1-Family Residential Solar System / Maximum Size
1-Family Residential Solar System / Maximum Size
(OP)
The utility that I currently work for has an approval process for 1-Family Residential Solar Systems that limits the installed capacity to the average annual energy consumption for the previous 2 years of electric billing history.
I have recently "rejected" several such Residential Solar System applications, as the installed capacity was around 2-to-3 times the average annual energy consumption. Before trying to change my utility's approval process, I wanted to check for any "case histories" where allowing Residential Solar Systems with a capacity 2-to-3 times larger than annual energy consumption directly led to problems.
Note that the 1-Family Residential Solar Systems that I am refering to are all less than 10 KW capacity and are connected to the utility 120/240V, 1-phase, 3-wire secondary distribuiton system.
I have recently "rejected" several such Residential Solar System applications, as the installed capacity was around 2-to-3 times the average annual energy consumption. Before trying to change my utility's approval process, I wanted to check for any "case histories" where allowing Residential Solar Systems with a capacity 2-to-3 times larger than annual energy consumption directly led to problems.
Note that the 1-Family Residential Solar Systems that I am refering to are all less than 10 KW capacity and are connected to the utility 120/240V, 1-phase, 3-wire secondary distribuiton system.






RE: 1-Family Residential Solar System / Maximum Size
RE: 1-Family Residential Solar System / Maximum Size
I would think you would also have to consider the peak demand periods - just using average kW would be pretty limiting, since power demand goes way down at night.
RE: 1-Family Residential Solar System / Maximum Size
RE: 1-Family Residential Solar System / Maximum Size
RE: 1-Family Residential Solar System / Maximum Size
RE: 1-Family Residential Solar System / Maximum Size
I cannot see the utility restricting the size of an installation as the more capacity you have, the more time that you will be able to supply all of your own needs with less than full sunlight available.
Some suggestions;
1> Limit the size of the amount of energy backfed into the grid but not the size of the solar array.
2> Develop a requirement for a protection and control package for customers wanting to install systems up to the size of capacity of the service. A part of this package may be an amended tariff to allow demand charges on the account.
You may have a customer using very little or no power from the grid but with the ability to demand full load current from the utility with no notice should their solar equipment fail. The standard justifications for demand charges apply.
3> Customers wanting to install larger systems than this would be subject to a full engineering review of plans and protection packages on an individual project basis.
Bill
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"Why not the best?"
Jimmy Carter
RE: 1-Family Residential Solar System / Maximum Size
Does the "installed capacity" take latitude and panel alignment into account, as well as efficiency of conversion?
RE: 1-Family Residential Solar System / Maximum Size
RE: 1-Family Residential Solar System / Maximum Size
RE: 1-Family Residential Solar System / Maximum Size
RE: 1-Family Residential Solar System / Maximum Size
Also, most of these installations require the meter be changed to a 'net' meter design, anyway.
RE: 1-Family Residential Solar System / Maximum Size
Now I think that is actually foolish of the utilities because they can mine their users for that valuable solar energy and credits if they instead did the standard net metering then continued to pay the customer a wholesale price above that. Many people with too much money would still put up vastly oversized solar arrays to "help the environment" as long as they could make some small amount, and not look like a sucker. Don't forget that the utility can still change "transmission charges" even if the customer net generated gobs of extra power.
It's interesting how the utilities are stuck in an ancient business model. I wish they'd get some entrepreneurial thoughts going.
Keith Cress
kcress - http://www.flaminsystems.com
RE: 1-Family Residential Solar System / Maximum Size
The Oregon PUC requires the investor owned utilities to donate the avoided cost of excess generation to low income energy assistance. Greenies can save the environment and help their fellow man while reducing or eliminating their energy bill. Are they suckers?
Publicly owned utilities have the option of paying the customer-generator for the avoided cost as you suggest.
RE: 1-Family Residential Solar System / Maximum Size
RE: 1-Family Residential Solar System / Maximum Size
RE: 1-Family Residential Solar System / Maximum Size
As to your first response, if the greenies understood that they were helping the poor to cover some of their bills they probably wouldn't feel like 'total'
It would still be better to pay them something to entice larger installs. I would expect large solar capacity in areas with heavy A/C loads would be a huge benefit to those utilities. Especially since the generation would be in step with their heaviest demands and nicely distributed too.
Keith Cress
kcress - http://www.flaminsystems.com
RE: 1-Family Residential Solar System / Maximum Size