Solar energy supply

Mature phreatophyte trees (poplar, willow, cottonwood, aspen, ash, alder, eucalyptus, mesquite, bald cypress, birch, and river cedar) typically can transpire 3700 to 6167 m3 (3 to 5 acre-ft) of water per year. This is equivalent to about 2 to 3.8m3 (600 to 1000 gal) of water per tree per year for a mature species planted at a density of 600 trees per hectare (1500 trees per acre). Transpiration rates in the first two years would be somewhat less, about 0.75 m3 per tree per year (200 gal per tree per year), and hardwood trees would transpire about half the water of a phreatophyte. Two meters of water per year is a practical maximum for transpiration in a system with complete canopy coverage (a theoretical maximum would be 4 m/yr based on the solar energy supplied at latitude 40°N on a clear day). 

Typically optimum storage capacity varies from I to 3 typical winter days solar energy supply, depending upon the site, and for a medium-size residence or small commercial building would be in die range of 1000 2000 gallons (38 76 hectoliters). A section of a comparatively small solar-heated building is shown in Fig. 7. 

Cook TR, Dogutan DK, Reece SY, Surendranath Y, Teets TS, Nocera DG (2010) Solar energy supply and storage for the legacy and nonlegacy worlds. Chem Rev 110 6474—6502... 

An active solar heating and cooling system consists of a solar energy collector (flat plate or concentrating), a storage component to supply heat when the... 

At the same time, our major energy supplies (oil, coal, and gas) are finite. They are not renewable, yet we burn through these fuels as if there were no tomorrow. The energy supplies which are renewable (solar, wind, thermal) are not being used as widely or thoughtfully as they should be. 

By 2050 total energy demand may have increased by a factor of 2 or 3 from today s. So, in order to meet such a condition, carbon-fiee energy supply would have to have grown by a factor of nearly 15. In that time-span the only sources of carbon free energy are renewables, such as solar biomass and wind, sequestration (exclusion of C02 from the atmosphere) and nuclear fission. There is considerable debate, but no conclusion, how fat and how fast renewables might grow, but clearly, if economic and acceptable, here is a major potential opening for nuclear power. 

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