If you've been researching solar panels, you've probably come across the term MCS. But what does it actually mean, and why should it matter when you're choosing an installer?

What is MCS?

MCS stands for Microgeneration Certification Scheme. It's an industry-led quality assurance scheme that certifies both products and installers in the microgeneration sector — which includes solar panels, battery storage, heat pumps, and small wind turbines.

To become MCS certified, an installer must demonstrate that they have the right qualifications, use approved products, follow best-practice installation standards, and carry appropriate insurance. Certification is assessed and renewed annually.

Why does MCS certification matter?

There are two main reasons MCS certification matters to you as a homeowner or business owner.

First, it's a mark of quality. An MCS-certified installer has been independently assessed and meets a defined standard. It's not a self-declared badge — it's verified.

Second, and perhaps more importantly, MCS certification is a legal requirement to access the Smart Export Guarantee (SEG). The SEG is the government scheme that pays you for excess electricity you export to the grid. Without an MCS-certified installation, you simply cannot register for it — meaning you lose out on payments for every unit your panels generate that you don't use yourself.

Does MCS certification cover products too?

Yes. As well as certifying installers, MCS maintains a list of approved products. Solar panels, inverters, and battery systems must appear on the MCS product database to be used in a certified installation. This protects you from substandard equipment being installed on your property.

What about grants and finance?

Most solar finance schemes, green mortgages, and local authority grant schemes also require MCS certification as a condition of eligibility. If you're planning to finance your solar installation or apply for any kind of subsidy, MCS certification from your installer is almost certainly required.