Lawrence Berkeley National Laboratory

Increasing the penetration of photovoltaics (PV) reduces the marginal grid value of PV electricity. Various strategies have been proposed for preserving this value. We analyze the net value (accounting for both cost and grid value) of these strategies in the USA. We find that established and emerging strategies designed to shift the timing of standalone PV generation at the expense of total generation - including orienting monofacial PV modules west or bifacial modules vertically - result in minor net-value benefits or penalties. Adding energy storage to such systems magnifies the net-value loss, because configurations that change the timing of PV production become redundant when the energy-shifting capabilities of storage are added. The largest net-value gains come from strategies that maximize generation (solar tracking plus oversized PV arrays) in conjunction with storage, especially at high PV penetrations. PV systems are long-lived assets. Our results suggest that efforts to promote generation-maximizing strategies today may yield increasing netvalue benefits as U.S. PV and storage deployments continue to accelerate over the coming decades.