8. (20 points) Cost analysis of wind power plus storage: Wind turbines currently can sell all of their output to the grid, without committing how much they will sup when wind power only supplies a small percent of total demand. However, as wind co a greater portion of grid electricity, it will have to be done in a fashion where it can meet a ply. Variability is managed by the grid through reserve capacity, which works ntributes amount. This problem analyzes two approaches to achieving such a more dependable supply: de-rating wind production so that a ready reserve exists vs use of storage batteries. For the analysis of this problem, lets assume that the capital cost of wind is $1400/KW, and has an annual 40% capacity factor. To provide more reliability, assume a de-rating of 2 0%. For the battery option, assume that batteries cost $600/kwh (current cost), and $200/kwh for expected storage concepts. Lets assume that if one one can achieve a 30% capacity factor, and if one used a battery sized at 40% of production capacity, and 40% capacity factor can be guaranteed. uses a battery sized at 20% of capacity, then Use a 16% capital recovery factor, which is based on a 15% interest rate with a 20 year period a) Evaluate the S/kwh cost for the following options: 1) total wind production sold (current case), 2) wind with 20% de-rating (so only a 20% capacity factor), 3) battery sized at 20% capacity, with 30% capacity factor (both storage prices), 4) larger battery with 40% capacity factor (both storage prices). What cost factor(s) where not explicitly analyzed above that could significantly affect the cost estimate? b) c) Wind is highly variable both during the day, and throughout the year. In part (a), we assume a capacity factor to determine expected cost. What other aspect of wind variability should be accounted for, and how would you approach analyzing this issue? 8. (20 points) Cost analysis of wind power plus storage: Wind turbines currently can sell all of their output to the grid, without committing how much they will sup when wind power only supplies a small percent of total demand. However, as wind co a greater portion of grid electricity, it will have to be done in a fashion where it can meet a ply. Variability is managed by the grid through reserve capacity, which works ntributes amount. This problem analyzes two approaches to achieving such a more dependable supply: de-rating wind production so that a ready reserve exists vs use of storage batteries. For the analysis of this problem, lets assume that the capital cost of wind is $1400/KW, and has an annual 40% capacity factor. To provide more reliability, assume a de-rating of 2 0%. For the battery option, assume that batteries cost $600/kwh (current cost), and $200/kwh for expected storage concepts. Lets assume that if one one can achieve a 30% capacity factor, and if one used a battery sized at 40% of production capacity, and 40% capacity factor can be guaranteed. uses a battery sized at 20% of capacity, then Use a 16% capital recovery factor, which is based on a 15% interest rate with a 20 year period a) Evaluate the S/kwh cost for the following options: 1) total wind production sold (current case), 2) wind with 20% de-rating (so only a 20% capacity factor), 3) battery sized at 20% capacity, with 30% capacity factor (both storage prices), 4) larger battery with 40% capacity factor (both storage prices). What cost factor(s) where not explicitly analyzed above that could significantly affect the cost estimate? b) c) Wind is highly variable both during the day, and throughout the year. In part (a), we assume a capacity factor to determine expected cost. What other aspect of wind variability should be accounted for, and how would you approach analyzing this issue