diy solar

diy solar

Scalable Micro Grid Tie Solar

I have just been looking into those, only snag I can see is docs state :
"
EVERY Enphase microinverter system requires an Envoy device to commission the system AND it needs to be left on site permanently in order to comply with G98/G99 regulations. Instructions for registering a system can be found here, whether you are a homeowner, first time installer or self-installer.
Please note you may receive a mixture of INT and FR version of this micro inverter. They will need a gird profile applied on install, this is completed using the Envoy."
Which I will also fool into thinking my power is grid power. ;)
 
I have just been looking into those, only snag I can see is docs state :
"
EVERY Enphase microinverter system requires an Envoy device to commission the system AND it needs to be left on site permanently in order to comply with G98/G99 regulations. Instructions for registering a system can be found here, whether you are a homeowner, first time installer or self-installer.
Please note you may receive a mixture of INT and FR version of this micro inverter. They will need a gird profile applied on install, this is completed using the Envoy."
the Enoy device is the local data logger.
 
- I am thinking at 330w I could just wire the ground, neutral, and live to a UK plug and plug it into a power socket. If I scale up I will use proper electrical connectors sized for the amperage.
Hiya. New guy here also in UK (south). Isn't this completely against the "rules"? As you will be energising circuits that will no longer be covered by the fuse board in your property? Very interested in your progress though as I am in a similar position! I have a constant 400w load and and currently investigating options for solar on our flat roof to offset this usage. cheers!
 
... looking for a sanity check... in the UK....

... constant daytime use of about 200w... 10% light I would need a 2kw system in order to generate that 200w.
If you had a good net-metering agreement (e.g., sell power to the grid at the rate you get charged for it) then 200 watts x 24 hours = 4.8 kWh/d.
Assuming a winter insolation of 1.5 (you'd have to look up your actual worst value) then 4.8 / 1.5 / .96 inverter efficiency = 3.6 kW array. In the summer, with an insolation of 5, that 3.6 kW array would generate 18 kWh of energy per day (over 4x what you need). You could just size for the summer (4.8 / 5 = 1 kW array) and take what you can get in winter. With a good net-metering agreement you pick somewhere inbetween to zero out the yearly bill.

Since you'd still be on grid you'd have power when you needed it, and since it's the average you don't have to worry about the 10%.

But, since you're in the UK, most places don't have net-metering agreements and you might not be able to "give" power to the grid (that is they might have laws against it - no worries, most inverters have some sort of zero-export feature).

If you put a battery into the mix, prices are going to go up and there's a round trip loss so you need more solar to accommodate it.

I would like to start very small at 330w and scale out from there.
Microinverters provide the ultimate in scalability. You don't need to plan much, you can scale to any size, they usually have 25-year warranties. Enphase can be set to zero-export (you need the envoy module). Unfortunately, AFAIK only Enphase currently places nice with batteries, other systems need to be AC coupled.

The good news is, a single 330W panel will cover your 200W energy needs for most of your daylight hours. Without a battery or a net-metering agreement, anything else won't do you any good.

I don't plan on having the inspections and certifying it to local regulations ( despite it being compliant ) and selling electricity back to the grid.
Most meters don't run backwards - so when you export to the grid, they run forwards - that is, without contacting your power company to get a bidirectional meter (which will probably require inspections), they will charge you for the power you put on the grid as if you were consuming it.

There is a 350w Chinese Y&H inverter at around £55 pounds, example: https://www.ebay.co.uk/itm/403087824719 that would match this panel.
I wouldn't skimp on that (I have Enphase), especially as you need so few. But, the things to check are: is it certified by a lab (e.g., CE, that's not a guarantee it won't set fire to your house; but better than nothing), can it be set to zero export, what's the warranty, do you get the data from an API that you need, do you get the support you need to operate it?

Price per ( potential ) KW would be about £720
In Australia, professionally installed costs are $0.50 to $1.00/w. In U.S. installed DIY typically runs around $1/W. Not sure what the UK costs are, but a $/W in U.S. dollars seems like it should be about .75£/W.

The initial system setup seems almost too simple, it this right ?
Usually, there's some setup through the API to program them. You'll also need over-current protection and to select the proper gauge using the temperature correction factors (see the FAQ). Microinverters like Enphase have all sorts of training and tools to help you, not sure what others like AP Systems have. Whatever system you pick should have documentation illustrating the right way to hook it up.
 
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Bob Hope, I am on the fence with my Y&H 120W MPPT Grid Tie Micro Inverter. It worked great for two months, Dec/Jan but then it blew the AC side fuse. I am getting two sets of parts to solder on for $7 each and they are confident this will fix it but for how long? I will be lucky to be able to repair it myself but have nothing to lose now. I think moving forward I will go with something a little bigger but can still live outside under the panels so I am not seeing much line loss. How is yours working so far or did you go with another option?
 
Hiya. New guy here also in UK (south). Isn't this completely against the "rules"? As you will be energising circuits that will no longer be covered by the fuse board in your property? Very interested in your progress though as I am in a similar position! I have a constant 400w load and and currently investigating options for solar on our flat roof to offset this usage. cheers!
In California they have the Legion Solar kits which are a bit over kill in my opinion. You need Anti Islanding Grid Tie Inverters. It's easy enough to test with a multi meter. No AC to the unit should mean no AC coming out of the extension cord. The Legion stuff has a transformer set that clips over your service going into your house to make sure you're not back feeding power. They call this a solar regulator. If you know you're always using X watts 24/7 then never build a system any bigger than that. One thing that scares me but didn't seem to be a problem with the Y&H was there was no mention if it was a pure sine or not. Adding dirty power to your house could cause other things to act up or die so be aware of that.
 
I just got a stack of 250W panels and my first SG1400 arrived. I am anxious to see how it goes. I got the wifi box for it, so i will be monitoring it.

I am going to start small. I need to be Zero Export. I don't like strings, but it seems like the string inverters (some of them) allow split phase and some kind of Zero Export. I am searching for the one that really has Zero Export and is an on grid with batteries. I see lots of debate about that in here.

I have been reading everywhere for months now. Total newb, but trying to be fully informed.

The cheap ebay WVC Micro Inverters have a very bad reputation. They blow FETs like candy. They also blow the ASIC chips. That is why I went for the SG. Since it is 1400W capable and I will feed it with 1000 watts, I should avoid overheating in the Sonoran Desert 120F temps. I will post here how it works out. Should have it running by next weekend. Got to build those bloody racks!
 
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