kugelfish

In this previous post , we looked at  how much of the current electricity demand could be met directly if the entire production were based on solar and wind. The observation was that depending on the country, about 70-80% could be covered in real-time by scaling up an optimal mix based on the current solar & wind generation capacity. This would leave about 20-30% of unmatched load at some times and the same amount of surplus at other times. In this post , we looked at how storage and in particular under-utilized car batteries could be used to help balance the grid between times of over and under-production. Another potential approach of increasing the balance between supply and demand would be to improve geographic diversity across wind or solar generation beyond the synoptic scale of common weather pattern which is in the order of a thousand or more kilometers. The image above shows the site of the Laufenburg substation , where in 1958 the national grids of France, Germany an...

Most cars stand around most of the time. The average driving distance per car is 30-40 km - even in the US and trips over 100km are quite rare ( less than 4% ). Assuming, some number of heavily used vehicles - taxis, service vehicles etc. means that there is a long tail of vehicles which might not move at all for several days except maybe the occasional trip on a week-end. Assuming some future state where (nearly) all cars are going to be electric, we will have a very large number of big batteries on wheels mostly standing around mostly under-utilized and already paid for by their owners. As we have seen in this previous post, there would be a significant imbalance on a weekly timescale between load and generation in a primarily wind & PV based power grid. Given the large amount of already paid for storage capacity, it would be temping to use it as grid storage (V2G vehicle-to-grid) over these time-ranges where investment in dedicated grid storage might be hard to economically jus...