Pt 2 Why can’t I have the Inverter size I want even though it has to be export limited!

Summary

The video explains why export-limiting a solar system does not mean homeowners can install an inverter of any size. An export limit controls how much surplus electricity is sent to the grid, but it does not stop a large inverter from supplying household demand while the sun is shining.

The main concern is a sudden drop in solar generation. If clouds or a storm quickly reduce output, household demand that was being met by solar shifts to the grid almost instantly. The speaker says generators cannot respond as quickly: gas turbines and spinning reserve take time to increase output. This mismatch could contribute to voltage or frequency instability and, in severe cases, generator disconnections.

Western Australia’s Grid

The speaker highlights several characteristics of Western Australia’s grid:

• The South West Interconnected System (SWIS) is effectively standalone, without connections to other states that could provide support.
• Rooftop solar already exceeds peak demand at some times, limiting the network’s need for additional exports.
• Feed-in tariffs have fallen substantially from the earlier 47-cent rate, reflecting the reduced value of surplus daytime solar to the network.

Possible System Responses

The video discusses ways the system is adapting. Export limits and programs such as Emergency Solar Management help manage solar output, while smarter inverters allow more capacity under network controls. The speaker notes that single-phase systems can now have 10 kW inverters in some circumstances.

Batteries are presented as a potential part of the solution because they can supply stored power immediately, unlike generators that need time to respond. The state subsidy’s virtual power plant (VPP) requirement is described as one way to coordinate batteries and support grid stability.

Inverter Types

The speaker briefly contrasts inverter types. Grid-tied inverters are described as transformerless electronic devices, while off-grid systems often use transformer-based inverters. Selectronic and Victron are given as examples.

Key Takeaway

Export limiting does not remove the grid impact of a large inverter. When solar generation suddenly falls, household demand can still transfer to the grid faster than generators can react.

Video Type and Source

This is an explanatory follow-up video about inverter sizing and grid stability. It does not review a specific product or provide a step-by-step installation guide.

The presenter is an electrician who says he has 25 years of experience in the solar industry.