Solar cost per kWh

AchmatK

AchmatK

Honorary Master
Joined
Dec 8, 2009
Messages
10,851
Reaction score
9,412
Location
Somerset West
I didn't want to include this in the monthly solar generation thread as its an interesting calculation on its own and can be used for even the smallest PV systems.

What is your current cost per kWh?

Basically the cost to install and all equipment plus any maintenance and upgrade costs divided by the total kWh generated.

My current average cost per kWh is R8.73/kWh as at the end of May 2022.

By the end of this year it should be down to R6.90/kWh and R4.80/kWh by the end of 2023 if I do not spend anything on upgrades or maintenance in that time.
 
AchmatK said:
I didn't want to include this in the monthly solar generation thread as its an interesting calculation on its own and can be used for even the smallest PV systems.

What is your current cost per kWh?

Basically the cost to install and all equipment plus any maintenance and upgrade costs divided by the total kWh generated.

My current average cost per kWh is R8.73/kWh as at the end of May 2022.

By the end of this year it should be down to R6.90/kWh and R4.80/kWh by the end of 2023 if I do not spend anything on upgrades or maintenance in that time.
Click to expand...

what maintenance are you doing or planning to do?
 
Steamy Tom said:
what maintenance are you doing or planning to do?
Click to expand...
Not planning on anything but just thought I'd include it in the calculation.

It could be that a panel need to be replaced or any other component needing repairs not covered by any warrantee.

I haven't spent anything on maintenance yet in the 22 months my system has been up and running.
 
This is what mine looks like from August 2020 to May 2022.

2 upgraded done in that time. First was adding more panels and the second was adding one UP5000 battery a couple of months ago.

Might add another battery by the end of this year. Screenshot_20220613-091941_Excel.jpg
 
R13... said:
I think there's a big saving in convenience. I wouldn't do it purely on ROI, because it probably doesn't have such good returns from a purely financial PoV.
Click to expand...
Agreed but this is not just about ROI.

Having real world data is useful. At my current trajectory I think my cost per kWh will be less than what it would cost to buy from CoCT by the end of 2023.

My wife works permanently from home so trying to factor that benefit into any ROI calculation is not possible.
 
Scooby_Doo said:
Is this math calculated using the total kWh produced or consumed?
Click to expand...

maybe I am confused, but unless you are feeding back to grid, which I am not even up to date on the latest of what is allowed or possible but i am sure 80+% of people do not, how do you produce more than you consume?
 
Steamy Tom said:
maybe I am confused, but unless you are feeding back to grid, which I am not even up to date on the latest of what is allowed or possible but i am sure 80+% of people do not, how do you produce more than you consume?
Click to expand...
He feeds into the grid

For us mortals its based on consumption

System just produces to top up bats and match load thereafter.

1655107154397.png
 
Total consumption would include any consumption from grid as well.

My total consumption is more than my total production.

Total production would either go towards loads or to charge batteries, or in my case, exporting to grid.

I would still go with total production even if you are not exporting.
 
AchmatK said:
Agreed but this is not just about ROI.

Having real world data is useful. At my current trajectory I think my cost per kWh will be less than what it would cost to buy from CoCT by the end of 2023.

My wife works permanently from home so trying to factor that benefit into any ROI calculation is not possible.
Click to expand...
So the CoCT is charging more than 4.8/kWh? That is rather excessive.
 
AchmatK said:
Total consumption would include any consumption from grid as well.

My total consumption is more than my total production.

Total production would either go towards loads or to charge batteries, or in my case, exporting to grid.

I would still go with total production even if you are not exporting.
Click to expand...

Yeah, so I guess what @Scooby_Doo is trying to calculate is more like "New Electricity Cost" = total electricity consumed / total spent on solar + total spent with municipality in same period.
 
AchmatK said:
My total consumption is more than my total production.

Total production would either go towards loads or to charge batteries, or in my case, exporting to grid.
Click to expand...
I'm a bit confused. If consumption exceeds production, then shouldn't there be nothing available to feed the grid?
 
zeb said:
I'm a bit confused. If consumption exceeds production, then shouldn't there be nothing available to feed the grid?
Click to expand...
Your not factoring in night time use which contributes to consumption...
 
Steamy Tom said:
maybe I am confused, but unless you are feeding back to grid, which I am not even up to date on the latest of what is allowed or possible but i am sure 80+% of people do not, how do you produce more than you consume?
Click to expand...


Feedback into the grid would make the calculations harder.

What I am getting at is that if you include "wasted" generation which is never consumed (due to over-spec or whatever) into the calculation that could skew the data away from a like-for-like comparison against a grid-consuming customer. If you do include wasted generation your "price per watt" will be artificially lower. Whereas the actual consumed price per watt will be much higher.
 
Scooby_Doo said:
Feedback into the grid would make the calculations harder.

What I am getting at is that if you include "wasted" generation which is never consumed (due to over-spec or whatever) into the calculation that could skew the data away from a like-for-like comparison against a grid-consuming customer.
Click to expand...

You can't generate power which isn't consumed. We'll I guess you can if you load up and ship out charged batteries, but who does that?
 
You must log in or register to reply here.
Back
Top
Sign up to the MyBroadband newsletter
X