How much auxiliary energy should a wind project allow for?

The short answer

Use the actual auxiliary equipment and its duty rather than assuming that the turbine powers every supporting function whenever needed. Controls, communications, actuators or cabinet services may have different supply and operating requirements. Their presence and consumption are configuration-specific. Calculate energy over time, and separately confirm that required functions still have a suitable power source during calm conditions, loss of the grid or a turbine shutdown.

Separate continuous and event-based consumption

Illustrative annual budget: an assumed continuous 20 W load uses 0.020 × 8,760 = 175.2 kWh/year. A separate assumed 200 W device operating for 50 hours uses 10 kWh/year. The combined example is 185.2 kWh, not a statement about any MARSTON product.

Do not assume a standby function runs continuously, or that an event-driven actuator has zero annual consumption. Obtain the relevant duty information for the actual configuration.

Energy and availability answer different questions

Check	What it establishes
Annual kWh	Effect on the defined net-energy boundary
Required instantaneous power	Supply capability during an event
Supply during a fault or outage	Whether the intended function remains available

A small annual-energy allowance can still support an operationally important function. Conversely, a large battery-energy figure does not establish the correct auxiliary voltage or control interface.

Make the quotation boundary explicit

Identify which auxiliary supplies are included with the turbine/control package and which must be supplied by the site. Record the measurement point used for net production so that externally supplied consumption is neither omitted nor deducted twice.

For MARSTON enquiries, confirm the equipment actually proposed. Historical cabinet descriptions do not prove that all current models include identical monitoring, actuators or backup supplies.

Avoid hidden consumption across the meter

If some controls draw power from a separate site supply, a turbine-output meter may not include their consumption. A net benefit calculation should show that external supply explicitly. Conversely, when an equipment output figure already includes an auxiliary load, deducting it again understates the same result. Keep a short boundary note beside the energy budget.