN ONSHORE?
Most of the issues revolve around Siemens Gamesa's 108 gigawatt (GW) onshore turbine fleet, where the group has discovered quality issues in certain components, including rotor blades and bearings.
Siemens Energy said that 15%-30% of the fleet could be affected by the problems, which were exposed during a review which noted "abnormal vibration behaviour of some components" and unspecified problems around product design.
WHICH ONSHORE TURBINES ARE AFFECTED?
According to management, it's the more recent platforms, including the 5X model, where problems had already been communicated last year.
Bernstein also pointed to quality issues around the 4X platform.
Management said part of the challenge was to develop a statistical model that could translate fault rates into firm indications of how turbines are expected to perform over their life span of some 20 years.
ARE THERE SEPARATE ISSUES IN OFFSHORE?
Yes.
Siemens Energy has said that there is a separate set of challenges in the offshore turbine part of Siemens Gamesa's business, centred around a delay in the 30% ramp-up of production.
This includes slower-than-expected headcount addition, the delay of production site construction, including manufacturing halls, as well as supply-chain issues.
It also includes the lack of ramp-up quality of components, the group said, without being more specific, as well as higher than expected material costs.
WHAT'S AT STAKE FINANCIALLY?
Potentially billions.
Siemens Energy has said fixing the problems is expected to cost at least 1 billion euros ($1.1 billion), adding this was an initial assessment of an ongoing review and included estimates for repairwork.
Quality issues had already caused a charge of nearly half a billion euros at Siemens Gamesa earlier this year.
Bernstein reckons that this translates into the risk that nearly a third of Siemens Gamesa's service orderbook could yield no margins for the "rest of its life".
Analysts at Jefferies expect costs of 2 billion euros in their calculation, 1.75 billion for onshore and 250 million for offshore.
"In our valuation, as well as rectification costs, we assume that investors price in potential litigation, general execution risk and corporate uncertainty to take (Siemens Gamesa) to negative value of -5.6 billion euros," they wrote.
Siemens Energy's cost estimate does not include any mitigation measures, which could include damages the company may seek from component suppliers.
WHO ARE THE SUPPLIERS?
Siemens Energy declined to comment on its supplier structure for bearings and turbines, but said suppliers would be made part of the review.
The world's top wind turbine bearings makers include China's Dalian Metallurgical Bearing Group, NTN Corp and NSK Ltd in Japan, Switzerland's Liebherr-International AG, and Germany's Thyssenkrupp (ETR:TKAG), IMO and Schaeffler.
WHAT DOES SIEMENS GAMESA DO?
Siemens Gamesa is a global company based in Spain which manufactures onshore and offshore turbines for the wind industry and offers services to wind power developers globally, with key markets including Europe and the Americas.
The company has provided more than 132 GW of wind turbines as of the end of April this year to all global regions: 108 GW of onshore wind and 22 GW of offshore wind.
It generates revenue of 9.8 billion euros a year and has an order backlog worth 34.6 billion euros.
WHO DOES SIEMENS GAMESA SUPPLY WITH TURBINES?
Siemens Gamesa has provided wind turbines to some of the biggest power companies and oil and gas majors worldwide.
In March, it announced an order from Scottish Power Renewables in Britain to supply 95 turbines to the East Anglia 3 wind power project in the North Sea, with a total capacity of 1.4 GW.
This would be enough to power 1.3 million UK homes.
In May, it signed contracts with Spain's Repsol (BME:REP) for the supply of 40 onshore wind turbines which would provide power to around 160,000 homes in Spain.
It has also agreed to tie up with Poland's PGE Group and Denmark's Orsted to supply 107 wind turbines for the Baltica 2 offshore wind project in the Baltic Sea.
WHAT IS SIEMENS GAMESA DOING ABOUT THE AFFECTED TURBINES?
Siemens Gamesa said it has launched a technical review of the installed onshore fleet and product designs, and that the announcement last Thursday of quality problems include problems uncovered so far.
The company is now evaluating measures to fix the problems and figure out the associated costs.
The company said that it would be able to provide a more accurate estimate of the costs from the problems when it publishes its third-quarter results on Aug. 7, after a full analysis of the situation.
($1 = 0.9173 euros)