Adding black start capabilities to a power generating station is not a typical retrofit. It means adding an alternate, new way of doing something — like starting offline gas turbines — to the method the power station has relied upon since its original construction.
And that can be tricky. I’ll explain why.
Many of the power stations now being equipped with the capability to start from black are peaking plants that help the grid meet demand during the summer months and other high-demand periods. The best time to add black start capabilities — a process that can take up to 10 months depending on lead times for equipment and materials — is, therefore, during cooler, off-peak months.
But not even a peaking plant can afford to shut down completely for that length of time. The challenge is to keep downtime to a minimum, reducing outages to hours instead of days or weeks.
So how do experts in black start design and construction do it?
Hour-by-Hour Scheduling
Firms that specialize in these facilities invest design and planning time to fully engineer the project and understand precisely what work must be performed before, during and after an outage. Work schedules are then mapped down to the hour, with outages reserved for only the work that can’t be completed during normal operations.
Location, Location, Location
A new system for restarting electric power generation turbines must tie into existing power plant operations. Primary tie-ins are electrical, mechanical and control systems interfaces.
A smart and efficient design will locate the components in places that minimize the distance between them and the power station systems to which they connect. The closer the two electrical systems are to each other physically, for example, the less high-voltage cable that must installed, resulting in savings of both installation time and money.
Minimizing tie-in time is also critical because most of today’s black start systems run primarily on fuel oil, which is often the back-up fuel a dual-fuel plant relies on when natural gas is unavailable. Fuel oil, in other words, is unavailable when that piping is being tied together. Minimizing tie-in time reduces the plant’s potential risk exposure.
The Bottom Line?
A successful black start project is one where construction crews can install the new system quickly and safely — and one that requires down-to-the-hour planning and an extra dose of communication.