Tandem photovoltaic modules with silicon bottom cells offer a promising route to exceed the single-junction photovoltaic efficiency limit and further lower the levelized cost of solar electricity. However, it is unclear whether continued improvements in efficiency will render tandem modules cost-competitive with their two constituent sub-cells, and with silicon technology in particular. Here, we construct a simple and versatile techno-economic model that, for a given balance-of-systems scenario, calculates the tandem module efficiency and cost from assumed sub-cell module efficiencies and costs. To understand which input conditions are likely to be representative of the future photovoltaic market, we calculate learning rates for both module and area-related balance-of-system costs, and find that the slower learning rate of the latter means that high-efficiency tandems will become increasingly attractive. Further, in the residential market in 2020, the model indicates that top-cell modules could cost up to US$100 m^–2—over twice that of the projected silicon module cost—and the associated tandem module would be cost-competitive if its energy yield, degradation rate, service life and financing terms are similar to those of silicon.

具有硅底部电池的串联光伏模块提供了一种超越单结光伏效率极限并进一步降低太阳能发电成本的有前途的途径。然而，尚不清楚效率的持续提高是否会使串联模块在其两个组成子电池（尤其是硅技术）方面具有成本竞争力。在这里，我们构建了一个简单而通用的技术经济模型，对于给定的系统平衡情况，该模型可从假定的子电池模块效率和成本计算串联模块效率和成本。为了了解哪些输入条件可能代表未来的光伏市场，我们计算模块和区域相关的系统平衡成本的学习率，并发现后者的学习速度较慢，意味着高效的鞣革将变得越来越有吸引力。此外，在2020年的住宅市场中，该模型表明，顶层电池模块的成本可能高达1亿美元。^–2 –是预计的硅模块成本的两倍之多，并且相关联的串联模块如果其能量产出，降解率，使用寿命和融资条款与硅相似，则将具有成本竞争力。