@Cosmacelf: There's a Raspberry Pi in each station that communicates via serial RAPI to the OpenEVSE. We have centralized management system and big data clusters running scheduling algorithms. Stations revert to a safe level of current if the network is lost. We can optimize at the transformer, garage, building, and/or campus levels.
@Vger: Yes, I think the scale for station deployment has been too small. In the bay area, there are many <10 station locations that are mobbed with 50+ EVs. Send an email when done, musical chairs style. I believe we can change all of that without major electrical upgrades...that's coming in our next project! =)
@Cottonwood: Demand charges is one area of optimization. Depending on the location...corporate offices, supermarkets, airports, campuses, there are different arrival/departure profiles that play into this. Fortunately for Caltech, we have our own mini powerplant and quite a bit of solar, so we can have access to relatively cheap electricity during the day. Unfortunately, this is a unique setup in terms of demand charges, so we have to keep that in mind when we deploy to other organizations. We are hoping through these projects our algorithms can suggest how much stationary storage is required to keep demand charges at a minimum...
I'm not sure why the campus prefers 3 phase 208v over single phase 240v. Could be just standardization? Single phase does make a lot of sense especially if it saves on primary side conduct count/cost.
@Chris1howell: Sure! You are welcome anytime...Thanks for building the OpenEVSE, it's been great!
@Abasile: In most cases I have seen, parking rules are king. So as long as there's no parking violation(72+ hours or something, or you block 3 spots horizontally), that should be fine. In fact, we are not painting the spots EV only, there will be some sort of dynamic marking method to designate EV spaces if too many become ICEd. The 50 station can reach something like 90 spots, so I really don't think it will be an issue. It will be a good problem to have if it does! So no, it won't be frowned upon.
@Rush: Thanks for the offer, but we have already sourced all of the 80A J1772 cables...
@Vger: Yes, I think the scale for station deployment has been too small. In the bay area, there are many <10 station locations that are mobbed with 50+ EVs. Send an email when done, musical chairs style. I believe we can change all of that without major electrical upgrades...that's coming in our next project! =)
@Cottonwood: Demand charges is one area of optimization. Depending on the location...corporate offices, supermarkets, airports, campuses, there are different arrival/departure profiles that play into this. Fortunately for Caltech, we have our own mini powerplant and quite a bit of solar, so we can have access to relatively cheap electricity during the day. Unfortunately, this is a unique setup in terms of demand charges, so we have to keep that in mind when we deploy to other organizations. We are hoping through these projects our algorithms can suggest how much stationary storage is required to keep demand charges at a minimum...
I'm not sure why the campus prefers 3 phase 208v over single phase 240v. Could be just standardization? Single phase does make a lot of sense especially if it saves on primary side conduct count/cost.
@Chris1howell: Sure! You are welcome anytime...Thanks for building the OpenEVSE, it's been great!
@Abasile: In most cases I have seen, parking rules are king. So as long as there's no parking violation(72+ hours or something, or you block 3 spots horizontally), that should be fine. In fact, we are not painting the spots EV only, there will be some sort of dynamic marking method to designate EV spaces if too many become ICEd. The 50 station can reach something like 90 spots, so I really don't think it will be an issue. It will be a good problem to have if it does! So no, it won't be frowned upon.
@Rush: Thanks for the offer, but we have already sourced all of the 80A J1772 cables...
