Commercial Solar Grid Connection Explained

Your site already has a connection to the local distribution network, rated for a certain amount of power. Adding solar means the site can also push electricity back onto the network. The network operator assesses whether the local cables, transformers and substations can accept that flow without breaching voltage or thermal limits. This assessment governs how much you are allowed to export.

For a modest rooftop system that mostly feeds on-site demand, the connection is usually straightforward. As system size rises, or where the local network is already busy, the available headroom becomes the deciding factor in how big a system you can connect.

If the network cannot accept your full potential export, you have two common paths. You can accept an export limit, where the system is set to send no more than an agreed amount back to the grid, using export limitation equipment. This lets you install a larger system for self-consumption while capping what leaves the site. Alternatively you can apply for a higher export capacity, which may trigger network reinforcement.

Export limitation is often the pragmatic answer for a business that uses most of its generation on site anyway, because the value is in displacing bought electricity rather than in selling surplus.

Where you need to export more than the local network can currently take, the operator may require reinforcement, such as upgrading a transformer or cable. This adds cost and time, and the connection offer will set out what is needed and who pays. Grid connection is a distinct question from the formal DNO application paperwork, though the two run together: connection capacity is the physical and technical constraint, while the application is the process for securing it.

For larger projects, checking likely connection capacity early can save a redesign later. It is better to know the constraint before finalising panel numbers.