Another DIY Solar Project

[JAS21]

With help, technical and other, and am very grateful to a friend,  we installed the system on a flat south facing roof. I also had the help from a couple of guys to locate the panels on the roof. I am just too old now to tackle that job.

 

So ended up with

One … Sofar ES5000 Hybrid Inverter

One … LVTopsun LV48100 5kwh battery

Seven … 450W Mono Panels. Kerry lost one  so only six installed at present

Seven … 340W Poly Panels.

 

Bit of a mixture but bought bit by bit.

 

The system has been up and working for a couple of weeks. Some delay was caused by LVTopsun sending the wrong battery to the company from which we bought the battery. 

 

Our minimum load is very low ie one fridge/freezer. However we have a PHEV with a 6.3kwh battery and several air con units, computers, TV’s, Coffee m/c, kettle, microwave, oven etc. Three of the aged air con units were replaced, very recently, with Daikin KTFM18WV’s. These considerably lowered our electrical usage. We are now running two units downstairs all day. Also put the bedroom one on mid afternoon, if we have spare generation. Our bedroom is at the front of the house.

 

The weather hasn’t been great since installation. The highest daily generation has been a little over 18kwh, actually no idea if this is good or not and highest max instantaneous being 4.11kws.

 

Sofar have a comprehensive monitoring system such that when you input your ‘Plant’ details you can access and download an amazing amount of info. It downloads straight into excel which is very handy.

 

The only oddity found so far is that the inverter gave more output when PV2 input was changed to be the seven mono cells.  On the face of it, this doesn’t make sense. When we finally install the last 450W cell I’ll swap the inputs over and see if it is still the case.

 

That is basically the reason why the PV1 and PV2 wires have, as yet, not been boxed in as it is much easier swapping the dc inputs at the breakers rather that at the inverter.

 

What have I learnt/would do differently ……

 

Yes you can install solar yourself and it would be much easier the second time. Isn’t it always the case?

 

Would probably have bought the inverter and the battery from the same supplier, more likely to help if had a problem.  Could have bought direct from China.  I have a Chinese speaking friend who would have sorted for us, but wanted to avoid hassle with customs etc. It could have been somewhat cheaper that way.

 

Should have understood better how to locate the rails for the panels as installation was delayed because of the need to add extra steels under the roof. Fortunately, due to the roof design MrsJ and myself managed to ‘slip in’ what was required but not without some difficulty. We put in 25mm2 galvanised pieces.

 

That painting galvanized steel using the wash with white vinegar first method isn’t always successful.

 

When buying steel there is in spec. and there is not in spec. What is called ‘one inch’ can come out at about 20mm. and we needed 24mm-25mm. square.  Had to buy twice.

 

Went for Hybrid as was concerned what would be the effect of in the future being given a no export meter. Now looking at all the data realize that we would have been much better installing a Grid-Tie system.  We just don’t get power cuts, well very infrequent. So if anyone wants a Hybrid inverter and 5kwh battery we would sell. PM me if interested.

 

It’s not that we are unhappy with the system, it is working well, just that the payback would have been shorter. I would certainly stick with Sofar though.

 

                                            Can see the space for the last solar panel...when it eventually arrives

 

 

                                                            Additional Roof steels...painting failed

 

 

                     Boxing of wiring still to finish    PV1 and PV2 input wiring reversed  going to raise the battery also

 

 

                                                                                           DC Switch Box

 

 

 

 

                                       Some system info from today ...generally thinish cloud..a couple of times not quite so thin

[Encid]

Congratulations 

Yes that battery certainly needs to be a bit higher, but otherwise looks like a nice neat installation.

 

By the way... you and I have the same make/model of electric lawn mower! 

 

[JAS21]

7 minutes ago, Encid said:

Congratulations 

Yes that battery certainly needs to be a bit higher, but otherwise looks like a nice neat installation.

 

By the way... you and I have the same make/model of electric lawn mower! 

 

Yes  ... that was my work bench ....

[Eleftheros]

How about the cost - I guess you saved on labor costs, but can you estimate the material costs? Plus, how much do you expect to save in a typical month? Thank you.

[007 RED]

Congratulations, a really nice installation.  As you mentioned, l would definately raise the battery off the floor to avoid any 'rising damp'.

[JAS21]

18 hours ago, Eleftheros said:

How about the cost - I guess you saved on labor costs, but can you estimate the material costs? Plus, how much do you expect to save in a typical month? Thank you.

 

Your first question is straight foreword to answer…and you can easily price the main bits yourself.

Hybrid Inverter ……….48Kthb

LVTopsun Battery …..65Kthb

Cells ……………………….58Kthb

All other bits … rails/fitments/cable/switches/extra steel etc ….11Kthb

 

Because we have

…. more than enough cells for the present situation

…. the fact that we can export  

….the fact that we have a battery

 

I can make, over a period, the import from the grid match our usage or even go negative PROVIDED we have a reasonable amount of sunshine. 

 

There is a topic discussing what sort of usage may not attract the attention of PEA/MEA.

 

So at present it seems that we can use as much electric as we like. We leave the aircon on when we go out. I don’t ask MrsJ anymore why she fills the kettle when she is only making one cup of coffee! I suggest that she does the washing and ironing during the day so that in the evening the battery is full.

 

Hope this goes someway to answering your question. But I would still change  to Grid-Tie if someone would buy our battery and inverter.

[JAS21]

So we have just had our first full month’s bill, Oct 16^th to Nov 15^th   and the system has been running throughout on ‘No Export’. Battery DOD set to 25%.

 

Generation was 416.91kWh and import from MEA was 82kWh (327.13 Baht).

 

System sometimes imports a small amount when I know that it should not, on one occasion I noticed 750Ws for a short period. I will increase the battery output kW setting just in case that figure is fed into some algorithm or whatever, that tells it to happen … also talk to Sofar for suggestion.

 

We have been very heavy on air con usage, but that was the idea for installing solar.

 

Our cooking facilities are all outside and now we can have the door open and a fan blowing cool air, when cooking etc … makes things somewhat less unpleasant.

 

Won’t know, for at least a year, what the payback might be, but it won’t be just 3-4 years! And of course no idea what will happen with the price of a kWh in the future.   

 

We have a PHEV with just a small 6.3kWh battery which, when shopping etc, will do at least 15kms. On gasoline, running around, it will do less than 10km/ltr. So we save about 50 baht whenever… not a lot but better than nothing.

 

At present if the battery is full when solar production ceases, then it will last until 2-3am. I foresee this not being the case when the hot season comes. Out night time load is one 18000btu inverter air con unit, one fridge freezer … rated at 704kWh/year …  and one 20.5 watt light bulb. So quite light.

 

When we were away the load was light bulb and Fridge Freezer and twenty four hour usage showed was 3.6kWh … not too far away from expected.

 

We could buy another battery and that would get rid of most of the MEA import. I wouldn’t have to pay as much for one as before … have a friend who speaks Chinese and he could sort for me.

 

So now more happy with the installation.

 

 

[JAS21]

As I said elsewhere this months usage was 75kWhs and running fully on No Export.

Our meter was read on the 16th and up to now (21st) we have only imported 4.5kWhs

 

The last few nights have been quite cool and on two of them we didnt use air con. The battery has been close to lasting the night (DOD set at 25%)... last night was an exception as Mrs J decided to spend twenty minutes washing her hair in the shower running at the full 4kWs. Water is a little cool now if you dont use the heater. 

 

From midnight until just now ...5pm the inverter software showed that we imported 0.96kWhs and actually exported 0.20kWhs. Not really surprised that the inverter software couldnt keep up with the load changes ... first my coffee at about 6:15am then several other high usages ...breakfast/car charging/two lots of cloths washing at 50DegC/ironing/watering garden ect etc.

 

The anti reflux cut in about 1:30 pm when the battery was full and demand had reduced.

 

Below a snip of the data

 

 

 

[TimeMachine]

Hi everyone,

I want to setup DIY solar, but instead of one large kw inverter I want to have several smaller shoebox style cheapie inverters around the house. I see the advantage in that if one goes out then I won't completely be without power. They are quite cheap on AliExpress but I know ratings are exaggerated. I have had half decent ones before where the label says 1500/3000watt and worked out at around 1000watt. Can anyone recommend anything half decent that gives real value of around 1000watt. On Lazada or Ali that you have tried. Cheers. 

[Crossy]

33 minutes ago, TimeMachine said:

Hi everyone,

I want to setup DIY solar, but instead of one large kw inverter I want to have several smaller shoebox style cheapie inverters around the house. I see the advantage in that if one goes out then I won't completely be without power. They are quite cheap on AliExpress but I know ratings are exaggerated. I have had half decent ones before where the label says 1500/3000watt and worked out at around 1000watt. Can anyone recommend anything half decent that gives real value of around 1000watt. On Lazada or Ali that you have tried. Cheers. 

 

Grid-tie, off-grid or hybrid?

 

Lots of choice of all flavours.

 

The low-cost stuff from Suoer and PowMr seems to get decent feedback, but if it fails buy a new one.