Hi Paul,
Thank you for the reply and looking into the requests. I also got in touch with Emma to get some clarity on REopt, who was extremely helpful.
I think that there is a manual way to size solar + BESS without using REopt. Emma recommended I direct this to the SAM forum.
I wanted to get your thoughts on the following.
In the attached file, for the solar only case, the NPV is $73,794.4(after -tax), project titled ‘solar only’.
When I model solar with a 250kW/250kWh Battery and peak shaving dispatch option, the NPV reduces to - $86,222.5. This is project titled ‘Battery_case1’.The negative NPV means, that the 250kW/250kWh BESS for demand charge savings does not make a financial case.
I then look at the ‘electricity to load from the battery (kW)’in the profiles tab and notice that the BESS only dispatches 15/20kW (max). This ‘kW’ dispatch appears to line up with the assumption that BESS is incorrectly sized. I also read this as that the BESS only charges/dispatches a certain ‘kW’ when it makes a financial sense to do so.
In the profiles tab(30mins) I review the ‘electrical load(kW)’ and ‘electricity battery power target profiles for automated dispatch(kW)‘. Based on these profiles, I estimate that a decrease in BESS’spower rating and an increase in the energy rating could yield better outcomes. I nominated a new BESS rated at 50kW/250kWh. The NPV changes to +$17,621 with a payback of 9.9years.The savings are approximately the same for solar and solar+BESS (50kW/250kWh) case, the exception being the cash flow is rather negative in the later half of the solar +BESS case.
Anyways, my takeaway is that I do not need REopt to size BESS, I can look at the financial indicators and play with standard BESS sizes to create some options.
Also, do I need to enter anything in the ‘battery dispatch' field under ‘custom dispatch’ option in system design tab? (please ignore project titled
BESSsizing with dispatch).
Many thanks!
