007 RED

@croftrobin  Just to illustrate the point that @Crossy has made above regarding the CT, I have attached below a graph taken from my inverter monitoring facility on the day that the meter reader came on the 16/12/22. 

 

The CT was switched into the NO EXPORT mode in order to stop any excess power being fed back into the grid and making the meter disc spin backwards.  Something that must be avoided at all cost when the meter reader comes.

 

As you will see from the graph below with the system in NO EXPORT mode, the blue production line never exceeds the red consumption line.  In fact the production line endeavors to mirrors the consumption line.

 

The large consumption spikes (e.g. 2.5kW) during the early afternoon were as a result of my better half baking bread.  Because my small scale system normally produces around 1.2kW maximum with good sunshine, the inverter could not match the consumption, hence the consumption spikes become very noticeable.

 

FYI.... When I say that the CT is switched into the NO EXPORT mode, I mean literally that.  Between the CT and the inverter I have a simple 'light switch' as shown below.  With the switch in the 'open' position the inverter can feed excess power into the grid.  With the switch 'closed' the CT can then communicate with the inverter (e.g. power consumption) and prevent the export of any excess power.  Simple, even my better half can operate it when necessary.

 

 

@Scouse123   "This is an area I know nothing about but I am seeing more and more frequently in home shops and various other stores Solar panels being advertised.

 

We have our own large detached Bungalow in the North East, (well three actually), and I was wondering if they are worthwhile investing in and do they provide the savings to warrant the purchase?

 

My family members have them in the UK but they also did a deal where they sold surplus back to the national grid and it worked well for them although the subsidies they initially got in the UK are coming to an end.

 

I know those things are not possible in Thailand."

 

If you are going to consider going totally off grid with solar and Electrical Storage System (batteries), then you don't need to involve your local PEA, but it's going to cost you mega bucks unless you are competent to DIY.

 

If you want a grid tied system that will feed any surplus power back into the grid and get paid for it, then you cannot DIY.  You are going to need to employ an installer who has been approved by your local PEA. This will involve a mountain of paperwork.  The installation supervisor must hold a BSc in electrical engineering, and be licenced to practice plus he/she must be onsite throughout the install.  The panel mounting (roof etc) must be inspected and certified by a licenced Chartered Civil Engineer thatthe roof etc can accommodate the weight of the panels and wind forces and that the proposed fixings conform to the EGAT requirements.  Once the install has been completed it must then be inspected/approved by the PEA senior engineer who in turn will then forward the mountain of paperwork to EGAT to get their approval for you to feedback into the grid  The list of bureaucracy is endless.  Such an install is also going to cost you mega, mega, bucks.  At the end of the day your local PEA will only pay you peanuts if for any feed into the grid if, and its a big if, they supply you with a meter that will record both consumption and feedback.  Hence your ROI is going to be a really long term investment.

 

FYI... If I recall correctly, one forum member has been waiting several years for a feedback meter to be installed by his PEA and he's not received a single Baht for what his system has been feeding back to the grid during that period.

 

Have I put you off the idea of going solar?  I hope not, because it really depends upon what you want to achieve at the end of the day.

 

I installed a small scale DIY grid tied solar system on my car port roof 14 months ago.  It comprises 4 x 415W half cut mono solar panels which are connected to a 2kW Sofar grid tied inverter.  The system produces approximately 75% of our daily electrical needs.  We don't have an ESS.   The total cost of the hardware was 28,000 THB (no labour costs as I did everything myself). 

 

 

 

In the first 12 months the system saved us just over 11,000 THB on our electricity bills, so I anticipate that the ROI is going to be about 2.5 years.  The only down side of such an installation is that it makes the meter disc spin backwards and because such action is frowned upon by the local PEA I need to ensure that the meter reader never sees the meter spinning backwards, or that we go into negative meter reading.

 

Hope this helps.

I just watched a short video on BBC World News concerning the sinking of this ship.  The video showed the ship listing heavily on its port (left) side.  The video looked as though it was taken from a rescue helicopter's FLIR unit.

 

I have taken a screen shot (below) from the video.  I would seriously question what looks to be possible damage midships below the water line.

 

If this is damage, then that would explain why the ship initially listed  to the starboard (right) side as water flooded into the lower compartments and then the swell pushed it over to the port side as seen above.

 

The past month (16 Nov - 16 Dec) has been really naff so far as my small scale solar system  production was concerned.  The weather has been well below par with many days having lots of clouds.  Even when there were minimal clouds, it was very hazy.  I also noted that the sun is now much lower towards the Southern horizon most of the day which also hinders solar production.

 

Below is my production graphs for the billing period Nov -Dec. which clearly shows that I failed to meet mt target of producing 75% of our electrical needs ????.

 

 

 

Note:  From the above graph it will be seen that on the 24th November the system only managed to produce about 1.5 units and I needed to purchase 5 Units from the PEA to meet our needs.  On that day we had very heavy clouds and it poured with rain for most of the day (lot of local flooding as a result).

Yesterday (15/11/22) was meter reading day, and we were presented with a massive bill for 57 units amounting to 239.86 THB, which equates to 4.2 THB per Unit.  This is the lowest that we've had since installing our small scale system some 13 months ago.  The system appears to be performing well given the fluctuation in weather conditions during the past month, as shown in the graphs below.

 

 

 

 

 

On 10/23/2022 at 7:37 PM, JAS21 said:

If you were to be given a ‘no export’ meter…how many units (kwh’s) do you think you would have to pay for in one month?

An interesting question.   I think it’s not “if”, but “when”.  That said, as TIT the “when” could be any time from tomorrow or sometime in the next millennium.  Who knows?

 

My small scale system (4 x 415 W panels connected to a 2.2kW GTI) in theory should be capable of producing 1.66kW under laboratory conditions.  However, given that we are living in the real world, the system is more likely to produce about 1.2kW under good sunshine and assuming 6 hours of decent sunshine a day, the system should be capable of producing around 7 units a day ????.

 

Although we have a range of household appliances, including a couple of air conditioning units, my wife and I are somewhat conservative electricity users.  Prior to installing the solar system, PEA billing records for the previous 2 years indicated that we were using on average 10 units/day.  So when I designed the system, I did so with the objective of the system being capable of producing a maximum of 75%, or 7 units/day, in order to avoid any risk of producing negative meter readings.

 

The graphs below for the current billing period shows that our small scale system is currently producing 65% of our needs, leaving us to purchase 35% from the local PEA.

 

 

It should be noted that weather conditions this month have been mainly overcast with the occasional heavy downpour, hence the somewhat lower than hoped for production yield ????.

 

As I type this post, the monitoring facility is showing that the solar panels are producing 1.24kW and hence my meter is merrily whizzing around backwards due to the nice blue sky and nice bright sunshine ????.  Obviously if the meter were to be replaced with an electronic type thus preventing backwards spinning, I will not be able to ‘store’ my surplus power in the grid for use when the sunshine disappears behind a cloud.

 

I have noticed from the system’s monitoring facility that on the couple of days when my system is in the NO EXPORT mode prior to the meter reader coming, the system appears to almost keep ‘pace’ with our needs, except for short periods when we are using the shower heater, water pump or washing machine.

 

I envisage that if/when the PEA install an electronic meter, because we are relatively low electrical users, we will only need to purchase a few additional units a month and I may well then consider installing an additional solar panel to compensate for the loss of 'free' storage convenience. 

 

Due to the high costs associated with hybrid systems, and our low consumption, I have no plans to go down the ESS route.

Today, 6/10/22, celebrates the 1st ‘birthday’ of my small scale grid tied solar system, so now is an opportune time to take stock and assess its performance during the past 365 days.

 

Background

 

The system comprises 4 x 415W half-cut mono panels connected in series to a 2.2kW Sofar grid tied inverter.  The system was a DIY project, so there were no labour costs, just my time and effort.  The total cost of the hardware worked out at a tad over 28,000 THB.

 

We (my wife and I) consider ourselves to be ‘conservative’ electricity users with our bills, prior to installing the solar system, averaging around 1,000 THB per month.

When I designed the system, I decided that the main objective of the system would be to reduce our electricity bills by approximately 75%.  This would ensure that we didn’t get into a situation where the system generates negative readings when the meter reader calls.

 

Under laboratory conditions, the 4 x 415W solar panels should be capable of producing 1.66kW, but of course were not living in a laboratory.  In reality, the panels are more likely to produce around 1.25kW in good sunshine.  Therefore, assuming 6 hours of good sunshine a day, the system should be able to produce (1.25 x 6) 7.5kWh a day, which is the figure that I considered to be the target for the system.

 

What has the system achieved during its first year of operation?

 

According to the system’s monitoring facility, it has generated 2,590kWh during the past 365 days, or an average of 7.1kWh per day.  Attached below is a graph illustrating what the system has produced, and what we purchased, since 6/10/21 to date.  I have also included what we purchased during the 9 months prior to the system becoming operational for comparison purposes.

 

Looking at the graph below, it may be seen that we have slightly increased our consumption since the system became operational.  I'll blame this on my better half who says that our electricity is free now ????.

 

 

Since the system became operational it has produced approximately 70% of our household electrical needs, resulting in us only having to purchase about 30% from our local PEA.  Although slightly lower than what I had hoped for, I still consider this to be perfectly acceptable, particularly given that the system was running in ‘NO EXPORT’ mode for nearly 3 weeks during May/June (See Note 1 below), and with very overcast conditions during late September/early October due to the monsoon season.

 

Taking the cost of electricity as being 4.2 THB per unit (See note 2 below), the system has saved us (2,590 x 4.2) 10,878 THB during its first year of operation.

 

Return on Investment

 

If the system continues to produce the same output level over the next couple of years, it would be reasonable to assume that it will have paid for itself (28,000 / 10,875) in just over 2.5 years.  Obviously if the price per unit of electricity increases, then the Return on Investment will be shorter ????.

 

Problems

 

Not wishing to speak to soon ????, but thankfully during its first year of operation there have been no major problems with the system. 

 

Shortly after turning the system on, I discovered that a MC4 cable connector (from the solar panels to the DC breaker box) was getting very warm.  Upon investigation I realized that I had not fully crimped the cable inside the connector.  Thankfully, this was identified/rectified before any real problems.  Definitely my bad.

 

The only maintenance the system has needed was to clean the panels on a couple of occasions to remove dust/dirt, although I’m not sure that this had any profound effect on the system’s performance.

 

Will I up-grade the system?

 

At this stage no.   I’m very satisfied with the system’s performance and hopefully it will continue to provide a reasonable daily contribution to our electricity fund.  If, and it’s a big if, the local PEA decide to replace our disc type meter with an electronic one, then I will have to seriously consider increasing the number of solar panels and possibly installing a second inverter.

 

Note 1.

I had to put the system into ‘NO EXPORT’ mode for almost 3 weeks during May/June because the new build house opposite was nearing completion and the electrical contractor had run the supply cables from the house to the pole outside our house, which also has our meter on it.  As we had no idea how long it would be before the local PEA would come to install the meter for the new house we decided to go into a ‘safe’ mode, as we obviously didn’t want the meter installer to see the disc spinning backwards on our meter.

 

Note 2.

The figure that I have used (4.2 THB per unit) was the average that we paid per unit during the 9 months prior to installing the system.

 

Note 3.

On a light-hearted note.  I recall a forum member some time ago suggesting that I was “penny pinching” by saving a few Baht a day.  Well, I would ask, other than a ‘Ponzi scheme’, what investment is going to give me nearly 38% interest per annum.?

 

If I was to put 28,000 THB into a basic bank savings account for the past year, I would be extremely lucky to get about 1,400 THB back in interest.  Then to add insult to injury, whatever interest is paid would be automatically reduced by X% ‘with-holding tax’. 

 

So, at the end of the day a Return on Investment of 10,626 THB  could well be considered a worthwhile payback.

1 hour ago, carlyai said:

I thought I saw someone here who installed 3 phase solar. 

I thought it was red007 but think I'm mistaken.

Sorry...... Not guilty.... I'm definitely on single phase supply.

1 hour ago, MJCM said:

Another question, this time about NO-Export

 

Suppose you have NO-Export turned on, and your house is only using let's say 300W, but the Panels are producing (again let's say) 1500W.

 

Where does those approx 1200W (difference between usage and producing) go instead of going into the grid?

As @Crossy has indicated above, it really never gets generated.  My inverter (Sofar 2.2kW GTI) can be set to export from zero to 100%.  I have it set to zero and activate 'NO EXPORT' a couple of days prior to meter reader visiting.  During the 'NO EXPORT' period the Current Transformer (CT) which is clamped over the live wire between the consumer box in the house and the meter on the pole outside is sending feedback to the inverter as to how much power we are using in the house.  The inverter then adjust itself to only produce enough power such that no power is exported thus making the meter spin backwards.

 

Take a look at the graph below produced from the system's monitoring facility the day before the meter reader came.  The system was in 'NO EXPORT' mode, and shows power production (blue) against power consumption (red). 

 

You will notice that at times the consumption 'hits the roof' and the system tries to match that demand but fails abysmally because there was not enough sunshine hitting the photocells.   You will also see that at other times the power production equals the power consumption even when there was good sunshine (mid-day) thus illustrating that power production is matching power consumption.