In Romania the major instrument supporting the RES technologies is quota obligations system. As a additional mean of support are subsidies. [54] Major instrument (quota obligation) is available for all of the RES technologies however there are additional requirements to met. In general wind parks and solar systems are supported for 15 years (there are also special conditions). Hydro and bio technologies have to met the same requirements and a few additional. Hydro power plant capacity have to be up to 10 MW. Biogas power plants can combust only following fuels: biogas, landfill gas and sewage gas. Biomass installations can combust only biomass or liquid bio-fuel which is not used in transport. The number of obtained certificates depends also from technology. New hydro power plants obtain 3 certificates for 1 MWh and modernised units 2 certificates. The other hydro systems which are not described here obtain 1 certificate per 2 MWh. To 2017 wind parks receive 2 certificates for 1 MWh however from 2018 that number is be decreased to 1 MWh. The highest number of certificates per MWh is for solar systems and equals 6 certificates. The rest of the RES technologies receive 3 certificates per MWh and relatively high efficient systems one more additional. The price of certificate equals the price achieved on the market. That value is between 27 to 55 . [54] Subsidies are eligible for all technologies without additional requirements. The subsidy amount can achieve 50% of projects costs (expect the Bucharest-Ilfov region where subsidy does not exceed 40%). The limit is 30 million Lei. [54] In the Romania the RES systems does not have priority however the grid operator is statutory obligated to conclude contract about grid connection without discrimination and to upgrade and expanse electrical network if it is necessary. Grid connections costs are covered by the grid operator only, system operator only or are shared for both. It depends from the system and grid location. [54] Regulation requirements in Romania are Electricity Law, Law no. 220/2008, Law on the Environmental Fund and Order no. 714/2010. [54]