ABSTRACT

Sustainable electricity systems need renewable and dispatchable energy sources. Solar energy is an abundant source of renewable energy globally which is, though, by nature only available during the day, and especially in clear weather conditions. We compare three technology configurations able to provide dispatchable solar power at times without sunshine: Photovoltaics (PV) combined with battery (BESS) or thermal energy storage (TES) and concentrating solar power (CSP) with TES. Modeling different periods without sunshine, we find that PV+BESS is competitive for shorter storage durations while CSP+TES gains economic advantages for longer storage periods (also over PV+TES). The corresponding tipping points lie at 2–3 hours (current cost), and 4–10 hours if expectations on future cost developments are taken into consideration. PV+TES becomes only more competitive than CSP+TES with immense additional cost reductions of PV. Hence, there remain distinct niches for two technologies: PV+BESS for short storage durations and CSP+TES for longer ones.

抽象的

可持续电力系统需要可再生和可调度的能源。太阳能是全球可再生能源的丰富来源，尽管如此，从本质上讲，太阳能仅在白天提供，尤其是在晴朗的天气条件下。我们比较了三种能够在没有阳光的情况下提供可调度太阳能的技术配置：光伏（PV）与电池（BESS）或热能存储（TES）结合以及聚光（CSP）与TES结合。通过对没有阳光的不同时期进行建模，我们发现PV + BESS在较短的存储时间方面具有竞争力，而CSP + TES在较长的存储时间（也超过PV + TES）方面具有经济优势。相应的临界点为2–3小时（当前成本），如果考虑到对未来成本发展的预期，则为4–10小时。PV + TES仅比CSP + TES具有更大的竞争力，而且可以大大降低PV的成本。因此，对于两种技术仍然存在明显的优势：PV + BESS的存储期限较短，而CSP + TES的存储期限较长。