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'Solar heating' is the usage of solar energy to provide process, space or water heating. The heating of water is covered in solar hot water. Solar heating design is divided into two groups:

★ Active solar heating uses pumps which move air or a liquid from the solar collector into the building or storage area.

★ Passive solar heating does not require electrical or mechanical equipment, and may rely on the design and structure of the house to collect, store and distribute heat throughout the building (passive solar building design).

Contents

Other uses

Worldwide

Solar heating in Europe

See also

References

Other uses

Solar heating also refers to the heating of any objects, including buildings, cars, hats, through solar radiation. Solar heating depends on the solar radiation, surface area, surface reflectance, surface emissivity, ambient temperature, and thermal convection from wind. With most all objects on Earth, solar heating reaches a state of temperature homeostasis as the heat imparted by the sun is offset by the heat given off through reflection, radiation, and convection. White objects stay dramatically cooler than other objects because the most important variables are characteristics of the surface, reflectance, emissivity, convection and surface area. Silvery objects get hot even though they are excellent reflectors because they are very poor in heat emission. Human skin, and many other living surfaces, like tree leaves, have near perfect emissivity (~1.0), and so stay pretty cool. A perfect sunscreen is a dye that perfectly absorbs, with high emissivity, or perfectly reflects, ultraviolet and infrared while being transparent in visible light.
It is worth noting that it is impossible for any material to be a good absorber of a given frequency and at the same time a poor emitter of the same frequency ( or the other way around). The difference in absorption and emission arises because the radiation emitted by a relatively cold object like a human, has much lower frequency than the radiation emitted by a hot object like the sun. Materials which have high emissivity for low frequencies but high absorption at higher frequencies will therefore stay much cooler than materials which have high absorption of high frequencies and low emission of low frequencies.

Worldwide

Solar heating 2005[1]
Country	milj. m2	GWth
China	79.3	55.5
EU	16.0	11.2
Turkey	8.1	5.7
Japan	7.2	5.0
Israel	4.7	3.3
Brazil	2.3	1.6
United States	2.3	1.6
Australia	1.7	1.2
India	1.5	1.1
World	125	88 ★
★ = without swimming pools: 23 GWth (2004)

Solar heating in Europe

Solar heating ★ (kWth[2]
Land	Total kWth	2006	2005	2004
Germany	5 637 800	1 050 000	665 000	525 000
Greece	2 301 040	168 000	154 350	150 500
Austria	1 828 139	204 868	163 429	127 816
Italy	598 661	130 200	88 941	68 417
Spain	491 516	122 500	74 760	63 000
France	430 920	154 000	85 050	36 400
Cyprus	392 140	42 000	35 000	21 000
Switzerland	310 484	36 304	27 392	21 812
Denmark	253 596	17 710	14 875	14 000
Netherlands	222 909	10 280	14 174	18 410
UK	175 644	37 800	19 600	17 500
Sweden	165 850	19 977	15 835	14 041
Portugal	126 665	14 000	11 200	7 000
Poland	117 264	28 980	19 390	20 230
Slovenia	76 510	4 830	3 360	1 260
Czech Republic	74 711	15 421	10 885	8 575
Belgium	72 883	24 945	14 164	10 290
Slovakia	50 925	5 950	5 250	3 850
Romania	48 370	280	280	280
Bulgaria	17 570	1 540	1 400	1 260
Malta	16 702	3 150	2 800	2 951
Finland	11 545	2 380	1 668	1 141
Luxembourg	11 130	1 750	1 330	1 190
Ireland	11 053	3 500	2 450	1 400
Hungary	4 375	700	700	1 050
Latvia	2 695	840	700	350
Lithuania	1 925	420	350	350
Estonia	784	210	175	175
EU27+CH GWth	'13.45'	' 2.10'	' 1.43'	'1.14'
★ = The relation between collector area and capacity:s1 m2 = 0.7 kWthermal

See also

★ Solar hot water

★ Solar gain

★ Solar combisystem

★ Solar furnace

★ Renewable energy

★ Seasonal thermal store

★ Solar design

★ Timeline of solar energy

★ Wood pellets‎

References

1. 2005: Record year for investments in renewable energy REN21: Renewables Global Status Report 2006 Update, 18.7.2006
2. Solar Thermal Markets in Europe, Trends and market statistics 2006 European Solar Thermal Industry Federation ESTIF, June 2007