Page 12 - North American Clean Energy May/June 2019 Issue

wind power
Contingency Planning
The clever solution before serious incidents strike
by Hans Christian Sørensen
FOR MANY WIND ENERGY STAKEHOLDERS,
serious incidents involving res, arc ashes, and lightning
are not a part of everyday life. is would explain why many companies are not prepared for these situations when they rear their ugly heads. For energy companies and OEM’s, these are sensitive matters that a ect many aspects of business, including reputation, safety, and reliability. Evidence shows that being prepared for such crises will signi cantly speed up the recovery process.
Fire and Arc Flash
One of the most signi cant risks in the wind energy industry
is an arc ash. An arc ash is the light and heat produced as part of an arc fault, a type of electrical discharge resulting
from a low-impedance connection (through air to ground, or another voltage phase in an electrical system) which can exceed temperatures of 35,000°F. Fires resulting from arc ashes cause direct and secondary damage to a Wind Turbine Generator (WTG). A direct loss results when equipment is burned out to the point where metal surfaces are damaged beyond repair.
Secondary damage, otherwise known as contamination,
is widespread damage in the WTG that is caused by residual chemicals after arc ashes incite re, explosion, or other combustion events. Equipment may also have light to moderate melting damage on the cabling, plastic pipes, and insulation, yet still be restorable. In many cases concerning WTGs, the
secondary damage may be up to 10-15 times more severe than the direct damage when measured in replacement costs.
Soot that covers the surface is the
most visible damage. It consists mostly
of carbon, which is conductive. Note:
It is important to not power up carbon contaminated equipment, as short circuits will more than likely occur, adding further damage to the equipment. What
is not immediately visible on the surface of equipment is the acid that develops
in the combustion of materials – this
acid is the worst type of contamination after a re or arc ash. Depending on the contamination and humidity levels, it will become visible in the form of corrosion.
During the combustion of various materials, several di erent acids may develop. Polyvinyl Chloride (PVC) is
a material that is used in almost every installation. e most common corrosive acid that develops during the combustion of PVC is known as hydrochloric acid (HCI). is acid is part of the warm smoke, which condenses on cold surfaces.
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