Virtual Power Plants Figure 2: Renewable Intermittency
ISO/wholesale market participation and/or distribution management? One way is through the use of Virtual Power Plants (VPPs). VPPs are an aggregation
of customers (i.e. residential, commercial or industrial) under one type of Pricing, Demand Response or Distributed Energy Resource program. While that concept sounds very similar to today, the key differentiators is that a VPP is defined at a more granular level than just the overall program. No longer do utilities need to group all customers with a particular program under one umbrella. The VPP concept allows utilities to aggregate these programs by type and location in the distribution topology or some other agreed upon aggregation. Why do this – grouping customers into segmentation based
on specific geographic or distribution definition? Segmentation provides the utility with better forecast and analytical information about the value these particular customers (and ostensibly programs) can bring to the utility (Figure 1). Grouping also allows a utility to collect customers under the same program into different group structures based on the utility’s needs. For example, the distribution organization may group customers into VPP’s that fit their distribution model, while the retailers or generators group customers by city or some other higher–level aggregation. Providing the flexibility to group customers based on the business need provides a lot of added value that is not necessarily available today. Providing segmentation not only improves forecasts but can
dramatically improve operational decision making. Another component of a VPP is that it contains plant-like characteristics that mimic a traditional generation plant. An example of a plant-like characteristic includes where a DR program might stipulate that the utility cannot shed a customer’s air conditioning unit more than once a day. This type of constraint would be an execution constraint. Other constraints could include a capacity forecast, customer payments (i.e. cost of running the program), opt-out limits and others. By assigning these attributes to an aggregation of customers under the same program, utilities can begin to determine which VPPs should be called upon against the rest of a utilities operational portfolio. Based on these decisions, VPP’s can then be dispatched based on the pricing or environmental constraints as part of the utility’s entire generation portfolio.
104
In that respect, VPPs represent the next generation of DR as integrated strategic resources for the utility company.
Dynamic Pricing & Demand Response with VPPs Forecasting can be a difficult process across a major utility’s
No longer do utilities need to group all customers with a particular program under one umbrella
geographical area, as residential and commercial customers (and their participation) vary greatly. A very good example is customers in Colorado Springs react quite differently to prices for the same program than customers 100 miles away in Boulder. While the physical gap is small, residents’ philosophies are significantly different due to socio-economic factors, regional weather patterns, even political views. Aggregating all of these customers together into one forecast limits the ability for utilities to truly understand which customers may be more reliable in program participation compared to others. VPPs can reduce the forecasting risks that utilities feel today. A utility can create VPPs that aggregate each available program at a distribution level or some other smaller geographic area. This means for each type of pricing, DR or DG program there would be a VPP for each commercially significant transmission zone or region. Each VPP would have a specific forecast for each program type and region. This more granular forecast would not only provide more accuracy in the forecast but also identify those VPP’s which more consistently participate when called upon.
While improving forecasts gives utilities a better idea of price
responsiveness to particular programs, the real challenge is how to choose to operate your generation in concert with the load. When optimising the portfolio, utilities should include pricing as well as direct load control programs as part of that optimization. Utilizing the concept of VPPs allows generation and integrated utilities to treat them as another operational plant, with standard attributes including maximum capacity, minimum capacity, ramp-up, ramp-down, etc.. And based on
worldPower 2010
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148