Yes, you can consume energy on site, provided that the wind turbine can connect into the site distribution board. Sometimes this is not possible because the wind turbine site is geographically separate from the site distribution board, or the cable run would be excessively long.
Whenever possible the preferred option would be to connect into the site distribution board because this allows you to offset imported energy which significantly increases the income from the wind turbine.
It is important to remember that electricity flows like water and will always follow the easiest route to the nearest load; this means that all of the site owner’s loads (i.e. lighting, sockets, machinery, air conditioners etc.) that connect to the same distribution board would be supplied firstly by the wind turbine, and only once all of these loads had been satisfied would any surplus energy from the wind turbine flow backwards through the incoming supply cables, either to the next nearest distribution board on the site, or out through the export meter to the grid.
Also, because the electricity produced by the wind turbine is fully grid-synchronised, it will mix seamlessly with grid-imported electricity. This means that if the wind turbine cannot supply all of the site’s loads, then all of the electricity from the wind turbine would go towards the loads and any deficit would be seamlessly imported from the grid.
Equally, if the wind turbine was supplying all of the local loads but then a reduction in the wind speed caused the output to suddenly drop, then the grid would instantly supply more to make up the deficit. From a consumers point of view the source of the electricity would be unknown; it could be from the wind turbine, the grid or a combination of both.
In the situation where the on-site loads far exceed what the wind turbine could ever produce, then all of the electricity generated by the wind turbine would be consumed on site. For example, if a wind turbine with a maximum power output of 500 kW was connected to a site that had a baseload (i.e. the minimum load 24/7) of 1 MW, then 100% of the energy generated by the wind turbine would be consumed on site.
Financially this would be a good arrangement because the price paid for importing electricity from the grid is typically 12 p/kWh (varies between 8 – 16 p/kWh depending on the import tariff), so if the amount of import could be reduced, for every kWh it was reduced by the site owner would save 12 p. If you compare this saving of 12 p/kWh to an export price of 6.5 p/kWh, you can see that offsetting on-site loads is worth almost double the value of exporting the electricity.
If it isn’t physically possible to connect to the onsite distribution board because the cable length would be too long, or the generation system is significantly larger than the onsite loads, or there simply isn’t an on-site distribution board, then the system would be directly connected to the grid via a dedicated grid connection.
Are you considering a wind turbine project?
The first step to develop any wind power site is to conduct a full Wind Turbine Feasibility Study.