Junior ADU and PGE - Adding Electrical Panel, El Cerrito

Hi! We are in early stages of considering making our bottom floor into a permitted junior ADU (within the existing footprint of the home).

It's my understanding that creating an ADU will require a separate electrical panel.

Our current panel is 100 amps and goes underground to the distribution pole. It's my understanding that replacing/updating our own panel (to, say 200amp) would require digging/trenching/replacing the conduit... and it would be very expensive. (Something I'd like to avoid)

Does anyone know if the Jr. ADU electrical panel would require that underground trenching too? Or does PGE allow "overhead drops" when adding a panel to ADU?

Thank you!

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It’s usually not PG&E that mandates under grounding the electrical, but the City. So I would recommend starting there. Many cities allow JrADUs to share an electrical meter (don’t know about El Cerrito), so you should confirm that you really need to upgrade to 2 meters.

Trenching, new conduit, and a new 2 meter 200 amp service panel is expensive, but might not be outrageous especially if the pole you’re feeding from is on your side of the street. If it’s on the opposite side of the street it will be a lot more.

In any event, it’s worth getting a price from a contractor to trench and put in the conduit before completely ruling it out. You might find that in the overall scheme of the project (an ADU is typically an expensive project) it’s not that big of a percentage of the cost.

We had a similar issue but when the PG&E engineer actually came to our house for our ADU construction and met with us and our electrical contractor they got a lot more creative to justify upgrading the capacity of that underground line. They considered things (if I memory serves) like looking more closely at the loads to see if a panel upgrade was really needed, and considering pulling a new conductor that was a different material through the existing conduit (pulling a new conductor would be relatively easy, digging a new trench would not be). The whole process was messy and not as straightforward as I thought, but perhaps if you can get your team together (including PG&E which is probably the most difficult) you can find an easier solution. That said, if we're going to move towards more electrical appliances rather than gas, maybe a panel upgrade is worthwhile (I'm asking myself this question right now).  On you question about whether you can go overhead for your new drop - do you have power lines out front and do others have overhead drops? On our street everything is underground and there is no other option.

Thank you for your responses! This is all extremely helpful. All very good ideas to think about.

Yes the pole is actually on our property, so it's not that far away (maybe 20-30 feet). 

We added an ADU that had used a subpanel off our a main 100 amp panel. It really depends on what you think the electric load of the ADU will be (ours was relatively low). We were trenching anyway for sewer service to the ADU, so running the electrical underground didn't add much cost.  Also, keep in mind that one electric meter for all units is preferable if you intend to use solar PV.