Some of you may remember us building this back in 2015.
Thread here https://forum.thaivisa.com/topic/481794-housebuilding-thread/?do=findComment&comment=9603407
Well the time has finally arrived for me to get my finger out and actually put some solar on the car port.
We spoke to our local PEA office who were quite enthusiastic and helpful until we said we didn't want to join the government scheme (IIRC it's called My Solar Roof), the contract was too long and restrictive and the feed-in rate silly.
So, we are NOT permitted to spin the meter backwards (net-metering) - At least not officially "don't let the meter reader see it going backwards" said the supervisor (he's not over enamoured with the government scheme either).
That along with the costs associated with doing the job "officially", approved inverters, approved installers (no DIY) decided me to do this on the QT.
Luckily for us (but not my wallet) we have a standing load of about 1100 Watts (mostly Madam's koi and the freezers), our base consumption hasn't gone below 1000 W for the last year or so (yes, I'm sad, we keep a log - ok the supply monitor does). So 1000W or so of solar would cover the base without the meter going backwards and still produce a visible saving on the power bill.
A quick and dirty estimate:-
1000W x 5 hours per day = 5 units per day generated. Times 30 days per month = 150 units per month. @ 4 Baht per unit thats 600 Baht per month = 1 case of beer!!
Our bill is usually 5500-6000 Baht so 10% reduction, enough to keep Madam's green desires happy.
So I went shopping:-
4 x 300W solar panels from Global House - On offer at 3,890 Baht a pop.
2 x 600W WVC micro-inverters from AliExpress - 6,500 Baht for the two including duties and VAT.
The cost of the "proper" mounting hardware scared me so a visit to our local steel supplier got us 11/2" square x 2mm wall thickness at 300 Baht a 6m length. I got 6 pieces, we don't need it all for 4 panels but I'm going to put all the mounting stuff up whilst I'm in roof-climbing mode. So 1800 Baht.
We also need some stand-off parts to keep everything off the actual roof, I had some 3" x 11/2" x 2mm "in stock" so I made 36 x 100mm long stand off pieces. This steel would probably cost another 400 Baht or so.
Washers, self drilling screws, angle fixings, primer and paint are all from stock, but I doubt they would cost more than a grand or so.
So, we've spent about 25 grand to save 600 Baht a month. Payback period 41 months, about 3.5 years. I can live with that.
I've not decided how to configure the rest of the roof space (there is room for 18 panels) yet, but if back-feeding remains off the option list I expect something with batteries is going to be on the cards (look up hybrid inverters). This would also provide a whole-house UPS facility and render our (noisy) genset redundant.
Photos as we progress so hopefully all will become clear.
Comments always welcome of course (or I wouldn't be posting).