Whilst reading up on the solar metering subject accuracy came up many times. 

This affected people reselling power back to their utilities. 

A lot of posts on this topic are everywhere. 

https://www.sciencedaily.com/releases/2017/03/170303180139.htm

This part caught my attention: The greatest inaccuracies were seen when dimmers combined with energy saving light bulbs and LED bulbs were connected to the system. 

I'm replacing all the LED bulbs I have with CFL's. Why? Because LED bulbs don't last. 🙂 

8 minutes ago, The Terrible Triplett said:

I'm replacing all the LED bulbs I have with CFL's. Why? Because LED bulbs don't last. 🙂 

CFLs don't last either. In my experience they both last about 6 months (for me at least). The cost is similar.

I do however have some of the very first Uniontech LED downlights. I probably bought around 30 of them starting in 2013. Three of them have failed so far.

8 minutes ago, The Terrible Triplett said:

This part caught my attention: The greatest inaccuracies were seen when dimmers combined with energy saving light bulbs and LED bulbs were connected to the system. 

Because it does newtonian integration. You want the area under the graph, so you take a power sample every delta-T seconds, and then the dP value is the watts times delta-T. Sum them all and you get Watt hours. But the accuracy depends on how small delta-T is, and how you measure it (peak value, average value?). It makes complete sense that you're going to over-calculate if you have spikey loads, and I mean spikey on a millisecond scale (which is what dimmers do).

Edited May 14, 20197 yr by plonkster

3 minutes ago, plonkster said:

CFLs don't last either.

interesting. In my case the CFL's last years.

And I HOPE the CFL are more stable on power than the LED's.

And the CFL's are better at night then the LED's. Something about LED lights and how everything looks in their light is starting to irritate me.

Interesting views.

In my case the cfl globes did not last. I replaced the last, which I installed when I switched all over to leds, last week. So far not one of the leds have failed - after more than three years. And they were made in China 😂 

Running on an inverter might make a difference to smooth the supply. 

Of more interest is that metering based on a ct is regarded as accurate. But these systems work out at $500 or more. 

I think that installing kwh meters on the mains income supply as well as the inverter outgoing side is the way to go. At least these meters are still affordable. Then simple record keeping will tell you what's going on. 

All measurements must be tested in some way to see how accurate the readings are.

We tend to accept readings at face value. Even though we've learned to check a car speedometer against a GPS. 

Edited May 14, 20197 yr by Johandup

I fitted around 300 3W LED downlighters in my house to replace the original 50W halogen jobs (300 of those make the meter spin rather nicely).

These were bought in the early days of LED lamps and where around R120 each. None of them have failed in about 4 years. Then I replaced 18 of these in one area with 6W jobs less than a year ago as I needed better illumination (these things are MUCH cheaper now). So far four of them needed replacing. Not because the LED chip itself is failing - it's badly made driver circuitry. Cost pressure is causing them to fail.

I have had 1 LED fail in this week after  just on 7 years running on solar, perhaps the build quality of these new type are of lower standard? and my bedrooms have cfl's of which 5 have had to be replaced in the same period..

23 minutes ago, The Bulldog said:

Cost pressure is causing them to fail.

I've bought cheapies at Pick and Pay. They last about 6 months, but since they are only R35 a pop... I can live with that. The most disappointing was some Osram lamps I bought to use in external fittings. My experience with Osram has always been good. Two of the three failed within two months.

But those early ones I bought, the first 6 was R150 a piece, the rest was R100 a piece... most of them has been here since 2013/2014... only 3 of the 30 has failed. I bought some Ellies downlights around the same time... they are ALL still here and working properly. But I have a couple of Eurolux 4W units... they make more light than the old 5W Uniontech ones... but they don't last as well.

Also, I have mostly MR16s (12V lamps), which takes a lot less strain than the GU10s. The bulk of the work is done by an old iron transformer. Makes for terrible power factor, but solid as a rock.

What gets me lately, and you don't pick it up easily unless people mention the low light, is that the LED bulbs slowly lose their lumens.

Of all the wot +-30 LED bulbs and a few 10w spots I have bought the last 8 years, not one of them are the originals anymore. Mix of cheapies and not so cheapies.

25 000 hours - BWHAHAHAHAHA, whatever.

My pal, he is one of those believers of the more you pay the better the quality, same with him. Also have replaced all his LED's. He now sees it my way: LED's don't last as advertised. 🙂 

What IS encouraging though is that some of you do seem to have successes. Maybe it is something with the power we get. 

But the inefficiency of LED's, the article above that started all this, that was just the cherry on the cake. Going to see what the CG says goes out of the DB versus the claimed wattages of the lights that are on one of these days.

2 minutes ago, The Terrible Triplett said:

inefficiency of LED's

Compared to what? It kicks CFL (15%) and Incandescent (2%) backside all the way to Thursday... even it if only manages around 20% itself. That's luminous efficiency.

1 minute ago, plonkster said:

That's luminous efficiency.

Recently I started buying bulbs on lumens vs watts instead of just the watts. Very interesting.

3 minutes ago, plonkster said:

Compared to what?

You make a good point ... don't throw the baby out with the water.

36 minutes ago, The Terrible Triplett said:

Recently I started buying bulbs on lumens vs watts instead of just the watts. Very interesting.

Long ago someone said to me to do a small division sum, divide those lumens into the wattage. Many 4W lamps now make more light than the 5W lamps of 5 years ago... but of course that must stress the LEDs more, right? This particular someone told me to buy lamps that are less stressed.

I didn't listen to him. I did whatever everyone else does: I buy whatever I can find that seems priced right 🙂 I lucked out with some brands though, or so it seems.

I have bought all the LED bulbs, various types, for the last 8 years from a company in Paarden Eiland called ISD International.

The brand is SMARTGLO.

I did my parents whole house, as well as mine, 8 years ago and have not replaced one single one at their place and only one downlight in mine.

Also started off at just over R 100 a pop, but now they are priced at about R 30. 

Edited May 15, 20197 yr by TheJoker