market is also allowed. Modelling by Carbon Tracker indicates that new solar power will become cheaper than all existing coal plants by 2023. According to a May 2022 report from think tank Ember wind and solar saved 7 billion dollars on gas imports in the preceding 12 months. Every gigawatt of solar power installed would save over US$100 million on gas import costs. According to a 2022 study by Shura almost all coal power could be replaced by renewables (mainly solar) by 2030. Export of solar power could increase together eventually with hydrogen produced by clean electricity. Operation and maintenance costs of concentrated solar power is about 2 UScent/kWh. Heating and hot water Sales of vacuum tube hot water systems have exceeded flat-plate collectors since 2019. Vacuum tubes are more efficient for households than flat plate. Turkey is second in the world in solar water heating collector capacity after China, with about 26 million square metres generating 1.15 million tonnes of oil equivalent heat energy each year. About two-thirds is residential and a third industrial. Installed domestic hot water systems are typically convection without pumping, with 2 flat plate collectors, each nearly 2 m². Solar combi (space and water heating backed up by gas) is starting to be installed in villas and hotels. The industry is well developed for hot water with high quality manufacturing and export capacity, but less so for space heating, and is hampered by subsidies for coal heating. A 2018 study found that solar water heating saved on average 13% energy and increased the value of properties. In 2021 the IEA recommended that the Turkish government should support solar water heating because "technology and infrastructure quality needs to improve significantly to maximise its potential". Solar heating is also used for agriculture in Turkey, for example drying produce with solar air heaters. Photovoltaics Photovoltaics (PV) growth was supported by the government during the 2010s. Monthly average efficiencies are from 12–17% depending on tilt and climate type; specific yield decreases with elevation. In 2020 solar cell manufacturing started in Turkey, and in 2022 Minister of Energy and Natural Resources Fatih Dönmez claimed that Turkey could assemble enough solar panels annually to produce 8 GW of power. Industry sometimes uses its own solar power for processes which need a lot of electricity, such as electrolysis. , unlike in the EU, obsolete solar panels are not classified as electronic waste