MCS — the Microgeneration Certification Scheme — is the UK's quality standard for small-scale renewable energy installations. It certifies both the products and the installers who fit them.
What is MCS?
For an installer to hold MCS certification, they must demonstrate technical competency, carry appropriate insurance, install to MCS standards, issue a formal installation certificate, and submit to periodic audits. Certification is renewed regularly — an installer certified five years ago is not automatically certified today. Verify any installer's current status at mcscertified.com/find-an-installer.
What the MCS installation certificate unlocks
1. Smart Export Guarantee (SEG) registration. No MCS = no SEG = no export payments. At 7–15p/kWh exported over 25 years, that's £2,000–£6,000 lost.
2. Government grant eligibility. Warm Homes Plan, ECO4 and related schemes all require MCS-certified installation.
3. Manufacturer warranty validity. A panel with a 25-year warranty fitted by a non-MCS contractor may be void — meaning you bear the cost of any component failure.
4. Mortgage and remortgage documentation. Solicitors and lenders increasingly ask for the MCS certificate as proof of compliant installation.
What it costs you to skip MCS
| Item | With MCS | Without MCS | Value of MCS |
|---|---|---|---|
| SEG earnings (10 years) | ~£800–£1,200 | £0 | £800–£1,200 |
| Grant eligibility | Eligible | Not eligible | Up to £12,000+ |
| Panel warranty | Valid (25 yr) | Potentially void | Repair/replace cost |
| Inverter warranty | Valid (10 yr) | Potentially void | £500–£1,500 |
| Property sale documentation | Clean | Complications likely | Delay/cost unknown |
The £1,000 discount is a false economy
MCS vs other certifications
- NICEIC — electrical installation quality and Part P self-certification. Complementary to MCS.
- TrustMark — business conduct, customer service and dispute resolution.
- RECC / HIES — consumer codes covering sales practice, deposit protection and aftercare.
A fully accredited installer holds MCS + NICEIC + TrustMark + HIES/RECC. Each accreditation is meaningful on its own; the combination is the gold standard.
Verify Alliant's MCS certification
Public record at mcscertified.com — Solar PV and Air Source Heat Pumps.
How to verify an installer's MCS status
- Go to mcscertified.com/find-an-installer
- Search by company name or postcode
- Confirm certification for the specific technology (Solar PV) and that it's current
You can also ask the installer for their MCS installer number directly. Any legitimate installer will provide it without hesitation.
Frequently asked questions
Can an MCS certificate be issued retroactively?
No. If a system was installed without MCS certification, it cannot subsequently be certified. The only routes are full reinstallation by an MCS installer or accepting the limitations — no SEG, no grants, potential warranty issues.
Is MCS the same as an MCS 'approved' product?
MCS certifies both products and installers. Both matter — a certified installer using uncertified products may not issue a valid certificate.
Does MCS apply to commercial solar?
MCS primarily covers domestic and small commercial installations up to 50 kWp. Larger commercial installs use different standards (G99 connection agreements, specific design requirements).
