Reverse osmosis (RO) is perhaps the most promising desalination technology, but it is facing growing economic challenges when coupled to an intermittent energy supply, such as renewable energy-based grids. A technology with similar components to reverse osmosis is pressure retarded osmosis (PRO), which produces energy from differences in salt concentration (blue energy). However, with the increasing cost-competitiveness of wind and solar photovoltaic renewable energy, PRO faces severe technoeconomic challenges as a stand-alone energy technology. To address cost and energy challenges of both RO and PRO, we propose a framework to intermittently operate RO with an instantaneous, electricity-producing PRO mode by taking advantage of the component overlap and existing infrastructure. Here, we analyze the process and component efficiencies associated with a hybridized RO-PRO system and outline the associated technoeconomic limitations. This approach considered operating PRO by mixing seawater RO brine with either RO permeate or a cheap low salinity water source. The results show that a hybridized system may make PRO viable in a niche subset of conditions, including a combination of relatively cheap water (<$1/m³), pricier electricity (>$0.15/kWh), and with electricity pricing schemes having large differences between lowest and highest prices. This hybridization may effectively allow a hybrid PRO-mode system to act as a cheaper, yet less efficient, salinity gradient energy storage mechanism. However, the economics are extremely challenging unless there is inexpensive, or even free, low salinity water source (e.g. treated wastewater) available.

反渗透（RO）也许是最有前途的海水淡化技术，但是与间歇性能源供应（例如基于可再生能源的电网）结合使用时，它正面临着日益严峻的经济挑战。具有与反渗透类似的成分的技术是压力渗透（PRO），它通过盐浓度的差异产生能量（蓝色能量）。但是，随着风能和太阳能光伏可再生能源成本竞争力的提高，PRO作为独立的能源技术面临着严峻的技术经济挑战。为了解决RO和PRO的成本和能源挑战，我们提出了一个框架，以利用组件重叠和现有基础结构，以瞬时发电PRO模式间歇性地运行RO。这里，我们分析了与混合RO-PRO系统相关的过程和组件效率，并概述了相关的技术经济局限性。该方法考虑通过将海水RO盐水与RO渗透液或廉价的低盐度水源混合来运行PRO。结果表明，杂交系统可以使PRO在特定条件的特定环境中可行，包括相对便宜的水（<$ 1 / m³），较高的电价（> $ 0.15 / kWh），并且电价方案在最低价和最高价之间有很大差异。这种杂交可以有效地允许混合PRO模式系统充当更便宜但效率更低的盐度梯度能量存储机制。但是，除非有廉价甚至免费的低盐度水源（例如经过处理的废水）可用，否则经济学将极具挑战性。