Price difference from PV generated and bought AC energy

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  • bernard
    Solar Fanatic
    • Oct 2014
    • 114

    Price difference from PV generated and bought AC energy

    I am interested in the price that one would get for a single kWh generated with home PV system which got back into the grid (surplus power) and a single kWh that you would normally pay from your local electricity company.

    What is the difference in prices at your location?

    Thank you.
  • SunEagle
    Super Moderator
    • Oct 2012
    • 15125

    #2
    Originally posted by bernard
    I am interested in the price that one would get for a single kWh generated with home PV system which got back into the grid (surplus power) and a single kWh that you would normally pay from your local electricity company.

    What is the difference in prices at your location?

    Thank you.
    Bernard

    Hard to say with all of the different size and types of PV systems out there along with how much someone uses in a year.

    If you keep "energy storage" out of the formula I would say a 6kw grid tie system would have paid for itself in about 9 years where my electric costs have been around $0.13/kWh and usage is a little below 18,000kWh per year.

    Comment

    • J.P.M.
      Solar Fanatic
      • Aug 2013
      • 14926

      #3
      The answer to your question is a large part of why people get PV electricity.

      There are as many answers to your question as there are people to ask. Unfortunately, many/most reasoned answers are a bit complicated (see SunEagle's example).

      For starters, begin by internalizing the concept that it's always cheaper to not use something than to buy or manufacture (generate) more of it.

      Comment

      • bernard
        Solar Fanatic
        • Oct 2014
        • 114

        #4
        Thank you for the replies SunEagle and J.P.M.

        Maybe the question was not that clear, but my intention was not to know how much time I need to pay off the initial capital/maintenance PV costs, and how financially "useful" is to get one.

        I just wanted to know how much do you pay for 1kWh used from your electrical company, in comparison to how much you would get payed for 1kWh generated by your PV system.
        I imagine the former would be a bit higher, but how much higher?

        I understand that this all depends on the amount of ac energy one consumes (the higher amount the more expensive the kWh), state, city, electrical company, PV system... Still, I am interested in individual replies.
        Thank you.

        Comment

        • adoublee
          Solar Fanatic
          • Aug 2009
          • 251

          #5
          Originally posted by bernard
          Thank you for the replies SunEagle and J.P.M.
          I just wanted to know how much do you pay for 1kWh used from your electrical company, in comparison to how much you would get payed for 1kWh generated by your PV system.
          I imagine the former would be a bit higher, but how much higher?
          December or July? With taxes or without? With fuel and purchased power fees or not? Avoidable rate or overall blended rate?

          It's all about rate design and ability to attack if grid interactive.

          Comment

          • SunEagle
            Super Moderator
            • Oct 2012
            • 15125

            #6
            Originally posted by bernard
            Thank you for the replies SunEagle and J.P.M.

            Maybe the question was not that clear, but my intention was not to know how much time I need to pay off the initial capital/maintenance PV costs, and how financially "useful" is to get one.

            I just wanted to know how much do you pay for 1kWh used from your electrical company, in comparison to how much you would get payed for 1kWh generated by your PV system.
            I imagine the former would be a bit higher, but how much higher?

            I understand that this all depends on the amount of ac energy one consumes (the higher amount the more expensive the kWh), state, city, electrical company, PV system... Still, I am interested in individual replies.
            Thank you.
            Too many variables to pin down exactly how much a grid tie pv system is costing to generate each kWh. All you can do is estimate based on data from PVWatts or use basic math concerning the kw size of your system and average amount of useful solar hours you get in a year. You can't come up with a "fixed" $/kWh due to all of the changes with weather and available sun light.

            Or are you asking how much the POCO credits you for "Net Metering". That changes year to year and city to city.
            Last edited by SunEagle; 05-19-2015, 01:54 PM. Reason: added last sentence

            Comment

            • bernard
              Solar Fanatic
              • Oct 2014
              • 114

              #7
              Originally posted by adoublee
              December or July? With taxes or without? With fuel and purchased power fees or not? Avoidable rate or overall blended rate?

              It's all about rate design and ability to attack if grid interactive.
              You can write all of them, if you know them. Or some of them. Thank you.

              Originally posted by SunEagle
              Too many variables to pin down exactly how much a grid tie pv system is costing to generate each kWh. All you can do is estimate based on data from PVWatts or use basic math concerning the kw size of your system and average amount of useful solar hours you get in a year. You can't come up with a "fixed" $/kWh due to all of the changes with weather and available sun light.

              Or are you asking how much the POCO credits you for "Net Metering". That changes year to year and city to city.
              No, not POCO credits.
              PVWatts basically multiplies the annual yield in kWh with some initial set price of currency/kWh.
              But I am not interested in this.

              Just a couple of examples (which as we have seen depend on a lot of factors and vary) on how much do you pay for 1kWh, and how much you get paid when you feed it to the grid. That's it.

              Comment

              • SunEagle
                Super Moderator
                • Oct 2012
                • 15125

                #8
                Originally posted by bernard
                You can write all of them, if you know them. Or some of them. Thank you.



                No, not POCO credits.
                PVWatts basically multiplies the annual yield in kWh with some initial set price of currency/kWh.
                But I am not interested in this.

                Just a couple of examples (which as we have seen depend on a lot of factors and vary) on how much do you pay for 1kWh, and how much you get paid when you feed it to the grid. That's it.
                Again what each customer gets paid selling the excess power to the POCO is based on each POCO and what was the details in the "Net Metering" contract.

                For some people they get paid as little as $0.0/kWh while others get paid exactly what they get charged for each kWh they purchase from their POCO. That is true "Net-Metering".

                Some contracts indicate the "credits" and "charges" are based on the TOU or the volume of kWh consumed based on specific Tier rates.

                I am not sure what you are looking for or what your data base will show you except the difference between what you pay for and what the POCO pays for will be vastly different around the US.

                Comment

                • J.P.M.
                  Solar Fanatic
                  • Aug 2013
                  • 14926

                  #9
                  Bernard: I'm guessing that any meaningful answers to your question(s) may be in a different form than you're expecting and/or needing (25 words or less ?). It's not as simple as you seem to want to want to make it.

                  Comment

                  • solarix
                    Super Moderator
                    • Apr 2015
                    • 1415

                    #10
                    OP is asking how much does the utility "pay" for excess solar generation - not what it costs to generate. Of course this varies with your local utility, but in general - if they are required to offer you "net metering" the price they pay you is equal to what they charge you power used from the utility. In fact, they don't even credit you in dollars, they credit you in the kWh of electricity they've received from you and you can then use that credit to offset your usage at a later time.
                    BSEE, R11, NABCEP, Chevy BoltEV, >3000kW installed

                    Comment

                    • foo1bar
                      Solar Fanatic
                      • Aug 2014
                      • 1833

                      #11
                      Originally posted by solarix
                      OP is asking how much does the utility "pay" for excess solar generation - not what it costs to generate. Of course this varies with your local utility, but in general - if they are required to offer you "net metering" the price they pay you is equal to what they charge you power used from the utility. In fact, they don't even credit you in dollars, they credit you in the kWh of electricity they've received from you and you can then use that credit to offset your usage at a later time.
                      Depends on the state - here they credit you in dollars for net metering. So a time-of-use plan where you generate $10 credit during the day can offset many more kwh bought at night during off-peak.

                      Comment

                      • adoublee
                        Solar Fanatic
                        • Aug 2009
                        • 251

                        #12
                        4.00 cents/kWh in summer months, 3.52 cents/kWh in winter months for every kWh produced beyond kWhs consumed in one billing cycle for net metering customers. So net excess production is monetized at the end of every month, with this dollar amount (net energy credit) carried forward and a check cut at the end of year if credit still exists. Just this takes to much resources for NREL to be able to model accurately with SAM, because even net metering doesn't have one definition.

                        Comment

                        • J.P.M.
                          Solar Fanatic
                          • Aug 2013
                          • 14926

                          #13
                          As I suggested: Seems as many answers as people (and opinions).

                          Comment

                          • foo1bar
                            Solar Fanatic
                            • Aug 2014
                            • 1833

                            #14
                            Originally posted by bernard
                            I just wanted to know how much do you pay for 1kWh used from your electrical company, in comparison to how much you would get payed for 1kWh generated by your PV system.
                            I imagine the former would be a bit higher, but how much higher?
                            I pay ~$.11/kwh for electricity I use from POCO.
                            I get credit at the same rate for power I put into the grid up to the amount of kwh that I use.
                            I get paid $.04/kwh for electricity that I generate in excess of what I use in a year.

                            Friends living 1/4 mile away with a different POCO are using TOU plan.
                            They get credit of $.35/kwh for most of the kwh they generate and put into the grid.
                            They pay $.12-$.15 (can't remember exactly) for kwh they use during off-peak.
                            Once a year they and the POCO have a reckoning. Last year they wound up paying ~$50 because the $ generated wasn't quite enough to cover the $ consumed.
                            They could also have had $0 bill, but used more kwh than they consumed (And the extra $ in credits would have evaporated)
                            The third possibility is if they had produced more kwh than they consumed, they could get a check for ~$.04/kwh for the excess production.

                            Comment

                            • inetdog
                              Super Moderator
                              • May 2012
                              • 9909

                              #15
                              bernard, you can say that you are not interested in rate of return or payoff period, but the simple economics of actually installing a PV system means that unless you specify a period over which to amortize the upfront cost of the system there is no way that you can calculate a cost per kWh of the power produced.

                              The ongoing expenses are minimal out to the estimated 20 year life of the system, but you may not realistically continue to own the property and operate the system for that long. So the way you account for the acquisition costs can make a difference of a factor of two or even more in the calculated cost of solar power.
                              In the case of ground mount you may also need to take into account other uses you would be making of the real estate if the panels were not there.
                              SunnyBoy 3000 US, 18 BP Solar 175B panels.

                              Comment

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