5 ms·

Running the numbers from sunset to sunrise is extremely optimistic if you want 100% renewables. I've seen estimates of more like 4-7 days. However, that's not

Running the numbers from sunset to sunrise is extremely optimistic if you want 100% renewables. I've seen estimates of more like 4-7 days. However, that's not the biggest problem, current world wide lithium battery production is around 300GWh per year. Typical demand in the UK is around 30GW, even your 16 hours is around 1.5x the current battery manufacturing capabilities. You'd be competing against every car, laptop, tablet and phone manufacturer for that capacity.

ben_w 6y ago
Given battery factories are being built as fast as possible, and given the batteries in the cars are often suggested as overnight storage (and that transport is such a major part of overall power use), I disagree that this a problem. I would instead describe it as an economic opportunity. Also, the cost of grid storage batteries is dominated by the short lifespan rather than by the number of days or hours it can replace supply. If the battery is enough for a week of zero power from all sources in your entire grid, the wear from normal use takes longer to become a significant cost.
- VBprogrammer 6y ago
  Battery factories are being build as quickly as possible. That is certainly true. However we're still at the level where one small countries electricity demand would demand a significant percentage of global production for some years to build out. That puts us many years away from grid storage being useable worldwide. Vehicle to grid is interesting but the number of chargers which currently support it very low. It requires a non-trivial amount of infrastructure to invert high voltage DC from the battery back back to a grid synchronous AC signal. In addition to the extra wear on the battery it's had to see how this would be good value while being acceptable to consumers. In some respects recycling of batteries after their service life in a car is a more interesting scenario for grid storage.
  - Retric 6y ago
    Current manufacturing capacity is irrelevant as we only need to keep up with solar power generation capacity. Assuming 100GWh of battery manufacturing capacity is built per year that will provide a 20h worth of the world’s electricity demand in ~32 years. However that’s quite conservative, we can extend battery manufacturing much faster than that.
    - VBprogrammer 6y ago
      If you are trying to price something which requires more than the annual production capacity you have to account for the impact your own buying is going to have on the price. I'm not sure how you can wave that away.
      - Retric 6y ago
        Steady ramping up production of a manufactured item lowers per unit prices. So, sure considering the price drop is relevant from an adoption standpoint, but manufacturing capacity is what’s at issue not cost.
        VBprogrammer 6y ago
        Electric vehicle production is already constrained by battery capacity. Increasing capacity leads to efficiency which leads to the price going doing. Except when the demand is outstripping supply. Which of us right? I guess we can agree to meet up in 20 years and find out.
        Retric 6y ago
        EV production is only constrained on a month by month basis. Going year over year the ~40% compound annually ramp up in production would hit 100% of new car sales going EV in by 2032. That’s clearly not going to happen so things are slowing down. That said, grid batteries should ideally be using different chemistry to handle the increased charge/discharge cycling.
        6y ago
Retric 6y ago
Anyone assuming you need 4-7 days of backup is modeling insufficient solar power generation. Solar is stupid cheap, just build more is a perfectly viable option. To put things into perspective the fuel cost alone on gas turbines is twice what solar cost. Which means if 50% of all solar energy generated is absolutely useless, it’s still dramatically cheaper than natural gas, which is it’s self dramatically cheaper than coal, and coal is dramatically cheaper than unsubsidized nuclear. Model enough hydro, wind, and solar to provide sufficient power 99% of the time and even on days that fail the failure is minimal. Further, batteries don’t like to be deep discharged, so a price optimized 16 hour reserve includes a more expensive reserve which would require a week of 1% days to eat into. Except on that timescale demand is somewhat flexible which solves the problem.
- VBprogrammer 6y ago
  Perhaps it's worth bearing in mind that London's latitude is somewhere North of St John's Newfoundland, solar still works but it's not nearly as clear cut as it is in California for example. You can't plan for an average of 99% of days because the whole of December has solar irradiance a tenth that of July. We already have >10GWh of pumped hydro storage (most of which at Dinorwig Power Station) which is required to balance a grid with a mixture of Gas, Nuclear and Wind power.
  - Retric 6y ago
    England already imports significant power from France and has large scale wind production. So, it’s local solar production is no more relevant than McMurdo Station in Antarctica. That said the southern tip of England is noticeably better than London. So, having some minimal local production is viable.
    - VBprogrammer 6y ago
      Significant? There is a 2GW interlink with France, typical demand is 30-40GW. Its use generally reflects French over production of Nuclear power. Large scale wind production? Maybe, but it's still less than the nuclear component.

ben_w 6y ago

Given battery factories are being built as fast as possible, and given the batteries in the cars are often suggested as overnight storage (and that transport is such a major part of overall power use), I disagree that this a problem. I would instead describe it as an economic opportunity. Also, the cost of grid storage batteries is dominated by the short lifespan rather than by the number of days or hours it can replace supply. If the battery is enough for a week of zero power from all sources in your entire grid, the wear from normal use takes longer to become a significant cost.

VBprogrammer 6y ago
Battery factories are being build as quickly as possible. That is certainly true. However we're still at the level where one small countries electricity demand would demand a significant percentage of global production for some years to build out. That puts us many years away from grid storage being useable worldwide. Vehicle to grid is interesting but the number of chargers which currently support it very low. It requires a non-trivial amount of infrastructure to invert high voltage DC from the battery back back to a grid synchronous AC signal. In addition to the extra wear on the battery it's had to see how this would be good value while being acceptable to consumers. In some respects recycling of batteries after their service life in a car is a more interesting scenario for grid storage.
- Retric 6y ago
  Current manufacturing capacity is irrelevant as we only need to keep up with solar power generation capacity. Assuming 100GWh of battery manufacturing capacity is built per year that will provide a 20h worth of the world’s electricity demand in ~32 years. However that’s quite conservative, we can extend battery manufacturing much faster than that.
  - VBprogrammer 6y ago
    If you are trying to price something which requires more than the annual production capacity you have to account for the impact your own buying is going to have on the price. I'm not sure how you can wave that away.
    - Retric 6y ago
      Steady ramping up production of a manufactured item lowers per unit prices. So, sure considering the price drop is relevant from an adoption standpoint, but manufacturing capacity is what’s at issue not cost.
      - VBprogrammer 6y ago
        Electric vehicle production is already constrained by battery capacity. Increasing capacity leads to efficiency which leads to the price going doing. Except when the demand is outstripping supply. Which of us right? I guess we can agree to meet up in 20 years and find out.
        Retric 6y ago
        EV production is only constrained on a month by month basis. Going year over year the ~40% compound annually ramp up in production would hit 100% of new car sales going EV in by 2032. That’s clearly not going to happen so things are slowing down. That said, grid batteries should ideally be using different chemistry to handle the increased charge/discharge cycling.
        6y ago

Retric 6y ago

Anyone assuming you need 4-7 days of backup is modeling insufficient solar power generation. Solar is stupid cheap, just build more is a perfectly viable option. To put things into perspective the fuel cost alone on gas turbines is twice what solar cost. Which means if 50% of all solar energy generated is absolutely useless, it’s still dramatically cheaper than natural gas, which is it’s self dramatically cheaper than coal, and coal is dramatically cheaper than unsubsidized nuclear. Model enough hydro, wind, and solar to provide sufficient power 99% of the time and even on days that fail the failure is minimal. Further, batteries don’t like to be deep discharged, so a price optimized 16 hour reserve includes a more expensive reserve which would require a week of 1% days to eat into. Except on that timescale demand is somewhat flexible which solves the problem.

VBprogrammer 6y ago
Perhaps it's worth bearing in mind that London's latitude is somewhere North of St John's Newfoundland, solar still works but it's not nearly as clear cut as it is in California for example. You can't plan for an average of 99% of days because the whole of December has solar irradiance a tenth that of July. We already have >10GWh of pumped hydro storage (most of which at Dinorwig Power Station) which is required to balance a grid with a mixture of Gas, Nuclear and Wind power.
- Retric 6y ago
  England already imports significant power from France and has large scale wind production. So, it’s local solar production is no more relevant than McMurdo Station in Antarctica. That said the southern tip of England is noticeably better than London. So, having some minimal local production is viable.
  - VBprogrammer 6y ago
    Significant? There is a 2GW interlink with France, typical demand is 30-40GW. Its use generally reflects French over production of Nuclear power. Large scale wind production? Maybe, but it's still less than the nuclear component.