The impact of variable renewable energy (VRE) sources on an electricity system depends on technological characteristics, demand, regulatory practices and renewable resources. The costs of integrating wind or solar power into electricity networks have been debated for decades yet remain controversial and often misunderstood. Here we undertake a systematic review of the international evidence on the cost and impact of integrating wind and solar to provide policymakers with evidence to inform strategic choices about which technologies to support. We find a wide range of costs across the literature that depend largely on the price and availability of flexible system operation. Costs are small at low penetrations of VRE and can even be negative. Data are scarce at high penetrations, but show that the range widens. Nonetheless, VRE sources can be a key part of a least-cost route to decarbonization.

可变可再生能源（VRE）来源对电力系统的影响取决于技术特征，需求，监管实践和可再生资源。将风能或太阳能整合到电网中的成本已经争论了数十年，但仍存在争议，并且常常被误解。在这里，我们对有关风能和太阳能整合的成本和影响的国际证据进行了系统的审查，以为决策者提供证据，以就支持哪些技术提供战略选择。我们在各种文献中发现了各种各样的成本，这些成本在很大程度上取决于灵活的系统操作的价格和可用性。在VRE渗透率低的情况下，成本很小，甚至可能是负数。高穿透率的数据很少，但表明范围扩大了。尽管如此，