It's not technically feasible, not economically feasible.

这在技术上不可行，在经济上也不可行。

Solar heating is technically and economically feasible.

太阳能供热在技术上和经济上都可行。

Rare earth elements can often be found, but in many areas, it’s not economically feasible to extract them due to low concentrations.

稀土元素经常可以找到，但在许多地区，由于浓度低， 提取它们在经济上不可行。

Well, they also say, the experts, that in order to be economically feasible, it has to come in at 100 dollars a ton or less.

嗯，专家们还说， 为了经济上可行，它的价格必须达到每吨 100 美元或更低。

So all of a sudden, the very energy-intensive process of cracking hydrogen from water becomes economically feasible, and it can be substituted for coal and gas, and that's already being done.

所以突然之间，从水中裂解氢气的能源密集型过程在经济上变得可行， 它可以替代煤和天然气， 而且已经在这样做了。