Most studies that examine $C{O}_2$-neutral, or near $C{O}_2$-neutral, power systems by using energy system models investigate Europe or the United States, while similar studies for other regions are rare. In this paper, we focus on the Middle East and North Africa (MENA), where weather conditions, especially for solar, differ substantially from those in Europe. We use a green-field linear capacity expansion model with over-night investment to assess the effect on the system cost of (i) limiting/expanding the amount of land available for wind and solar farms, (ii) allowing for nuclear power and (iii) disallowing for international transmission. The assessment is done under three different cost regimes for solar PV and battery storage.

First, we find that the amount of available land for wind and solar farms can have a significant impact on the system cost, with a cost increase of 0–50% as a result of reduced available land. In MENA, the impact on system cost from land availability is contingent on the PV and battery cost regime, while in Europe it is not. Second, allowing for nuclear power has a minor effect in MENA, while it may decrease the system cost in Europe by up to 20%. In Europe, the effect on system cost from allowing for nuclear power is highly dependent on the PV and battery cost regime. Third, disallowing for international transmission increases the system cost by up to 25% in both Europe and MENA, and the cost increase depends on the cost regime for PV and batteries.

The impacts on system cost from these three controversial and policy-relevant factors in a decarbonized power system thus play out differently, depending on (i) the region and (ii) uncertain future investment costs for solar PV and storage. We conclude that a renewable power system in MENA is likely to be less costly than one in Europe, irrespective of future uncertainties regarding investment cost for PV and batteries, and policies surrounding nuclear power, transmission, and land available for wind- and solar farms. In MENA, the system cost varies between 42 and 96 $/MWh. In Europe, the system cost varies between 51 and 102 $/MWh.

大多数研究 $C{Ø}_2$-中立或接近 $C{Ø}_2$-中性，通过使用能源系统模型的电力系统研究了欧洲或美国，而其他地区的类似研究则很少。在本文中，我们将重点放在中东和北非（MENA），那里的气候条件（尤其是太阳能）与欧洲的气候条件有很大不同。我们使用隔夜投资的绿地线性容量扩展模型来评估以下方面对系统成本的影响：（i）限制/扩展风能和太阳能农场的可用土地数量；（ii）允许使用核电和（ iii）禁止国际传播。评估是在三种不同的太阳能光伏和电池存储成本制度下进行的。

首先，我们发现风电场和太阳能发电场的可用土地数量会对系统成本产生重大影响，由于可用土地减少，成本增加了0％至50％。在中东和北非地区，土地供应对系统成本的影响取决于光伏和电池成本制度，而在欧洲则不是。第二，允许核电对中东和北非地区的影响不大，而在欧洲则可以将系统成本降低多达20％。在欧洲，允许使用核电对系统成本的影响高度取决于光伏和电池成本制度。第三，在欧洲和中东和北非，不允许国际传输将系统成本提高了25％，而成本的增长取决于光伏和电池的成本制度。

因此，脱碳电力系统中这三个有争议且与政策相关的因素对系统成本的影响有所不同，具体取决于（i）地区和（ii）太阳能光伏和储能的未来不确定投资成本。我们得出的结论是，与未来有关光伏和电池投资成本的不确定性以及围绕核能，输电以及风能和太阳能农场的土地的政策存在不确定性一样，中东和北非地区的可再生能源系统的成本可能比欧洲低。在中东和北非地区，系统成本在42至96美元/兆瓦时之间。在欧洲，系统成本在51到102美元/兆瓦时之间。