As previously noted, Article 36 TFEU only prohibits ‘arbitrary discrimination’, thereby enabling the Member States to adopt measures which discriminate against products based on their origin if the discrimination is based on objective grounds and is necessary to achieve the legitimate aim pursued. Measures based on other ‘overriding requirements relating to the public interest’ have traditionally been regarded as not allowing for any discrimination. In recent years, however, this distinction has become increasingly blurred, and the Court of Justice has even accepted explicitly discriminatory measures outside the ambit of Article 36.
As early as 1992, in the so-called Wallonian waste case, the Court of Justice found that a prohibition against importation and subsequent disposal of waste from other Member States or from regions of Belgium other than Wallonia could be justified with reference to protection of the environment.      The Court actually described the measure as one that could not be regarded as discriminatory/4 This was rather bewildering since the Court had confirmed that even non-recyclable and non-reusable waste is to be considered as goods. It is thus hard to see how a national measure that explicitly treats waste originating outside a specific region less favourably than waste originating in that region itself could be anything but discriminatory.75 However, referring to the ‘particular nature of waste’ and the principles of self-sufficiency and proximity set out in the Basel Convention on the control of transboundary movements of hazardous wastes, the Court found that the differences between waste produced in different places and the connection of the waste with its place of production enabled national measures to make a distinction based on origin without thereby being discriminatory. By emphasising the particular nature of waste the Court was able at the same time to reaffirm that imperative requirements can be taken into account only in the case of measures which apply without distinction to both domestic and imported products/6
In Aher-Waggon, decided in 1998, a discriminatory measure without any connection to waste—a German rule according to which aircraft that had previously been registered in another Member State had to meet strict noise limits when being registered in Germany, whereas aircraft that had already obtained German registration before the noise limits were adopted could retain that registration—was accepted by the Court of Justice without any mention of discrimination/7 The Court also broadly referred to the possibility that the measures could be ‘justified by considerations of public health and environmental protection’ without distinguishing between human health and other environmental concerns. More significantly, it did not base its acceptance of the German measures on the provisions of Article 36 TFEU but instead found that Article 34 did not preclude the national legislation at issue. Without explicitly saying so, it thus appears that the Court used the doctrine of mandatory requirement to justify a de iure discriminatory measure.
In PreussenElektra, decided in 2001, the Court of Justice was asked to rule on a German law requiring electricity supply undertakings operating a general supply network to purchase the electricity produced from renewable energy sources in their area of supply at minimum prices, thereby guaranteeing the producers of renewable energy a higher income than they could otherwise expect/8 Since the obligation to buy electricity from renewable energy sources applied only within the scope of the specific statute and thereby only to renewable energy sources in Germany, it was evident that the national measures made a distinction based on origin. The Court initially established that an obligation placed on traders in a Member State to obtain a certain percentage of their supplies of a given product from a national supplier limits to that extent the possibility of importing the same product from other Member States. The Court also found, however, that when establishing the compatibility of the measure with Article 34 TFEU, account had to be taken of the aim of the provision in question as well as of the particular features of the electricity market. It noted that the use of renewable energy sources for producing electricity is useful for protecting the environment in so far as it contributes to mitigating climate change, which the EU and its Member States have pledged to combat. The Court also referred, inter alia, to the fact that environmental protection requirements must be integrated into the definition and implementation of other EU policies in accordance with what is now Article 11 TFEU. As to the specific nature of energy, it noted that it is difficult to determine its origin, and in particular the source of energy from which it was produced once it has been allowed into the transmission or distribution system.81 By way of conclusion the Court of Justice found, without any mention of discrimination, that in the current state of EU law concerning the electricity market, the German legislation was compatible with Article 34. Once more a national measure that was both de facto and de iure discriminatory had thus seemingly been justified as a mandatory requirement.
In a later case concerning ‘green electricity’ the Court applied another reasoning. In Alands Vindkraf the Court of Justice assessed support schemes for renewable electricity using green certificates according to which certificates were awarded solely in respect of green electricity produced in the national territory of the Member State concerned.82 This time the Court found the national measure to be contrary to Article 34 TFEU since it was clear that the scheme was capable of impeding electricity imports from other Member States. However, it went on to hold that the territorial limitation could be regarded as necessary, and thus justifiable, in order to attain the legitimate objective pursued. Since EU law has not harmonised the national support schemes for green electricity, it is, according to the Court, possible in principle for Member States to limit access to such schemes to green electricity production located in their territory.83 This was perhaps not too surprising, given both the previous case law and the fact that the 2009 Directive on the promotion of the use of energy from renewable sources defines it as ‘essential’ that Member States are able to determine if and to what extent their national support schemes apply to energy from renewable sources produced in other Member States.84 Interestingly, the Court this time made it clear that it considered an increase in the use of renewable energy sources to be designed to protect the health and life of humans, animals, and plants, thereby being among the public interest grounds listed in Article 36 TFEU.85 The justification of the discriminatory certificates scheme can thus not be seen as an example of the Court’s acceptance of non-arbitrary discrimination outside Article 36. However, there are also other cases, not related to electricity markets, in which the Court seems to have accepted that environmental concerns can justify discriminatory national measures without reference to Article 36.86
Despite this rather obvious acceptance of national measures that make a distinction between imported and domestically produced goods outside the ambit of Article 36 TFEU, the Court of Justice has still to recognise explicitly that the nondiscrimination requirement no longer applies, or explicitly indicate under which conditions measures which do not apply without distinction to foreign and national products may nevertheless be justified on environmental grounds.
Among others, Advocate General Jacobs has argued in favour of a more flexible approach to applying the imperative requirement of environmental protection. In support of this position he has held that the obligation to integrate environmental protection requirements into the definition and implementation of all relevant EU policies necessitates special account to be taken of environmental concerns in interpreting the Treaty provisions on the free movement of goods. He has also observed that if environmental measures can be justified only where they are applicable without distinction the very purpose of such measures risks being defeated, since
national measures for the protection of the environment are inherently liable to differentiate on the basis of the nature and origin of the cause of harm, and are therefore liable to be found discriminatory, precisely because they are based on such accepted principles as that environmental damage should as a priority be rectified at sourceA
Although it has yet to be explicitly declared by the Court of Justice, it should be clear by now that environmental measures can in fact be justified as pursuing imperative requirements even when they make a distinction between goods imported from other Member States and those of domestic origin.
-  Case C-2/90 Commission v Belgium (n 65). 74 Ibid, para 36.
-  75 See further eg F G Jacobs ‘The Role of the European Court of Justice in the Protection of the
-  Environment’ (2006) 16 Journal of Environmental Law 185—205, 189.
-  76 Case C-2/90 Commission v Belgium (n 65), paras 34—6.
-  Case C-389/96 Aher-Waggon ECLI:EU:C:1998:357.
-  Case C-379/98 PreussenElektra ECLI:EU:C:2001:160.
-  Ibid, para 70. 80 Ibid, paras 72—3. 81 Ibid, paras 76 and 79. 82 Case C-573/12 Alands VindkraftECLI:EU:C:2014:2037. 83 Ibid, paras 92, 94, and 104.
-  84 Directive 2009/28/EC of the European Parliament and of the Council on the promotion of theuse of energy from renewable sources and amending and subsequently repealing Directives 2001/77/EC and 2003/30/EC  OJ L 140/16, preambular para 25.