Non-depletable forms of energy and technology are still available when people have used them, or can be produced as quickly as they are used.

They recommend that non-depletable resources (such as software and online tools) should be provided to users without charge.

Only SBSP (space-based solar power) fulfils all the essential criteria: it is low-cost, nondepletable, environmentally clean, and available to everyone. 只有SBSP（太空太阳能）满足所有的基本标准：低成本，不可耗尽，环境清洁，并且每个人都可以使用。