DIY Solar or MCS?

scottishsteve85

I've always had an interest in solar PV, actually, technology in general, but with the recent introduction of plug-in solar, it really got me interested.

Could I install a system that would generate electricity to power my home, potentially store some of it in a battery like the EcoFlow Stream 5000, and ultimately save money on my energy bills?

My idea was to DIY the parts I could. I enjoy the learning, the challenge, and I have pretty high standards when it comes to workmanship. So, for the avoidance of doubt, I would always want a qualified electrician (who happens to be one of my best mates!) involved in the electrical design, cable runs, connections, testing and certification.

While I want to do the bulk of the labour myself, this isn't about cutting corners. It's about doing something myself, maintaining the appropriate standards and saving money on labour costs. Quite simply, without those savings, I probably couldn't afford to install solar in the first place.

The further I dug into solar, the more I realised that my circumstances were probably better suited to a traditional solar PV installation rather than a plug-in system.

It was all going rather well until... I discovered MCS, and later Flexi-Orb.

Most energy suppliers require MCS or equivalent certification before they'll pay you for exporting electricity. I'm aware that Octopus offers a non-MCS route, but it got me thinking.

Why should MCS certification be the deciding factor in whether a homeowner can access export tariffs?

Surely the DNO's primary concern is that any generation equipment connected to its network is safe, compliant and won't cause problems for the electricity network?

I appreciate that DNO approval and installation certification serve different purposes, but why couldn't we have a system where a homeowner obtains independent certification demonstrating that their installation meets all the necessary technical and safety standards, receives the appropriate DNO approval, and can then access the wider export tariff market?

For example, a homeowner could design a system with professional input, have a qualified electrician approve the electrical design, purchase a K2 mounting system with a manufacturer-approved mounting design, an ENA type-tested inverter, appropriate quality cabling and an EcoFlow or Sigenergy battery system.

They could undertake the mechanical installation and cable routing themselves, have the installation independently inspected, and employ a qualified electrician to complete the electrical connections, testing and certification.

They could then obtain the necessary DNO approval or acknowledgement.

And yet, despite all that, they could still find themselves excluded from many export tariffs simply because the installation wasn't completed through an MCS or equivalent accredited installer.

Why are MCS and equivalent installer certification schemes effectively the gatekeepers?

I've looked into the consumer protection argument too, including workmanship warranties and insurance-backed guarantees. I can absolutely see the value in those protections, particularly for people paying an installer to undertake the entire job.

But those protections aren't unconditional guarantees, and installers can cease trading. Personally, I'm quite happy to accept responsibility for workmanship on my own installation, provided it's independently verified as safe and compliant.

I'm not suggesting that homeowners should be allowed to bypass electrical regulations, structural requirements, DNO procedures or safety standards. Quite the opposite. I just want an accessible route to showing that I've met them.

If the purpose of MCS is to ensure solar installations meet recognised standards, why can't a homeowner demonstrate compliance with those same standards through an independent assessment?

If an installation meets the required standards, surely the question should be whether it's compliant, rather than who physically installed it?

And here's another comparison I've been thinking about.

Car owners can replace their own brake pads, a component absolutely critical to the safety of the vehicle, its occupants and other road users. An hour later, that same car could be travelling down a motorway at 70 mph. When the car goes for an MOT, the tester doesn't ask, "Where's the certificate from the person who installed your brake pads?" The vehicle is assessed against a prescribed set of safety standards. It either meets those standards or it doesn't.

Nobody is suggesting that brakes aren't safety-critical, or that an incorrectly installed set of brakes couldn't have catastrophic consequences. Of course they could.

Yet we allow people to undertake that work themselves and hold them responsible for ensuring their vehicle is safe. The safety standards don't change depending on who fitted the parts.

So why can't we apply a similar principle to domestic solar PV, where a homeowner can take responsibility for the work they've undertaken, have the installation professionally assessed against the relevant standards and obtain the necessary DNO approval?

I'm interested to hear what others think, particularly anyone who's undertaken a DIY installation, qualified electricians or MCS installers.

Am I missing something fundamental here, or is there a genuine argument for changing how domestic solar installations are certified in the UK?

sheenas

You seems to have written a book. Thing are moving away from the export model towards battery solutions. If you want the panels on the roof then you’re going to need to pay for scaffolding so that is around £1500.. flat roof or patios are cheaper alternatives.
There is nothing stopping you using the ecoflow 5000 with roof mounted panels. Either way at the moment you need it installing by an electrician..

Scot_39

Plug in solar has to be approved as well as I believe a complete system.

No swapping of components - AFAIK even fairly standard things that a diy person - no DC or AC cable extensions - probably wouldnt think twice about.

There's a link in the plug in thread to approved kits.

But some have done diy panel systems and connected them up to spurs in garages etc.

Is the Octopus work around for DIY - or merely for those without their old MCS certificates but a professional install - e.g. when bought a house with panels already professionally installed ?

prowla

To export electricity you have to have an export certificate.

They can't have anybody just connecting kit to the network.

Part of the concern is that anything which exports must be certain to stop pushing out power in the event of a power cut.

This is to protect the workforce, who may be coming into contact with the cables whilst doing repairs.

Therefore the gate is the certification path and exactly who only approved kits may be used and without modification.

I don't know what precisely happens if they find the lines are still live if the substation has been switched off; presumably time would be lost in further identifying and isolating rogue power feeding onto them.

HalfFull

I've done some DIY projects. There are some checks and hoops to jump through, and some things to understand for your own and the safety of others, but everything you ned to know and do is documented somewhere, if you have the time to do some reading . But not insurmountable, and helps if you have some suitably qualified acquaintances for some steps.

We are about 90% self consumed so never bothered with export, but may do that exercise next year on the Octopus scheme.

For a money saving forum, this is the most compelling bit, once you realise you don't need MCS, while others are looking at 7-10 year paybacks, my last project broke even in 30 days this summer (though I admit I'll probably not replicate that return again)

scottishsteve85

https://forums.moneysavingexpert.com/discussion/comment/82182107#Comment_82182107

Theres no suggesting of having 'just anyone' connect it. The plan is always to have it designed by an eletrician, terminated and the G99 application done.

I just dont need someone to physically attach hooks & rails or run cables or purchase the kit for me and i'd far rather do it myself.

scottishsteve85

The thing I'm suggesting is that from a connection and electrical perspective I'm fully happy to get a qualified electricion to do the work so I'd ensure to eliminate any of those risks.

If a homeowners system is safe and can be inspected and proven to be safe (happy to do so) why is there no pathway for that?

scottishsteve85

https://forums.moneysavingexpert.com/discussion/comment/82182014#Comment_82182014

Thankfully I have a very large scaffolding tower to hand so thats £1500 saved 😂

I think a qualified electrician should always be involved. The thing is, beyond that, installing hooks and rails (I already have an approved design from K2) fitting the panels and running the cables etc (discussed with the elecrician).

The issue isnt compromising safety, I'm all for it. The issue I have is that someone can have a perfectly safe system installed yet is still locked out of energy tariffs because there is no mechanism allowing it. That becomes more about who installed it (MCS) rather than what and whether its safe.

sheenas

https://forums.moneysavingexpert.com/discussion/comment/82182196#Comment_82182196

I think the point is that you have have to consider the investment verses reward element. A MCS system opens up the Smart Export Guarantee (SEG) for sure. If a 4kW system saves you £500 in electric bills and earns you £350 in export payments each year, it will pay for itself in 6-8 years. While a solar with battery solution can around 3-4 years. The latter solution is the route I have chosen. 4 solar panels and an Ecoflow 5000 battery. Smidge under £2,500 all in. Tidy install on a flat roof and Sparky made £150 for 30 mins work. My estimates are around 3.5-4 year payback. The MCS route would have been £4500 upwards installed and a 7-8 payback based on my usage.

prowla

https://forums.moneysavingexpert.com/discussion/comment/82182185#Comment_82182185

Sure, but it has to cover the not so savvy too.