heating. Where the primary source of electrical energy is hydroelectric, nuclear, or wind, transferring electricity via the grid can be convenient, since the resource may be too distant for direct heating applications (with the notable exception of solar thermal energy). The electrification of heat of space and water heating is increasingly proposed as a way forward to decarbonise the current energy system, particularly with heat pumps. In case of large-scale electrification, impacts on the electricity grid due to potential increase in peak electricity demand and exposure to extreme weather events needs to be considered. Economic aspects The operation of electric resistance heaters to heat an area for long periods is costly in many regions. However, intermittent or partial day use can be more cost efficient than whole building heating due to superior zonal control. For example: A lunch room in an office setting has limited hours of operation. During low-use periods a "monitor" level of heat () is provided by the central heating system. Peak use times between the hours of 11:00 and 14:00 are heated to "comfort levels" (). Significant savings can be realized in overall energy consumption, since infrared radiation losses through thermal radiation are not as large with a smaller temperature gradient both between this space and unheated outside air, as well as between the refrigerator and the (now cooler) lunch room. Economically, electric heat can be compared to other sources of home heating by multiplying the local cost per kilowatt hour for electricity by the number of kilowatts the heater uses. E.g.: 1500-watt heater at 12 cents per kilowatt hour 1.5×12=18 cents per hour. When comparing to burning fuel it may be useful to convert kilowatt hours to BTUs: 1.5 kWh × 3412.142=5118 BTU. Industrial electric heating Electric heating is widely used in industry. Advantages of electric heating methods over other forms include precision control of temperature and distribution of heat energy, combustion not used to develop heat, and the ability to attain temperatures not readily achievable with chemical combustion. Electric heat can be accurately applied at the precise point needed in a process, at high concentration of power per unit area or volume. Electric heating devices can be built in any required size and can be located anywhere within a plant. Electric heating processes are generally clean, quiet, and do not emit much byproduct heat to the surroundings. Electrical heating equipment has a high speed