Storage Cost-Benefit Model

[dpinney]

NEED We need an OMF model (like solarFinancial) that calculates how much money a distribution utility can make with batteries.

TODO

• Review the literature and come up with a list of relevant publications. Emphasize Gridlab-D and distribution utilities.
• Find a feeder to develop tests on.
• @dpinney, find a utility partner.
• @dpinney, provide a test real feeder.
• @dpinney needs to provide value stream document handbook thing.

[dpinney]

@jcfuller1, have there been any big papers on using Gridlab to model storage? I mean ones I won't find via googling here in a second.

[dpinney]

Back to @trevorhardy for the moment. Could you help me with:

1. What could be a good taxonomy feeder to test storage on? Maybe 1 of each type, but there are like 50 types?
2. Did we miss any use cases in #66?
3. Who has published on Gridlab-D storage applications? A list of paper titles would be helpful. I Googled but only found conference poster-session stuff.
4. Read some of the Sandia-EPRI-NRECA storage handbook and figure out whether running a .glm could improve any of these use cases?

Basically these are just the steps I would take before talking to utilities to make sure I'd done my homework.

[trevorhardy]

1. Referencing http://gridlabd.me.uvic.ca/wiki/index.php/Feeder_Taxonomy , it looks like there are a few rural feeders. Not knowing what makes a good representative feeder for our purposes, I'd suggest any/all them:
   • R1-25.00-1 - light rural, West Coast climate region, 25kV distribution voltage
   • R2-25.00-1 - light rural, North Central and North East region, 25kV distribution voltage
   • R4-25.00.1 - light rural, non-coastal Southeast and Central region, 25kV distribution voltage
   • R5-12.47-3 - moderate rural, coastal Southeast, 12.47kV distribution voltage
2. See my answer to 4 below.
3. The only ones I've found use electric vehicles as the energy storage. Here's a few that I found but they don't seem to be plentiful: http://www.pnnl.gov/main/publications/external/technical_reports/PNNL-22064.pdf http://qspace.library.queensu.ca/bitstream/1974/8608/1/Taylor_David_J_201401_MASc.pdf http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6135898
4. I spent a bit of time yesterday looking through this document and brainstorming on my own and came up with more questions than answers. Let me see if I can boil those thoughts down.

I think the best use of storage for OMF will depend on the needs of the co-ops. There are many things storage could be used for but the ones that make the most sense will be the ones that the co-ops might actually see a need for. For example, does storage provide capacity credit for them? Do they need to do load-following/regulation themselves or are they able to buy that service from the larger grid? Is renewable integration a problem now or in the near future?

Without specific answers to those questions, here's what I think Gridlab-D could provide some useful insight into the following applications for energy storage:

• Expensive wholesale energy purchase avoidance - This can go by many names and applications but it all boils down to using energy storage to avoid having to pay for energy when it gets expensive. It could be called energy arbitrage or peak-shaving but the batteries behavior is the same: it charges at low load/price times and discharges at high load/price times. Gridlab-D has got this covered through the peak-shaving (also called load-following) function.
• Upgrade deferral - We called this line load relief in #66 but it could also be used to relieve overloading on transformers or other equipment. Again, Gridlab-d has this functionality covered via peak-shaving.
• Renewable support - I don't know if renewables are a significant issue for co-ops but we have basic solar and wind turbine models that can be included in the feeders. I think peak-shaving would probably work here as well.
• Voltage support - As discussed in #66, using the energy storage power-factor regulation function will help with voltage support so Gridlab-D can help out here.
• Power factor correction - Explicitly supported with energy storage in Gridlab-D.

I think there are two complications with all these use cases:

• Can and how can these benefits be stacked? The economics of energy storage make the most sense when applied to multiple use cases simultaneously. Is there a way we can accomplish this in OMF? I think we wall want to find a way to do this if we want to represent energy storage well.
• How do we quantify the benefits energy storage provides? Most if not all of these use cases are savings presented to the co-op rather than a revenue stream. Do we have a good financial analysis method that can be used in these cases?

[dpinney]

v1.0 finished in e47704ed1104e7d88f0fffe47848d8c807f1e507

Delysis assigned before close since he did most of the work.