Afternoon Gents

Long time lurker here and i was hoping some of you solar gurus could be of some help.

Earlier this year my parents had a solar system installed, nothing crazy but enough to hold them by just in case they received some load shedding.

Now the installer did an excellent job and said that we should expect some power saving *nothing drastic but some* with the system installed.

From my understanding everything with a plug was connected to the system except for the pool pump,stoves,microwave and geysers, rest was all connected to the system.

Before the system was installed we replaced every single light in the house with LED and insulated our geysers/dropped the temp slightly also just for that little extra saving.

Well its been about 3 months and this morning i received the power bill via email *as city of JHB still forwards me some of the bills* and daily consumption was at 23kWh.

I thought this was strange and trawled back through my older emails from the city of JHB and all our old powerbills cira 2017  showed pretty much the same consumption of 22/23kWh?

So i messaged my brother quickly who still lives at the house and asked him if the system was up and running.

I told him to send me a pic of the install which i have posted below, I then asked him to open the garage door and see if the inverter was applying a load, and indeed it was.

Make note that no one is at the house from 08:00 till 18:00 so in that time the fridge for example should be running completely off solar if it kicks on?

Pretty much i have no idea why the power usage is the way it is, even after solar. I was expecting atleast some saving but its having no effect on the consumption what so ever.

Any ideas would be great and if any one more clued up in the Randburg area could even stop by and check it out please let me know.

 

Thank you

 

 

Edited June 7, 20186 yr by Launge

Well if that 86W is more or less the base load then I think its safe to say that if that, that load can be powered for say 8 hours a day depending on your array size.

 

That gives you around 700W for the day from the solar (if no one switches anything else on, that can also make use of excess solar power)

and depending to what your folks are prepared to discharge their bank at night there could be another say 2-4kwh worth of power on tap unless they want the batteries to always be full in case they get hit with load shedding in which case you will probably end up only saving lets say 800W a day when someone happens to actually use the power while they are home, obviously over weekends this will be the case, but in weekdays with no-one at home, you are probably only using 800W-1Kwh per day. 

If you want to consume more of your available power: 

-Start discharging your batteries more at night

-Find more ways to power loads at day time when excess solar is available.

 

If you want a cheap great improvement on your power usage, get a solar geyser.

My daily usage is now around 11-13kwh per day  (2 person household), with a solar geyser and I am working on getting that sub 10 

Thanks for the reply, I think solar geyser is next on the cards. 

 

I guess I don't fully grasp this system.

My thought was battery charge fully during the day and they use the bank in the eve but I'm starting to wonder if the inverter priorities the batteries in the eve, so as soon as the batteries drain they pull straight away from Eskom to keep them topped up instead of being drained down?

 

Edited June 7, 20186 yr by Launge

Guys any idea on how I can remotely set the inverter to make it drain batteries in the eve only and and then pull from Eskom top up once the batteries reach a certain voltage?

The questions asked above, is next level. 

Step 1: In the evenings when everyone is asleep, what is using power.
These 24/7/365 base loads, 100w - 500watts, used when people are sleeping, is what costs the MOST ito electricity bill / money wasted.
Find them, switch them off.

Step 2: Now we are getting clever:
To maximize savings, you have to use as much of the solar power during the day as possible. Like heating geyser, washing machine, dang, everything you want to use, us it daytime with little to no batteries used obviously.

Step 3: Do not go below a DOD of below 20% (SOC of 80%) - or whatever one decides - on them Trojans. unless it is needed.
This means that in the evenings, use them batteries to the set level.
To do Step 3 requires some software that will switch the inverter back to grid if the BMV battery monitor reaches 80% SOC.

With these high-level steps, you start saving. I wrote something up here:

http://powerforum.co.za/topic/1902-diy-install-advice-before-i-start-wasting-my-cash/?tab=comments#comment-31931

 

 

86W doesn't sound like much. Can you possibly confirm that it draws more at other times? Especially when something is switched on. I have everything on the same inverter, extect the geyser and stove - though the geyser will go onto the inverter in the new future as well. Our loads during the day idle at about 400W and spike upto 2.6Kw. 

When I did the research for solar the conclusion I came to was that solar payback would be difficult for the people who are away the whole daylight day.

The solar panels are generating power but somebody must be around to use it.

I was away for a break now and switched off everything but the fridges, security and lights.

On my return I found that the daily consumption was 10kwhr (from the prepaid meter). As a basis I I think this a bit high but I am not prepared to fiddle with it.

If you really want to reduce costs you need an intelligent distribution board with timers built into it that can start items like geysers, swimming pool pump and battery charger in a way to utilise the solar panels. This will be very complicated (as well as expensive) to do and I don’t think the power savings will cover the costs.

It is also time to get rid of the high amperage aplliances that run in your house  You mention geysers which must be connected to timers to heat from say 9:00-12:00. And if they still have 3kw elements you can forget about it. So a conversion to an intelligent geyser controller and a fancy titanium element can easily set you back R4k. Per geyser of course. You can buy a lot of kwhrs for that money. Hopefully all of this will be able to fit into your distribution board ;-)

And food preparation needs to go onto gas (same costs as electricity) or slow cookers and other implements using less power than a hob and oven.

Life gets complicated to say the least.

Solar installations is hardly ever about a return on investment and more about having an dependable electricity supply.

I am contemplating installing solar panels now but all of the above cloud the logic into how many and where to install it. And my distribution board is not intelligent and would require manual switching (lol).  As a financial calculation it would hardly makes sense as all my reading shows that I can save 50% off my bill by spending R50k. The saving I can bargain on will be about R600 per month which gives me a payback of roughly +7 years. The saving grace for this calculation is the unknown increases awaiting us and less reliability on municipal power.

And I am still waiting for a solar panel price reduction after the Donald Trump interference in the USA solar imports.

Edited June 12, 20186 yr by Johandup
Expanded a bit.

4 minutes ago, Johandup said:

The saving I can bargain on will be about R600 per month which gives me a payback of roughly +7 years.

If your calculation is correct (it differs for each individual) then a payback of 7 years translates to an ROI of 15% pa - that would be difficult to achieve anywhere else. With unknown Eksdom increases in the future that is likely to improve.

27 minutes ago, pilotfish said:

If your calculation is correct (it differs for each individual) then a payback of 7 years translates to an ROI of 15% pa - that would be difficult to achieve anywhere else. With unknown Eksdom increases in the future that is likely to improve.

Such a calc does not take into account that the original R50k could have been invested elsewhere at about 8% (hahahaha...). That would reduce the ROI to a real 7%.

But no calcs ever work out and the saving is also tax and vat free. 

What puts me off is the complexity of electrical management to get the the most from such a system.

When I go for such a system my capital investment would exceed R150k - only because I am a citizen with a useless government...

Edited June 12, 20186 yr by Johandup

Timers don't need to be complicated. You get one that can be wired into your db board, or ones that you just plug into the outlet. I have a number of them. One runs my borehole pump for 30 mins at 10am, 12 and 2pm, another puts security lights on from 6 to 6, another puts the fridge and freezer off overnight. I don't have electric geysers, but you get very fancy geyser timers that are easy to install. When my system was smaller, I had a monstrous multiadapter with every conceivable charger plugged in to it than was time to run when the sun shone. If you forgot to charge your phone, tough! (wasn't popular though)

Edited June 12, 20186 yr by DeepBass9

51 minutes ago, Johandup said:

Such a calc does not take into account that the original R50k could have been invested elsewhere at about 8% (hahahaha...).

Well the ROI is still 15%, but it is better than your alternative investment by a margin of 7% (if all goes according to plan) - still sounds bloody marvelous!

42 minutes ago, pilotfish said:

Well the ROI is still 15%, but it is better than your alternative investment by a margin of 7% (if all goes according to plan) - still sounds bloody marvelous!

I agree 15% RIO is still amazing especially considering the JSE All Share has only gone up by 15% over the past 3 years...

Edited June 12, 20186 yr by PJJ

52 minutes ago, PJJ said:

I agree 15% RIO is still amazing especially considering the JSE All Share has only gone up by 15% over the past 3 years...

Yup, 15% with less risk than real estate or stocks sounds amazing. Well probably not less than real estate, but definitely less than stocks.

17 minutes ago, plonkster said:

Yup, 15% with less risk than real estate or stocks sounds amazing. Well probably not less than real estate, but definitely less than stocks.

Well my in-laws have a few flats they rent out, and I can safely say this is safer than real estate, their one tenant went 3 months without paying rent and just getting him out to get a paying one in was a mission on its own, and as a nice little cherry on top rental income is subject to tax and this is not

3 hours ago, Johandup said:

Such a calc does not take into account that the original R50k could have been invested elsewhere at about 8% (hahahaha...). That would reduce the ROI to a real 7%.

But no calcs ever work out and the saving is also tax and vat free. 

What puts me off is the complexity of electrical management to get the the most from such a system.

When I go for such a system my capital investment would exceed R150k - only because I am a citizen with a useless government...

.

Edited June 12, 20186 yr by ibiza

On 2018/06/07 at 12:43 PM, Launge said:

Pretty much i have no idea why the power usage is the way it is, even after solar. I was expecting atleast some saving but its having no effect on the consumption what so ever.

Any ideas would be great and if any one more clued up in the Randburg area could even stop by and check it out please let me know.

Ideally you should have your loads during the day to coincide with your production.  I think you system is idly along as there is virtually no load on it and then probably at night you are on grid. The next day you have no batteries to charge as the are still full and you have very little load.

On 2018/06/07 at 2:10 PM, Launge said:

Guys any idea on how I can remotely set the inverter to make it drain batteries in the eve only and and then pull from Eskom top up once the batteries reach a certain voltage?

Manie's ICC and you can VPN into the machine running his software.

 

On 2018/06/10 at 7:45 PM, SilverNodashi said:

86W doesn't sound like much. Can you possibly confirm that it draws more at other times? Especially when something is switched on. I have everything on the same inverter, extect the geyser and stove - though the geyser will go onto the inverter in the new future as well. Our loads during the day idle at about 400W and spike upto 2.6Kw. 

I agree with Silver your loads look light/insubstantial.

Can you tell us what are the settings on your Axpert?

4 hours ago, PJJ said:

Well my in-laws have a few flats they rent out, and I can safely say this is safer than real estate, their one tenant went 3 months without paying rent and just getting him out to get a paying one in was a mission on its own, and as a nice little cherry on top rental income is subject to tax and this is not

Yup, I'm a landlord too. I've had the non-paying tenant issue as well, but I was lucky, I took a softer legal option (there are companies that step in and handle this for you) and got payment. Didn't have to do a formal eviction which is a real pain since the PIE law.

(Ironically this law, which is supposed to protect tenants, actually made rentals more expensive).

But the reason I said that real estate might still be a slightly lower risk is because it generally has better resale value than solar equipment, and because you generally need a house to mount the solar equipment on, so the one is sort-of dependent on the other. If the housing market gets hurt in a big way (say government tampers with property ownership laws for example), the solar market will be toast too.

In terms of rental income though you are right, solar is likely the better investment.

25 minutes ago, plonkster said:

(Ironically this law, which is supposed to protect tenants, actually made rentals more expensive).

Yup, as the saying goes, the road to hell is paved with good intentions. 

 

28 minutes ago, plonkster said:

But the reason I said that real estate might still be a slightly lower risk is because it generally has better resale value than solar equipment, and because you generally need a house to mount the solar equipment on, so the one is sort-of dependent on the other. If the housing market gets hurt in a big way (say government tampers with property ownership laws for example), the solar market will be toast too.

For sure, you are also capped in terms of your "return" based on the amount of power you would have bought, since we can't sell excess power your RIO would also always be tied to this, so there is only so much "return" to be had, whereas you can go and buy as many flats/shares/cows as your hearth desires in seek of a investment return.

 

But something people more often than not consider, if you are looking for a high yielding, tax free investment, look no further! Its called paying your debt

CC, Store accounts, Personal loans - 18-28% -Interest 

Car loans - 11-15%- Interest

Home loans - 9-12% Interest 

Obviously if you are using gearing and climbing the property ladder with other peoples money debt is great, but  T's and C's apply

But you are obviously a clever bloke so I feel like I am preaching to the choir  

ROI on solar at 15% ... I really cannot see that happening. 

Paul did the sums, comparing it with a investment of same amount. It is here on the forum somewhere.

What caused an issue, was that the repair / replacements costs over the period, was difficult to quantify.

30 minutes ago, The Terrible Triplett said:

What caused an issue, was that the repair / replacements costs over the period, was difficult to quantify.

That's why I'm always going on about the warranty. It isn't everything, there is a large marketing part in it (if the comeback number is low enough over x years, then you advertise x years), but it is somewhat of an indication of the confidence the manufacturer has in his product. Especially electronics that run 24 hours a day :-)

14 minutes ago, plonkster said:

That's why I'm always going on about the warranty

The problem with that is that you pay for the risk that the company takes. Fair market would be low price low warranty high risk to your self and the other way around. 

On ROI

Just for fun  

13 hours ago, Johandup said:

I can save 50% off my bill by spending R50k

The assumption would be  that if you spend R1200 per month on your bill that should put you around 1000 kwh per month ( Pulled a quick average price per kwh form the net) 

1000/30 = 33 kwh per day or 1.3 kw per hour base load - now that is sort off normal 

A R 50k system is fairly small ( It is too late to search for what R 50 k would buy now a days but a while back a 345 system would cost about R90k ( 3 kw Panels , 4oo ah bats , 5 kva Inverter)
So you will have to reduce your base load to make the system work well and not hammer that bats to much. By making some lifestyle changes you can reduce you base to as low as 10 kwh per day and all of a sudden your bill falls to R 400 per month and that can be achieved without Solar , but with a solar geyser that will cost you a few bucks.

You will be hard pressed to get a ROI of 15% with those low values. 

BUT this is only applicable IF you look at it from a cost perspective and most of us dont as there is nothing more lekker than boiling the kettle and knowing it comes from the Sun.

Just for fun here is some stats for the last 6 moths at my place 

First the total energy used by the house from January 

The last 30 days 

As it is now winter I started to heating the geyser with the panels  so the consumption per day is increasing but the grid units is still on about 100 per month so solar is used. 

Grid units used 

 

It did took a while but as you can see it can be done!

 

Been thinking on this a bit. 

This post is to give more thoughts, NOT debate or argue the merits of solar. We all are different with different needs and applications. 
This post assumes you have Eskom, and not on a farm relying on a generator. Then solar makes a HUGE sense.

Also to note, if you want to tinker with solar, stop reading. Go forth and enjoy. But forget a ROI. ;-)

If you want to save money, then continue reading and give this some serious thought before you spend once cent on solar.

The ROI solar installers gooi out, the "savings / planet / whatnot", they take your current consumption over say 12 months, and quote you a system, and they do not include replacements costs - that I have seen. And they use scare tactics on Eskom increases, that for the last 6 years, has not materialized at all. 

And each time Eskom increases their charge per kwh, we can avert thatswitch more things off to keep costs contained. 

Solar installers miss:
1) That to save, you must use the power in the day. Trick is, most users are at work. When the family returns, most of the power is used at night.
2) Change your lights LED's. Now how is that a saving? Lights work on batteries and per kwh, Eskom is cheaper by far when you think batteries + inverter + + + to power the lights.

The real savings, as Paul touched on, starts with "lifestyle" changes, A++ electrical equipment etc, and Switch. Things. Off. ... to go from +-R1200 down to +-R600 per month, without solar.

So now that we are on R600pm, equipment being A++ and all that (which cost a pretty small fortune to do), now we go solar and bring that down to wot, R150pm.

How? If you put in a lot of effort and very clever systems with switches and all that, you can optimally use solar during the day, true.
But, here is the part no-one tells you, at night, we switch even more things off to protect the overuse of the batteries.

Now here is a thought, actually a must before anyone goes solar, I believe.

Once you have reached half of your original bill, now switch off the DB board, when all goes to bed. T&C apply for like alarms etc.
Or if no-one is home during the day, switch off the DB then.

The 24/7/365 loads are the biggest cost factor. Once they are mastered, you can be on Eskom on +-R150 pm if your geyser is on EV tubes, and the family takes 90 second showers(to save water) so the geyser never uses Eskom, as geysers where the biggest load for most houses at one time.

Kettle, microwave, bah, they don't use enough power kwh wise, to spend on solar to save. They DO push up the solar costs to carry the peak loads, and not trip the whole system.

So, FIRST lower you consumption to the bare bare minimum, it is a HUGE effort. 
Then look at the ROI of solar, for I bet, most of your usage is at night.

Same logic goes for grid-tied, if you don't use that power during the day, you are wasting money.

So very true . Started with 660 KWh/month now using about 40 kWh/ month .We are pensioners and use solar as much as possible . Replaced globes with LEDs and most equipment at least A+ . For me it is not about the money , I know I can't do better than big power stations . But if you life in an area where the substation fuses have to be replaced up 3 times per week ( Can take up to 4 hours ) and you can see the oil leaking out the transformer you wonder how long it will still last . I will pay more and enjoy solar as a hobby . It is nice to know that alarms is always on and no frustration when the power is of .

i think very soon the cost per kWh coming out of the batteries will fall substantially below the cost from the grid. The moment this happens all solar systems will have batteries and all the tricks we use at the moment to maximize daytime solar use will be a thing of the past. The only issue will be to optimally size the individual components for the specific application. No more tinkering! It will be boring and a lot of us will have to find a new hobby .

49 minutes ago, Fuenkli said:

The moment this happens all solar systems will have batteries

That's when Scheduled Charging will also become a thing. Electricity distributors will incentivise use of electricity in low-demand times, and people will charge their batteries (and their cars) at these times.

Of course in Africa we're in for serious amounts of trouble, because the funding model includes cheap and free electricity for the disadvantaged. That funding model would have to change.