2. Paragraph 1 shall be without prejudice to the possibility for transmission system operators to develop alternatives to reverse-flow investments, such as smart grid solutions or connection to other network operators including the direct connection of production facilities of renewable gas and low-carbon gas to the transmission network. Firm capacity access may be limited to offering capacities subject to operational limitations, in order to ensure infrastructure safety and economic efficiency. The regulatory authority shall be responsible for reviewing and approving the transmission system operators’ conditions for conditional capacity and shall ensure that any limitations in firm capacity or operational limitations are introduced by transmission system operators on the basis of transparent and non-discriminatory procedures and do not create undue barriers to market entry. Where the production facility bears the costs related to ensuring firm capacity, no limitation shall apply.