Help on a larger system's design

[DomB]

Hi all,

We've been asked to look at installing PV to some large farmyard storage barns.

We're organising a structural and asbestos survey but I think we'll also need a commercial electrical survey and some help designing the array itself.

If anyone's got experience at this level or used such third parties in the past I'd be really interested to hear how it went or how you got started etc

Thanks very much

 

[TedM]

I can't help with the 3rd party bit but one thing to watch out for will be any large loads that are switched on/off regularly that could cause the voltage to dip out of bounds and the inverter(s) to initiate a disconnect/reconnect cycle. (Depends what type of farm it is.)

Also obviously check the voltage levels in the first place as you need 'head room' for the inverter to operate - some farms have extra high voltage settings on their transformers to mitigate volt drop across all the buildings.

 

[DomB]

Thanks TedM. We've lined up some Mechanical & Electrical engineers who seem good for conducting an electrical infrastructure survey. Also lined up the structural surveyor.

I'm going to now need some help on the actual solar PV design itself. Think I'll approach a couple of distributors to see what they say

 

[DomB]

Just to close this thread, we found the following very useful http://www.solarsense-uk.com/Downloads/pres-sol.pdf. Must say I'd love to go see the Worthy Farm install sometime.

 

[SRE]

We've been asked to do a few of these in the last couple of weeks. We're just going through the DNO process with one farm at the minute to see what the upgrade costs from single phase to three phase are. What are your thoughts about the type of panels to use??? We usually use Sharp but since the cost of the Schott panels has dropped and they have the amonia test certificates we're recommending those on the byres and Sharp on the other buildings. What are you planning to use?

 

[DomB]

We priced up Schott. The barns we're looking at are used for storage only but we figured the Schotts were more futureproof. We let the customer know the reasoning and just said Sharps were a cheaper option. I noticed Worthy Farm is using Romags.

What sort of barn roofs do you have - any thoughts yet on fixings / roof anchoring?

 

[SRE]

250mm hanger bolts and Renusol kit. We did a 3.9kwp system on a similar barn next to a farmhouse that was a listed building and it went on really well. Quicker than slate - our current bug bear! Our structural engineer didn't even come out and look, most of the barns are made the same where we are and once we'd provided the dimensions of the steel beams and the purlins he was more than happy (unusual really!)

Is the asbestos survey expensive? We've got one coming up that might need one.

 

[DomB]

Thanks re the roof kit.

TBH with the asbestos I just did a quick web search and based our quote (more of an estimate) around that.

We've quoted him for 4kWp, 10kWp, 50kWp and 100kWp. It sounds like the Dept for Energy etc are going to clamp down on anything over 50.

For those larger systems I susepct we're gonna need some help on the actual electrical design, inc inverters etc. Did you guys do that yourselves?

 

[SRE]

We're working through it at the minute with the help of our wholesaler, inverter technical help and the DNO. We weren't intending to do bigger jobs but we're getting asked to do so many at the minute that we've decided to grasp the nettle and get on with it! The only thing with bigger jobs is that they take longer to come through than domestics so there's a bit of down time in between.