Shed solar on a budget

[nowty]

So I have 6 panels pointing South East, then the three pointing west. Could switch two of the SE ones to be more S I suppose. I'm hoping that the sun will average out throughout the day and give me usable energy rather than chasing peaks that I will end up exporting.

Worth explaining to SWMBO about strings and the lowest generating panel being the ceiling for the whole string of panels.

If these are on a single string you can add TIGO's (voltage optimisers, about £35 each) onto the three pointing west. They work by maintaining the natural string current of the non TIGO panels (the SE ones) and sacrificing some voltage in order to do so.

That gets you around the lowest generating panel ceiling but its going to cost you another £100. But better getting it right by design, rather than resorting to workaround add ons.

https://www.tradesparky.com/solarsparky ... -frm-mount

[nowty]

Just thinking out load about my last post, you might also consider a second small inverter, say 1kW or 1.5kW and that would still keep you to G98 rules.

Then split the W and SE panels onto separate inverters, that would work better than my post about TIGO's and cost a similar price.

Shame you did not get a dual MPPT inverter form the off.

[drjim]

Yes this is true, dual MPPT would be handy, but not cheap!

I'm revising the concept already, I could get two more of these panels on the shed array, but any more gets closer to the house and shaded for a couple of hours in the morning. I've now got the westerly panels attached to my 700w chinese microinverter, I also have the two enecsys micros that could go on two panels located somewhere else.

Also contemplating getting some 400ish watt panels for the shed (CEF seem to have Longi at £45),to maximise what I get there, and putting all the 250w ones down the side of the house to get the westerly sun in the evening.

[nowty]

Many of us have gone through these learning curves. Sometimes I say learn from us and go large from the start, but then again it’s half the fun tinkering with it all.

We still get there in the end.

[drjim]

There would be little fun in just handing over a big pile of cash and having someone install it all.

[drjim]

Today I worked out how to get a power feed from the consumer unit to the immersion in the boiler room without dismantling half the house to get into the roof void above and/or lifting floorboards and making loads of mess. It involves a 4mm arctic flex cable that I previously used to run power to the pool heater. Immersion is connected to that via a DP switch, and that goes into the solic which is next to the CU. Solic is running off a 2.5 heat resistant flex on a 13A plug, connected to the utility room socket circuit - currently running the washer and very occasionally the tumble drier. Only one room on the circuit.

As and when I go "Big" on this I can run more cables via that route fairly easily. The CU cupboard isn't really big enough for batteries/inverters etc so they will be out the back on a suitable cable.

[drjim]

So today I pondered why the Solic didn't seem to do anything and then found the thermal cutout on the immersion had, well, cut out. Given the immersion has effectively never been used since install in 2010 all seems odd, but a quick screwfix app purchase and I have a new thermostat with built in cutout. The sun hasn't shone enough to fire up the solic while we have the washer going and I'm cooking on the induction hob, but we'll see if it works tomorrow.

Oh and I decided that the 1kw shed roof and 500w on the other shed with an optimiser was not enough, so I ordered 5x longhi 410w panels from city plumbing for delivery on Monday all being well, then I got a used 2kw inverter off ebay to put all the existing 250w panels on. Still cheaper than a dual MPPT inverter. And I don't have toy budget for battery/hybrid at this stage. I'm going to have 2kw on the westerly side of the house which will give me an idea what the roof way up above it would do (slightly North West rather than West), then I can get the new panels all pointing SE with the Tigo I got off ebay on the panel that will be shaded in the earlier part of the morning.

So heading for 4kW by next week.

I did of course buy the new growatt 2kW for a reason, I need to have a proper G98/99 one to tell the DNO about, even if there's a G83 hiding in its shadow!

[AGT]

Just thinking out load about my last post, you might also consider a second small inverter, say 1kW or 1.5kW and that would still keep you to G98 rules.

Then split the W and SE panels onto separate inverters, that would work better than my post about TIGO's and cost a similar price.

Shame you did not get a dual MPPT inverter form the off.

How can you tell if an inverter is dual MPPT? Just from looking at it in its powered down condition?
Just wondering as the sunny boy 2500 I’m working on has 3 sets of PV inputs?

[drjim]

Update time.

1600w of longi panels on the shed roof, one panel left to be set up. I've reconfigured the westwards array to be flat on the roof of the other sheds down the side of the house. Shaded until after 1300, currently 1500w of panels connected to a £60 G83 Sunny roo inverter from ebay.

My hot water is now very hot thanks to the immersion running off the solic 200. We've had the washer on twice alongside baseload and my input CT showed 300w while the sun was shining.

I think I'm pretty happy. However I still have the other 410w of new panel and 750w of the older ones that aren't connected to anything yet. Sadly I think my old 700w microinverter has died, but I have two enecsys things and a 20A charge contoller that could play with some batteries....

Oh and I'm showing 100 kWH generated on the ketotek meter! £30 on our current tariff.

[Fintray]

Good to hear that it is working well for you.