Solar panel survey visit - questions to ask.

Bod_1234

Had a local company quote, and also put out a few internet requests.  Got a visit tomorrow from of the companies.   I'm still undecided on battery.

Trying to think of questions to ask.  Some i have.

Make, model, specifications of panels and inverter.

Overview of installation 

Battery, yes/no

Battery does it cover supply during blackout.

Company: how many installs? Local references?

Any downsides to owning solar panels (not looking at moving and paying outright)

Krakkkers

What is max number of panels that will fit on your roof, where will they put the inverter, battery and generation meter.
do you want a diverter?

Mister_G

Probably the most important question at the moment is - When can you fit them!

A lot of installers are quoting very long lead times - like well into next year!

Astria

I assume you've done the basics: How much electric do you use per year? Compared with the solar output of nearby installations, how much will you save? This will tell you how fast the panels will pay you back.

Be careful of random internet companies, some will quote makes & models of certain panels but then supply others as they probably don't expect you to notice (they'll be on the roof after all) and then say something like "Oh, we didn't have those in stock"

How much energy do you use at night? This will typically be when the battery is in use. Pointless having it install if you are not going to use it. Also, don't let them quote you for a huge battery - only what you can effectively charge up throughout the day and use at night.

If your roof is damaged during installation then they'll fix it through insurance (typically) but if you have to have your roof repaired for any reason afterwards then what happens? It might or might not have been caused by the panels, and any repair cost could easily have thousands added to it if the panels needs to be removed and reinstalled.

[Deleted User]

This is probably not the right forum but there are a few important things that you should know.

You cannot install an array that produces more than 3.86kW of output (16amps/phase) without your DNOs prior approval.

If you want to claim export payments under the SEG Scheme then you would be well-advised to choose an installer that is MCS certified.

If you want ‘islanding’ in the event of a Grid failure then this requires either a Gateway such as that offered by Tesla, or a dedicated essential circuit which is totally isolated from the Grid. The DNO needs to approve a Gateway solution.

I sense from reading some other forums that some installers are adopting the mantra of ‘fit now and ask for DNO forgiveness later.’ This is a dangerous strategy for the homeowner as the responsibility for getting approval sits with the system owner. Late DNO applications can result in a refusal or the imposition of an export limitation whilst the local infrastructure is examined for its capability to accept the additional load.

[Deleted User]

[Deleted User] said:

I sense from reading some other forums that some installers are adopting the mantra of ‘fit now and ask for DNO forgiveness later.’ This is a dangerous strategy for the homeowner as the responsibility for getting approval sits with the system owner. Late DNO applications can result in a refusal or the imposition of an export limitation whilst the local infrastructure is examined for its capability to accept the additional load.

Even up to the point of requiring an upgraded connection or export agreement at substantial cost.

PennyForThem_2

I am interested in this too.  

OP: Which? has free guidance articles - google.  MCS - you can check the company's registration or lack thereof on their site https://mcscertified.com/

So SparkyGrad and / or Dolor - DNO is not utility company but the infrastructure company - i.e. in SE Wales Western Power Distribution.  Are you saying I should assure myself that the MCS company I may go with must do this before installing panels?

[Deleted User]

PennyForThem_2 said:

I am interested in this too.  

OP: Which? has free guidance articles - google.  MCS - you can check the company's registration or lack thereof on their site https://mcscertified.com/

So SparkyGrad and / or Dolor - DNO is not utility company but the infrastructure company - i.e. in SE Wales Western Power Distribution.  Are you saying I should assure myself that the MCS company I may go with must do this before installing panels?

You should use an MCS-certified installer and they should be doing the paperwork on your behalf.

Things to watch out for are companies that offer you a 6kWp system (or anything over 16A/ph) and don't know to do an application beforehand, or who offer a gateway solution that they can't verify is approved by the DNO.

A properly certified installer should be aware of all these things.

MWT

Astria said:

How much energy do you use at night? This will typically be when the battery is in use. Pointless having it install if you are not going to use it. Also, don't let them quote you for a huge battery - only what you can effectively charge up throughout the day and use at night.

There are other factors to consider when sizing a battery as you might want to use an off-peak tariff overnight to charge the battery to minimize grid use in the peak period for example...

Especially over December/January when your chances of actually covering even the house load during the daylight hours will be slim, and the prospects for putting much into the battery, almost non-existent...

[Deleted User]

PennyForThem_2 said:

I am interested in this too.  

OP: Which? has free guidance articles - google.  MCS - you can check the company's registration or lack thereof on their site https://mcscertified.com/

So SparkyGrad and / or Dolor - DNO is not utility company but the infrastructure company - i.e. in SE Wales Western Power Distribution.  Are you saying I should assure myself that the MCS company I may go with must do this before installing panels?

It depends on the power of the array. You can put 100kWp of panels on your roof and there is no need to seek prior DNO approval provided the inverter output is limited to 3.86kW. When the inverter output is 3.86kW or less, the DNO just has to be advised post installation. The larger the array, the greater the possibility that the DNO might insist on a 3-phase connection. I have 2 commercial solar installations within 5 miles of my home. When the sun shines the Grid voltage goes up by 5 volts. For the purposes of DNO approval, the battery inverter is also treated as a potential generator. My array and battery could potentially export 10kW. 

If you require DNO approval there may be a cost. SPEN charged £350 and took 3 months to approve my 6.35kWp array and Powerwall 2 installation. The DNO submission made by my supplier ran to 20 pages. I got final DNO sign off about a month after completion of the installation after the compliance testing had been reviewed; eg; shutdown times in the event of a Grid failure; confirmation of any inverter export limit etc.

MCS is the only certification authority accepted by some suppliers (eg; Octopus). There are other certification bodies available. If you want to apply for SEG (export) payments, Octopus will want to see both the MCS Certificate and DNO sign off on the final installation. It will then apply to the DNO for an export MPAN. You will end up with one smart meter with 2 MPANs.

markin

What price is the system? They really shouldn't need to come until you've actually decided if you want a battery or not and 'sell' you one on the spot.