Tuesday, November 28, 2017

Rain when sea temperatures are greater than minimum air temperatures

Cape Town is one city where the minimum (night) temperatures are generally colder than the sea temperatures (see photo). This means that if you can create a spray over the sea with floating spray pumps at night you will have this situation: The warmer sea will have a spray "mist cloud" of low elevation over the sea. This cloud will capture radiation from the sea (greenhouse effect, with sea hotter than air above) and warm up, because clouds are good absorbers of infrared radiation. So at night the air will become warm and humidified. During the next day the land will heat up and a sea breeze will develop (at about midday). The warm moist air will blow onto land and the hot land will heat this moist air from below, increasing chances of rain. I am trying to get other countries interested in this concept, so perhaps South Africa will be able to observe what happens in other countries. 
See http://www.asterism.org/tutorials/tut37%20Radiative%20Cooling.pdf to gain insight to the radiation effect from the sea.
Many cities have this property.
See photo for Cape Town below.

Note that sea spray is natural and occurs in massive amounts when wind blows over the sea.

Tuesday, November 14, 2017

Water from seawater

Here is a method to make clean water from the sea: Geothermal heat pumps use ground as a heat sink. The air is cooled above and the heat pumped to the ground. 
To make clean water have a huge steel cylinder above the sea. Cool the steel using a heat pump that takes heat from the steel cylinder and puts the heat into the water. The heated water will evaporate into the steel cylinder and so the process will continue with water vapour condensing on the cool steel where it is collected. Solar energy could be also be used to heat the water below the steel cylinder. See https://en.wikipedia.org/wiki/Direct_exchange_geothermal_heat_pump
If a lot of solar energy were used to heat the water below the steel cylinder the heated water could also add more moisture to the surrounding air to slightly increase chances of rain.

Heat pumps are very efficient - you can get about 4 units of cooling with 1 unit of power. Wind, wave energy and batteries could be used to power the heat pump.
 If the air temperature inside the cylinder were 100 deg C and the cylinder walls were at a temperature of 80 deg C, the cylinder would cool by radiating heat and by being in contact with cooler air on the outside. This would enable increased condensation of water vapour on the cylinder walls.
Imagine a small scale system like this. If you use 1 kW of power to cool the cylinder you could get about 4 kW of cooling. So say you run it for an hour. Then you get 4kWh of cooling. It takes roughly 0.7 kWh to condense out a litre of water, so you should get about 4/0.7=5.7 litres an hour using power of 1 kW (assuming a coefficient of performance (COP) of 4). Note that as the water of the water heat sink evaporates it cools, making the system more efficient.

This whole system could be used in reverse to cool the sea and heat air in the cylinder. If the air were heated and seawater were sprayed in at the bottom, one could also create hot humid air and release it to the surroundings to increase chances of rain. One would need a huge cylinder and a lot of power to have a marked effect. With wind, wave and solar power it could work. Fortunately heat pumps do a lot of cooling or heating with a small amount of power (COP=4 or so).

COOLING THE SEA: If you can create cloud to shade the sea you can cool the sea down. Here is a method that will directly cool the sea and will cause convection above the sea by heating air above the sea. This will cause more clouds and rain. Rain cools the sea surface because it comes from cool regions higher up. Method: Use a heat pump to take water from the sea (sea is the fridge) and place it in some air cooled metal heat sink above the sea (fins of the fridge). The fins will warm the air causing upwards convection of warm air causing clouds and rain. Wind power could be used to power this heat pump. Heat pumps are very efficient and you can get about 4 units of cooling for 1 unit of input power - see https://en.wikipedia.org/wiki/Geothermal_heat_pump
Another desalination method I came across: https://atmocean.com

Monday, November 6, 2017

Green parties could play the blues

Green parties could play the blues to solve global warming: In some places daylight persists much longer than at other places and near the Arctic circle one has very long days in summer and phytoplankton must have adjusted to this. Phytoplankton remove huge quantities of carbon dioxide from the atmosphere by using green and blue light to flourish. The phytoplankton is harmed by ultraviolet light and so here I propose a global warming solution:
At night, when there is virtually no ultraviolet light, irradiate the ocean with green and blue light, that penetrates the night, reducing CO2 as revellers delight. The ocean could be irradiated from green and blues lights on tall poles on land while people dance on the sand. This would create an attraction, inviting to the rich tourist faction.
Would flashing green and blue lights harm the phytoplankton though? I am hoping the concept can be implemented on coastlines extensively.
See https://www.whoi.edu/oceanus/feature/shedding-light-on-light-in-the-ocean