Topic: Electricity generation connects to demand directly, bypasing Transmission and DistributionSubscribe | Previous | Next
Kshitiz Khanal 6/28/2016
67 Views Hi,
I am building a hypothetical energy access model for a rural community. After building the tree and branches in Analysis, when I switched to Diagram, I noticed that Electricity Generation is connected directly to demand, as opposed to connection through Transmission and Distribution, as shown in the attached diagram.
In modeling demand, small 5 W solar PV panels are expected to supply energy for small appliances like radio set, torch, mobile charger. That is why solar needs to connect directly to demand instead of through transmission and distribution.
The problem of connection of electricity generation directly to demand arises only after choosing solar as the fuel for technology like torch light. Till all the fuels for small appliances like torch lights is electricity, demand is connected through transmission and distribution.
So, why is solar affecting the diagram this way? Why other fuels like wood are not?
Help me, please. This is a big problem for the model I am developing.
Rural Nepal Model.leap [9]
Emily Ghosh 7/1/2016
64 Views Hi Kshitiz,
Thank you for attaching your model. You are correct that Demand should be connected to your T+D module, as that is the path through which the electricity fuel flows between production and consumption. However, we are aware of an issue with the Diagram view which occasionally interferes with this, which is why you are not seeing the connecting line. I'm afraid that since we are phasing out the Diagram view in favor of LEAP's new Sankey Diagrams,
http://www.energycommunity.org/WebHelpPro/Views/Sankey_Diagrams.htm
...we can no longer provide support for the Diagram View. Our apologies for the inconvenience.��
I'm afraid I don't understand your second point about solar being used to supply electricity. In your attached model, none of your electricity generation processes consume the fuel "Solar" as a feedstock, and the fuel appears on the demand side only to meet lighting requirements for Energy Access Tier 1 users. This means that in the Diagram view, you should observe the solar resource connected directly to demand, which you do.��
Hope this helps, and please feel free to follow up with additional clarification about how you intend to use solar to meet various electrical end-uses,
Emily & Taylor
Kshitiz Khanal 7/6/2016
54 Views Hi Emily and Taylor,
Thank you for your answer.
If it's the error of diagram view, it's all right. Could I be making any strategic mistake that is making the diagram this way?
Sankey diagrams are beautiful. I have made Sankey Diagrams using JavaScript before, but LEAP has made it easy for me now.
The solar systems in the module are unitary small solar home systems. For Tier 1, they are 5 W solar systems. For higher levels, they may be of higher capacities, eg 100 W. I am not connecting solar home systems to the mini grid.
So, after reading your answer, I created another module in T&D branch for distribution of solar home systems and changed electricity as the fuel in all demand branches that previously had solar. For now the problem seems solved.
My concern, now, is whether it will complicate things when I have to enter the costs of fuel, cost of T&D for both solar home and minigrid. What do you think? Is the modification the correct (or commonly practiced) logical order of things?
I have attached the modified file.
With warm regards,
Kshitiz Khanal
Rural Nepal Model Modified.leap [5]
Taylor Binnington 7/6/2016
53 Views Hi Kshitiz,
There are often two different ways that something like distributed solar generation may be modeled - the first is to represent the systems as a consumption on the demand side of a fuel called "Solar", the other is to represent the technology on the supply side in a similar way to other electricity generation processes. You have begun to adopt the second of these approaches, which is a fine strategy. However, I think you may be confused about the way that LEAP uses different processes to generate module output fuels. I'd like to address these issues before discussing costs.
Recall that a "module" is a collection of on or more processes, each consuming one or more input fuels in order to produce one or more output fuels. Here are two pictures of a simple type of module (like your T+D module) and a standard type:
Keeping this in mind, it's apparent that your process "Solar PV Home Systems", as represented as a process inside your Electricity Generation module, can be used to produce the same fuel - "electricity" - as each of the other processes in this module. This may be fine, but you may also wish to separate the "type" of electricity generated by small solar PV so that it is not simply grouped with the rest of the electricity in your model. This would allow you, for example, to apply a different T+D loss factor for this type of electricity than for the fuel which is simply called "electricity".
There have been a few discussions on the forum about this topic. Please begin by having a look through these:
You're welcome to follow up here with additional questions which are specific to your case.
Good luck,
Taylor
Brief end-note: including two processes which consume the same feedstock fuel in a simple, non-dispatched transformation module (as you have in your T+D module, by including two processes consuming electricity) is ambiguous and should be avoided. This is because as electricity flows through the module, it is unclear which of the loss factors from the two processes will be incurred (in your case, 30% or 0%).