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Extending Existing Solar Arrays

April 18, 2021

For many businesses that installed solar panels between 2010 – 2015 it was something of a gamble.

Solar was far from a proven technology in the UK, and the cost of the installation was very high.
As a result, many businesses did not necessarily realise the full potential of their roof or land as they chose to invest based upon a budget, the ‘FIT bands’ and their appetite for risk.
Fast forward to 2021 and solar is now very much a mature technology; as of December 2020 over 55 million solar panels have been installed across nearly 1 million homes and thousands of businesses.
Additionally, advances in technology and manufacturing processes have seen the cost of solar fall by as much as 30% since 2010.
With all of this in mind, some businesses may now start to wonder whether it is worth extending their existing system to cover more of their electricity demand.

So, is it possible?

Firstly, it’s important to note that an existing solar PV system is not an immediate barrier to putting up more solar.
Providing you have the space, and we can work with the grid it is entirely possible to add more solar to an existing system.
The equipment need not be the same as originally installed so, for the most part, it would be treated as a brand new installation.

I have a Feed-in Tariff -

will I lose it?

This question is likely to be the main cause of concern for businesses who might like to extend their solar system.
The Feed-in Tariff (or FIT, for short) was a lucrative subsidy payment that was guaranteed for 20/25 years for the early adopters of the technology, and in almost all cases helped underpin the economics of the initial investment; depending on the size of the system, it’s likely that losing this income stream would negate entirely the economic viability of the extension.
The good news is that extending the solar array will not jeopardise your existing FIT agreement. Whilst the extension will not qualify for the FIT, the original system will continue as it used to.

How will it work?

The system will be developed, designed and installed in exactly the same manner as the original system – with all of the benefits of experience the past 10 years has given us.
It may however mean that additional work is needed at the point of connection into your electrical infrastructure as it is likely that the ability to connect the original system was based on that system size at the time.
Critically, one of two things will then happen – 
1. The extension would be connected before your existing generation meter. This means that the power generated by the extension would flow through the generation meter that is currently installed. However, because the extension would be ineligible for FIT payments whereas the original system might be, the owner of the asset would be expected to declare the Total Installed Capacity (TIC) of the extension to their FIT licensee and they would simply pro-rata the generation meter reading between the eligible and ineligible systems.
2. The extension would be connected after your existing generation meter. This means that the power generated by the extension would not flow through the generation meter that is currently installed and no further action would be needed by the owner of the asset.

Extension rules and additional capacity

6.75. Any extension to an accredited FIT installation that is commissioned on or after 15 January 2016 is not eligible for FIT payments. This applies to both generation and export payments.

6.76. If FIT licensees are informed that an installation has been extended and the commissioning date of this extension means that it is ineligible for payments, then they should contact the CFR team to inform them of this change.

6.77. If an accredited installation and an ineligible installation share the same meter then it is possible to pro-rate the meter readings taken from this meter.