Refused Connection

[jason121]

Had my first refusal today for 50 KW system due to western power primary sub station not able to with stand all the Solar PV in the area.
I have to wait for the upgrades in a few months.

To much reverse power anyone else experience this yet

 

[a1colly]

Not yet, didn't you get it connected within the written agreement timescales? I was always under the impression you didn't get an accept unless the upgrade work had been completed and no other connections were allowed until your offer had expired.

 

[driverman]

Should you /customer of informed them before you started? At least there is an upgrade coming later. What would of happened if no upgrade being planned?

 

[jason121]

Paper work stage not installed yet.

 

[driverman]

Paper work stage not installed yet.

Ahh good then. So all is not lost then , especially with upgrade on the horizon.

 

[a1colly]

Ahhhh that's good, had plenty of them currently sitting on a £65k upgrade for 24kwp - 1.7kwp system x 20 and the client has agreed to pay

 

[jason121]

The govt want all these roof top mounted solar but the grid cant cope

 

[Worcester]

Yep had one refused in Leciestershire not so long ago (200kWp) got around it when we agreed not to export >3.68kW per phase

We estimated the total cost to the business based on matching their half hourly consumption data to half hourly generation data predictions was less than 4% so the project was still a goer

 

[jason121]

What make and type did you use to limit current capacity

 

[Energetic]

We've had 30kw turned down in devon as it's not far from a multi-acre solar farm. Have been told by WPD that Devon and Cornwall is 'full'. Unlikely to be any private upgrades that will fix it, they reckon it will take billions in infrastructure upgrades.

 

[jason121]

Time to burn your tool box and retire

 

[snowhead]

We've had 30kw turned down in devon as it's not far from a multi-acre solar farm. Have been told by WPD that Devon and Cornwall is 'full'. Unlikely to be any private upgrades that will fix it, they reckon it will take billions in infrastructure upgrades.

The solution would be to encourage some heavy (power consuming) industry into the area.

 

[Gavin A]

What make and type did you use to limit current capacity

we use power one with the PMU unit to control it, and elios 3 phase unit for the actual export limitation... it works, but waiting for a firmware upgrade to actually lock the setting.

currently only does up to 100A supplies though due to the CT clamps, another thing on my list to get sorted....... (looks at Andy Sibert)

 

[jason121]

Spoke to Andy about the elios upgrade for 100 amp plus they have no intention yet to do so.
I need to limit 200 kw plus

 

[shanky887614]

Spoke to Andy about the elios upgrade for 100 amp plus they have no intention yet to do so.
I need to limit 200 kw plus

if it is limited to 100amp.

can't you split the strings?

it might add a bit more with the cost of inverters etc but surely that would make it possible then

 

[jason121]

The idea would be to switch of each individual inverter relative to output current but keeping in the DNO limit of export. Also would be good idea to rotate inverters to keep same number of hours usage.

 

[Worcester]

Speak to Andy he can put you in touch with the G59 Panel manufacturers, works excatly that way, drops out the inverters one by one to keep below the value.

That's the advantage of multiple string inverters of a central one

Of course it would be nice if they could monitor them all, look at the generation. load and limits and choose which one to drop next , that would be too clever!! Instead at this point in time you'll have to choose in advance and set the order up based on your knowledge of their likely load levels and typical generation - hence our half hourly analysis - only took about 8 hours to do.

 

[jason121]

I make my own G59 panels. Just need to find the right current limiting relay. SMA do one and like the idea of the elios, but that's limited to 50kw.

 

[SibertSolar]

FYI, 4-Noks are going to port across a similar system to the Elios PRO that they use in mainland Europe that allows export management for up to 200kW (maybe 250kW) systems, with security/lockout of parameters. It's an available solution but just not yet configured for the UK market. Would be handy to have an idea of potential demand though, although I know personally of multiple situations where this is required, and will probably be more frequently required as the grid gets more and more saturated.

The electromechanical solution that Worcester refers to is a valid option that is almost 100% fail safe but it's primitive in that it switches off inverter(s) completely. Most modern European manufactured inverters have a facility to throttle their output to a preset % of peak power, in several steps - something that the German/Italian/Spanish grid operators do remotely if required (or managed by 3rd parties according to grid demand etc). We have somewhat different challenges over here to facilitate this kind of control but a closed loop feedback system using something like the P1 (ABB) PMU that Gavin is using, along with an export energy monitor like the Elios can provide a decent granularity of control compared to actually switching inverters off.

 

[Gavin A]

FYI, 4-Noks are going to port across a similar system to the Elios PRO that they use in mainland Europe that allows export management for up to 200kW (maybe 250kW) systems, with security/lockout of parameters. It's an available solution but just not yet configured for the UK market. Would be handy to have an idea of potential demand though, although I know personally of multiple situations where this is required, and will probably be more frequently required as the grid gets more and more saturated.

bagsy

The UK is going to be the biggest market in europe for this scale of installation, in coming years, and export limiting is going to be vital to this development, so the market potential is at least as big as any of their existing markets.

Not sure what it is with EU manufacturers not actually sussing this stuff out tbh, we're a top 5 global solar country, they need to start treating us as such, not like some sort of naughty child that they might give a few crumbs to if mainland Europe leaves anything for us.