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No, that's not what I'm saying. What I'm writing about has little to do with what SDG & E calls "excess generation", or how SDG & E pays customers for that excess at trueup.
On "Net Surplus Compensation": What users are paid for at trueup is any excess kWh a system may generate over a true up period (~ 1 yr.) that is over and above what the user consumes for that same period (again,~ 1 year) multiplied by the prevailing, blended, average "wholesale" rate" for energy the POCO pays when buys from their sources and then transmits to their customers.
To be clear, that is not what appears on your bill in the table "Net Energy Metering Summary", in the columns "NEM Credits", "Applied Credits" or "Remaining Credits". Those credits as they appear on your bill can only be used to offset usage and charges for that usage.
You will never see that amount or anything close to it on a check from SDG & E. Any "Excess Generation" from SDG & E is currently paid at a rate of ~ $0.03/kWh or so of excess. The "credits" appearing on a bill reflect retail rates as they are in effect per the tariff the bill is working to and are something like an order of magnitude higher than the rate used for the "excess generation credit", which is the "wholesale rate" that SDG & E claims to pay for power that they buy.
Mostly separate from the issue of "Net Surplus Generation" or "net Surplus Compensation" as SDG & E may define those terms:
What I'm writing about in this thread is not about those things. What I'm writing about is a slightly different way of looking at how a residential PV system can be thought of as a "revenue generator" that produces a form of a product that has a certain value and specific use - electrical energy that can be thought of as a type of "revenue" - that can be thought of (in one sense) as the additional money that would be paid to the POCO if the "revenue generator" (more commonly understood to be a PV system) did not exist. That revenue cannot be thought of as money in your pocket to spend in other ways. You can only spend such "revenue" to offset your electric bill.
Along with that is a slight change in thinking about how power goes to and from your home that is away from thinking in some bottom line lump, net sum of usage and incurred expense way to one that separates what a PV system might generate over a year or other period from what a user consumes over the same period before combing the two. Doing so can give additional information that can be useful for decision making with respect to PV acquisition and sizing, and also any plans opr considerations for such things as time shifting of loads and the PITA/$ saving tradeoffs.
If, for system design and sizing purposes, a PV model's output can be defined as a reasonable definition of what a PV system might generate by hour over a period of, say, 1 year, the idea is that, using a model's output of a PV system, such as from something like PVWatts in conjunction with a TOU billing tariff that is a true TOU tariff (like DR-SES for SDG & E customers with PV systems), it's possible to combine generation by hour with the corresponding hourly charge from the POCO for that power generated from the tariff schedules which are a matter of public record and easily obtainable. Then, all such hourly revenue can be summed over a year.
That can be done because all generation for any hour (actually any 15 minute period) is either consumed on site (if power consumption for that period exceeds PV generation for that period), or sent out to the grid (if PV system generation for that period exceeds consumption). Either way, the effect on the bill is the same per kWh generated whether it's consumed on site or sent to the grid.
If a, say, 5kW system generates, say, 9,000 kWh/yr., the quantity of that generation and the hourly value of that generation summed over a year to offset an electric bill will be unaffected by how much electricity the residence that the system is connected to actually uses. Whether the household uses 10,000 kWh/yr, or 15,000 kWh/yr., the value of the 9,000 kWh/yr. that the PV system generates as a means of offsetting the resulting (and variable) electric bill will be unaffected. (and at this time in N. County San Diego, that quantity amounts to ~ $2,250/yr. or so for a 5 kW system billed under DR-SES). The bill will certainly be a larger $ amount for the higher usage, but the system generation and it's worth will be unaffected by use - provided the annual generation is less than annual consumption. Separate from that "Net Surplus Generation" scenario, the owner/user can then spend the $2,250 on as much or any pattern of usage of their choosing. The ~ $2,250 of generation is what it is regardless of usage, again provided that annual usage stays above generation, and again, provided the billing tariff is true TOU without tiers laid over it.
When annual generation exceeds annual usage, that's when the "Net Excess Generation" payment with the much lower per kWh rates happen - One of the best ways to kill system cost effectiveness and pretty much how a lot of users shoot themselves in the foot - provided one big goal of the exercise is to provide the least cost way to supply electricity to a residence rather than get PV for its own sake or some other reason(s).
On "Net Surplus Compensation": What users are paid for at trueup is any excess kWh a system may generate over a true up period (~ 1 yr.) that is over and above what the user consumes for that same period (again,~ 1 year) multiplied by the prevailing, blended, average "wholesale" rate" for energy the POCO pays when buys from their sources and then transmits to their customers.
To be clear, that is not what appears on your bill in the table "Net Energy Metering Summary", in the columns "NEM Credits", "Applied Credits" or "Remaining Credits". Those credits as they appear on your bill can only be used to offset usage and charges for that usage.
You will never see that amount or anything close to it on a check from SDG & E. Any "Excess Generation" from SDG & E is currently paid at a rate of ~ $0.03/kWh or so of excess. The "credits" appearing on a bill reflect retail rates as they are in effect per the tariff the bill is working to and are something like an order of magnitude higher than the rate used for the "excess generation credit", which is the "wholesale rate" that SDG & E claims to pay for power that they buy.
Mostly separate from the issue of "Net Surplus Generation" or "net Surplus Compensation" as SDG & E may define those terms:
What I'm writing about in this thread is not about those things. What I'm writing about is a slightly different way of looking at how a residential PV system can be thought of as a "revenue generator" that produces a form of a product that has a certain value and specific use - electrical energy that can be thought of as a type of "revenue" - that can be thought of (in one sense) as the additional money that would be paid to the POCO if the "revenue generator" (more commonly understood to be a PV system) did not exist. That revenue cannot be thought of as money in your pocket to spend in other ways. You can only spend such "revenue" to offset your electric bill.
Along with that is a slight change in thinking about how power goes to and from your home that is away from thinking in some bottom line lump, net sum of usage and incurred expense way to one that separates what a PV system might generate over a year or other period from what a user consumes over the same period before combing the two. Doing so can give additional information that can be useful for decision making with respect to PV acquisition and sizing, and also any plans opr considerations for such things as time shifting of loads and the PITA/$ saving tradeoffs.
If, for system design and sizing purposes, a PV model's output can be defined as a reasonable definition of what a PV system might generate by hour over a period of, say, 1 year, the idea is that, using a model's output of a PV system, such as from something like PVWatts in conjunction with a TOU billing tariff that is a true TOU tariff (like DR-SES for SDG & E customers with PV systems), it's possible to combine generation by hour with the corresponding hourly charge from the POCO for that power generated from the tariff schedules which are a matter of public record and easily obtainable. Then, all such hourly revenue can be summed over a year.
That can be done because all generation for any hour (actually any 15 minute period) is either consumed on site (if power consumption for that period exceeds PV generation for that period), or sent out to the grid (if PV system generation for that period exceeds consumption). Either way, the effect on the bill is the same per kWh generated whether it's consumed on site or sent to the grid.
If a, say, 5kW system generates, say, 9,000 kWh/yr., the quantity of that generation and the hourly value of that generation summed over a year to offset an electric bill will be unaffected by how much electricity the residence that the system is connected to actually uses. Whether the household uses 10,000 kWh/yr, or 15,000 kWh/yr., the value of the 9,000 kWh/yr. that the PV system generates as a means of offsetting the resulting (and variable) electric bill will be unaffected. (and at this time in N. County San Diego, that quantity amounts to ~ $2,250/yr. or so for a 5 kW system billed under DR-SES). The bill will certainly be a larger $ amount for the higher usage, but the system generation and it's worth will be unaffected by use - provided the annual generation is less than annual consumption. Separate from that "Net Surplus Generation" scenario, the owner/user can then spend the $2,250 on as much or any pattern of usage of their choosing. The ~ $2,250 of generation is what it is regardless of usage, again provided that annual usage stays above generation, and again, provided the billing tariff is true TOU without tiers laid over it.
When annual generation exceeds annual usage, that's when the "Net Excess Generation" payment with the much lower per kWh rates happen - One of the best ways to kill system cost effectiveness and pretty much how a lot of users shoot themselves in the foot - provided one big goal of the exercise is to provide the least cost way to supply electricity to a residence rather than get PV for its own sake or some other reason(s).
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