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> the only good solution (nuclear) has become politically untenable Not just politically: also economically untenable. At the moment, gas peakers remain the o

by GlennS 5y ago

> the only good solution (nuclear) has become politically untenable Not just politically: also economically untenable. At the moment, gas peakers remain the only good solution to this. Hopefully in the future overbuilding renewables or some sort of advancement in storage will work. Unsolved problem for the 2040s. > Can Hydrogen be used to store energy at the scale of a power grid? Probably not because of the inefficiencies. It may well be useful as a kind of "last line of defence" to handle low probability situations where a lot . However, it does seem like it may be the best solution for air travel, and perhaps also shipping and heavy good vehicles.

pfdietz 5y ago
The inefficiency of hydrogen doesn't matter as much for the use cases hydrogen would be good for: long term storage, and rare event backup (like, no wind over Europe for two weeks). There are few charge/discharge cycles for these use cases, so low capital cost is far more important than round trip efficiency.
coderenegade 5y ago
The efficiency argument implicitly assumes that electricity will be scarce, but this is unlikely to be the case if the majority of the world's energy needs are met through wind and solar. To give you an idea of why, Germany and California, at less than 50% renewable penetration, already curtail around 9TWh of energy a year due to mismatched supply and demand. This is enough to charge on the order of 130 million BEVs. As renewable penetration increases, so too does the need to provide statistical confidence in generation capacity. If you want to ensure that your wind farm is able to provide X units of power, say, 80% of the time, you'll be overproducing pretty much constantly. Connecting cities doesn't really change this either, because the problem is one of stochasticity and confidence. In order for two sites A and B to cover shortfalls for one another, it has to be true that both A and B are capable of overproducing, and that at least some of the time, both will overproduce (unless they're perfectly negatively correlated). If you want to ensure that A and B both have enough power with some statistical confidence, then your system will produce excess most of the time.

by GlennS 5y ago

pfdietz 5y ago

The inefficiency of hydrogen doesn't matter as much for the use cases hydrogen would be good for: long term storage, and rare event backup (like, no wind over Europe for two weeks). There are few charge/discharge cycles for these use cases, so low capital cost is far more important than round trip efficiency.

coderenegade 5y ago

The efficiency argument implicitly assumes that electricity will be scarce, but this is unlikely to be the case if the majority of the world's energy needs are met through wind and solar. To give you an idea of why, Germany and California, at less than 50% renewable penetration, already curtail around 9TWh of energy a year due to mismatched supply and demand. This is enough to charge on the order of 130 million BEVs. As renewable penetration increases, so too does the need to provide statistical confidence in generation capacity. If you want to ensure that your wind farm is able to provide X units of power, say, 80% of the time, you'll be overproducing pretty much constantly. Connecting cities doesn't really change this either, because the problem is one of stochasticity and confidence. In order for two sites A and B to cover shortfalls for one another, it has to be true that both A and B are capable of overproducing, and that at least some of the time, both will overproduce (unless they're perfectly negatively correlated). If you want to ensure that A and B both have enough power with some statistical confidence, then your system will produce excess most of the time.