Solar cells on the roof etc., but no batteries

[scorecard]

Hoping for an expert comment from Crossy or another of our experts.

 

A question:

 

- Is it possible to install solar cells and use the power generated direct into the house wiring during the daytime but with no batteries installed?  (And use main grid power after dark.)

 

Further if this is possible, could it be set up as a first step in a house installation, adding batteries at a later date without a major rewiring/major re-set-up? 

 

Thanks.

[Crossy]

Yup, grid-tie. Loads of us doing it.

 

Moving to the Alternative Energy Forum.

 

Have a read here for a start.

 

 

[Crossy]

Going grid-tie will let your solar offset your power bill, if your consumption goes over the solar production the extra is simply drawn from the grid, totally seamless.

 

Start with 2 or 3 panels and a 1kW grid-tie inverter to generate about 3 units a day of free power.

 

If you plan to add batteries in the reasonably near future you may want to spend rather more $$$ on a grid-tie hybrid inverter. Personally I wouldn't just yet.

 

Do you have a conventional (spinning disc) or electronic electricity meter?

 

[scorecard]

44 minutes ago, Crossy said:

Going grid-tie will let your solar offset your power bill, if your consumption goes over the solar production the extra is simply drawn from the grid, totally seamless.

 

Start with 2 or 3 panels and a 1kW grid-tie inverter to generate about 3 units a day of free power.

 

If you plan to add batteries in the reasonably near future you may want to spend rather more $$$ on a grid-tie hybrid inverter. Personally I wouldn't just yet.

 

Do you have a conventional (spinning disc) or electronic electricity meter?

 

Thanks, We have an electronic electricity meter.

[Crossy]

15 minutes ago, scorecard said:

Thanks, We have an electronic electricity meter.

 

OK, in that case you need an inverter with the "no-export" function, you cannot send energy back to the grid and at least one member has reported that his electronic meter actually billed him for the units he exported.

 

Quite a few small (and not so small) inverters available now with this function.

 

A grid-tie hybrid inverter would be the way to go, store any excess juice in batteries once you get some.

 

We have this one:- https://www.lazada.co.th/products/i2064152396-s6736374882.html

But as you can see it's not a cheap animal.

 

Beware of some of the very cheap hybrids, they either don't do grid-tie at all or their actual grid tie capability is low.

 

[sezze]

13 hours ago, Crossy said:

 

OK, in that case you need an inverter with the "no-export" function, you cannot send energy back to the grid and at least one member has reported that his electronic meter actually billed him for the units he exported.

 

Quite a few small (and not so small) inverters available now with this function.

 

A grid-tie hybrid inverter would be the way to go, store any excess juice in batteries once you get some.

 

We have this one:- https://www.lazada.co.th/products/i2064152396-s6736374882.html

But as you can see it's not a cheap animal.

 

Beware of some of the very cheap hybrids, they either don't do grid-tie at all or their actual grid tie capability is low.

 

The OP doesn't want batteries , so he can go with a simple grid tie inverter with limiter .

https://www.lazada.co.th/products/sofar-grid-tie-on-grid-inverter-3300tl-g3-ct-clamp-5-i1513152367-s4001404783.html?spm=a2o4m.searchlist.list.127.119a379aSlc0Gl&search=1

https://www.lazada.co.th/products/must-grid-tie-inverteron-grid-3000w-6000w-pure-sine-with-anti-backflow-control-ph50-3000mph50-6000m-i345224535-s673566456.html?spm=a2o4m.searchlist.list.79.32a0379aIUOD5a&search=1

 

Which are a lot cheaper then the hybrids . They do not offer any support for batteries , and if you do not put the CT connector on the line , it will grid tie ( put back in the grid ) . They also make 0 noise , since they work without fan .

[Crossy]

17 minutes ago, sezze said:

The OP doesn't want batteries , so he can go with a simple grid tie inverter with limiter .

https://www.lazada.co.th/products/sofar-grid-tie-on-grid-inverter-3300tl-g3-ct-clamp-5-i1513152367-s4001404783.html?spm=a2o4m.searchlist.list.127.119a379aSlc0Gl&search=1

https://www.lazada.co.th/products/must-grid-tie-inverteron-grid-3000w-6000w-pure-sine-with-anti-backflow-control-ph50-3000mph50-6000m-i345224535-s673566456.html?spm=a2o4m.searchlist.list.79.32a0379aIUOD5a&search=1

 

Which are a lot cheaper then the hybrids . They do not offer any support for batteries , and if you do not put the CT connector on the line , it will grid tie ( put back in the grid ) . They also make 0 noise , since they work without fan .

 

Indeed, we have the 6kW version of that Sofar inverter, as well as the newly arrived hybrid.

 

But our OP notes that he may want to add batteries "in future", just how far in future would determine whether he should bite the bullet now and get a hybrid or go for a pure grid-tie and replace it later.

 

Also, if, like many of us, his main usage is at night, he will need some means of time-shifting his energy if he wants to do more than just zero his daytime consumption. In the absence of net-metering batteries are the only way forwards.

 

Actually I came across some small inverters with limiters which could either operate directly off panels or off batteries (with an external solar charge controller). Let me see if I can find the link.

 

EDIT Found it https://www.aliexpress.com/item/4001054628033.html

 

Best of both worlds, run directly off panels with a limiter (up to 3 units on one limiter). Later add batteries and a solar charge controller and you have a psuedo-hybrid.

 

Note: I've used that AliExpress seller in the past and found them reliable.

[oobar]

Another question for Crossy:  My house is 3-phase, with one phase supplying upstairs, another feeding downstairs, and a third taking care of our workshop needs.  All phases are metered through the same meter, a mechanical type (not an electronic display).  If I install a solar panel array on a single phase, say the second floor, I assume the solar generation will be reflected in the total "credit" overall (of the three phases).  Is this correct, even if, for example, the solar phase produces more electricity than that phase uses?

[khunPer]

On 7/19/2021 at 11:17 AM, Crossy said:

Start with 2 or 3 panels and a 1kW grid-tie inverter to generate about 3 units a day of free power.

It's about 12 baht a day, with 200 sunny days a year it's 2,400 baht, and with 300 sunny days it's 3,600 baht. How much is installation cost?

[Crossy]

19 minutes ago, oobar said:

Another question for Crossy:  My house is 3-phase, with one phase supplying upstairs, another feeding downstairs, and a third taking care of our workshop needs.  All phases are metered through the same meter, a mechanical type (not an electronic display).  If I install a solar panel array on a single phase, say the second floor, I assume the solar generation will be reflected in the total "credit" overall (of the three phases).  Is this correct, even if, for example, the solar phase produces more electricity than that phase uses?

 

Yes, the "simple" mechanical meters will happily account for one phase exporting whilst the others import.

[Crossy]

1 minute ago, khunPer said:

It's about 12 baht a day, with 200 sunny days a year it's 2,400 baht, and with 300 sunny days it's 3,600 baht. How much is installation cost?

 

If you DIY like we did expect a payback period of 3-4 years (we are on target for 3 years).

 

After that your solar is free energy, the panels should be good for 20 years +, the inverter, depends upon too many variables, get a quality unit (pay a bit more).

 

 

[scorecard]

10 hours ago, Crossy said:

 

Indeed, we have the 6kW version of that Sofar inverter, as well as the newly arrived hybrid.

 

But our OP notes that he may want to add batteries "in future", just how far in future would determine whether he should bite the bullet now and get a hybrid or go for a pure grid-tie and replace it later.

 

Also, if, like many of us, his main usage is at night, he will need some means of time-shifting his energy if he wants to do more than just zero his daytime consumption. In the absence of net-metering batteries are the only way forwards.

 

Actually I came across some small inverters with limiters which could either operate directly off panels or off batteries (with an external solar charge controller). Let me see if I can find the link.

 

EDIT Found it https://www.aliexpress.com/item/4001054628033.html

 

Best of both worlds, run directly off panels with a limiter (up to 3 units on one limiter). Later add batteries and a solar charge controller and you have a psuedo-hybrid.

 

Note: I've used that AliExpress seller in the past and found them reliable.

Thanks for all the replies.

 

Bottom line, the house is owned/occupied by my Thai son, his Thai wife and 3 kids, and me, in CM.

 

Son wants to eventually make big dent in his electric bill. Biggest daytime electric consumption is electric cooking hob and oven, several ceiling fans, water heaters, lights, TV.  In evening little cooking, but some fan us, TV etc., and several air-cons.

 

Son has zero electrical or engineering knowledge but he doesn't hesitate to ask good questions and he's a good listener. I have no electrical/engineering knowledge.

 

One of sons buddies has recently installed panels but not batteries (installed them himself) with no design and no advice from anybody, and is less than satisfied that he has achieve anything. The buddy has no electrical or engineering knowledge/experience at all. This 'result' is what prompts my son to think that maybe (with good advice/help) it's possible to take a 2 step approach:

• Step 1: Install panels and some form of system, but no batteries, to power the house in daylight hours.
• Step 2: Add batteries with overall aim to reduce the total power bill by maybe 80%. Best guess of timing to add the batteries might be 2 to 3 years after Step 1. He's realizing that what gets installed in a Step 1, needs to be good foundations for Step 2.

Son has asked some questions at a couple of Thai owned/operated electrical engineering shops / contractors but says he can't get any clear holistic answers.

 

End result:  'Dad, can you please ask some farang people to comment'. 

 

Edited July 20, 2021 by scorecard

[carlyai]

11 hours ago, Crossy said:

 

Yes, the "simple" mechanical meters will happily account for one phase exporting whilst the others import.

Wouldn't it be better to see if the brand of hybrid inverter Crossy bought comes with a 3 phase 5 KW model? 

If it is then possible to migrate grid tie phases connections to batteries when ready.

[Crossy]

1 minute ago, carlyai said:

Wouldn't it be better to see if the brand of hybrid inverter Crossy bought comes with a 3 phase 5 KW model? 

If it is then possible to migrate grid tie phases connections to batteries when ready.

 

They do 3-phase versions, but only in larger sizes. Personally, if you are going 3-phase solar I'd use 3 x single-phase inverters. With the somewhat "interesting" power in Thailand I'm not sure how the 3-phase units react to loss of one phase, it would probably shut down completely which one doesn't really want.

[Crossy]

@scorecard a few questions.

• Will you DIY or use a contractor (it's not rocket science but DIY would mean you can't join the Solar Roof scheme)?
• Roughly what is the daytime energy consumption? (read the meter at 8:30 and 16:30 to fit in with max solar production)
• What environment will the inverter(s) live in some have noisy fans (you don't want it in your lounge), others are IP65 sealed (damp and gekko proof)?
• Are the panels going on a house roof or car port or ground mounts?
• Do you have a budget?

 

[BritManToo]

13 hours ago, scorecard said:

Son has asked some questions at a couple of Thai owned/operated electrical engineering shops / contractors but says he can't get any clear holistic answers.

My building contractor asked a local CM solar shop for advice after trying to copy my install.

They told him to connect the solar panels in series .... when he had a GTI that required them to be connected in parallel. GTI went bang.

 

You can't trust local shops to give advice.

[BritManToo]

On 7/19/2021 at 4:17 PM, Crossy said:

Start with 2 or 3 panels and a 1kW grid-tie inverter to generate about 3 units a day of free power.

I have 2 of these, now 2 years old, (2 x330w and 3x 340w panels) work perfectly, fans a bit noisy sometimes. I just mounted the panels on my back wall, bit of shadow after 3pm but making an average of 130 units/month in total.

SUOER 1000W (VA) Inverter อินเวอร์เตอร์ ON GRID TIE INVERTER GTI-D1000B ประกัน 1 ปีเต็ม | Shopee Thailand

 

 

Edited July 21, 2021 by BritManToo

[sezze]

For the price right now and efficiency , a better quality inverter would be a better investment . 1 y ago , inverters were still 15k at least for the better quality ones , making the Suoer units at +/-3000b very attractive .

Now you can have something like this

https://www.lazada.co.th/products/sofar-grid-tie-on-grid-inverter-g3-g2-16kw-22kw-33kw-5kw-11kw-wifi-5-spnmenergy-i1394320262-s3562036278.html?

https://www.lazada.co.th/products/jfy-grid-tie-inverter-on-grid-jsi-2000tl-wifi-plug-i380480124-s740622024.html?spm=a2o4m.searchlist.list.20.6622379aPkNEN0&search=1

and while it may look a lot more expensive , we are talking now totally silent ( fanless ) , higher power  , higher efficiency (10% more )  , for just over 10k .

Not saying the Suoer units are bad , they just aren't the best around , they do their job which does make it a good unit especially in Thailand . Higher quality equals higher price , but at the pricepoint now , the other units are looking much more attractive .

[BritManToo]

7 minutes ago, sezze said:

For the price right now and efficiency , a better quality inverter would be a better investment . 1 y ago , inverters were still 15k at least for the better quality ones , making the Suoer units at +/-3000b very attractive .

You think 11kbht for a 2k2 unit is better value than 2k5bht for a 1k unit?

My math says it's twice as expensive, and you are holding twice as many eggs in your basket.

[sezze]

18 minutes ago, BritManToo said:

You think 11kbht for a 2k2 unit is better value than 2k5bht for a 1k unit?

My math says it's twice as expensive, and you are holding twice as many eggs in your basket.

True but its supposed to be more reliable , higher efficiency and better quality whatsoever . Like always choosing price vs quality it is difficult and tough to decide . It is everybody making their own decisions , but for double the price i do know my choice . I'm very budget minded , hating to spend money on advertising or unneeded value . For me anything above 1000Watt is a easy choice . I make my choice , anybody else makes theirs , we just give them the options around . If you can find a 2000W unit fanless for less then 15000 baht , i'd say it is a good choice , but everybody on its own to make the choice . The Suoers are about the cheapest around , and like i said , they aren't bad , they aren't the best either . 2500 baht for a 1000 w inverter is certainly good value for money .

[BritManToo]

2 minutes ago, sezze said:

If you can find a 2000W unit fanless for less then 15000 baht , i'd say it is a good choice ,

I've always found anything 'fanless' fails quite quickly in the tropics.

[Crossy]

2 minutes ago, BritManToo said:

I've always found anything 'fanless' fails quite quickly in the tropics.

 

Our 6kW Sofar GTI is doing OK, unlike those little micro-inverters I had originally the heatsink never gets too hot to touch even when it's running at full chat. The new hybrid seems similar.

 

Both are IP65, the issue with having fans (apart from noise) is that the ventilation slots leave an ingress path for the local wildlife. If ants and gekkos aren't an issue in your location great, we have them by the zillion ???? 

 

[scorecard]

2 hours ago, Crossy said:

@scorecard a few questions.

• Will you DIY or use a contractor (it's not rocket science but DIY would mean you can't join the Solar Roof scheme)?
• Roughly what is the daytime energy consumption? (read the meter at 8:30 and 16:30 to fit in with max solar production)
• What environment will the inverter(s) live in some have noisy fans (you don't want it in your lounge), others are IP65 sealed (damp and gekko proof)?
• Are the panels going on a house roof or car port or ground mounts?
• Do you have a budget?

 

Thanks Crossy:

 

Some answers:

- At the right time I will encourage my son to do more checking to find a local experienced credible contractor. 

- I'll get my son organised to get the data you mention.

- The inverter etc., and eventually the batteries will be in a small room/cabinet my son will get constructed on the outside of the wall that holds up the outer side of the carport. The technology/battery room/cabinet will be about 1.8m wide, up to the ceiling, about 40cm depth, slated doors for air circulation, I'm hoping that will be big enough. (When the doors are open the whole width, height, depth of the cabinet will be open for full access). This room/cabinet will be under quite wide eaves and well protected from rain. The carport is fully under the main roof of the house (black cement roof tiles, steel framework).

- Panels will be on the main roof of the house. It's a bigger house, 5 bedrooms, 4.5 bathrooms, big living, dining, kitchen, store rooms so the roof has an area which could support many panels. 

- Budget not yet confirmed, but I have told my son if he gives me a good proposal* I will support Step 1. up to 40,000Baht. (*but let me be honest I don't know what a good proposal for this project would look like. Also, 40,000Baht is a wild guess on my part and I'd much appreciate any comments/advice on this.)

 

Thanks again. 

[Crossy]

I've moved us over to the Alternative Energy forum ???? 

 

@Thaifish had a pretty big system fully installed by contactors.

 

Good thread here:-

 

[BritManToo]

1 hour ago, scorecard said:

- Panels will be on the main roof of the house. It's a bigger house, 5 bedrooms, 4.5 bathrooms, big living, dining, kitchen, store rooms so the roof has an area which could support many panels. 

I need to clean my panels 4-6  times a year.

Careful where you put them.

[scorecard]

3 hours ago, BritManToo said:

I have 2 of these, now 2 years old, (2 x330w and 3x 340w panels) work perfectly, fans a bit noisy sometimes. I just mounted the panels on my back wall, bit of shadow after 3pm but making an average of 130 units/month in total.

SUOER 1000W (VA) Inverter อินเวอร์เตอร์ ON GRID TIE INVERTER GTI-D1000B ประกัน 1 ปีเต็ม | Shopee Thailand

 

 

Thanks for sharing.

 

You mentioned : SUOER 1000W (VA) Inverter อินเวอร์เตอร์ ON GRID TIE INVERTER GTI-D1000B ประกัน 1 ปีเต็ม | Shopee Thailand

 

Forgive my ignorance, can you please share the meaning/implications of the words 'ON GRID'.

 

Also, is your whole system with or without batteries?

 

Thanks again.

Edited July 21, 2021 by scorecard

[BritManToo]

3 minutes ago, scorecard said:

You mentioned : SUOER 1000W (VA) Inverter อินเวอร์เตอร์ ON GRID TIE INVERTER GTI-D1000B ประกัน 1 ปีเต็ม | Shopee Thailand

 

Forgive my ignorance, can you please share the meaning/implications of the words 'ON GRID'.

Also, is your whole system with or without batteries?

Thanks again.

I'm an advocate of small distributed power generation.

I feel those that put all their solar panels on one larger unit are making a mistake they'll regret later.

On Grid means, if the mains electricity fails, your solar cells stop producing electricity at the same time.

 

There's no battery in my solar system, 3 panels plus 1 GTI = 3 units electricity production a day for an investment of around 12,000bht (3 panels x3k, 1 GTI x2k5, 500bht steel/welding). Cheap to set up, easy to fix if anything fails. All that can really fail is the GTI at a loss of 2,500bht.

 

I do have a separate Suoer 1kw 'pass through' inverter and 100AH battery to keep my computer/TV/entertainment powered during power cuts of up to 3 hours.

[Crossy]

14 minutes ago, scorecard said:

Forgive my ignorance, can you please share the meaning/implications of the words 'ON GRID'.

 

Same as "grid-tie", no batteries.

 

[scorecard]

On 7/21/2021 at 2:09 PM, BritManToo said:

I'm an advocate of small distributed power generation.

I feel those that put all their solar panels on one larger unit are making a mistake they'll regret later.

On Grid means, if the mains electricity fails, your solar cells stop producing electricity at the same time.

 

There's no battery in my solar system, 3 panels plus 1 GTI = 3 units electricity production a day for an investment of around 12,000bht (3 panels x3k, 1 GTI x2k5, 500bht steel/welding). Cheap to set up, easy to fix if anything fails. All that can really fail is the GTI at a loss of 2,500bht.

 

I do have a separate Suoer 1kw 'pass through' inverter and 100AH battery to keep my computer/TV/entertainment powered during power cuts of up to 3 hours.

Hope you don't mind If I ask a couple more questions:

 

1. You mentioned "I do have a separate Suoer 1kw 'pass through' inverter and 100AH battery to keep my computer/TV/entertainment powered during power cuts of up to 3 hours." We're also located in Chiang Mai (Urbana 1 village on the superhighway just after Big C Don Chan on the road South), here we get an occasional black out but mostly fixed within a few minutes. The only equipment we have which would be a problem if the power is off for several hours or more is the fridge. Being on line/using notebooks etc., can wait a few hours. So can I guess that we probably don't need 'Suoer 1kw 'pass through' inverter and 100AH battery to keep my computer/TV/entertainment powered during power cuts of up to 3 hours' unless of course the price is very reasonable and easy to install. Would appreciate your comment on this.

 

2. In the earlier thread I think it was you (maybe crossy) who mentioned that there's currently a gov't assistance package to buy cells (and maybe other components).  Can you please share a little more detail on this subject.

 

Thanks again.