allowing the soot to be easily removed (soot is a byproduct of the process and damaged the working parts in the past -most notably the nickel-iron-cobaltcatalyst-). The soot (which contains the carbon) can then be stored underground and is not released into the atmosphere. Phase out of fossil fuel power plants there is still a chance of keeping global warming below 1.5 °C if no more fossil fuel power plants are built and some existing fossil fuel power plants are shut down early, together with other measures such as reforestation. Alternatives to fossil fuel power plants include nuclear power, solar power, geothermal power, wind power, hydropower, biomass power plants and other renewable energies (see non-carbon economy). Most of these are proven technologies on an industrial scale, but others are still in prototype form. Some countries only include the cost to produce the electrical energy, and do not take into account the social cost of carbon or the indirect costs associated with the many pollutants created by burning coal (e.g. increased hospital admissions due to respiratory diseases caused by fine smoke particles). Relative cost by generation source When comparing power plant costs, it is customary to start by calculating the cost of power at the generator terminals by considering several main factors. External costs such as connections costs, the effect of each plant on the distribution grid are considered separately as an additional cost to the calculated power cost at the terminals. Initial factors considered are: Capital costs, including waste disposal and decommissioning costs for nuclear energy. Operating and maintenance costs. Fuel costs for fossil fuel and biomass sources, and which may be negative for wastes. Likely annual hours per year run or load factor, which may be as low as 30% for wind energy, or as high as 90% for nuclear energy. Offset sales of heat, for example in combined heat and power district heating (CHP/DH). These costs occur over the 30–50 year life of the fossil fuel power plants, using discounted cash flows. See also Biomass Biomass power station Boiler (power generation) Coal analyzer Coal mining Combined heat and power Cooling tower system Environmental impact of the coal industry Flue gas stacks Fossil fuel phase-out Geothermal power Global Energy Monitor Global warming Greenhouse gas List of coal power stations List of thermal power station failures Mercury vapor turbine Natural gas Power station Relative cost of electricity generated by different