Hi all Powerknobs,

Im new to the forum and joined to learn more about solar

Already earmarked a system with an installer but still have lots of questions.

Im sure i will get a lot of knowledge here.

2 hours ago, Intaka said:

Hi all Powerknobs,

Im new to the forum and joined to learn more about solar

Already earmarked a system with an installer but still have lots of questions.

Im sure i will get a lot of knowledge here.

Welcome and fire away and list all the detail like panels, Inverter and proposed battery you intent using. 

Welcome

18 hours ago, Scorp007 said:

Welcome and fire away and list all the detail like panels, Inverter and proposed battery you intent using. 

@Scorp007, thank you.

I own a guest house with 14 rooms. In Aug 2018 we had a 3 week period with no electricity which forced me to install gas geyesers and a small 6.5 kva generater.

This was also the time of loadshedding more often so the decision was made to change electrical hotplates. All hot plate and kettles were replaced with gas stoves and non electrical kettles.

After all the changes usage history of over a year showed daily kwh usage of between 50 and 70 during peak periods. This depends based on the nuber of bookings we receive. So monthly usage average out on 1800. In our quiet times it can drop as low as 900 a month.

We run a water harvesting system with 1.0kw Tallas inverter pump and a 1.5kw pump for moving water to the main holding tanks.

I decided on setup of a SunSync 16kw Hybrid inverter, 36 Canadian 555W pv and 3 x 10kw Volta batteries. Would have prefered the SunSync battery but its Rk10 more per battery. That Rk30 can contribute to the pv mounting structure.

Any suggestions re the above setup would be appreciated.

7 minutes ago, Intaka said:

@Scorp007, thank you.

I own a guest house with 14 rooms. In Aug 2018 we had a 3 week period with no electricity which forced me to install gas geyesers and a small 6.5 kva generater.

This was also the time of loadshedding more often so the decision was made to change electrical hotplates. All hot plate and kettles were replaced with gas stoves and non electrical kettles.

After all the changes usage history of over a year showed daily kwh usage of between 50 and 70 during peak periods. This depends based on the nuber of bookings we receive. So monthly usage average out on 1800. In our quiet times it can drop as low as 900 a month.

We run a water harvesting system with 1.0kw Tallas inverter pump and a 1.5kw pump for moving water to the main holding tanks.

I decided on setup of a SunSync 16kw Hybrid inverter, 36 Canadian 555W pv and 3 x 10kw Volta batteries. Would have prefered the SunSync battery but its Rk10 more per battery. That Rk30 can contribute to the pv mounting structure.

Any suggestions re the above setup would be appreciated.

In order for assistance based on information provided can you just give a approximate area and the angle and directions of the panels. 

Is this a single-phase 80A supply to the property, or a 3-phase supply?

Is the 6.5kVA generator enough to run the property on in the absence of the grid? What is your load profile looking like during the day, and what's your highest instantaneous power consumption on these 14 units? I'm imagining something like high morning usage with breakfast, toast, etc. then little to no guests during the day, but housekeeping and water management. And then an evening rush when all the guests come in. How many heaters are being run in the rooms at any time in Winter?

Will you be going off-grid, or will you keep connected to the grid?

Just trying to understand better to see whether any tweaking makes sense, but your plan seems like a good base to work from already.

1 hour ago, Intaka said:

@Scorp007, thank you.

I own a guest house with 14 rooms. In Aug 2018 we had a 3 week period with no electricity which forced me to install gas geyesers and a small 6.5 kva generater.

This was also the time of loadshedding more often so the decision was made to change electrical hotplates. All hot plate and kettles were replaced with gas stoves and non electrical kettles.

After all the changes usage history of over a year showed daily kwh usage of between 50 and 70 during peak periods. This depends based on the nuber of bookings we receive. So monthly usage average out on 1800. In our quiet times it can drop as low as 900 a month.

We run a water harvesting system with 1.0kw Tallas inverter pump and a 1.5kw pump for moving water to the main holding tanks.

I decided on setup of a SunSync 16kw Hybrid inverter, 36 Canadian 555W pv and 3 x 10kw Volta batteries. Would have prefered the SunSync battery but its Rk10 more per battery. That Rk30 can contribute to the pv mounting structure.

Any suggestions re the above setup would be appreciated.

I assume you have 3 phase power there? 

May be a good idea to use the 3 phase machines then. 12kw, or even push up to the 50kw, for future growth. You could run with 30kw of battery for now and add more as finances permit 

15 hours ago, GreenFields said:

Is this a single-phase 80A supply to the property, or a 3-phase supply?

Is the 6.5kVA generator enough to run the property on in the absence of the grid? What is your load profile looking like during the day, and what's your highest instantaneous power consumption on these 14 units? I'm imagining something like high morning usage with breakfast, toast, etc. then little to no guests during the day, but housekeeping and water management. And then an evening rush when all the guests come in. How many heaters are being run in the rooms at any time in Winter?

Will you be going off-grid, or will you keep connected to the grid?

Just trying to understand better to see whether any tweaking makes sense, but your plan seems like a good base to work from already.

@GreenFieldsWe have single phase. The genie has been replaced with a 8kw and it seems to handle load better. Only problem during loadshedding is guests ignore requests not to use microwaves, electric kettles (non-selfcatering rooms still have electric kettles) and also not to use irons. The 8kw genie supply all lights inside/outside, all tv's, decoders, fridges. The main kitchen do use a microwave during loadshedding.

Funny enough our load profile day vs night very much the same 50/50 winter time and 60/40 summer time.

From memory highest peak was bout 80kwh/day but this mainly winter time or when fully booked. I do not have any instantaneous peak info. But it is highly unlikely that everything will be switched on at the same time. If that would happen, surely it will trip at municipal supply pole. In fact the pole did trip once before in winter when we were fully booked and all rooms were fitted with small elecric heaters. At 5:30 in the morning when staff started breakfast the load was just too much. End of story, no more heaters in rooms and now all beds fitted with electric under blanket warmers. Problem solved.

We will be grid-tied, but honestly, the less i can use municipal electricity and not to worry about loadshedding wil make me extremely happy.

 

Edited May 15, 20242 yr by Intaka

15 hours ago, abd7 said:

I assume you have 3 phase power there? 

May be a good idea to use the 3 phase machines then. 12kw, or even push up to the 50kw, for future growth. You could run with 30kw of battery for now and add more as finances permit 

@abd7 We are on single phase.

15 hours ago, GreenFields said:

Is this a single-phase 80A supply to the property, or a 3-phase supply?

Is the 6.5kVA generator enough to run the property on in the absence of the grid? What is your load profile looking like during the day, and what's your highest instantaneous power consumption on these 14 units? I'm imagining something like high morning usage with breakfast, toast, etc. then little to no guests during the day, but housekeeping and water management. And then an evening rush when all the guests come in. How many heaters are being run in the rooms at any time in Winter?

Will you be going off-grid, or will you keep connected to the grid?

Just trying to understand better to see whether any tweaking makes sense, but your plan seems like a good base to work from already.

@GreenFields Few things I forgot to mention in my first post.

Future plan is to fit inverter aircons to all rooms and dining hall. Currently only 2 rooms fitted with ac.

I have a workshop on site and do welding, grinding, painting etc from there. This might be a problem when on solar. Not sure how I am going to handle this one. Suggestions please guys.

With so many aircons etc and what seems like a big operation, probably best to get 3 phase power from eskom. 

Thereafter you can decide on essentials / non essentials and wire accordingly for whatever inverter you decide on. 

Edited May 15, 20242 yr by abd7

@abd7 I agree but the municipal costs quoted I can just as well put on another 16kw system. Crazy what they charge and I most defenitely dont want to be dependant on the local municipal supply. 5 years forward it will be 100times worse than now.

3 hours ago, Intaka said:

@GreenFields Few things I forgot to mention in my first post.

Future plan is to fit inverter aircons to all rooms and dining hall. Currently only 2 rooms fitted with ac.

I have a workshop on site and do welding, grinding, painting etc from there. This might be a problem when on solar. Not sure how I am going to handle this one. Suggestions please guys.

Take a smoke break. Or don't put it on the backed up circuits.

You have a 16kW inverter. It will probably allow short bursts over that for a couple of seconds, but if the load on the backed up circuits exceeds 16kW you are running into trouble. The inverter will trip. If it's half-way decent it will reset after a minute or so. But if the high load persists then it will trip again.

If the batteries don't trip first, and since you have 15kWh of battery, they likely will.

You are going to have to live with compromises. 

I'm not an electrician, so I don't want to comment on how you can split up the house and especially the rooms so that they can have lights but no microwave. Heaters will also cause problems, hair dryers - anything that makes stuff hot. Fridges don't use much power when they're running, but there is a short (milliseconds) peak when the motor starts up, unless you have newer fridges with inverter drives. 

I think you're underspecced. You want to fit aircons. If those are to be backed up then build a system now that will have the capacity.

 

If your business is properly registered with SARS and you don't have any ongoing disputes, you can probably write off the system quite quickly. Then the problem is if you have or can raise the tax cash for a larger system. Get a tax consultant to advise you.

Edited May 15, 20242 yr by Bobster.
tax/cash

22 hours ago, Intaka said:

@Scorp007, thank you.

I own a guest house with 14 rooms. In Aug 2018 we had a 3 week period with no electricity which forced me to install gas geyesers and a small 6.5 kva generater.

This was also the time of loadshedding more often so the decision was made to change electrical hotplates. All hot plate and kettles were replaced with gas stoves and non electrical kettles.

After all the changes usage history of over a year showed daily kwh usage of between 50 and 70 during peak periods. This depends based on the nuber of bookings we receive. So monthly usage average out on 1800. In our quiet times it can drop as low as 900 a month.

We run a water harvesting system with 1.0kw Tallas inverter pump and a 1.5kw pump for moving water to the main holding tanks.

I decided on setup of a SunSync 16kw Hybrid inverter, 36 Canadian 555W pv and 3 x 10kw Volta batteries. Would have prefered the SunSync battery but its Rk10 more per battery. That Rk30 can contribute to the pv mounting structure.

Any suggestions re the above setup would be appreciated.

I have dealt with similar setups as you are describing. I don't know which installs are the worst to deal with guest house or gauard houses not the installation but the people and guests. I had a similar installation in the Drakensberg on a guest farm. People on holiday or business away from home will have kettles,toasters,hairdryers that will be plugged in no matter what your rules are. The problem escalates as the venue becomes busier. 

The problem you currently have is the utility supply that would max out at 14kw before you start tripping supply breakers. You need to hard manage the supply to each room. The way i normally manage this is by installing ECU..( energy controll)units on each supply to the rooms but to successfully achieve this each room needs to have seperate supplies with dedicated sub breakers, plugs lights aircon ect. You will then use the plug curcuit to deactivate high current loads like aircons ect. You will need a electrician that understand load shifting and load control to design the best outcome for your specific needs. Attached a link to a short video explaining the working of the ECU.

Ps. The 16kw SS inverter can pass through 200A continuous and surge rating of 32kw for 10 seconds in islanding.( off grid)mode.

 

After good replies I will just add to perhaps have a dedicated socket say at the TV which is wired via a DB that is fed from the inverter but limited via the adjustable setting of a Sonoff pow2/3 say at 4A. This is fed from the inverter. Then have the fridges on another socket circuit which might not be on the inverter. Sonoff controlled via phone for on and off and power allowed before tripping. Using this gadget means you can from remote switch on the socket if it did trip. I take it there is WiFi on via inverter 24/7.

Provide a green/red pilot light and guidelines that when red is on the premises are on LS and normal sockets will be off but the TV socket has power 24/7 but with limited output for TV, phones and laptop only. 

No suggestion yet for the future aircons. That could be part of a future expansion. 

Edited May 15, 20242 yr by Scorp007

3 hours ago, Intaka said:

@abd7 I agree but the municipal costs quoted I can just as well put on another 16kw system. Crazy what they charge and I most defenitely dont want to be dependant on the local municipal supply. 5 years forward it will be 100times worse than now.

In rainy/ cloudy weather you will be forced to use the municipal power generally, and with 14 aircons etc I would seriously do a load assessment and determine if the single phase municipal supply can handle whatever you have planned. Before choosing your inverter, this is important.

Unless you have way too many batteries or a big enough generator , the municipal power is needed even with the best solar system. 

Edited May 15, 20242 yr by abd7

Thank you everyone for your valuable input. Some of the comments made me realise that this is a much complicated issue. So many things to consider.

The biggest concern is the whole premises was wired not with a guesthouse in mind.

Keep in mind we have 5 guest rooms in the main house with a reception, lounge kitchen and dining hall. Two stand alone 2-bedroom houses seperate from each other each one with their own sub DB's. Then another stand alone building with its own sub db (fed from another sub db) consisting of 2 guest rooms, a laundry and a double garage. Then there is a rondawel with its own sub db. There is also a stand alone outside guest room with its own sub db. There is another standalone double garage with its own sub db. And lastly there is the workshop section with its own sub db. This makes it impossible to have dedicated circuit breakers for TV and charging essentials/non-essentials set up from the sub db's. What makes matters worse is different rooms share same circuit breakers for plus or lights. Imagine you have sub DB2 fed from sub DB1 feb from main DB. My thinking is the whole premises should be rewired which we cannot afford. 

What are the alternatives??

Any advise suggestions?

56 minutes ago, Intaka said:

Thank you everyone for your valuable input. Some of the comments made me realise that this is a much complicated issue. So many things to consider.

The biggest concern is the whole premises was wired not with a guesthouse in mind.

Keep in mind we have 5 guest rooms in the main house with a reception, lounge kitchen and dining hall. Two stand alone 2-bedroom houses seperate from each other each one with their own sub DB's. Then another stand alone building with its own sub db (fed from another sub db) consisting of 2 guest rooms, a laundry and a double garage. Then there is a rondawel with its own sub db. There is also a stand alone outside guest room with its own sub db. There is another standalone double garage with its own sub db. And lastly there is the workshop section with its own sub db. This makes it impossible to have dedicated circuit breakers for TV and charging essentials/non-essentials set up from the sub db's. What makes matters worse is different rooms share same circuit breakers for plus or lights. Imagine you have sub DB2 fed from sub DB1 feb from main DB. My thinking is the whole premises should be rewired which we cannot afford. 

What are the alternatives??

Any advise suggestions?

I'm wondering if you couldn't consider going for off-grid inverters while still keeping the grid and generator as backup for charging and running critical loads. For the price of a 16kW Sunsynk you could nearly get 6 Luxpower SNA5000 inverters, and that would be coupled with 30kWh of 1C batteries (compatibility TBC). Maybe you could cluster the inverters to supply different sub-sections of the property. Not sure if it's not still too much solar for your grid supply, or if that limitation only applies to grid-tied; you really are under-powered for your planned needs.

16 hours ago, abd7 said:

In rainy/ cloudy weather you will be forced to use the municipal power generally, and with 14 aircons etc I would seriously do a load assessment and determine if the single phase municipal supply can handle whatever you have planned. Before choosing your inverter, this is important.

This 👆

It is very expensive and quite difficult to go completely off-grid, for the reasons given. There are people who have done it, but they tend to live out in the wilderness, have a big ass generator as a standby, and have to make compromises that won't sit well with paying guests. "Overcast today. Martha. No microwave and no hairdryer honey."

Also when time comes to sell, you will have to find a buyer who doesn't mind not having a grid connection or wants a price drop because they'll have to pay for one and wait for one.

As it is, your electricity bill must be substantial, and a propertly sized and configured system will take a big chunk out of that.

@Bobster. I want a grid-tied system but would like to get as much as I possibly can from a 16kw system without overstepping boundaries.

Even though aircons in every room is a dream of the future this will have to be pushed out much further in the future. So, I am not going to waste time thinking bout that now.

The main focus now is to install a 16kw system and where demand exceed what the system can handle to draw this from the grid.

Yes I know the question, But what if you fully book? Or wjay if its a blackout etc, etc.

Till now we have come by albeit with lots of frustrations and we will just have to deal with it as it arise.

Our current electricity bill is not that high average 900kWh quiete times and 1500kWh fully book times.

But with all the gas geyesers and stove we have a reasonable high gas usage mothly. Estimate R1750 monthly.

 

 

@Intaka I guess you will have to consider spending time/getting input as to change your various DBs in order to take care of limiting power to each unit. The distribution will be key to going forward.

Even if you use 1 big DB with circuits marked clearly for the grid power and the limited power for each unit. 

Just what I would do. 

@Scorp007 thank you for the suggestion. It make sense to do that. A daunting task but not impossible.

Having non essentials for each unit  means running a separate set of cables to each db, which may be a huge cost. 

@abd7 Agree, even a bigger issue is rooms share a bd. Theoretically each room should have its own db.

What are the alrenatives?