Bid Estimate for Upgrading Electrical Service

[DeFreitas Enterprises]

Inspection of the customer's existing motor load and the nameplate ratings of them is paramount. Motor's not rated for the lower voltage of 208 will be a hindrance.

I am not sure what you are referring to regarding motor loads but they are just an insurance company who uses some lights and computers. They rent out the other space. I think one might actually be a dentist office.

I look forward to auditing this building this coming week.

Thanks for the help so far.

-Alex

 

[al hildenbrand]

Motor loads of concern will not be 120 V motors, as that voltage remains after the conversion from 120/240 to 208 three phase.

Think: air conditioning, air compressors, pumps, heating equipment, etc. Also, consider the dentist's X-ray nameplate.

 

[DeFreitas Enterprises]

Motor loads of concern will not be 120 V motors, as that voltage remains after the conversion from 120/240 to 208 three phase.

Think: air conditioning, air compressors, pumps, heating equipment, etc. Also, consider the dentist's X-ray nameplate.

That's what I thought you were getting at. I'll be thorough on the full site audit. Thanks for the tip.

 

[mbrooke]

One thing that I do not get is how the 10k cap for net metering magically gets removed if it becomes a three phase service.
Part of the reason for the 10k limit is business related, not phase imbalance related.
NG might accept a higher power limit on a three phase connection but still not offer net metering.
So the economically effective size for the system could be smaller based on the timing of the customers own local loads. Exporting power at wholesale rate has a longer payback period than banking it for use at another time.

I disagree, under the right conditions enough solar on one phase will give problems.

 

[kwired]

I disagree, under the right conditions enough solar on one phase will give problems.

Just like excess load on one phase can give problems as well. POCO needs to balance the single phase services across their lines as well as possible.

 

[mbrooke]

Just like excess load on one phase can give problems as well. POCO needs to balance the single phase services across their lines as well as possible.

They do, but not all those customers will have solar, or be in the same location. Any significant co-generation or customer owned generation needs to be 3 phase.

 

[kwired]

They do, but not all those customers will have solar, or be in the same location. Any significant co-generation or customer owned generation needs to be 3 phase.

Key word - significant. 10kVA is not much to a utility company.

 

[DeFreitas Enterprises]

I have attached an excel with the cash flows and graphs for the three phase system. I increased the service upgrade from $20,000 all the way to $50,000.

At $20,000, he has an 18 % IRR and Year 4/5 Payback.
At $50,000 he has a 13% IRR and Year 6 Payback.


From an investment standpoint, the single phase system won't require a service upgrade and gives over a 20% IRR. But from a cash flow, the three phase systems will make the owner aboutr $65,000 more than the single phase system. ($175,000 for three phase compared to $110,000 for the single phase system).