generally solar pv systems that generate electricity from sunlight cost between $ 2 50 to $ 7 per installed watt typically the larger the system the lower price per watt large commercial systems are typically well below $ 4 per watt
NASA researcher checking hydroponic onions with Bibb lettuce to his left and radishes to the right. Hydroponics is a subset of hydroculture, the method of growing plants without soil, using mineral nutrient solutions in a water solvent. Terrestrial plants may be grown with only their roots exposed to the mineral solution, or the roots may be supported by an inert medium, such as perlite or gravel. The nutrients in hydroponics can be from fish waste, duck manure, or normal nutrients.
Hydroponics, in its purest form, is also referred to as Deep Water Culture or DWC for short. No substrate growing media is required. The plants' roots literally dangle straight into water.Now, for those of you who have been continually warned about over-watering plants, this may seem a little odd.WC systems are very simple. All you need is a container, lid, pump and a net pot. The container holds the nutrient solution (usually around 2.5-4 gallons (10-15 liters)) and the lid supports a single plant growing in a net pot. Roots grow out the net pot and into the nutrient solution held in the container below.